newline battles continue

vendor/go.mongodb.org/mongo-driver/x/bsonx/array.go

@@ -0,0 +1,97 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsonx // import "go.mongodb.org/mongo-driver/x/bsonx"
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"strconv"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+)
+
+// ErrNilArray indicates that an operation was attempted on a nil *Array.
+var ErrNilArray = errors.New("array is nil")
+
+// Arr represents an array in BSON.
+type Arr []Val
+
+// String implements the fmt.Stringer interface.
+func (a Arr) String() string {
+	var buf bytes.Buffer
+	buf.Write([]byte("bson.Array["))
+	for idx, val := range a {
+		if idx > 0 {
+			buf.Write([]byte(", "))
+		}
+		fmt.Fprintf(&buf, "%s", val)
+	}
+	buf.WriteByte(']')
+
+	return buf.String()
+}
+
+// MarshalBSONValue implements the bsoncodec.ValueMarshaler interface.
+func (a Arr) MarshalBSONValue() (bsontype.Type, []byte, error) {
+	if a == nil {
+		// TODO: Should we do this?
+		return bsontype.Null, nil, nil
+	}
+
+	idx, dst := bsoncore.ReserveLength(nil)
+	for idx, value := range a {
+		t, data, _ := value.MarshalBSONValue() // marshalBSONValue never returns an error.
+		dst = append(dst, byte(t))
+		dst = append(dst, strconv.Itoa(idx)...)
+		dst = append(dst, 0x00)
+		dst = append(dst, data...)
+	}
+	dst = append(dst, 0x00)
+	dst = bsoncore.UpdateLength(dst, idx, int32(len(dst[idx:])))
+	return bsontype.Array, dst, nil
+}
+
+// UnmarshalBSONValue implements the bsoncodec.ValueUnmarshaler interface.
+func (a *Arr) UnmarshalBSONValue(t bsontype.Type, data []byte) error {
+	if a == nil {
+		return ErrNilArray
+	}
+	*a = (*a)[:0]
+
+	elements, err := bsoncore.Document(data).Elements()
+	if err != nil {
+		return err
+	}
+
+	for _, elem := range elements {
+		var val Val
+		rawval := elem.Value()
+		err = val.UnmarshalBSONValue(rawval.Type, rawval.Data)
+		if err != nil {
+			return err
+		}
+		*a = append(*a, val)
+	}
+	return nil
+}
+
+// Equal compares this document to another, returning true if they are equal.
+func (a Arr) Equal(a2 Arr) bool {
+	if len(a) != len(a2) {
+		return false
+	}
+	for idx := range a {
+		if !a[idx].Equal(a2[idx]) {
+			return false
+		}
+	}
+	return true
+}
+
+func (Arr) idoc() {}

vendor/go.mongodb.org/mongo-driver/x/bsonx/bsoncore/bsoncore.go

@@ -0,0 +1,827 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+// Package bsoncore contains functions that can be used to encode and decode BSON
+// elements and values to or from a slice of bytes. These functions are aimed at
+// allowing low level manipulation of BSON and can be used to build a higher
+// level BSON library.
+//
+// The Read* functions within this package return the values of the element and
+// a boolean indicating if the values are valid. A boolean was used instead of
+// an error because any error that would be returned would be the same: not
+// enough bytes. This library attempts to do no validation, it will only return
+// false if there are not enough bytes for an item to be read. For example, the
+// ReadDocument function checks the length, if that length is larger than the
+// number of bytes availble, it will return false, if there are enough bytes, it
+// will return those bytes and true. It is the consumers responsibility to
+// validate those bytes.
+//
+// The Append* functions within this package will append the type value to the
+// given dst slice. If the slice has enough capacity, it will not grow the
+// slice. The Append*Element functions within this package operate in the same
+// way, but additionally append the BSON type and the key before the value.
+package bsoncore // import "go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"strconv"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+// AppendType will append t to dst and return the extended buffer.
+func AppendType(dst []byte, t bsontype.Type) []byte { return append(dst, byte(t)) }
+
+// AppendKey will append key to dst and return the extended buffer.
+func AppendKey(dst []byte, key string) []byte { return append(dst, key+string(0x00)...) }
+
+// AppendHeader will append Type t and key to dst and return the extended
+// buffer.
+func AppendHeader(dst []byte, t bsontype.Type, key string) []byte {
+	dst = AppendType(dst, t)
+	dst = append(dst, key...)
+	return append(dst, 0x00)
+	// return append(AppendType(dst, t), key+string(0x00)...)
+}
+
+// TODO(skriptble): All of the Read* functions should return src resliced to start just after what
+// was read.
+
+// ReadType will return the first byte of the provided []byte as a type. If
+// there is no availble byte, false is returned.
+func ReadType(src []byte) (bsontype.Type, []byte, bool) {
+	if len(src) < 1 {
+		return 0, src, false
+	}
+	return bsontype.Type(src[0]), src[1:], true
+}
+
+// ReadKey will read a key from src. The 0x00 byte will not be present
+// in the returned string. If there are not enough bytes available, false is
+// returned.
+func ReadKey(src []byte) (string, []byte, bool) { return readcstring(src) }
+
+// ReadKeyBytes will read a key from src as bytes. The 0x00 byte will
+// not be present in the returned string. If there are not enough bytes
+// available, false is returned.
+func ReadKeyBytes(src []byte) ([]byte, []byte, bool) { return readcstringbytes(src) }
+
+// ReadHeader will read a type byte and a key from src. If both of these
+// values cannot be read, false is returned.
+func ReadHeader(src []byte) (t bsontype.Type, key string, rem []byte, ok bool) {
+	t, rem, ok = ReadType(src)
+	if !ok {
+		return 0, "", src, false
+	}
+	key, rem, ok = ReadKey(rem)
+	if !ok {
+		return 0, "", src, false
+	}
+
+	return t, key, rem, true
+}
+
+// ReadHeaderBytes will read a type and a key from src and the remainder of the bytes
+// are returned as rem. If either the type or key cannot be red, ok will be false.
+func ReadHeaderBytes(src []byte) (header []byte, rem []byte, ok bool) {
+	if len(src) < 1 {
+		return nil, src, false
+	}
+	idx := bytes.IndexByte(src[1:], 0x00)
+	if idx == -1 {
+		return nil, src, false
+	}
+	return src[:idx], src[idx+1:], true
+}
+
+// ReadElement reads the next full element from src. It returns the element, the remaining bytes in
+// the slice, and a boolean indicating if the read was successful.
+func ReadElement(src []byte) (Element, []byte, bool) {
+	if len(src) < 1 {
+		return nil, src, false
+	}
+	t := bsontype.Type(src[0])
+	idx := bytes.IndexByte(src[1:], 0x00)
+	if idx == -1 {
+		return nil, src, false
+	}
+	length, ok := valueLength(src[idx+2:], t) // We add 2 here because we called IndexByte with src[1:]
+	if !ok {
+		return nil, src, false
+	}
+	elemLength := 1 + idx + 1 + int(length)
+	if elemLength > len(src) {
+		return nil, src, false
+	}
+	return src[:elemLength], src[elemLength:], true
+}
+
+// AppendValueElement appends value to dst as an element using key as the element's key.
+func AppendValueElement(dst []byte, key string, value Value) []byte {
+	dst = AppendHeader(dst, value.Type, key)
+	dst = append(dst, value.Data...)
+	return dst
+}
+
+// ReadValue reads the next value as the provided types and returns a Value, the remaining bytes,
+// and a boolean indicating if the read was successful.
+func ReadValue(src []byte, t bsontype.Type) (Value, []byte, bool) {
+	data, rem, ok := readValue(src, t)
+	if !ok {
+		return Value{}, src, false
+	}
+	return Value{Type: t, Data: data}, rem, true
+}
+
+// AppendDouble will append f to dst and return the extended buffer.
+func AppendDouble(dst []byte, f float64) []byte {
+	return appendu64(dst, math.Float64bits(f))
+}
+
+// AppendDoubleElement will append a BSON double element using key and f to dst
+// and return the extended buffer.
+func AppendDoubleElement(dst []byte, key string, f float64) []byte {
+	return AppendDouble(AppendHeader(dst, bsontype.Double, key), f)
+}
+
+// ReadDouble will read a float64 from src. If there are not enough bytes it
+// will return false.
+func ReadDouble(src []byte) (float64, []byte, bool) {
+	bits, src, ok := readu64(src)
+	if !ok {
+		return 0, src, false
+	}
+	return math.Float64frombits(bits), src, true
+}
+
+// AppendString will append s to dst and return the extended buffer.
+func AppendString(dst []byte, s string) []byte {
+	return appendstring(dst, s)
+}
+
+// AppendStringElement will append a BSON string element using key and val to dst
+// and return the extended buffer.
+func AppendStringElement(dst []byte, key, val string) []byte {
+	return AppendString(AppendHeader(dst, bsontype.String, key), val)
+}
+
+// ReadString will read a string from src. If there are not enough bytes it
+// will return false.
+func ReadString(src []byte) (string, []byte, bool) {
+	return readstring(src)
+}
+
+// AppendDocumentStart reserves a document's length and returns the index where the length begins.
+// This index can later be used to write the length of the document.
+//
+// TODO(skriptble): We really need AppendDocumentStart and AppendDocumentEnd.
+// AppendDocumentStart would handle calling ReserveLength and providing the index of the start of
+// the document. AppendDocumentEnd would handle taking that start index, adding the null byte,
+// calculating the length, and filling in the length at the start of the document.
+func AppendDocumentStart(dst []byte) (index int32, b []byte) { return ReserveLength(dst) }
+
+// AppendDocumentStartInline functions the same as AppendDocumentStart but takes a pointer to the
+// index int32 which allows this function to be used inline.
+func AppendDocumentStartInline(dst []byte, index *int32) []byte {
+	idx, doc := AppendDocumentStart(dst)
+	*index = idx
+	return doc
+}
+
+// AppendDocumentElementStart writes a document element header and then reserves the length bytes.
+func AppendDocumentElementStart(dst []byte, key string) (index int32, b []byte) {
+	return AppendDocumentStart(AppendHeader(dst, bsontype.EmbeddedDocument, key))
+}
+
+// AppendDocumentEnd writes the null byte for a document and updates the length of the document.
+// The index should be the beginning of the document's length bytes.
+func AppendDocumentEnd(dst []byte, index int32) ([]byte, error) {
+	if int(index) > len(dst)-4 {
+		return dst, fmt.Errorf("not enough bytes available after index to write length")
+	}
+	dst = append(dst, 0x00)
+	dst = UpdateLength(dst, index, int32(len(dst[index:])))
+	return dst, nil
+}
+
+// AppendDocument will append doc to dst and return the extended buffer.
+func AppendDocument(dst []byte, doc []byte) []byte { return append(dst, doc...) }
+
+// AppendDocumentElement will append a BSON embeded document element using key
+// and doc to dst and return the extended buffer.
+func AppendDocumentElement(dst []byte, key string, doc []byte) []byte {
+	return AppendDocument(AppendHeader(dst, bsontype.EmbeddedDocument, key), doc)
+}
+
+// BuildDocument will create a document with the given elements and will append it to dst.
+func BuildDocument(dst []byte, elems []byte) []byte {
+	idx, dst := ReserveLength(dst)
+	dst = append(dst, elems...)
+	dst = append(dst, 0x00)
+	dst = UpdateLength(dst, idx, int32(len(dst[idx:])))
+	return dst
+}
+
+// BuildDocumentFromElements will create a document with the given slice of elements and will append
+// it to dst and return the extended buffer.
+func BuildDocumentFromElements(dst []byte, elems ...[]byte) []byte {
+	idx, dst := ReserveLength(dst)
+	for _, elem := range elems {
+		dst = append(dst, elem...)
+	}
+	dst = append(dst, 0x00)
+	dst = UpdateLength(dst, idx, int32(len(dst[idx:])))
+	return dst
+}
+
+// ReadDocument will read a document from src. If there are not enough bytes it
+// will return false.
+func ReadDocument(src []byte) (doc Document, rem []byte, ok bool) { return readLengthBytes(src) }
+
+// AppendArrayStart appends the length bytes to an array and then returns the index of the start
+// of those length bytes.
+func AppendArrayStart(dst []byte) (index int32, b []byte) { return ReserveLength(dst) }
+
+// AppendArrayElementStart appends an array element header and then the length bytes for an array,
+// returning the index where the length starts.
+func AppendArrayElementStart(dst []byte, key string) (index int32, b []byte) {
+	return AppendArrayStart(AppendHeader(dst, bsontype.Array, key))
+}
+
+// AppendArrayEnd appends the null byte to an array and calculates the length, inserting that
+// calculated length starting at index.
+func AppendArrayEnd(dst []byte, index int32) ([]byte, error) { return AppendDocumentEnd(dst, index) }
+
+// AppendArray will append arr to dst and return the extended buffer.
+func AppendArray(dst []byte, arr []byte) []byte { return append(dst, arr...) }
+
+// AppendArrayElement will append a BSON array element using key and arr to dst
+// and return the extended buffer.
+func AppendArrayElement(dst []byte, key string, arr []byte) []byte {
+	return AppendArray(AppendHeader(dst, bsontype.Array, key), arr)
+}
+
+// BuildArray will append a BSON array to dst built from values.
+func BuildArray(dst []byte, values ...Value) []byte {
+	idx, dst := ReserveLength(dst)
+	for pos, val := range values {
+		dst = AppendValueElement(dst, strconv.Itoa(pos), val)
+	}
+	dst = append(dst, 0x00)
+	dst = UpdateLength(dst, idx, int32(len(dst[idx:])))
+	return dst
+}
+
+// BuildArrayElement will create an array element using the provided values.
+func BuildArrayElement(dst []byte, key string, values ...Value) []byte {
+	return BuildArray(AppendHeader(dst, bsontype.Array, key), values...)
+}
+
+// ReadArray will read an array from src. If there are not enough bytes it
+// will return false.
+func ReadArray(src []byte) (arr Document, rem []byte, ok bool) { return readLengthBytes(src) }
+
+// AppendBinary will append subtype and b to dst and return the extended buffer.
+func AppendBinary(dst []byte, subtype byte, b []byte) []byte {
+	if subtype == 0x02 {
+		return appendBinarySubtype2(dst, subtype, b)
+	}
+	dst = append(appendLength(dst, int32(len(b))), subtype)
+	return append(dst, b...)
+}
+
+// AppendBinaryElement will append a BSON binary element using key, subtype, and
+// b to dst and return the extended buffer.
+func AppendBinaryElement(dst []byte, key string, subtype byte, b []byte) []byte {
+	return AppendBinary(AppendHeader(dst, bsontype.Binary, key), subtype, b)
+}
+
+// ReadBinary will read a subtype and bin from src. If there are not enough bytes it
+// will return false.
+func ReadBinary(src []byte) (subtype byte, bin []byte, rem []byte, ok bool) {
+	length, rem, ok := ReadLength(src)
+	if !ok {
+		return 0x00, nil, src, false
+	}
+	if len(rem) < 1 { // subtype
+		return 0x00, nil, src, false
+	}
+	subtype, rem = rem[0], rem[1:]
+
+	if len(rem) < int(length) {
+		return 0x00, nil, src, false
+	}
+
+	if subtype == 0x02 {
+		length, rem, ok = ReadLength(rem)
+		if !ok || len(rem) < int(length) {
+			return 0x00, nil, src, false
+		}
+	}
+
+	return subtype, rem[:length], rem[length:], true
+}
+
+// AppendUndefinedElement will append a BSON undefined element using key to dst
+// and return the extended buffer.
+func AppendUndefinedElement(dst []byte, key string) []byte {
+	return AppendHeader(dst, bsontype.Undefined, key)
+}
+
+// AppendObjectID will append oid to dst and return the extended buffer.
+func AppendObjectID(dst []byte, oid primitive.ObjectID) []byte { return append(dst, oid[:]...) }
+
+// AppendObjectIDElement will append a BSON ObjectID element using key and oid to dst
+// and return the extended buffer.
+func AppendObjectIDElement(dst []byte, key string, oid primitive.ObjectID) []byte {
+	return AppendObjectID(AppendHeader(dst, bsontype.ObjectID, key), oid)
+}
+
+// ReadObjectID will read an ObjectID from src. If there are not enough bytes it
+// will return false.
+func ReadObjectID(src []byte) (primitive.ObjectID, []byte, bool) {
+	if len(src) < 12 {
+		return primitive.ObjectID{}, src, false
+	}
+	var oid primitive.ObjectID
+	copy(oid[:], src[0:12])
+	return oid, src[12:], true
+}
+
+// AppendBoolean will append b to dst and return the extended buffer.
+func AppendBoolean(dst []byte, b bool) []byte {
+	if b {
+		return append(dst, 0x01)
+	}
+	return append(dst, 0x00)
+}
+
+// AppendBooleanElement will append a BSON boolean element using key and b to dst
+// and return the extended buffer.
+func AppendBooleanElement(dst []byte, key string, b bool) []byte {
+	return AppendBoolean(AppendHeader(dst, bsontype.Boolean, key), b)
+}
+
+// ReadBoolean will read a bool from src. If there are not enough bytes it
+// will return false.
+func ReadBoolean(src []byte) (bool, []byte, bool) {
+	if len(src) < 1 {
+		return false, src, false
+	}
+
+	return src[0] == 0x01, src[1:], true
+}
+
+// AppendDateTime will append dt to dst and return the extended buffer.
+func AppendDateTime(dst []byte, dt int64) []byte { return appendi64(dst, dt) }
+
+// AppendDateTimeElement will append a BSON datetime element using key and dt to dst
+// and return the extended buffer.
+func AppendDateTimeElement(dst []byte, key string, dt int64) []byte {
+	return AppendDateTime(AppendHeader(dst, bsontype.DateTime, key), dt)
+}
+
+// ReadDateTime will read an int64 datetime from src. If there are not enough bytes it
+// will return false.
+func ReadDateTime(src []byte) (int64, []byte, bool) { return readi64(src) }
+
+// AppendTime will append time as a BSON DateTime to dst and return the extended buffer.
+func AppendTime(dst []byte, t time.Time) []byte {
+	return AppendDateTime(dst, t.Unix()*1000+int64(t.Nanosecond()/1e6))
+}
+
+// AppendTimeElement will append a BSON datetime element using key and dt to dst
+// and return the extended buffer.
+func AppendTimeElement(dst []byte, key string, t time.Time) []byte {
+	return AppendTime(AppendHeader(dst, bsontype.DateTime, key), t)
+}
+
+// ReadTime will read an time.Time datetime from src. If there are not enough bytes it
+// will return false.
+func ReadTime(src []byte) (time.Time, []byte, bool) {
+	dt, rem, ok := readi64(src)
+	return time.Unix(dt/1e3, dt%1e3*1e6), rem, ok
+}
+
+// AppendNullElement will append a BSON null element using key to dst
+// and return the extended buffer.
+func AppendNullElement(dst []byte, key string) []byte { return AppendHeader(dst, bsontype.Null, key) }
+
+// AppendRegex will append pattern and options to dst and return the extended buffer.
+func AppendRegex(dst []byte, pattern, options string) []byte {
+	return append(dst, pattern+string(0x00)+options+string(0x00)...)
+}
+
+// AppendRegexElement will append a BSON regex element using key, pattern, and
+// options to dst and return the extended buffer.
+func AppendRegexElement(dst []byte, key, pattern, options string) []byte {
+	return AppendRegex(AppendHeader(dst, bsontype.Regex, key), pattern, options)
+}
+
+// ReadRegex will read a pattern and options from src. If there are not enough bytes it
+// will return false.
+func ReadRegex(src []byte) (pattern, options string, rem []byte, ok bool) {
+	pattern, rem, ok = readcstring(src)
+	if !ok {
+		return "", "", src, false
+	}
+	options, rem, ok = readcstring(rem)
+	if !ok {
+		return "", "", src, false
+	}
+	return pattern, options, rem, true
+}
+
+// AppendDBPointer will append ns and oid to dst and return the extended buffer.
+func AppendDBPointer(dst []byte, ns string, oid primitive.ObjectID) []byte {
+	return append(appendstring(dst, ns), oid[:]...)
+}
+
+// AppendDBPointerElement will append a BSON DBPointer element using key, ns,
+// and oid to dst and return the extended buffer.
+func AppendDBPointerElement(dst []byte, key, ns string, oid primitive.ObjectID) []byte {
+	return AppendDBPointer(AppendHeader(dst, bsontype.DBPointer, key), ns, oid)
+}
+
+// ReadDBPointer will read a ns and oid from src. If there are not enough bytes it
+// will return false.
+func ReadDBPointer(src []byte) (ns string, oid primitive.ObjectID, rem []byte, ok bool) {
+	ns, rem, ok = readstring(src)
+	if !ok {
+		return "", primitive.ObjectID{}, src, false
+	}
+	oid, rem, ok = ReadObjectID(rem)
+	if !ok {
+		return "", primitive.ObjectID{}, src, false
+	}
+	return ns, oid, rem, true
+}
+
+// AppendJavaScript will append js to dst and return the extended buffer.
+func AppendJavaScript(dst []byte, js string) []byte { return appendstring(dst, js) }
+
+// AppendJavaScriptElement will append a BSON JavaScript element using key and
+// js to dst and return the extended buffer.
+func AppendJavaScriptElement(dst []byte, key, js string) []byte {
+	return AppendJavaScript(AppendHeader(dst, bsontype.JavaScript, key), js)
+}
+
+// ReadJavaScript will read a js string from src. If there are not enough bytes it
+// will return false.
+func ReadJavaScript(src []byte) (js string, rem []byte, ok bool) { return readstring(src) }
+
+// AppendSymbol will append symbol to dst and return the extended buffer.
+func AppendSymbol(dst []byte, symbol string) []byte { return appendstring(dst, symbol) }
+
+// AppendSymbolElement will append a BSON symbol element using key and symbol to dst
+// and return the extended buffer.
+func AppendSymbolElement(dst []byte, key, symbol string) []byte {
+	return AppendSymbol(AppendHeader(dst, bsontype.Symbol, key), symbol)
+}
+
+// ReadSymbol will read a symbol string from src. If there are not enough bytes it
+// will return false.
+func ReadSymbol(src []byte) (symbol string, rem []byte, ok bool) { return readstring(src) }
+
+// AppendCodeWithScope will append code and scope to dst and return the extended buffer.
+func AppendCodeWithScope(dst []byte, code string, scope []byte) []byte {
+	length := int32(4 + 4 + len(code) + 1 + len(scope)) // length of cws, length of code, code, 0x00, scope
+	dst = appendLength(dst, length)
+
+	return append(appendstring(dst, code), scope...)
+}
+
+// AppendCodeWithScopeElement will append a BSON code with scope element using
+// key, code, and scope to dst
+// and return the extended buffer.
+func AppendCodeWithScopeElement(dst []byte, key, code string, scope []byte) []byte {
+	return AppendCodeWithScope(AppendHeader(dst, bsontype.CodeWithScope, key), code, scope)
+}
+
+// ReadCodeWithScope will read code and scope from src. If there are not enough bytes it
+// will return false.
+func ReadCodeWithScope(src []byte) (code string, scope []byte, rem []byte, ok bool) {
+	length, rem, ok := ReadLength(src)
+	if !ok || len(src) < int(length) {
+		return "", nil, src, false
+	}
+
+	code, rem, ok = readstring(rem)
+	if !ok {
+		return "", nil, src, false
+	}
+
+	scope, rem, ok = ReadDocument(rem)
+	if !ok {
+		return "", nil, src, false
+	}
+	return code, scope, rem, true
+}
+
+// AppendInt32 will append i32 to dst and return the extended buffer.
+func AppendInt32(dst []byte, i32 int32) []byte { return appendi32(dst, i32) }
+
+// AppendInt32Element will append a BSON int32 element using key and i32 to dst
+// and return the extended buffer.
+func AppendInt32Element(dst []byte, key string, i32 int32) []byte {
+	return AppendInt32(AppendHeader(dst, bsontype.Int32, key), i32)
+}
+
+// ReadInt32 will read an int32 from src. If there are not enough bytes it
+// will return false.
+func ReadInt32(src []byte) (int32, []byte, bool) { return readi32(src) }
+
+// AppendTimestamp will append t and i to dst and return the extended buffer.
+func AppendTimestamp(dst []byte, t, i uint32) []byte {
+	return appendu32(appendu32(dst, i), t) // i is the lower 4 bytes, t is the higher 4 bytes
+}
+
+// AppendTimestampElement will append a BSON timestamp element using key, t, and
+// i to dst and return the extended buffer.
+func AppendTimestampElement(dst []byte, key string, t, i uint32) []byte {
+	return AppendTimestamp(AppendHeader(dst, bsontype.Timestamp, key), t, i)
+}
+
+// ReadTimestamp will read t and i from src. If there are not enough bytes it
+// will return false.
+func ReadTimestamp(src []byte) (t, i uint32, rem []byte, ok bool) {
+	i, rem, ok = readu32(src)
+	if !ok {
+		return 0, 0, src, false
+	}
+	t, rem, ok = readu32(rem)
+	if !ok {
+		return 0, 0, src, false
+	}
+	return t, i, rem, true
+}
+
+// AppendInt64 will append i64 to dst and return the extended buffer.
+func AppendInt64(dst []byte, i64 int64) []byte { return appendi64(dst, i64) }
+
+// AppendInt64Element will append a BSON int64 element using key and i64 to dst
+// and return the extended buffer.
+func AppendInt64Element(dst []byte, key string, i64 int64) []byte {
+	return AppendInt64(AppendHeader(dst, bsontype.Int64, key), i64)
+}
+
+// ReadInt64 will read an int64 from src. If there are not enough bytes it
+// will return false.
+func ReadInt64(src []byte) (int64, []byte, bool) { return readi64(src) }
+
+// AppendDecimal128 will append d128 to dst and return the extended buffer.
+func AppendDecimal128(dst []byte, d128 primitive.Decimal128) []byte {
+	high, low := d128.GetBytes()
+	return appendu64(appendu64(dst, low), high)
+}
+
+// AppendDecimal128Element will append a BSON primitive.28 element using key and
+// d128 to dst and return the extended buffer.
+func AppendDecimal128Element(dst []byte, key string, d128 primitive.Decimal128) []byte {
+	return AppendDecimal128(AppendHeader(dst, bsontype.Decimal128, key), d128)
+}
+
+// ReadDecimal128 will read a primitive.Decimal128 from src. If there are not enough bytes it
+// will return false.
+func ReadDecimal128(src []byte) (primitive.Decimal128, []byte, bool) {
+	l, rem, ok := readu64(src)
+	if !ok {
+		return primitive.Decimal128{}, src, false
+	}
+
+	h, rem, ok := readu64(rem)
+	if !ok {
+		return primitive.Decimal128{}, src, false
+	}
+
+	return primitive.NewDecimal128(h, l), rem, true
+}
+
+// AppendMaxKeyElement will append a BSON max key element using key to dst
+// and return the extended buffer.
+func AppendMaxKeyElement(dst []byte, key string) []byte {
+	return AppendHeader(dst, bsontype.MaxKey, key)
+}
+
+// AppendMinKeyElement will append a BSON min key element using key to dst
+// and return the extended buffer.
+func AppendMinKeyElement(dst []byte, key string) []byte {
+	return AppendHeader(dst, bsontype.MinKey, key)
+}
+
+// EqualValue will return true if the two values are equal.
+func EqualValue(t1, t2 bsontype.Type, v1, v2 []byte) bool {
+	if t1 != t2 {
+		return false
+	}
+	v1, _, ok := readValue(v1, t1)
+	if !ok {
+		return false
+	}
+	v2, _, ok = readValue(v2, t2)
+	if !ok {
+		return false
+	}
+	return bytes.Equal(v1, v2)
+}
+
+// valueLength will determine the length of the next value contained in src as if it
+// is type t. The returned bool will be false if there are not enough bytes in src for
+// a value of type t.
+func valueLength(src []byte, t bsontype.Type) (int32, bool) {
+	var length int32
+	ok := true
+	switch t {
+	case bsontype.Array, bsontype.EmbeddedDocument, bsontype.CodeWithScope:
+		length, _, ok = ReadLength(src)
+	case bsontype.Binary:
+		length, _, ok = ReadLength(src)
+		length += 4 + 1 // binary length + subtype byte
+	case bsontype.Boolean:
+		length = 1
+	case bsontype.DBPointer:
+		length, _, ok = ReadLength(src)
+		length += 4 + 12 // string length + ObjectID length
+	case bsontype.DateTime, bsontype.Double, bsontype.Int64, bsontype.Timestamp:
+		length = 8
+	case bsontype.Decimal128:
+		length = 16
+	case bsontype.Int32:
+		length = 4
+	case bsontype.JavaScript, bsontype.String, bsontype.Symbol:
+		length, _, ok = ReadLength(src)
+		length += 4
+	case bsontype.MaxKey, bsontype.MinKey, bsontype.Null, bsontype.Undefined:
+		length = 0
+	case bsontype.ObjectID:
+		length = 12
+	case bsontype.Regex:
+		regex := bytes.IndexByte(src, 0x00)
+		if regex < 0 {
+			ok = false
+			break
+		}
+		pattern := bytes.IndexByte(src[regex+1:], 0x00)
+		if pattern < 0 {
+			ok = false
+			break
+		}
+		length = int32(int64(regex) + 1 + int64(pattern) + 1)
+	default:
+		ok = false
+	}
+
+	return length, ok
+}
+
+func readValue(src []byte, t bsontype.Type) ([]byte, []byte, bool) {
+	length, ok := valueLength(src, t)
+	if !ok || int(length) > len(src) {
+		return nil, src, false
+	}
+
+	return src[:length], src[length:], true
+}
+
+// ReserveLength reserves the space required for length and returns the index where to write the length
+// and the []byte with reserved space.
+func ReserveLength(dst []byte) (int32, []byte) {
+	index := len(dst)
+	return int32(index), append(dst, 0x00, 0x00, 0x00, 0x00)
+}
+
+// UpdateLength updates the length at index with length and returns the []byte.
+func UpdateLength(dst []byte, index, length int32) []byte {
+	dst[index] = byte(length)
+	dst[index+1] = byte(length >> 8)
+	dst[index+2] = byte(length >> 16)
+	dst[index+3] = byte(length >> 24)
+	return dst
+}
+
+func appendLength(dst []byte, l int32) []byte { return appendi32(dst, l) }
+
+func appendi32(dst []byte, i32 int32) []byte {
+	return append(dst, byte(i32), byte(i32>>8), byte(i32>>16), byte(i32>>24))
+}
+
+// ReadLength reads an int32 length from src and returns the length and the remaining bytes. If
+// there aren't enough bytes to read a valid length, src is returned unomdified and the returned
+// bool will be false.
+func ReadLength(src []byte) (int32, []byte, bool) { return readi32(src) }
+
+func readi32(src []byte) (int32, []byte, bool) {
+	if len(src) < 4 {
+		return 0, src, false
+	}
+
+	return (int32(src[0]) | int32(src[1])<<8 | int32(src[2])<<16 | int32(src[3])<<24), src[4:], true
+}
+
+func appendi64(dst []byte, i64 int64) []byte {
+	return append(dst,
+		byte(i64), byte(i64>>8), byte(i64>>16), byte(i64>>24),
+		byte(i64>>32), byte(i64>>40), byte(i64>>48), byte(i64>>56),
+	)
+}
+
+func readi64(src []byte) (int64, []byte, bool) {
+	if len(src) < 8 {
+		return 0, src, false
+	}
+	i64 := (int64(src[0]) | int64(src[1])<<8 | int64(src[2])<<16 | int64(src[3])<<24 |
+		int64(src[4])<<32 | int64(src[5])<<40 | int64(src[6])<<48 | int64(src[7])<<56)
+	return i64, src[8:], true
+}
+
+func appendu32(dst []byte, u32 uint32) []byte {
+	return append(dst, byte(u32), byte(u32>>8), byte(u32>>16), byte(u32>>24))
+}
+
+func readu32(src []byte) (uint32, []byte, bool) {
+	if len(src) < 4 {
+		return 0, src, false
+	}
+
+	return (uint32(src[0]) | uint32(src[1])<<8 | uint32(src[2])<<16 | uint32(src[3])<<24), src[4:], true
+}
+
+func appendu64(dst []byte, u64 uint64) []byte {
+	return append(dst,
+		byte(u64), byte(u64>>8), byte(u64>>16), byte(u64>>24),
+		byte(u64>>32), byte(u64>>40), byte(u64>>48), byte(u64>>56),
+	)
+}
+
+func readu64(src []byte) (uint64, []byte, bool) {
+	if len(src) < 8 {
+		return 0, src, false
+	}
+	u64 := (uint64(src[0]) | uint64(src[1])<<8 | uint64(src[2])<<16 | uint64(src[3])<<24 |
+		uint64(src[4])<<32 | uint64(src[5])<<40 | uint64(src[6])<<48 | uint64(src[7])<<56)
+	return u64, src[8:], true
+}
+
+// keep in sync with readcstringbytes
+func readcstring(src []byte) (string, []byte, bool) {
+	idx := bytes.IndexByte(src, 0x00)
+	if idx < 0 {
+		return "", src, false
+	}
+	return string(src[:idx]), src[idx+1:], true
+}
+
+// keep in sync with readcstring
+func readcstringbytes(src []byte) ([]byte, []byte, bool) {
+	idx := bytes.IndexByte(src, 0x00)
+	if idx < 0 {
+		return nil, src, false
+	}
+	return src[:idx], src[idx+1:], true
+}
+
+func appendstring(dst []byte, s string) []byte {
+	l := int32(len(s) + 1)
+	dst = appendLength(dst, l)
+	dst = append(dst, s...)
+	return append(dst, 0x00)
+}
+
+func readstring(src []byte) (string, []byte, bool) {
+	l, rem, ok := ReadLength(src)
+	if !ok {
+		return "", src, false
+	}
+	if len(src[4:]) < int(l) {
+		return "", src, false
+	}
+
+	return string(rem[:l-1]), rem[l:], true
+}
+
+// readLengthBytes attempts to read a length and that number of bytes. This
+// function requires that the length include the four bytes for itself.
+func readLengthBytes(src []byte) ([]byte, []byte, bool) {
+	l, _, ok := ReadLength(src)
+	if !ok {
+		return nil, src, false
+	}
+	if len(src) < int(l) {
+		return nil, src, false
+	}
+	return src[:l], src[l:], true
+}
+
+func appendBinarySubtype2(dst []byte, subtype byte, b []byte) []byte {
+	dst = appendLength(dst, int32(len(b)+4)) // The bytes we'll encode need to be 4 larger for the length bytes
+	dst = append(dst, subtype)
+	dst = appendLength(dst, int32(len(b)))
+	return append(dst, b...)
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/bsoncore/document.go

@@ -0,0 +1,399 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncore
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+
+	"github.com/go-stack/stack"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+)
+
+// DocumentValidationError is an error type returned when attempting to validate a document.
+type DocumentValidationError string
+
+func (dve DocumentValidationError) Error() string { return string(dve) }
+
+// NewDocumentLengthError creates and returns an error for when the length of a document exceeds the
+// bytes available.
+func NewDocumentLengthError(length, rem int) error {
+	return DocumentValidationError(
+		fmt.Sprintf("document length exceeds available bytes. length=%d remainingBytes=%d", length, rem),
+	)
+}
+
+// InsufficientBytesError indicates that there were not enough bytes to read the next component.
+type InsufficientBytesError struct {
+	Source    []byte
+	Remaining []byte
+	Stack     stack.CallStack
+}
+
+// NewInsufficientBytesError creates a new InsufficientBytesError with the given Document, remaining
+// bytes, and the current stack.
+func NewInsufficientBytesError(src, rem []byte) InsufficientBytesError {
+	return InsufficientBytesError{Source: src, Remaining: rem, Stack: stack.Trace().TrimRuntime()}
+}
+
+// Error implements the error interface.
+func (ibe InsufficientBytesError) Error() string {
+	return "too few bytes to read next component"
+}
+
+// ErrorStack returns a string representing the stack at the point where the error occurred.
+func (ibe InsufficientBytesError) ErrorStack() string {
+	s := bytes.NewBufferString("too few bytes to read next component: [")
+
+	for i, call := range ibe.Stack {
+		if i != 0 {
+			s.WriteString(", ")
+		}
+
+		// go vet doesn't like %k even though it's part of stack's API, so we move the format
+		// string so it doesn't complain. (We also can't make it a constant, or go vet still
+		// complains.)
+		callFormat := "%k.%n %v"
+
+		s.WriteString(fmt.Sprintf(callFormat, call, call, call))
+	}
+
+	s.WriteRune(']')
+
+	return s.String()
+}
+
+// Equal checks that err2 also is an ErrTooSmall.
+func (ibe InsufficientBytesError) Equal(err2 error) bool {
+	switch err2.(type) {
+	case InsufficientBytesError:
+		return true
+	default:
+		return false
+	}
+}
+
+// InvalidDepthTraversalError is returned when attempting a recursive Lookup when one component of
+// the path is neither an embedded document nor an array.
+type InvalidDepthTraversalError struct {
+	Key  string
+	Type bsontype.Type
+}
+
+func (idte InvalidDepthTraversalError) Error() string {
+	return fmt.Sprintf(
+		"attempt to traverse into %s, but it's type is %s, not %s nor %s",
+		idte.Key, idte.Type, bsontype.EmbeddedDocument, bsontype.Array,
+	)
+}
+
+// ErrMissingNull is returned when a document's last byte is not null.
+const ErrMissingNull DocumentValidationError = "document end is missing null byte"
+
+// ErrNilReader indicates that an operation was attempted on a nil io.Reader.
+var ErrNilReader = errors.New("nil reader")
+
+// ErrInvalidLength indicates that a length in a binary representation of a BSON document is invalid.
+var ErrInvalidLength = errors.New("document length is invalid")
+
+// ErrEmptyKey indicates that no key was provided to a Lookup method.
+var ErrEmptyKey = errors.New("empty key provided")
+
+// ErrElementNotFound indicates that an Element matching a certain condition does not exist.
+var ErrElementNotFound = errors.New("element not found")
+
+// ErrOutOfBounds indicates that an index provided to access something was invalid.
+var ErrOutOfBounds = errors.New("out of bounds")
+
+// Document is a raw bytes representation of a BSON document.
+type Document []byte
+
+// Array is a raw bytes representation of a BSON array.
+type Array = Document
+
+// NewDocumentFromReader reads a document from r. This function will only validate the length is
+// correct and that the document ends with a null byte.
+func NewDocumentFromReader(r io.Reader) (Document, error) {
+	if r == nil {
+		return nil, ErrNilReader
+	}
+
+	var lengthBytes [4]byte
+
+	// ReadFull guarantees that we will have read at least len(lengthBytes) if err == nil
+	_, err := io.ReadFull(r, lengthBytes[:])
+	if err != nil {
+		return nil, err
+	}
+
+	length, _, _ := readi32(lengthBytes[:]) // ignore ok since we always have enough bytes to read a length
+	if length < 0 {
+		return nil, ErrInvalidLength
+	}
+	document := make([]byte, length)
+
+	copy(document, lengthBytes[:])
+
+	_, err = io.ReadFull(r, document[4:])
+	if err != nil {
+		return nil, err
+	}
+
+	if document[length-1] != 0x00 {
+		return nil, ErrMissingNull
+	}
+
+	return document, nil
+}
+
+// Lookup searches the document, potentially recursively, for the given key. If there are multiple
+// keys provided, this method will recurse down, as long as the top and intermediate nodes are
+// either documents or arrays. If an error occurs or if the value doesn't exist, an empty Value is
+// returned.
+func (d Document) Lookup(key ...string) Value {
+	val, _ := d.LookupErr(key...)
+	return val
+}
+
+// LookupErr is the same as Lookup, except it returns an error in addition to an empty Value.
+func (d Document) LookupErr(key ...string) (Value, error) {
+	if len(key) < 1 {
+		return Value{}, ErrEmptyKey
+	}
+	length, rem, ok := ReadLength(d)
+	if !ok {
+		return Value{}, NewInsufficientBytesError(d, rem)
+	}
+
+	length -= 4
+
+	var elem Element
+	for length > 1 {
+		elem, rem, ok = ReadElement(rem)
+		length -= int32(len(elem))
+		if !ok {
+			return Value{}, NewInsufficientBytesError(d, rem)
+		}
+		if elem.Key() != key[0] {
+			continue
+		}
+		if len(key) > 1 {
+			tt := bsontype.Type(elem[0])
+			switch tt {
+			case bsontype.EmbeddedDocument:
+				val, err := elem.Value().Document().LookupErr(key[1:]...)
+				if err != nil {
+					return Value{}, err
+				}
+				return val, nil
+			case bsontype.Array:
+				val, err := elem.Value().Array().LookupErr(key[1:]...)
+				if err != nil {
+					return Value{}, err
+				}
+				return val, nil
+			default:
+				return Value{}, InvalidDepthTraversalError{Key: elem.Key(), Type: tt}
+			}
+		}
+		return elem.ValueErr()
+	}
+	return Value{}, ErrElementNotFound
+}
+
+// Index searches for and retrieves the element at the given index. This method will panic if
+// the document is invalid or if the index is out of bounds.
+func (d Document) Index(index uint) Element {
+	elem, err := d.IndexErr(index)
+	if err != nil {
+		panic(err)
+	}
+	return elem
+}
+
+// IndexErr searches for and retrieves the element at the given index.
+func (d Document) IndexErr(index uint) (Element, error) {
+	length, rem, ok := ReadLength(d)
+	if !ok {
+		return nil, NewInsufficientBytesError(d, rem)
+	}
+
+	length -= 4
+
+	var current uint
+	var elem Element
+	for length > 1 {
+		elem, rem, ok = ReadElement(rem)
+		length -= int32(len(elem))
+		if !ok {
+			return nil, NewInsufficientBytesError(d, rem)
+		}
+		if current != index {
+			current++
+			continue
+		}
+		return elem, nil
+	}
+	return nil, ErrOutOfBounds
+}
+
+// DebugString outputs a human readable version of Document. It will attempt to stringify the
+// valid components of the document even if the entire document is not valid.
+func (d Document) DebugString() string {
+	if len(d) < 5 {
+		return "<malformed>"
+	}
+	var buf bytes.Buffer
+	buf.WriteString("Document")
+	length, rem, _ := ReadLength(d) // We know we have enough bytes to read the length
+	buf.WriteByte('(')
+	buf.WriteString(strconv.Itoa(int(length)))
+	length -= 4
+	buf.WriteString("){")
+	var elem Element
+	var ok bool
+	for length > 1 {
+		elem, rem, ok = ReadElement(rem)
+		length -= int32(len(elem))
+		if !ok {
+			buf.WriteString(fmt.Sprintf("<malformed (%d)>", length))
+			break
+		}
+		fmt.Fprintf(&buf, "%s ", elem.DebugString())
+	}
+	buf.WriteByte('}')
+
+	return buf.String()
+}
+
+// String outputs an ExtendedJSON version of Document. If the document is not valid, this method
+// returns an empty string.
+func (d Document) String() string {
+	if len(d) < 5 {
+		return ""
+	}
+	var buf bytes.Buffer
+	buf.WriteByte('{')
+
+	length, rem, _ := ReadLength(d) // We know we have enough bytes to read the length
+
+	length -= 4
+
+	var elem Element
+	var ok bool
+	first := true
+	for length > 1 {
+		if !first {
+			buf.WriteByte(',')
+		}
+		elem, rem, ok = ReadElement(rem)
+		length -= int32(len(elem))
+		if !ok {
+			return ""
+		}
+		fmt.Fprintf(&buf, "%s", elem.String())
+		first = false
+	}
+	buf.WriteByte('}')
+
+	return buf.String()
+}
+
+// Elements returns this document as a slice of elements. The returned slice will contain valid
+// elements. If the document is not valid, the elements up to the invalid point will be returned
+// along with an error.
+func (d Document) Elements() ([]Element, error) {
+	length, rem, ok := ReadLength(d)
+	if !ok {
+		return nil, NewInsufficientBytesError(d, rem)
+	}
+
+	length -= 4
+
+	var elem Element
+	var elems []Element
+	for length > 1 {
+		elem, rem, ok = ReadElement(rem)
+		length -= int32(len(elem))
+		if !ok {
+			return elems, NewInsufficientBytesError(d, rem)
+		}
+		if err := elem.Validate(); err != nil {
+			return elems, err
+		}
+		elems = append(elems, elem)
+	}
+	return elems, nil
+}
+
+// Values returns this document as a slice of values. The returned slice will contain valid values.
+// If the document is not valid, the values up to the invalid point will be returned along with an
+// error.
+func (d Document) Values() ([]Value, error) {
+	length, rem, ok := ReadLength(d)
+	if !ok {
+		return nil, NewInsufficientBytesError(d, rem)
+	}
+
+	length -= 4
+
+	var elem Element
+	var vals []Value
+	for length > 1 {
+		elem, rem, ok = ReadElement(rem)
+		length -= int32(len(elem))
+		if !ok {
+			return vals, NewInsufficientBytesError(d, rem)
+		}
+		if err := elem.Value().Validate(); err != nil {
+			return vals, err
+		}
+		vals = append(vals, elem.Value())
+	}
+	return vals, nil
+}
+
+// Validate validates the document and ensures the elements contained within are valid.
+func (d Document) Validate() error {
+	length, rem, ok := ReadLength(d)
+	if !ok {
+		return NewInsufficientBytesError(d, rem)
+	}
+	if int(length) > len(d) {
+		return d.lengtherror(int(length), len(d))
+	}
+	if d[length-1] != 0x00 {
+		return ErrMissingNull
+	}
+
+	length -= 4
+	var elem Element
+
+	for length > 1 {
+		elem, rem, ok = ReadElement(rem)
+		length -= int32(len(elem))
+		if !ok {
+			return NewInsufficientBytesError(d, rem)
+		}
+		err := elem.Validate()
+		if err != nil {
+			return err
+		}
+	}
+
+	if len(rem) < 1 || rem[0] != 0x00 {
+		return ErrMissingNull
+	}
+	return nil
+}
+
+func (Document) lengtherror(length, rem int) error {
+	return DocumentValidationError(fmt.Sprintf("document length exceeds available bytes. length=%d remainingBytes=%d", length, rem))
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/bsoncore/document_sequence.go

@@ -0,0 +1,167 @@
+package bsoncore
+
+import (
+	"errors"
+	"io"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+)
+
+// DocumentSequenceStyle is used to represent how a document sequence is laid out in a slice of
+// bytes.
+type DocumentSequenceStyle uint32
+
+// These constants are the valid styles for a DocumentSequence.
+const (
+	_ DocumentSequenceStyle = iota
+	SequenceStyle
+	ArrayStyle
+)
+
+// DocumentSequence represents a sequence of documents. The Style field indicates how the documents
+// are laid out inside of the Data field.
+type DocumentSequence struct {
+	Style DocumentSequenceStyle
+	Data  []byte
+	Pos   int
+}
+
+// ErrCorruptedDocument is returned when a full document couldn't be read from the sequence.
+var ErrCorruptedDocument = errors.New("invalid DocumentSequence: corrupted document")
+
+// ErrNonDocument is returned when a DocumentSequence contains a non-document BSON value.
+var ErrNonDocument = errors.New("invalid DocumentSequence: a non-document value was found in sequence")
+
+// ErrInvalidDocumentSequenceStyle is returned when an unknown DocumentSequenceStyle is set on a
+// DocumentSequence.
+var ErrInvalidDocumentSequenceStyle = errors.New("invalid DocumentSequenceStyle")
+
+// DocumentCount returns the number of documents in the sequence.
+func (ds *DocumentSequence) DocumentCount() int {
+	if ds == nil {
+		return 0
+	}
+	switch ds.Style {
+	case SequenceStyle:
+		var count int
+		var ok bool
+		rem := ds.Data
+		for len(rem) > 0 {
+			_, rem, ok = ReadDocument(rem)
+			if !ok {
+				return 0
+			}
+			count++
+		}
+		return count
+	case ArrayStyle:
+		_, rem, ok := ReadLength(ds.Data)
+		if !ok {
+			return 0
+		}
+
+		var count int
+		for len(rem) > 1 {
+			_, rem, ok = ReadElement(rem)
+			if !ok {
+				return 0
+			}
+			count++
+		}
+		return count
+	default:
+		return 0
+	}
+}
+
+//ResetIterator resets the iteration point for the Next method to the beginning of the document
+//sequence.
+func (ds *DocumentSequence) ResetIterator() {
+	if ds == nil {
+		return
+	}
+	ds.Pos = 0
+}
+
+// Documents returns a slice of the documents. If nil either the Data field is also nil or could not
+// be properly read.
+func (ds *DocumentSequence) Documents() ([]Document, error) {
+	if ds == nil {
+		return nil, nil
+	}
+	switch ds.Style {
+	case SequenceStyle:
+		rem := ds.Data
+		var docs []Document
+		var doc Document
+		var ok bool
+		for {
+			doc, rem, ok = ReadDocument(rem)
+			if !ok {
+				if len(rem) == 0 {
+					break
+				}
+				return nil, ErrCorruptedDocument
+			}
+			docs = append(docs, doc)
+		}
+		return docs, nil
+	case ArrayStyle:
+		if len(ds.Data) == 0 {
+			return nil, nil
+		}
+		vals, err := Document(ds.Data).Values()
+		if err != nil {
+			return nil, ErrCorruptedDocument
+		}
+		docs := make([]Document, 0, len(vals))
+		for _, v := range vals {
+			if v.Type != bsontype.EmbeddedDocument {
+				return nil, ErrNonDocument
+			}
+			docs = append(docs, v.Data)
+		}
+		return docs, nil
+	default:
+		return nil, ErrInvalidDocumentSequenceStyle
+	}
+}
+
+// Next retrieves the next document from this sequence and returns it. This method will return
+// io.EOF when it has reached the end of the sequence.
+func (ds *DocumentSequence) Next() (Document, error) {
+	if ds == nil || ds.Pos >= len(ds.Data) {
+		return nil, io.EOF
+	}
+	switch ds.Style {
+	case SequenceStyle:
+		doc, _, ok := ReadDocument(ds.Data[ds.Pos:])
+		if !ok {
+			return nil, ErrCorruptedDocument
+		}
+		ds.Pos += len(doc)
+		return doc, nil
+	case ArrayStyle:
+		if ds.Pos < 4 {
+			if len(ds.Data) < 4 {
+				return nil, ErrCorruptedDocument
+			}
+			ds.Pos = 4 // Skip the length of the document
+		}
+		if len(ds.Data[ds.Pos:]) == 1 && ds.Data[ds.Pos] == 0x00 {
+			return nil, io.EOF // At the end of the document
+		}
+		elem, _, ok := ReadElement(ds.Data[ds.Pos:])
+		if !ok {
+			return nil, ErrCorruptedDocument
+		}
+		ds.Pos += len(elem)
+		val := elem.Value()
+		if val.Type != bsontype.EmbeddedDocument {
+			return nil, ErrNonDocument
+		}
+		return val.Data, nil
+	default:
+		return nil, ErrInvalidDocumentSequenceStyle
+	}
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/bsoncore/element.go

@@ -0,0 +1,152 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncore
+
+import (
+	"bytes"
+	"fmt"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+)
+
+// MalformedElementError represents a class of errors that RawElement methods return.
+type MalformedElementError string
+
+func (mee MalformedElementError) Error() string { return string(mee) }
+
+// ErrElementMissingKey is returned when a RawElement is missing a key.
+const ErrElementMissingKey MalformedElementError = "element is missing key"
+
+// ErrElementMissingType is returned when a RawElement is missing a type.
+const ErrElementMissingType MalformedElementError = "element is missing type"
+
+// Element is a raw bytes representation of a BSON element.
+type Element []byte
+
+// Key returns the key for this element. If the element is not valid, this method returns an empty
+// string. If knowing if the element is valid is important, use KeyErr.
+func (e Element) Key() string {
+	key, _ := e.KeyErr()
+	return key
+}
+
+// KeyBytes returns the key for this element as a []byte. If the element is not valid, this method
+// returns an empty string. If knowing if the element is valid is important, use KeyErr. This method
+// will not include the null byte at the end of the key in the slice of bytes.
+func (e Element) KeyBytes() []byte {
+	key, _ := e.KeyBytesErr()
+	return key
+}
+
+// KeyErr returns the key for this element, returning an error if the element is not valid.
+func (e Element) KeyErr() (string, error) {
+	key, err := e.KeyBytesErr()
+	return string(key), err
+}
+
+// KeyBytesErr returns the key for this element as a []byte, returning an error if the element is
+// not valid.
+func (e Element) KeyBytesErr() ([]byte, error) {
+	if len(e) <= 0 {
+		return nil, ErrElementMissingType
+	}
+	idx := bytes.IndexByte(e[1:], 0x00)
+	if idx == -1 {
+		return nil, ErrElementMissingKey
+	}
+	return e[1 : idx+1], nil
+}
+
+// Validate ensures the element is a valid BSON element.
+func (e Element) Validate() error {
+	if len(e) < 1 {
+		return ErrElementMissingType
+	}
+	idx := bytes.IndexByte(e[1:], 0x00)
+	if idx == -1 {
+		return ErrElementMissingKey
+	}
+	return Value{Type: bsontype.Type(e[0]), Data: e[idx+2:]}.Validate()
+}
+
+// CompareKey will compare this element's key to key. This method makes it easy to compare keys
+// without needing to allocate a string. The key may be null terminated. If a valid key cannot be
+// read this method will return false.
+func (e Element) CompareKey(key []byte) bool {
+	if len(e) < 2 {
+		return false
+	}
+	idx := bytes.IndexByte(e[1:], 0x00)
+	if idx == -1 {
+		return false
+	}
+	if index := bytes.IndexByte(key, 0x00); index > -1 {
+		key = key[:index]
+	}
+	return bytes.Equal(e[1:idx+1], key)
+}
+
+// Value returns the value of this element. If the element is not valid, this method returns an
+// empty Value. If knowing if the element is valid is important, use ValueErr.
+func (e Element) Value() Value {
+	val, _ := e.ValueErr()
+	return val
+}
+
+// ValueErr returns the value for this element, returning an error if the element is not valid.
+func (e Element) ValueErr() (Value, error) {
+	if len(e) <= 0 {
+		return Value{}, ErrElementMissingType
+	}
+	idx := bytes.IndexByte(e[1:], 0x00)
+	if idx == -1 {
+		return Value{}, ErrElementMissingKey
+	}
+
+	val, rem, exists := ReadValue(e[idx+2:], bsontype.Type(e[0]))
+	if !exists {
+		return Value{}, NewInsufficientBytesError(e, rem)
+	}
+	return val, nil
+}
+
+// String implements the fmt.String interface. The output will be in extended JSON format.
+func (e Element) String() string {
+	if len(e) <= 0 {
+		return ""
+	}
+	t := bsontype.Type(e[0])
+	idx := bytes.IndexByte(e[1:], 0x00)
+	if idx == -1 {
+		return ""
+	}
+	key, valBytes := []byte(e[1:idx+1]), []byte(e[idx+2:])
+	val, _, valid := ReadValue(valBytes, t)
+	if !valid {
+		return ""
+	}
+	return fmt.Sprintf(`"%s": %v`, key, val)
+}
+
+// DebugString outputs a human readable version of RawElement. It will attempt to stringify the
+// valid components of the element even if the entire element is not valid.
+func (e Element) DebugString() string {
+	if len(e) <= 0 {
+		return "<malformed>"
+	}
+	t := bsontype.Type(e[0])
+	idx := bytes.IndexByte(e[1:], 0x00)
+	if idx == -1 {
+		return fmt.Sprintf(`bson.Element{[%s]<malformed>}`, t)
+	}
+	key, valBytes := []byte(e[1:idx+1]), []byte(e[idx+2:])
+	val, _, valid := ReadValue(valBytes, t)
+	if !valid {
+		return fmt.Sprintf(`bson.Element{[%s]"%s": <malformed>}`, t, key)
+	}
+	return fmt.Sprintf(`bson.Element{[%s]"%s": %v}`, t, key, val)
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/bsoncore/tables.go

@@ -0,0 +1,223 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+//
+// Based on github.com/golang/go by The Go Authors
+// See THIRD-PARTY-NOTICES for original license terms.
+
+package bsoncore
+
+import "unicode/utf8"
+
+// safeSet holds the value true if the ASCII character with the given array
+// position can be represented inside a JSON string without any further
+// escaping.
+//
+// All values are true except for the ASCII control characters (0-31), the
+// double quote ("), and the backslash character ("\").
+var safeSet = [utf8.RuneSelf]bool{
+	' ':      true,
+	'!':      true,
+	'"':      false,
+	'#':      true,
+	'$':      true,
+	'%':      true,
+	'&':      true,
+	'\'':     true,
+	'(':      true,
+	')':      true,
+	'*':      true,
+	'+':      true,
+	',':      true,
+	'-':      true,
+	'.':      true,
+	'/':      true,
+	'0':      true,
+	'1':      true,
+	'2':      true,
+	'3':      true,
+	'4':      true,
+	'5':      true,
+	'6':      true,
+	'7':      true,
+	'8':      true,
+	'9':      true,
+	':':      true,
+	';':      true,
+	'<':      true,
+	'=':      true,
+	'>':      true,
+	'?':      true,
+	'@':      true,
+	'A':      true,
+	'B':      true,
+	'C':      true,
+	'D':      true,
+	'E':      true,
+	'F':      true,
+	'G':      true,
+	'H':      true,
+	'I':      true,
+	'J':      true,
+	'K':      true,
+	'L':      true,
+	'M':      true,
+	'N':      true,
+	'O':      true,
+	'P':      true,
+	'Q':      true,
+	'R':      true,
+	'S':      true,
+	'T':      true,
+	'U':      true,
+	'V':      true,
+	'W':      true,
+	'X':      true,
+	'Y':      true,
+	'Z':      true,
+	'[':      true,
+	'\\':     false,
+	']':      true,
+	'^':      true,
+	'_':      true,
+	'`':      true,
+	'a':      true,
+	'b':      true,
+	'c':      true,
+	'd':      true,
+	'e':      true,
+	'f':      true,
+	'g':      true,
+	'h':      true,
+	'i':      true,
+	'j':      true,
+	'k':      true,
+	'l':      true,
+	'm':      true,
+	'n':      true,
+	'o':      true,
+	'p':      true,
+	'q':      true,
+	'r':      true,
+	's':      true,
+	't':      true,
+	'u':      true,
+	'v':      true,
+	'w':      true,
+	'x':      true,
+	'y':      true,
+	'z':      true,
+	'{':      true,
+	'|':      true,
+	'}':      true,
+	'~':      true,
+	'\u007f': true,
+}
+
+// htmlSafeSet holds the value true if the ASCII character with the given
+// array position can be safely represented inside a JSON string, embedded
+// inside of HTML <script> tags, without any additional escaping.
+//
+// All values are true except for the ASCII control characters (0-31), the
+// double quote ("), the backslash character ("\"), HTML opening and closing
+// tags ("<" and ">"), and the ampersand ("&").
+var htmlSafeSet = [utf8.RuneSelf]bool{
+	' ':      true,
+	'!':      true,
+	'"':      false,
+	'#':      true,
+	'$':      true,
+	'%':      true,
+	'&':      false,
+	'\'':     true,
+	'(':      true,
+	')':      true,
+	'*':      true,
+	'+':      true,
+	',':      true,
+	'-':      true,
+	'.':      true,
+	'/':      true,
+	'0':      true,
+	'1':      true,
+	'2':      true,
+	'3':      true,
+	'4':      true,
+	'5':      true,
+	'6':      true,
+	'7':      true,
+	'8':      true,
+	'9':      true,
+	':':      true,
+	';':      true,
+	'<':      false,
+	'=':      true,
+	'>':      false,
+	'?':      true,
+	'@':      true,
+	'A':      true,
+	'B':      true,
+	'C':      true,
+	'D':      true,
+	'E':      true,
+	'F':      true,
+	'G':      true,
+	'H':      true,
+	'I':      true,
+	'J':      true,
+	'K':      true,
+	'L':      true,
+	'M':      true,
+	'N':      true,
+	'O':      true,
+	'P':      true,
+	'Q':      true,
+	'R':      true,
+	'S':      true,
+	'T':      true,
+	'U':      true,
+	'V':      true,
+	'W':      true,
+	'X':      true,
+	'Y':      true,
+	'Z':      true,
+	'[':      true,
+	'\\':     false,
+	']':      true,
+	'^':      true,
+	'_':      true,
+	'`':      true,
+	'a':      true,
+	'b':      true,
+	'c':      true,
+	'd':      true,
+	'e':      true,
+	'f':      true,
+	'g':      true,
+	'h':      true,
+	'i':      true,
+	'j':      true,
+	'k':      true,
+	'l':      true,
+	'm':      true,
+	'n':      true,
+	'o':      true,
+	'p':      true,
+	'q':      true,
+	'r':      true,
+	's':      true,
+	't':      true,
+	'u':      true,
+	'v':      true,
+	'w':      true,
+	'x':      true,
+	'y':      true,
+	'z':      true,
+	'{':      true,
+	'|':      true,
+	'}':      true,
+	'~':      true,
+	'\u007f': true,
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/constructor.go

@@ -0,0 +1,166 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsonx
+
+import (
+	"encoding/binary"
+	"math"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+// IDoc is the interface implemented by Doc and MDoc. It allows either of these types to be provided
+// to the Document function to create a Value.
+type IDoc interface {
+	idoc()
+}
+
+// Double constructs a BSON double Value.
+func Double(f64 float64) Val {
+	v := Val{t: bsontype.Double}
+	binary.LittleEndian.PutUint64(v.bootstrap[0:8], math.Float64bits(f64))
+	return v
+}
+
+// String constructs a BSON string Value.
+func String(str string) Val { return Val{t: bsontype.String}.writestring(str) }
+
+// Document constructs a Value from the given IDoc. If nil is provided, a BSON Null value will be
+// returned.
+func Document(doc IDoc) Val {
+	var v Val
+	switch tt := doc.(type) {
+	case Doc:
+		if tt == nil {
+			v.t = bsontype.Null
+			break
+		}
+		v.t = bsontype.EmbeddedDocument
+		v.primitive = tt
+	case MDoc:
+		if tt == nil {
+			v.t = bsontype.Null
+			break
+		}
+		v.t = bsontype.EmbeddedDocument
+		v.primitive = tt
+	default:
+		v.t = bsontype.Null
+	}
+	return v
+}
+
+// Array constructs a Value from arr. If arr is nil, a BSON Null value is returned.
+func Array(arr Arr) Val {
+	if arr == nil {
+		return Val{t: bsontype.Null}
+	}
+	return Val{t: bsontype.Array, primitive: arr}
+}
+
+// Binary constructs a BSON binary Value.
+func Binary(subtype byte, data []byte) Val {
+	return Val{t: bsontype.Binary, primitive: primitive.Binary{Subtype: subtype, Data: data}}
+}
+
+// Undefined constructs a BSON binary Value.
+func Undefined() Val { return Val{t: bsontype.Undefined} }
+
+// ObjectID constructs a BSON objectid Value.
+func ObjectID(oid primitive.ObjectID) Val {
+	v := Val{t: bsontype.ObjectID}
+	copy(v.bootstrap[0:12], oid[:])
+	return v
+}
+
+// Boolean constructs a BSON boolean Value.
+func Boolean(b bool) Val {
+	v := Val{t: bsontype.Boolean}
+	if b {
+		v.bootstrap[0] = 0x01
+	}
+	return v
+}
+
+// DateTime constructs a BSON datetime Value.
+func DateTime(dt int64) Val { return Val{t: bsontype.DateTime}.writei64(dt) }
+
+// Time constructs a BSON datetime Value.
+func Time(t time.Time) Val {
+	return Val{t: bsontype.DateTime}.writei64(t.Unix()*1e3 + int64(t.Nanosecond()/1e6))
+}
+
+// Null constructs a BSON binary Value.
+func Null() Val { return Val{t: bsontype.Null} }
+
+// Regex constructs a BSON regex Value.
+func Regex(pattern, options string) Val {
+	regex := primitive.Regex{Pattern: pattern, Options: options}
+	return Val{t: bsontype.Regex, primitive: regex}
+}
+
+// DBPointer constructs a BSON dbpointer Value.
+func DBPointer(ns string, ptr primitive.ObjectID) Val {
+	dbptr := primitive.DBPointer{DB: ns, Pointer: ptr}
+	return Val{t: bsontype.DBPointer, primitive: dbptr}
+}
+
+// JavaScript constructs a BSON javascript Value.
+func JavaScript(js string) Val {
+	return Val{t: bsontype.JavaScript}.writestring(js)
+}
+
+// Symbol constructs a BSON symbol Value.
+func Symbol(symbol string) Val {
+	return Val{t: bsontype.Symbol}.writestring(symbol)
+}
+
+// CodeWithScope constructs a BSON code with scope Value.
+func CodeWithScope(code string, scope IDoc) Val {
+	cws := primitive.CodeWithScope{Code: primitive.JavaScript(code), Scope: scope}
+	return Val{t: bsontype.CodeWithScope, primitive: cws}
+}
+
+// Int32 constructs a BSON int32 Value.
+func Int32(i32 int32) Val {
+	v := Val{t: bsontype.Int32}
+	v.bootstrap[0] = byte(i32)
+	v.bootstrap[1] = byte(i32 >> 8)
+	v.bootstrap[2] = byte(i32 >> 16)
+	v.bootstrap[3] = byte(i32 >> 24)
+	return v
+}
+
+// Timestamp constructs a BSON timestamp Value.
+func Timestamp(t, i uint32) Val {
+	v := Val{t: bsontype.Timestamp}
+	v.bootstrap[0] = byte(i)
+	v.bootstrap[1] = byte(i >> 8)
+	v.bootstrap[2] = byte(i >> 16)
+	v.bootstrap[3] = byte(i >> 24)
+	v.bootstrap[4] = byte(t)
+	v.bootstrap[5] = byte(t >> 8)
+	v.bootstrap[6] = byte(t >> 16)
+	v.bootstrap[7] = byte(t >> 24)
+	return v
+}
+
+// Int64 constructs a BSON int64 Value.
+func Int64(i64 int64) Val { return Val{t: bsontype.Int64}.writei64(i64) }
+
+// Decimal128 constructs a BSON decimal128 Value.
+func Decimal128(d128 primitive.Decimal128) Val {
+	return Val{t: bsontype.Decimal128, primitive: d128}
+}
+
+// MinKey constructs a BSON minkey Value.
+func MinKey() Val { return Val{t: bsontype.MinKey} }
+
+// MaxKey constructs a BSON maxkey Value.
+func MaxKey() Val { return Val{t: bsontype.MaxKey} }

vendor/go.mongodb.org/mongo-driver/x/bsonx/document.go

@@ -0,0 +1,305 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsonx
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+)
+
+// ErrNilDocument indicates that an operation was attempted on a nil *bson.Document.
+var ErrNilDocument = errors.New("document is nil")
+
+// KeyNotFound is an error type returned from the Lookup methods on Document. This type contains
+// information about which key was not found and if it was actually not found or if a component of
+// the key except the last was not a document nor array.
+type KeyNotFound struct {
+	Key   []string      // The keys that were searched for.
+	Depth uint          // Which key either was not found or was an incorrect type.
+	Type  bsontype.Type // The type of the key that was found but was an incorrect type.
+}
+
+func (knf KeyNotFound) Error() string {
+	depth := knf.Depth
+	if depth >= uint(len(knf.Key)) {
+		depth = uint(len(knf.Key)) - 1
+	}
+
+	if len(knf.Key) == 0 {
+		return "no keys were provided for lookup"
+	}
+
+	if knf.Type != bsontype.Type(0) {
+		return fmt.Sprintf(`key "%s" was found but was not valid to traverse BSON type %s`, knf.Key[depth], knf.Type)
+	}
+
+	return fmt.Sprintf(`key "%s" was not found`, knf.Key[depth])
+}
+
+// Doc is a type safe, concise BSON document representation.
+type Doc []Elem
+
+// ReadDoc will create a Document using the provided slice of bytes. If the
+// slice of bytes is not a valid BSON document, this method will return an error.
+func ReadDoc(b []byte) (Doc, error) {
+	doc := make(Doc, 0)
+	err := doc.UnmarshalBSON(b)
+	if err != nil {
+		return nil, err
+	}
+	return doc, nil
+}
+
+// Copy makes a shallow copy of this document.
+func (d Doc) Copy() Doc {
+	d2 := make(Doc, len(d))
+	copy(d2, d)
+	return d2
+}
+
+// Append adds an element to the end of the document, creating it from the key and value provided.
+func (d Doc) Append(key string, val Val) Doc {
+	return append(d, Elem{Key: key, Value: val})
+}
+
+// Prepend adds an element to the beginning of the document, creating it from the key and value provided.
+func (d Doc) Prepend(key string, val Val) Doc {
+	// TODO: should we just modify d itself instead of doing an alloc here?
+	return append(Doc{{Key: key, Value: val}}, d...)
+}
+
+// Set replaces an element of a document. If an element with a matching key is
+// found, the element will be replaced with the one provided. If the document
+// does not have an element with that key, the element is appended to the
+// document instead.
+func (d Doc) Set(key string, val Val) Doc {
+	idx := d.IndexOf(key)
+	if idx == -1 {
+		return append(d, Elem{Key: key, Value: val})
+	}
+	d[idx] = Elem{Key: key, Value: val}
+	return d
+}
+
+// IndexOf returns the index of the first element with a key of key, or -1 if no element with a key
+// was found.
+func (d Doc) IndexOf(key string) int {
+	for i, e := range d {
+		if e.Key == key {
+			return i
+		}
+	}
+	return -1
+}
+
+// Delete removes the element with key if it exists and returns the updated Doc.
+func (d Doc) Delete(key string) Doc {
+	idx := d.IndexOf(key)
+	if idx == -1 {
+		return d
+	}
+	return append(d[:idx], d[idx+1:]...)
+}
+
+// Lookup searches the document and potentially subdocuments or arrays for the
+// provided key. Each key provided to this method represents a layer of depth.
+//
+// This method will return an empty Value if they key does not exist. To know if they key actually
+// exists, use LookupErr.
+func (d Doc) Lookup(key ...string) Val {
+	val, _ := d.LookupErr(key...)
+	return val
+}
+
+// LookupErr searches the document and potentially subdocuments or arrays for the
+// provided key. Each key provided to this method represents a layer of depth.
+func (d Doc) LookupErr(key ...string) (Val, error) {
+	elem, err := d.LookupElementErr(key...)
+	return elem.Value, err
+}
+
+// LookupElement searches the document and potentially subdocuments or arrays for the
+// provided key. Each key provided to this method represents a layer of depth.
+//
+// This method will return an empty Element if they key does not exist. To know if they key actually
+// exists, use LookupElementErr.
+func (d Doc) LookupElement(key ...string) Elem {
+	elem, _ := d.LookupElementErr(key...)
+	return elem
+}
+
+// LookupElementErr searches the document and potentially subdocuments for the
+// provided key. Each key provided to this method represents a layer of depth.
+func (d Doc) LookupElementErr(key ...string) (Elem, error) {
+	// KeyNotFound operates by being created where the error happens and then the depth is
+	// incremented by 1 as each function unwinds. Whenever this function returns, it also assigns
+	// the Key slice to the key slice it has. This ensures that the proper depth is identified and
+	// the proper keys.
+	if len(key) == 0 {
+		return Elem{}, KeyNotFound{Key: key}
+	}
+
+	var elem Elem
+	var err error
+	idx := d.IndexOf(key[0])
+	if idx == -1 {
+		return Elem{}, KeyNotFound{Key: key}
+	}
+
+	elem = d[idx]
+	if len(key) == 1 {
+		return elem, nil
+	}
+
+	switch elem.Value.Type() {
+	case bsontype.EmbeddedDocument:
+		switch tt := elem.Value.primitive.(type) {
+		case Doc:
+			elem, err = tt.LookupElementErr(key[1:]...)
+		case MDoc:
+			elem, err = tt.LookupElementErr(key[1:]...)
+		}
+	default:
+		return Elem{}, KeyNotFound{Type: elem.Value.Type()}
+	}
+	switch tt := err.(type) {
+	case KeyNotFound:
+		tt.Depth++
+		tt.Key = key
+		return Elem{}, tt
+	case nil:
+		return elem, nil
+	default:
+		return Elem{}, err // We can't actually hit this.
+	}
+}
+
+// MarshalBSONValue implements the bsoncodec.ValueMarshaler interface.
+//
+// This method will never return an error.
+func (d Doc) MarshalBSONValue() (bsontype.Type, []byte, error) {
+	if d == nil {
+		// TODO: Should we do this?
+		return bsontype.Null, nil, nil
+	}
+	data, _ := d.MarshalBSON()
+	return bsontype.EmbeddedDocument, data, nil
+}
+
+// MarshalBSON implements the Marshaler interface.
+//
+// This method will never return an error.
+func (d Doc) MarshalBSON() ([]byte, error) { return d.AppendMarshalBSON(nil) }
+
+// AppendMarshalBSON marshals Doc to BSON bytes, appending to dst.
+//
+// This method will never return an error.
+func (d Doc) AppendMarshalBSON(dst []byte) ([]byte, error) {
+	idx, dst := bsoncore.ReserveLength(dst)
+	for _, elem := range d {
+		t, data, _ := elem.Value.MarshalBSONValue() // Value.MarshalBSONValue never returns an error.
+		dst = append(dst, byte(t))
+		dst = append(dst, elem.Key...)
+		dst = append(dst, 0x00)
+		dst = append(dst, data...)
+	}
+	dst = append(dst, 0x00)
+	dst = bsoncore.UpdateLength(dst, idx, int32(len(dst[idx:])))
+	return dst, nil
+}
+
+// UnmarshalBSON implements the Unmarshaler interface.
+func (d *Doc) UnmarshalBSON(b []byte) error {
+	if d == nil {
+		return ErrNilDocument
+	}
+
+	if err := bsoncore.Document(b).Validate(); err != nil {
+		return err
+	}
+
+	elems, err := bsoncore.Document(b).Elements()
+	if err != nil {
+		return err
+	}
+	var val Val
+	for _, elem := range elems {
+		rawv := elem.Value()
+		err = val.UnmarshalBSONValue(rawv.Type, rawv.Data)
+		if err != nil {
+			return err
+		}
+		*d = d.Append(elem.Key(), val)
+	}
+	return nil
+}
+
+// UnmarshalBSONValue implements the bson.ValueUnmarshaler interface.
+func (d *Doc) UnmarshalBSONValue(t bsontype.Type, data []byte) error {
+	if t != bsontype.EmbeddedDocument {
+		return fmt.Errorf("cannot unmarshal %s into a bsonx.Doc", t)
+	}
+	return d.UnmarshalBSON(data)
+}
+
+// Equal compares this document to another, returning true if they are equal.
+func (d Doc) Equal(id IDoc) bool {
+	switch tt := id.(type) {
+	case Doc:
+		d2 := tt
+		if len(d) != len(d2) {
+			return false
+		}
+		for idx := range d {
+			if !d[idx].Equal(d2[idx]) {
+				return false
+			}
+		}
+	case MDoc:
+		unique := make(map[string]struct{}, 0)
+		for _, elem := range d {
+			unique[elem.Key] = struct{}{}
+			val, ok := tt[elem.Key]
+			if !ok {
+				return false
+			}
+			if !val.Equal(elem.Value) {
+				return false
+			}
+		}
+		if len(unique) != len(tt) {
+			return false
+		}
+	case nil:
+		return d == nil
+	default:
+		return false
+	}
+
+	return true
+}
+
+// String implements the fmt.Stringer interface.
+func (d Doc) String() string {
+	var buf bytes.Buffer
+	buf.Write([]byte("bson.Document{"))
+	for idx, elem := range d {
+		if idx > 0 {
+			buf.Write([]byte(", "))
+		}
+		fmt.Fprintf(&buf, "%v", elem)
+	}
+	buf.WriteByte('}')
+
+	return buf.String()
+}
+
+func (Doc) idoc() {}

vendor/go.mongodb.org/mongo-driver/x/bsonx/element.go

@@ -0,0 +1,53 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsonx
+
+import (
+	"fmt"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+)
+
+const validateMaxDepthDefault = 2048
+
+// ElementTypeError specifies that a method to obtain a BSON value an incorrect type was called on a bson.Value.
+//
+// TODO: rename this ValueTypeError.
+type ElementTypeError struct {
+	Method string
+	Type   bsontype.Type
+}
+
+// Error implements the error interface.
+func (ete ElementTypeError) Error() string {
+	return "Call of " + ete.Method + " on " + ete.Type.String() + " type"
+}
+
+// Elem represents a BSON element.
+//
+// NOTE: Element cannot be the value of a map nor a property of a struct without special handling.
+// The default encoders and decoders will not process Element correctly. To do so would require
+// information loss since an Element contains a key, but the keys used when encoding a struct are
+// the struct field names. Instead of using an Element, use a Value as a value in a map or a
+// property of a struct.
+type Elem struct {
+	Key   string
+	Value Val
+}
+
+// Equal compares e and e2 and returns true if they are equal.
+func (e Elem) Equal(e2 Elem) bool {
+	if e.Key != e2.Key {
+		return false
+	}
+	return e.Value.Equal(e2.Value)
+}
+
+func (e Elem) String() string {
+	// TODO(GODRIVER-612): When bsoncore has appenders for extended JSON use that here.
+	return fmt.Sprintf(`bson.Element{"%s": %v}`, e.Key, e.Value)
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/mdocument.go

@@ -0,0 +1,231 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsonx
+
+import (
+	"bytes"
+	"fmt"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+)
+
+// MDoc is an unordered, type safe, concise BSON document representation. This type should not be
+// used if you require ordering of values or duplicate keys.
+type MDoc map[string]Val
+
+// ReadMDoc will create a Doc using the provided slice of bytes. If the
+// slice of bytes is not a valid BSON document, this method will return an error.
+func ReadMDoc(b []byte) (MDoc, error) {
+	doc := make(MDoc, 0)
+	err := doc.UnmarshalBSON(b)
+	if err != nil {
+		return nil, err
+	}
+	return doc, nil
+}
+
+// Copy makes a shallow copy of this document.
+func (d MDoc) Copy() MDoc {
+	d2 := make(MDoc, len(d))
+	for k, v := range d {
+		d2[k] = v
+	}
+	return d2
+}
+
+// Lookup searches the document and potentially subdocuments or arrays for the
+// provided key. Each key provided to this method represents a layer of depth.
+//
+// This method will return an empty Value if they key does not exist. To know if they key actually
+// exists, use LookupErr.
+func (d MDoc) Lookup(key ...string) Val {
+	val, _ := d.LookupErr(key...)
+	return val
+}
+
+// LookupErr searches the document and potentially subdocuments or arrays for the
+// provided key. Each key provided to this method represents a layer of depth.
+func (d MDoc) LookupErr(key ...string) (Val, error) {
+	elem, err := d.LookupElementErr(key...)
+	return elem.Value, err
+}
+
+// LookupElement searches the document and potentially subdocuments or arrays for the
+// provided key. Each key provided to this method represents a layer of depth.
+//
+// This method will return an empty Element if they key does not exist. To know if they key actually
+// exists, use LookupElementErr.
+func (d MDoc) LookupElement(key ...string) Elem {
+	elem, _ := d.LookupElementErr(key...)
+	return elem
+}
+
+// LookupElementErr searches the document and potentially subdocuments for the
+// provided key. Each key provided to this method represents a layer of depth.
+func (d MDoc) LookupElementErr(key ...string) (Elem, error) {
+	// KeyNotFound operates by being created where the error happens and then the depth is
+	// incremented by 1 as each function unwinds. Whenever this function returns, it also assigns
+	// the Key slice to the key slice it has. This ensures that the proper depth is identified and
+	// the proper keys.
+	if len(key) == 0 {
+		return Elem{}, KeyNotFound{Key: key}
+	}
+
+	var elem Elem
+	var err error
+	val, ok := d[key[0]]
+	if !ok {
+		return Elem{}, KeyNotFound{Key: key}
+	}
+
+	if len(key) == 1 {
+		return Elem{Key: key[0], Value: val}, nil
+	}
+
+	switch val.Type() {
+	case bsontype.EmbeddedDocument:
+		switch tt := val.primitive.(type) {
+		case Doc:
+			elem, err = tt.LookupElementErr(key[1:]...)
+		case MDoc:
+			elem, err = tt.LookupElementErr(key[1:]...)
+		}
+	default:
+		return Elem{}, KeyNotFound{Type: val.Type()}
+	}
+	switch tt := err.(type) {
+	case KeyNotFound:
+		tt.Depth++
+		tt.Key = key
+		return Elem{}, tt
+	case nil:
+		return elem, nil
+	default:
+		return Elem{}, err // We can't actually hit this.
+	}
+}
+
+// MarshalBSONValue implements the bsoncodec.ValueMarshaler interface.
+//
+// This method will never return an error.
+func (d MDoc) MarshalBSONValue() (bsontype.Type, []byte, error) {
+	if d == nil {
+		// TODO: Should we do this?
+		return bsontype.Null, nil, nil
+	}
+	data, _ := d.MarshalBSON()
+	return bsontype.EmbeddedDocument, data, nil
+}
+
+// MarshalBSON implements the Marshaler interface.
+//
+// This method will never return an error.
+func (d MDoc) MarshalBSON() ([]byte, error) { return d.AppendMarshalBSON(nil) }
+
+// AppendMarshalBSON marshals Doc to BSON bytes, appending to dst.
+//
+// This method will never return an error.
+func (d MDoc) AppendMarshalBSON(dst []byte) ([]byte, error) {
+	idx, dst := bsoncore.ReserveLength(dst)
+	for k, v := range d {
+		t, data, _ := v.MarshalBSONValue() // Value.MarshalBSONValue never returns an error.
+		dst = append(dst, byte(t))
+		dst = append(dst, k...)
+		dst = append(dst, 0x00)
+		dst = append(dst, data...)
+	}
+	dst = append(dst, 0x00)
+	dst = bsoncore.UpdateLength(dst, idx, int32(len(dst[idx:])))
+	return dst, nil
+}
+
+// UnmarshalBSON implements the Unmarshaler interface.
+func (d *MDoc) UnmarshalBSON(b []byte) error {
+	if d == nil {
+		return ErrNilDocument
+	}
+
+	if err := bsoncore.Document(b).Validate(); err != nil {
+		return err
+	}
+
+	elems, err := bsoncore.Document(b).Elements()
+	if err != nil {
+		return err
+	}
+	var val Val
+	for _, elem := range elems {
+		rawv := elem.Value()
+		err = val.UnmarshalBSONValue(rawv.Type, rawv.Data)
+		if err != nil {
+			return err
+		}
+		(*d)[elem.Key()] = val
+	}
+	return nil
+}
+
+// Equal compares this document to another, returning true if they are equal.
+func (d MDoc) Equal(id IDoc) bool {
+	switch tt := id.(type) {
+	case MDoc:
+		d2 := tt
+		if len(d) != len(d2) {
+			return false
+		}
+		for key, value := range d {
+			value2, ok := d2[key]
+			if !ok {
+				return false
+			}
+			if !value.Equal(value2) {
+				return false
+			}
+		}
+	case Doc:
+		unique := make(map[string]struct{}, 0)
+		for _, elem := range tt {
+			unique[elem.Key] = struct{}{}
+			val, ok := d[elem.Key]
+			if !ok {
+				return false
+			}
+			if !val.Equal(elem.Value) {
+				return false
+			}
+		}
+		if len(unique) != len(d) {
+			return false
+		}
+	case nil:
+		return d == nil
+	default:
+		return false
+	}
+
+	return true
+}
+
+// String implements the fmt.Stringer interface.
+func (d MDoc) String() string {
+	var buf bytes.Buffer
+	buf.Write([]byte("bson.Document{"))
+	first := true
+	for key, value := range d {
+		if !first {
+			buf.Write([]byte(", "))
+		}
+		fmt.Fprintf(&buf, "%v", Elem{Key: key, Value: value})
+		first = false
+	}
+	buf.WriteByte('}')
+
+	return buf.String()
+}
+
+func (MDoc) idoc() {}

vendor/go.mongodb.org/mongo-driver/x/bsonx/primitive_codecs.go

@@ -0,0 +1,638 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsonx
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+
+	"go.mongodb.org/mongo-driver/bson/bsoncodec"
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+)
+
+var primitiveCodecs PrimitiveCodecs
+
+var tDocument = reflect.TypeOf((Doc)(nil))
+var tMDoc = reflect.TypeOf((MDoc)(nil))
+var tArray = reflect.TypeOf((Arr)(nil))
+var tValue = reflect.TypeOf(Val{})
+var tElementSlice = reflect.TypeOf(([]Elem)(nil))
+
+// PrimitiveCodecs is a namespace for all of the default bsoncodec.Codecs for the primitive types
+// defined in this package.
+type PrimitiveCodecs struct{}
+
+// RegisterPrimitiveCodecs will register the encode and decode methods attached to PrimitiveCodecs
+// with the provided RegistryBuilder. if rb is nil, a new empty RegistryBuilder will be created.
+func (pc PrimitiveCodecs) RegisterPrimitiveCodecs(rb *bsoncodec.RegistryBuilder) {
+	if rb == nil {
+		panic(errors.New("argument to RegisterPrimitiveCodecs must not be nil"))
+	}
+
+	rb.
+		RegisterEncoder(tDocument, bsoncodec.ValueEncoderFunc(pc.DocumentEncodeValue)).
+		RegisterEncoder(tArray, bsoncodec.ValueEncoderFunc(pc.ArrayEncodeValue)).
+		RegisterEncoder(tValue, bsoncodec.ValueEncoderFunc(pc.ValueEncodeValue)).
+		RegisterEncoder(tElementSlice, bsoncodec.ValueEncoderFunc(pc.ElementSliceEncodeValue)).
+		RegisterDecoder(tDocument, bsoncodec.ValueDecoderFunc(pc.DocumentDecodeValue)).
+		RegisterDecoder(tArray, bsoncodec.ValueDecoderFunc(pc.ArrayDecodeValue)).
+		RegisterDecoder(tValue, bsoncodec.ValueDecoderFunc(pc.ValueDecodeValue)).
+		RegisterDecoder(tElementSlice, bsoncodec.ValueDecoderFunc(pc.ElementSliceDecodeValue))
+}
+
+// DocumentEncodeValue is the ValueEncoderFunc for *Document.
+func (pc PrimitiveCodecs) DocumentEncodeValue(ec bsoncodec.EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tDocument {
+		return bsoncodec.ValueEncoderError{Name: "DocumentEncodeValue", Types: []reflect.Type{tDocument}, Received: val}
+	}
+
+	if val.IsNil() {
+		return vw.WriteNull()
+	}
+
+	doc := val.Interface().(Doc)
+
+	dw, err := vw.WriteDocument()
+	if err != nil {
+		return err
+	}
+
+	return pc.encodeDocument(ec, dw, doc)
+}
+
+// DocumentDecodeValue is the ValueDecoderFunc for *Document.
+func (pc PrimitiveCodecs) DocumentDecodeValue(dctx bsoncodec.DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if !val.CanSet() || val.Type() != tDocument {
+		return bsoncodec.ValueDecoderError{Name: "DocumentDecodeValue", Types: []reflect.Type{tDocument}, Received: val}
+	}
+
+	return pc.documentDecodeValue(dctx, vr, val.Addr().Interface().(*Doc))
+}
+
+func (pc PrimitiveCodecs) documentDecodeValue(dctx bsoncodec.DecodeContext, vr bsonrw.ValueReader, doc *Doc) error {
+
+	dr, err := vr.ReadDocument()
+	if err != nil {
+		return err
+	}
+
+	return pc.decodeDocument(dctx, dr, doc)
+}
+
+// ArrayEncodeValue is the ValueEncoderFunc for *Array.
+func (pc PrimitiveCodecs) ArrayEncodeValue(ec bsoncodec.EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tArray {
+		return bsoncodec.ValueEncoderError{Name: "ArrayEncodeValue", Types: []reflect.Type{tArray}, Received: val}
+	}
+
+	if val.IsNil() {
+		return vw.WriteNull()
+	}
+
+	arr := val.Interface().(Arr)
+
+	aw, err := vw.WriteArray()
+	if err != nil {
+		return err
+	}
+
+	for _, val := range arr {
+		dvw, err := aw.WriteArrayElement()
+		if err != nil {
+			return err
+		}
+
+		err = pc.encodeValue(ec, dvw, val)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return aw.WriteArrayEnd()
+}
+
+// ArrayDecodeValue is the ValueDecoderFunc for *Array.
+func (pc PrimitiveCodecs) ArrayDecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if !val.CanSet() || val.Type() != tArray {
+		return bsoncodec.ValueDecoderError{Name: "ArrayDecodeValue", Types: []reflect.Type{tArray}, Received: val}
+	}
+
+	ar, err := vr.ReadArray()
+	if err != nil {
+		return err
+	}
+
+	if val.IsNil() {
+		val.Set(reflect.MakeSlice(tArray, 0, 0))
+	}
+	val.SetLen(0)
+
+	for {
+		vr, err := ar.ReadValue()
+		if err == bsonrw.ErrEOA {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		var elem Val
+		err = pc.valueDecodeValue(dc, vr, &elem)
+		if err != nil {
+			return err
+		}
+
+		val.Set(reflect.Append(val, reflect.ValueOf(elem)))
+	}
+
+	return nil
+}
+
+// ElementSliceEncodeValue is the ValueEncoderFunc for []*Element.
+func (pc PrimitiveCodecs) ElementSliceEncodeValue(ec bsoncodec.EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tElementSlice {
+		return bsoncodec.ValueEncoderError{Name: "ElementSliceEncodeValue", Types: []reflect.Type{tElementSlice}, Received: val}
+	}
+
+	if val.IsNil() {
+		return vw.WriteNull()
+	}
+
+	return pc.DocumentEncodeValue(ec, vw, val.Convert(tDocument))
+}
+
+// ElementSliceDecodeValue is the ValueDecoderFunc for []*Element.
+func (pc PrimitiveCodecs) ElementSliceDecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if !val.CanSet() || val.Type() != tElementSlice {
+		return bsoncodec.ValueDecoderError{Name: "ElementSliceDecodeValue", Types: []reflect.Type{tElementSlice}, Received: val}
+	}
+
+	if val.IsNil() {
+		val.Set(reflect.MakeSlice(val.Type(), 0, 0))
+	}
+
+	val.SetLen(0)
+
+	dr, err := vr.ReadDocument()
+	if err != nil {
+		return err
+	}
+	elems := make([]reflect.Value, 0)
+	for {
+		key, vr, err := dr.ReadElement()
+		if err == bsonrw.ErrEOD {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		var elem Elem
+		err = pc.elementDecodeValue(dc, vr, key, &elem)
+		if err != nil {
+			return err
+		}
+
+		elems = append(elems, reflect.ValueOf(elem))
+	}
+
+	val.Set(reflect.Append(val, elems...))
+	return nil
+}
+
+// ValueEncodeValue is the ValueEncoderFunc for *Value.
+func (pc PrimitiveCodecs) ValueEncodeValue(ec bsoncodec.EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tValue {
+		return bsoncodec.ValueEncoderError{Name: "ValueEncodeValue", Types: []reflect.Type{tValue}, Received: val}
+	}
+
+	v := val.Interface().(Val)
+
+	return pc.encodeValue(ec, vw, v)
+}
+
+// ValueDecodeValue is the ValueDecoderFunc for *Value.
+func (pc PrimitiveCodecs) ValueDecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if !val.CanSet() || val.Type() != tValue {
+		return bsoncodec.ValueDecoderError{Name: "ValueDecodeValue", Types: []reflect.Type{tValue}, Received: val}
+	}
+
+	return pc.valueDecodeValue(dc, vr, val.Addr().Interface().(*Val))
+}
+
+// encodeDocument is a separate function that we use because CodeWithScope
+// returns us a DocumentWriter and we need to do the same logic that we would do
+// for a document but cannot use a Codec.
+func (pc PrimitiveCodecs) encodeDocument(ec bsoncodec.EncodeContext, dw bsonrw.DocumentWriter, doc Doc) error {
+	for _, elem := range doc {
+		dvw, err := dw.WriteDocumentElement(elem.Key)
+		if err != nil {
+			return err
+		}
+
+		err = pc.encodeValue(ec, dvw, elem.Value)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return dw.WriteDocumentEnd()
+}
+
+// DecodeDocument haves decoding into a Doc from a bsonrw.DocumentReader.
+func (pc PrimitiveCodecs) DecodeDocument(dctx bsoncodec.DecodeContext, dr bsonrw.DocumentReader, pdoc *Doc) error {
+	return pc.decodeDocument(dctx, dr, pdoc)
+}
+
+func (pc PrimitiveCodecs) decodeDocument(dctx bsoncodec.DecodeContext, dr bsonrw.DocumentReader, pdoc *Doc) error {
+	if *pdoc == nil {
+		*pdoc = make(Doc, 0)
+	}
+	*pdoc = (*pdoc)[:0]
+	for {
+		key, vr, err := dr.ReadElement()
+		if err == bsonrw.ErrEOD {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		var elem Elem
+		err = pc.elementDecodeValue(dctx, vr, key, &elem)
+		if err != nil {
+			return err
+		}
+
+		*pdoc = append(*pdoc, elem)
+	}
+	return nil
+}
+
+func (pc PrimitiveCodecs) elementDecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader, key string, elem *Elem) error {
+	var val Val
+	switch vr.Type() {
+	case bsontype.Double:
+		f64, err := vr.ReadDouble()
+		if err != nil {
+			return err
+		}
+		val = Double(f64)
+	case bsontype.String:
+		str, err := vr.ReadString()
+		if err != nil {
+			return err
+		}
+		val = String(str)
+	case bsontype.EmbeddedDocument:
+		var embeddedDoc Doc
+		err := pc.documentDecodeValue(dc, vr, &embeddedDoc)
+		if err != nil {
+			return err
+		}
+		val = Document(embeddedDoc)
+	case bsontype.Array:
+		arr := reflect.New(tArray).Elem()
+		err := pc.ArrayDecodeValue(dc, vr, arr)
+		if err != nil {
+			return err
+		}
+		val = Array(arr.Interface().(Arr))
+	case bsontype.Binary:
+		data, subtype, err := vr.ReadBinary()
+		if err != nil {
+			return err
+		}
+		val = Binary(subtype, data)
+	case bsontype.Undefined:
+		err := vr.ReadUndefined()
+		if err != nil {
+			return err
+		}
+		val = Undefined()
+	case bsontype.ObjectID:
+		oid, err := vr.ReadObjectID()
+		if err != nil {
+			return err
+		}
+		val = ObjectID(oid)
+	case bsontype.Boolean:
+		b, err := vr.ReadBoolean()
+		if err != nil {
+			return err
+		}
+		val = Boolean(b)
+	case bsontype.DateTime:
+		dt, err := vr.ReadDateTime()
+		if err != nil {
+			return err
+		}
+		val = DateTime(dt)
+	case bsontype.Null:
+		err := vr.ReadNull()
+		if err != nil {
+			return err
+		}
+		val = Null()
+	case bsontype.Regex:
+		pattern, options, err := vr.ReadRegex()
+		if err != nil {
+			return err
+		}
+		val = Regex(pattern, options)
+	case bsontype.DBPointer:
+		ns, pointer, err := vr.ReadDBPointer()
+		if err != nil {
+			return err
+		}
+		val = DBPointer(ns, pointer)
+	case bsontype.JavaScript:
+		js, err := vr.ReadJavascript()
+		if err != nil {
+			return err
+		}
+		val = JavaScript(js)
+	case bsontype.Symbol:
+		symbol, err := vr.ReadSymbol()
+		if err != nil {
+			return err
+		}
+		val = Symbol(symbol)
+	case bsontype.CodeWithScope:
+		code, scope, err := vr.ReadCodeWithScope()
+		if err != nil {
+			return err
+		}
+		var doc Doc
+		err = pc.decodeDocument(dc, scope, &doc)
+		if err != nil {
+			return err
+		}
+		val = CodeWithScope(code, doc)
+	case bsontype.Int32:
+		i32, err := vr.ReadInt32()
+		if err != nil {
+			return err
+		}
+		val = Int32(i32)
+	case bsontype.Timestamp:
+		t, i, err := vr.ReadTimestamp()
+		if err != nil {
+			return err
+		}
+		val = Timestamp(t, i)
+	case bsontype.Int64:
+		i64, err := vr.ReadInt64()
+		if err != nil {
+			return err
+		}
+		val = Int64(i64)
+	case bsontype.Decimal128:
+		d128, err := vr.ReadDecimal128()
+		if err != nil {
+			return err
+		}
+		val = Decimal128(d128)
+	case bsontype.MinKey:
+		err := vr.ReadMinKey()
+		if err != nil {
+			return err
+		}
+		val = MinKey()
+	case bsontype.MaxKey:
+		err := vr.ReadMaxKey()
+		if err != nil {
+			return err
+		}
+		val = MaxKey()
+	default:
+		return fmt.Errorf("Cannot read unknown BSON type %s", vr.Type())
+	}
+
+	*elem = Elem{Key: key, Value: val}
+	return nil
+}
+
+// encodeValue does not validation, and the callers must perform validation on val before calling
+// this method.
+func (pc PrimitiveCodecs) encodeValue(ec bsoncodec.EncodeContext, vw bsonrw.ValueWriter, val Val) error {
+	var err error
+	switch val.Type() {
+	case bsontype.Double:
+		err = vw.WriteDouble(val.Double())
+	case bsontype.String:
+		err = vw.WriteString(val.StringValue())
+	case bsontype.EmbeddedDocument:
+		var encoder bsoncodec.ValueEncoder
+		encoder, err = ec.LookupEncoder(tDocument)
+		if err != nil {
+			break
+		}
+		err = encoder.EncodeValue(ec, vw, reflect.ValueOf(val.Document()))
+	case bsontype.Array:
+		var encoder bsoncodec.ValueEncoder
+		encoder, err = ec.LookupEncoder(tArray)
+		if err != nil {
+			break
+		}
+		err = encoder.EncodeValue(ec, vw, reflect.ValueOf(val.Array()))
+	case bsontype.Binary:
+		// TODO: FIX THIS (╯°□°）╯︵ ┻━┻
+		subtype, data := val.Binary()
+		err = vw.WriteBinaryWithSubtype(data, subtype)
+	case bsontype.Undefined:
+		err = vw.WriteUndefined()
+	case bsontype.ObjectID:
+		err = vw.WriteObjectID(val.ObjectID())
+	case bsontype.Boolean:
+		err = vw.WriteBoolean(val.Boolean())
+	case bsontype.DateTime:
+		err = vw.WriteDateTime(val.DateTime())
+	case bsontype.Null:
+		err = vw.WriteNull()
+	case bsontype.Regex:
+		err = vw.WriteRegex(val.Regex())
+	case bsontype.DBPointer:
+		err = vw.WriteDBPointer(val.DBPointer())
+	case bsontype.JavaScript:
+		err = vw.WriteJavascript(val.JavaScript())
+	case bsontype.Symbol:
+		err = vw.WriteSymbol(val.Symbol())
+	case bsontype.CodeWithScope:
+		code, scope := val.CodeWithScope()
+
+		var cwsw bsonrw.DocumentWriter
+		cwsw, err = vw.WriteCodeWithScope(code)
+		if err != nil {
+			break
+		}
+
+		err = pc.encodeDocument(ec, cwsw, scope)
+	case bsontype.Int32:
+		err = vw.WriteInt32(val.Int32())
+	case bsontype.Timestamp:
+		err = vw.WriteTimestamp(val.Timestamp())
+	case bsontype.Int64:
+		err = vw.WriteInt64(val.Int64())
+	case bsontype.Decimal128:
+		err = vw.WriteDecimal128(val.Decimal128())
+	case bsontype.MinKey:
+		err = vw.WriteMinKey()
+	case bsontype.MaxKey:
+		err = vw.WriteMaxKey()
+	default:
+		err = fmt.Errorf("%T is not a valid BSON type to encode", val.Type())
+	}
+
+	return err
+}
+
+func (pc PrimitiveCodecs) valueDecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader, val *Val) error {
+	switch vr.Type() {
+	case bsontype.Double:
+		f64, err := vr.ReadDouble()
+		if err != nil {
+			return err
+		}
+		*val = Double(f64)
+	case bsontype.String:
+		str, err := vr.ReadString()
+		if err != nil {
+			return err
+		}
+		*val = String(str)
+	case bsontype.EmbeddedDocument:
+		var embeddedDoc Doc
+		err := pc.documentDecodeValue(dc, vr, &embeddedDoc)
+		if err != nil {
+			return err
+		}
+		*val = Document(embeddedDoc)
+	case bsontype.Array:
+		arr := reflect.New(tArray).Elem()
+		err := pc.ArrayDecodeValue(dc, vr, arr)
+		if err != nil {
+			return err
+		}
+		*val = Array(arr.Interface().(Arr))
+	case bsontype.Binary:
+		data, subtype, err := vr.ReadBinary()
+		if err != nil {
+			return err
+		}
+		*val = Binary(subtype, data)
+	case bsontype.Undefined:
+		err := vr.ReadUndefined()
+		if err != nil {
+			return err
+		}
+		*val = Undefined()
+	case bsontype.ObjectID:
+		oid, err := vr.ReadObjectID()
+		if err != nil {
+			return err
+		}
+		*val = ObjectID(oid)
+	case bsontype.Boolean:
+		b, err := vr.ReadBoolean()
+		if err != nil {
+			return err
+		}
+		*val = Boolean(b)
+	case bsontype.DateTime:
+		dt, err := vr.ReadDateTime()
+		if err != nil {
+			return err
+		}
+		*val = DateTime(dt)
+	case bsontype.Null:
+		err := vr.ReadNull()
+		if err != nil {
+			return err
+		}
+		*val = Null()
+	case bsontype.Regex:
+		pattern, options, err := vr.ReadRegex()
+		if err != nil {
+			return err
+		}
+		*val = Regex(pattern, options)
+	case bsontype.DBPointer:
+		ns, pointer, err := vr.ReadDBPointer()
+		if err != nil {
+			return err
+		}
+		*val = DBPointer(ns, pointer)
+	case bsontype.JavaScript:
+		js, err := vr.ReadJavascript()
+		if err != nil {
+			return err
+		}
+		*val = JavaScript(js)
+	case bsontype.Symbol:
+		symbol, err := vr.ReadSymbol()
+		if err != nil {
+			return err
+		}
+		*val = Symbol(symbol)
+	case bsontype.CodeWithScope:
+		code, scope, err := vr.ReadCodeWithScope()
+		if err != nil {
+			return err
+		}
+		var scopeDoc Doc
+		err = pc.decodeDocument(dc, scope, &scopeDoc)
+		if err != nil {
+			return err
+		}
+		*val = CodeWithScope(code, scopeDoc)
+	case bsontype.Int32:
+		i32, err := vr.ReadInt32()
+		if err != nil {
+			return err
+		}
+		*val = Int32(i32)
+	case bsontype.Timestamp:
+		t, i, err := vr.ReadTimestamp()
+		if err != nil {
+			return err
+		}
+		*val = Timestamp(t, i)
+	case bsontype.Int64:
+		i64, err := vr.ReadInt64()
+		if err != nil {
+			return err
+		}
+		*val = Int64(i64)
+	case bsontype.Decimal128:
+		d128, err := vr.ReadDecimal128()
+		if err != nil {
+			return err
+		}
+		*val = Decimal128(d128)
+	case bsontype.MinKey:
+		err := vr.ReadMinKey()
+		if err != nil {
+			return err
+		}
+		*val = MinKey()
+	case bsontype.MaxKey:
+		err := vr.ReadMaxKey()
+		if err != nil {
+			return err
+		}
+		*val = MaxKey()
+	default:
+		return fmt.Errorf("Cannot read unknown BSON type %s", vr.Type())
+	}
+
+	return nil
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/registry.go

@@ -0,0 +1,22 @@
+package bsonx
+
+import (
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/bsoncodec"
+)
+
+// DefaultRegistry is the default bsoncodec.Registry. It contains the default codecs and the
+// primitive codecs.
+var DefaultRegistry = NewRegistryBuilder().Build()
+
+// NewRegistryBuilder creates a new RegistryBuilder configured with the default encoders and
+// deocders from the bsoncodec.DefaultValueEncoders and bsoncodec.DefaultValueDecoders types and the
+// PrimitiveCodecs type in this package.
+func NewRegistryBuilder() *bsoncodec.RegistryBuilder {
+	rb := bsoncodec.NewRegistryBuilder()
+	bsoncodec.DefaultValueEncoders{}.RegisterDefaultEncoders(rb)
+	bsoncodec.DefaultValueDecoders{}.RegisterDefaultDecoders(rb)
+	bson.PrimitiveCodecs{}.RegisterPrimitiveCodecs(rb)
+	primitiveCodecs.RegisterPrimitiveCodecs(rb)
+	return rb
+}

vendor/go.mongodb.org/mongo-driver/x/bsonx/value.go

@@ -0,0 +1,899 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsonx
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+)
+
+// Val represents a BSON value.
+type Val struct {
+	// NOTE: The bootstrap is a small amount of space that'll be on the stack. At 15 bytes this
+	// doesn't make this type any larger, since there are 7 bytes of padding and we want an int64 to
+	// store small values (e.g. boolean, double, int64, etc...). The primitive property is where all
+	// of the larger values go. They will use either Go primitives or the primitive.* types.
+	t         bsontype.Type
+	bootstrap [15]byte
+	primitive interface{}
+}
+
+func (v Val) reset() Val {
+	v.primitive = nil // clear out any pointers so we don't accidentally stop them from being garbage collected.
+	v.t = bsontype.Type(0)
+	v.bootstrap[0] = 0x00
+	v.bootstrap[1] = 0x00
+	v.bootstrap[2] = 0x00
+	v.bootstrap[3] = 0x00
+	v.bootstrap[4] = 0x00
+	v.bootstrap[5] = 0x00
+	v.bootstrap[6] = 0x00
+	v.bootstrap[7] = 0x00
+	v.bootstrap[8] = 0x00
+	v.bootstrap[9] = 0x00
+	v.bootstrap[10] = 0x00
+	v.bootstrap[11] = 0x00
+	v.bootstrap[12] = 0x00
+	v.bootstrap[13] = 0x00
+	v.bootstrap[14] = 0x00
+	return v
+}
+
+func (v Val) string() string {
+	if v.primitive != nil {
+		return v.primitive.(string)
+	}
+	// The string will either end with a null byte or it fills the entire bootstrap space.
+	length := uint8(v.bootstrap[0])
+	return string(v.bootstrap[1 : length+1])
+}
+
+func (v Val) writestring(str string) Val {
+	switch {
+	case len(str) < 15:
+		v.bootstrap[0] = uint8(len(str))
+		copy(v.bootstrap[1:], str)
+	default:
+		v.primitive = str
+	}
+	return v
+}
+
+func (v Val) i64() int64 {
+	return int64(v.bootstrap[0]) | int64(v.bootstrap[1])<<8 | int64(v.bootstrap[2])<<16 |
+		int64(v.bootstrap[3])<<24 | int64(v.bootstrap[4])<<32 | int64(v.bootstrap[5])<<40 |
+		int64(v.bootstrap[6])<<48 | int64(v.bootstrap[7])<<56
+}
+
+func (v Val) writei64(i64 int64) Val {
+	v.bootstrap[0] = byte(i64)
+	v.bootstrap[1] = byte(i64 >> 8)
+	v.bootstrap[2] = byte(i64 >> 16)
+	v.bootstrap[3] = byte(i64 >> 24)
+	v.bootstrap[4] = byte(i64 >> 32)
+	v.bootstrap[5] = byte(i64 >> 40)
+	v.bootstrap[6] = byte(i64 >> 48)
+	v.bootstrap[7] = byte(i64 >> 56)
+	return v
+}
+
+// IsZero returns true if this value is zero or a BSON null.
+func (v Val) IsZero() bool { return v.t == bsontype.Type(0) || v.t == bsontype.Null }
+
+func (v Val) String() string {
+	// TODO(GODRIVER-612): When bsoncore has appenders for extended JSON use that here.
+	return fmt.Sprintf("%v", v.Interface())
+}
+
+// Interface returns the Go value of this Value as an empty interface.
+//
+// This method will return nil if it is empty, otherwise it will return a Go primitive or a
+// primitive.* instance.
+func (v Val) Interface() interface{} {
+	switch v.Type() {
+	case bsontype.Double:
+		return v.Double()
+	case bsontype.String:
+		return v.StringValue()
+	case bsontype.EmbeddedDocument:
+		switch v.primitive.(type) {
+		case Doc:
+			return v.primitive.(Doc)
+		case MDoc:
+			return v.primitive.(MDoc)
+		default:
+			return primitive.Null{}
+		}
+	case bsontype.Array:
+		return v.Array()
+	case bsontype.Binary:
+		return v.primitive.(primitive.Binary)
+	case bsontype.Undefined:
+		return primitive.Undefined{}
+	case bsontype.ObjectID:
+		return v.ObjectID()
+	case bsontype.Boolean:
+		return v.Boolean()
+	case bsontype.DateTime:
+		return v.DateTime()
+	case bsontype.Null:
+		return primitive.Null{}
+	case bsontype.Regex:
+		return v.primitive.(primitive.Regex)
+	case bsontype.DBPointer:
+		return v.primitive.(primitive.DBPointer)
+	case bsontype.JavaScript:
+		return v.JavaScript()
+	case bsontype.Symbol:
+		return v.Symbol()
+	case bsontype.CodeWithScope:
+		return v.primitive.(primitive.CodeWithScope)
+	case bsontype.Int32:
+		return v.Int32()
+	case bsontype.Timestamp:
+		t, i := v.Timestamp()
+		return primitive.Timestamp{T: t, I: i}
+	case bsontype.Int64:
+		return v.Int64()
+	case bsontype.Decimal128:
+		return v.Decimal128()
+	case bsontype.MinKey:
+		return primitive.MinKey{}
+	case bsontype.MaxKey:
+		return primitive.MaxKey{}
+	default:
+		return primitive.Null{}
+	}
+}
+
+// MarshalBSONValue implements the bsoncodec.ValueMarshaler interface.
+func (v Val) MarshalBSONValue() (bsontype.Type, []byte, error) {
+	return v.MarshalAppendBSONValue(nil)
+}
+
+// MarshalAppendBSONValue is similar to MarshalBSONValue, but allows the caller to specify a slice
+// to add the bytes to.
+func (v Val) MarshalAppendBSONValue(dst []byte) (bsontype.Type, []byte, error) {
+	t := v.Type()
+	switch v.Type() {
+	case bsontype.Double:
+		dst = bsoncore.AppendDouble(dst, v.Double())
+	case bsontype.String:
+		dst = bsoncore.AppendString(dst, v.String())
+	case bsontype.EmbeddedDocument:
+		switch v.primitive.(type) {
+		case Doc:
+			t, dst, _ = v.primitive.(Doc).MarshalBSONValue() // Doc.MarshalBSONValue never returns an error.
+		case MDoc:
+			t, dst, _ = v.primitive.(MDoc).MarshalBSONValue() // MDoc.MarshalBSONValue never returns an error.
+		}
+	case bsontype.Array:
+		t, dst, _ = v.Array().MarshalBSONValue() // Arr.MarshalBSON never returns an error.
+	case bsontype.Binary:
+		subtype, bindata := v.Binary()
+		dst = bsoncore.AppendBinary(dst, subtype, bindata)
+	case bsontype.Undefined:
+	case bsontype.ObjectID:
+		dst = bsoncore.AppendObjectID(dst, v.ObjectID())
+	case bsontype.Boolean:
+		dst = bsoncore.AppendBoolean(dst, v.Boolean())
+	case bsontype.DateTime:
+		dst = bsoncore.AppendDateTime(dst, int64(v.DateTime()))
+	case bsontype.Null:
+	case bsontype.Regex:
+		pattern, options := v.Regex()
+		dst = bsoncore.AppendRegex(dst, pattern, options)
+	case bsontype.DBPointer:
+		ns, ptr := v.DBPointer()
+		dst = bsoncore.AppendDBPointer(dst, ns, ptr)
+	case bsontype.JavaScript:
+		dst = bsoncore.AppendJavaScript(dst, string(v.JavaScript()))
+	case bsontype.Symbol:
+		dst = bsoncore.AppendSymbol(dst, string(v.Symbol()))
+	case bsontype.CodeWithScope:
+		code, doc := v.CodeWithScope()
+		var scope []byte
+		scope, _ = doc.MarshalBSON() // Doc.MarshalBSON never returns an error.
+		dst = bsoncore.AppendCodeWithScope(dst, code, scope)
+	case bsontype.Int32:
+		dst = bsoncore.AppendInt32(dst, v.Int32())
+	case bsontype.Timestamp:
+		t, i := v.Timestamp()
+		dst = bsoncore.AppendTimestamp(dst, t, i)
+	case bsontype.Int64:
+		dst = bsoncore.AppendInt64(dst, v.Int64())
+	case bsontype.Decimal128:
+		dst = bsoncore.AppendDecimal128(dst, v.Decimal128())
+	case bsontype.MinKey:
+	case bsontype.MaxKey:
+	default:
+		panic(fmt.Errorf("invalid BSON type %v", t))
+	}
+
+	return t, dst, nil
+}
+
+// UnmarshalBSONValue implements the bsoncodec.ValueUnmarshaler interface.
+func (v *Val) UnmarshalBSONValue(t bsontype.Type, data []byte) error {
+	if v == nil {
+		return errors.New("cannot unmarshal into nil Value")
+	}
+	var err error
+	var ok = true
+	var rem []byte
+	switch t {
+	case bsontype.Double:
+		var f64 float64
+		f64, rem, ok = bsoncore.ReadDouble(data)
+		*v = Double(f64)
+	case bsontype.String:
+		var str string
+		str, rem, ok = bsoncore.ReadString(data)
+		*v = String(str)
+	case bsontype.EmbeddedDocument:
+		var raw []byte
+		var doc Doc
+		raw, rem, ok = bsoncore.ReadDocument(data)
+		doc, err = ReadDoc(raw)
+		*v = Document(doc)
+	case bsontype.Array:
+		var raw []byte
+		arr := make(Arr, 0)
+		raw, rem, ok = bsoncore.ReadArray(data)
+		err = arr.UnmarshalBSONValue(t, raw)
+		*v = Array(arr)
+	case bsontype.Binary:
+		var subtype byte
+		var bindata []byte
+		subtype, bindata, rem, ok = bsoncore.ReadBinary(data)
+		*v = Binary(subtype, bindata)
+	case bsontype.Undefined:
+		*v = Undefined()
+	case bsontype.ObjectID:
+		var oid primitive.ObjectID
+		oid, rem, ok = bsoncore.ReadObjectID(data)
+		*v = ObjectID(oid)
+	case bsontype.Boolean:
+		var b bool
+		b, rem, ok = bsoncore.ReadBoolean(data)
+		*v = Boolean(b)
+	case bsontype.DateTime:
+		var dt int64
+		dt, rem, ok = bsoncore.ReadDateTime(data)
+		*v = DateTime(dt)
+	case bsontype.Null:
+		*v = Null()
+	case bsontype.Regex:
+		var pattern, options string
+		pattern, options, rem, ok = bsoncore.ReadRegex(data)
+		*v = Regex(pattern, options)
+	case bsontype.DBPointer:
+		var ns string
+		var ptr primitive.ObjectID
+		ns, ptr, rem, ok = bsoncore.ReadDBPointer(data)
+		*v = DBPointer(ns, ptr)
+	case bsontype.JavaScript:
+		var js string
+		js, rem, ok = bsoncore.ReadJavaScript(data)
+		*v = JavaScript(js)
+	case bsontype.Symbol:
+		var symbol string
+		symbol, rem, ok = bsoncore.ReadSymbol(data)
+		*v = Symbol(symbol)
+	case bsontype.CodeWithScope:
+		var raw []byte
+		var code string
+		var scope Doc
+		code, raw, rem, ok = bsoncore.ReadCodeWithScope(data)
+		scope, err = ReadDoc(raw)
+		*v = CodeWithScope(code, scope)
+	case bsontype.Int32:
+		var i32 int32
+		i32, rem, ok = bsoncore.ReadInt32(data)
+		*v = Int32(i32)
+	case bsontype.Timestamp:
+		var i, t uint32
+		t, i, rem, ok = bsoncore.ReadTimestamp(data)
+		*v = Timestamp(t, i)
+	case bsontype.Int64:
+		var i64 int64
+		i64, rem, ok = bsoncore.ReadInt64(data)
+		*v = Int64(i64)
+	case bsontype.Decimal128:
+		var d128 primitive.Decimal128
+		d128, rem, ok = bsoncore.ReadDecimal128(data)
+		*v = Decimal128(d128)
+	case bsontype.MinKey:
+		*v = MinKey()
+	case bsontype.MaxKey:
+		*v = MaxKey()
+	default:
+		err = fmt.Errorf("invalid BSON type %v", t)
+	}
+
+	if !ok && err == nil {
+		err = bsoncore.NewInsufficientBytesError(data, rem)
+	}
+
+	return err
+}
+
+// Type returns the BSON type of this value.
+func (v Val) Type() bsontype.Type {
+	if v.t == bsontype.Type(0) {
+		return bsontype.Null
+	}
+	return v.t
+}
+
+// IsNumber returns true if the type of v is a numberic BSON type.
+func (v Val) IsNumber() bool {
+	switch v.Type() {
+	case bsontype.Double, bsontype.Int32, bsontype.Int64, bsontype.Decimal128:
+		return true
+	default:
+		return false
+	}
+}
+
+// Double returns the BSON double value the Value represents. It panics if the value is a BSON type
+// other than double.
+func (v Val) Double() float64 {
+	if v.t != bsontype.Double {
+		panic(ElementTypeError{"bson.Value.Double", v.t})
+	}
+	return math.Float64frombits(binary.LittleEndian.Uint64(v.bootstrap[0:8]))
+}
+
+// DoubleOK is the same as Double, but returns a boolean instead of panicking.
+func (v Val) DoubleOK() (float64, bool) {
+	if v.t != bsontype.Double {
+		return 0, false
+	}
+	return math.Float64frombits(binary.LittleEndian.Uint64(v.bootstrap[0:8])), true
+}
+
+// StringValue returns the BSON string the Value represents. It panics if the value is a BSON type
+// other than string.
+//
+// NOTE: This method is called StringValue to avoid it implementing the
+// fmt.Stringer interface.
+func (v Val) StringValue() string {
+	if v.t != bsontype.String {
+		panic(ElementTypeError{"bson.Value.StringValue", v.t})
+	}
+	return v.string()
+}
+
+// StringValueOK is the same as StringValue, but returns a boolean instead of
+// panicking.
+func (v Val) StringValueOK() (string, bool) {
+	if v.t != bsontype.String {
+		return "", false
+	}
+	return v.string(), true
+}
+
+func (v Val) asDoc() Doc {
+	doc, ok := v.primitive.(Doc)
+	if ok {
+		return doc
+	}
+	mdoc := v.primitive.(MDoc)
+	for k, v := range mdoc {
+		doc = append(doc, Elem{k, v})
+	}
+	return doc
+}
+
+func (v Val) asMDoc() MDoc {
+	mdoc, ok := v.primitive.(MDoc)
+	if ok {
+		return mdoc
+	}
+	doc := v.primitive.(Doc)
+	for _, elem := range doc {
+		mdoc[elem.Key] = elem.Value
+	}
+	return mdoc
+}
+
+// Document returns the BSON embedded document value the Value represents. It panics if the value
+// is a BSON type other than embedded document.
+func (v Val) Document() Doc {
+	if v.t != bsontype.EmbeddedDocument {
+		panic(ElementTypeError{"bson.Value.Document", v.t})
+	}
+	return v.asDoc()
+}
+
+// DocumentOK is the same as Document, except it returns a boolean
+// instead of panicking.
+func (v Val) DocumentOK() (Doc, bool) {
+	if v.t != bsontype.EmbeddedDocument {
+		return nil, false
+	}
+	return v.asDoc(), true
+}
+
+// MDocument returns the BSON embedded document value the Value represents. It panics if the value
+// is a BSON type other than embedded document.
+func (v Val) MDocument() MDoc {
+	if v.t != bsontype.EmbeddedDocument {
+		panic(ElementTypeError{"bson.Value.MDocument", v.t})
+	}
+	return v.asMDoc()
+}
+
+// MDocumentOK is the same as Document, except it returns a boolean
+// instead of panicking.
+func (v Val) MDocumentOK() (MDoc, bool) {
+	if v.t != bsontype.EmbeddedDocument {
+		return nil, false
+	}
+	return v.asMDoc(), true
+}
+
+// Array returns the BSON array value the Value represents. It panics if the value is a BSON type
+// other than array.
+func (v Val) Array() Arr {
+	if v.t != bsontype.Array {
+		panic(ElementTypeError{"bson.Value.Array", v.t})
+	}
+	return v.primitive.(Arr)
+}
+
+// ArrayOK is the same as Array, except it returns a boolean
+// instead of panicking.
+func (v Val) ArrayOK() (Arr, bool) {
+	if v.t != bsontype.Array {
+		return nil, false
+	}
+	return v.primitive.(Arr), true
+}
+
+// Binary returns the BSON binary value the Value represents. It panics if the value is a BSON type
+// other than binary.
+func (v Val) Binary() (byte, []byte) {
+	if v.t != bsontype.Binary {
+		panic(ElementTypeError{"bson.Value.Binary", v.t})
+	}
+	bin := v.primitive.(primitive.Binary)
+	return bin.Subtype, bin.Data
+}
+
+// BinaryOK is the same as Binary, except it returns a boolean instead of
+// panicking.
+func (v Val) BinaryOK() (byte, []byte, bool) {
+	if v.t != bsontype.Binary {
+		return 0x00, nil, false
+	}
+	bin := v.primitive.(primitive.Binary)
+	return bin.Subtype, bin.Data, true
+}
+
+// Undefined returns the BSON undefined the Value represents. It panics if the value is a BSON type
+// other than binary.
+func (v Val) Undefined() {
+	if v.t != bsontype.Undefined {
+		panic(ElementTypeError{"bson.Value.Undefined", v.t})
+	}
+	return
+}
+
+// UndefinedOK is the same as Undefined, except it returns a boolean instead of
+// panicking.
+func (v Val) UndefinedOK() bool {
+	if v.t != bsontype.Undefined {
+		return false
+	}
+	return true
+}
+
+// ObjectID returns the BSON ObjectID the Value represents. It panics if the value is a BSON type
+// other than ObjectID.
+func (v Val) ObjectID() primitive.ObjectID {
+	if v.t != bsontype.ObjectID {
+		panic(ElementTypeError{"bson.Value.ObjectID", v.t})
+	}
+	var oid primitive.ObjectID
+	copy(oid[:], v.bootstrap[:12])
+	return oid
+}
+
+// ObjectIDOK is the same as ObjectID, except it returns a boolean instead of
+// panicking.
+func (v Val) ObjectIDOK() (primitive.ObjectID, bool) {
+	if v.t != bsontype.ObjectID {
+		return primitive.ObjectID{}, false
+	}
+	var oid primitive.ObjectID
+	copy(oid[:], v.bootstrap[:12])
+	return oid, true
+}
+
+// Boolean returns the BSON boolean the Value represents. It panics if the value is a BSON type
+// other than boolean.
+func (v Val) Boolean() bool {
+	if v.t != bsontype.Boolean {
+		panic(ElementTypeError{"bson.Value.Boolean", v.t})
+	}
+	return v.bootstrap[0] == 0x01
+}
+
+// BooleanOK is the same as Boolean, except it returns a boolean instead of
+// panicking.
+func (v Val) BooleanOK() (bool, bool) {
+	if v.t != bsontype.Boolean {
+		return false, false
+	}
+	return v.bootstrap[0] == 0x01, true
+}
+
+// DateTime returns the BSON datetime the Value represents. It panics if the value is a BSON type
+// other than datetime.
+func (v Val) DateTime() int64 {
+	if v.t != bsontype.DateTime {
+		panic(ElementTypeError{"bson.Value.DateTime", v.t})
+	}
+	return v.i64()
+}
+
+// DateTimeOK is the same as DateTime, except it returns a boolean instead of
+// panicking.
+func (v Val) DateTimeOK() (int64, bool) {
+	if v.t != bsontype.DateTime {
+		return 0, false
+	}
+	return v.i64(), true
+}
+
+// Time returns the BSON datetime the Value represents as time.Time. It panics if the value is a BSON
+// type other than datetime.
+func (v Val) Time() time.Time {
+	if v.t != bsontype.DateTime {
+		panic(ElementTypeError{"bson.Value.Time", v.t})
+	}
+	i := v.i64()
+	return time.Unix(int64(i)/1000, int64(i)%1000*1000000)
+}
+
+// TimeOK is the same as Time, except it returns a boolean instead of
+// panicking.
+func (v Val) TimeOK() (time.Time, bool) {
+	if v.t != bsontype.DateTime {
+		return time.Time{}, false
+	}
+	i := v.i64()
+	return time.Unix(int64(i)/1000, int64(i)%1000*1000000), true
+}
+
+// Null returns the BSON undefined the Value represents. It panics if the value is a BSON type
+// other than binary.
+func (v Val) Null() {
+	if v.t != bsontype.Null && v.t != bsontype.Type(0) {
+		panic(ElementTypeError{"bson.Value.Null", v.t})
+	}
+	return
+}
+
+// NullOK is the same as Null, except it returns a boolean instead of
+// panicking.
+func (v Val) NullOK() bool {
+	if v.t != bsontype.Null && v.t != bsontype.Type(0) {
+		return false
+	}
+	return true
+}
+
+// Regex returns the BSON regex the Value represents. It panics if the value is a BSON type
+// other than regex.
+func (v Val) Regex() (pattern, options string) {
+	if v.t != bsontype.Regex {
+		panic(ElementTypeError{"bson.Value.Regex", v.t})
+	}
+	regex := v.primitive.(primitive.Regex)
+	return regex.Pattern, regex.Options
+}
+
+// RegexOK is the same as Regex, except that it returns a boolean
+// instead of panicking.
+func (v Val) RegexOK() (pattern, options string, ok bool) {
+	if v.t != bsontype.Regex {
+		return "", "", false
+	}
+	regex := v.primitive.(primitive.Regex)
+	return regex.Pattern, regex.Options, true
+}
+
+// DBPointer returns the BSON dbpointer the Value represents. It panics if the value is a BSON type
+// other than dbpointer.
+func (v Val) DBPointer() (string, primitive.ObjectID) {
+	if v.t != bsontype.DBPointer {
+		panic(ElementTypeError{"bson.Value.DBPointer", v.t})
+	}
+	dbptr := v.primitive.(primitive.DBPointer)
+	return dbptr.DB, dbptr.Pointer
+}
+
+// DBPointerOK is the same as DBPoitner, except that it returns a boolean
+// instead of panicking.
+func (v Val) DBPointerOK() (string, primitive.ObjectID, bool) {
+	if v.t != bsontype.DBPointer {
+		return "", primitive.ObjectID{}, false
+	}
+	dbptr := v.primitive.(primitive.DBPointer)
+	return dbptr.DB, dbptr.Pointer, true
+}
+
+// JavaScript returns the BSON JavaScript the Value represents. It panics if the value is a BSON type
+// other than JavaScript.
+func (v Val) JavaScript() string {
+	if v.t != bsontype.JavaScript {
+		panic(ElementTypeError{"bson.Value.JavaScript", v.t})
+	}
+	return v.string()
+}
+
+// JavaScriptOK is the same as Javascript, except that it returns a boolean
+// instead of panicking.
+func (v Val) JavaScriptOK() (string, bool) {
+	if v.t != bsontype.JavaScript {
+		return "", false
+	}
+	return v.string(), true
+}
+
+// Symbol returns the BSON symbol the Value represents. It panics if the value is a BSON type
+// other than symbol.
+func (v Val) Symbol() string {
+	if v.t != bsontype.Symbol {
+		panic(ElementTypeError{"bson.Value.Symbol", v.t})
+	}
+	return v.string()
+}
+
+// SymbolOK is the same as Javascript, except that it returns a boolean
+// instead of panicking.
+func (v Val) SymbolOK() (string, bool) {
+	if v.t != bsontype.Symbol {
+		return "", false
+	}
+	return v.string(), true
+}
+
+// CodeWithScope returns the BSON code with scope value the Value represents. It panics if the
+// value is a BSON type other than code with scope.
+func (v Val) CodeWithScope() (string, Doc) {
+	if v.t != bsontype.CodeWithScope {
+		panic(ElementTypeError{"bson.Value.CodeWithScope", v.t})
+	}
+	cws := v.primitive.(primitive.CodeWithScope)
+	return string(cws.Code), cws.Scope.(Doc)
+}
+
+// CodeWithScopeOK is the same as JavascriptWithScope,
+// except that it returns a boolean instead of panicking.
+func (v Val) CodeWithScopeOK() (string, Doc, bool) {
+	if v.t != bsontype.CodeWithScope {
+		return "", nil, false
+	}
+	cws := v.primitive.(primitive.CodeWithScope)
+	return string(cws.Code), cws.Scope.(Doc), true
+}
+
+// Int32 returns the BSON int32 the Value represents. It panics if the value is a BSON type
+// other than int32.
+func (v Val) Int32() int32 {
+	if v.t != bsontype.Int32 {
+		panic(ElementTypeError{"bson.Value.Int32", v.t})
+	}
+	return int32(v.bootstrap[0]) | int32(v.bootstrap[1])<<8 |
+		int32(v.bootstrap[2])<<16 | int32(v.bootstrap[3])<<24
+}
+
+// Int32OK is the same as Int32, except that it returns a boolean instead of
+// panicking.
+func (v Val) Int32OK() (int32, bool) {
+	if v.t != bsontype.Int32 {
+		return 0, false
+	}
+	return int32(v.bootstrap[0]) | int32(v.bootstrap[1])<<8 |
+			int32(v.bootstrap[2])<<16 | int32(v.bootstrap[3])<<24,
+		true
+}
+
+// Timestamp returns the BSON timestamp the Value represents. It panics if the value is a
+// BSON type other than timestamp.
+func (v Val) Timestamp() (t, i uint32) {
+	if v.t != bsontype.Timestamp {
+		panic(ElementTypeError{"bson.Value.Timestamp", v.t})
+	}
+	return uint32(v.bootstrap[4]) | uint32(v.bootstrap[5])<<8 |
+			uint32(v.bootstrap[6])<<16 | uint32(v.bootstrap[7])<<24,
+		uint32(v.bootstrap[0]) | uint32(v.bootstrap[1])<<8 |
+			uint32(v.bootstrap[2])<<16 | uint32(v.bootstrap[3])<<24
+}
+
+// TimestampOK is the same as Timestamp, except that it returns a boolean
+// instead of panicking.
+func (v Val) TimestampOK() (t uint32, i uint32, ok bool) {
+	if v.t != bsontype.Timestamp {
+		return 0, 0, false
+	}
+	return uint32(v.bootstrap[4]) | uint32(v.bootstrap[5])<<8 |
+			uint32(v.bootstrap[6])<<16 | uint32(v.bootstrap[7])<<24,
+		uint32(v.bootstrap[0]) | uint32(v.bootstrap[1])<<8 |
+			uint32(v.bootstrap[2])<<16 | uint32(v.bootstrap[3])<<24,
+		true
+}
+
+// Int64 returns the BSON int64 the Value represents. It panics if the value is a BSON type
+// other than int64.
+func (v Val) Int64() int64 {
+	if v.t != bsontype.Int64 {
+		panic(ElementTypeError{"bson.Value.Int64", v.t})
+	}
+	return v.i64()
+}
+
+// Int64OK is the same as Int64, except that it returns a boolean instead of
+// panicking.
+func (v Val) Int64OK() (int64, bool) {
+	if v.t != bsontype.Int64 {
+		return 0, false
+	}
+	return v.i64(), true
+}
+
+// Decimal128 returns the BSON decimal128 value the Value represents. It panics if the value is a
+// BSON type other than decimal128.
+func (v Val) Decimal128() primitive.Decimal128 {
+	if v.t != bsontype.Decimal128 {
+		panic(ElementTypeError{"bson.Value.Decimal128", v.t})
+	}
+	return v.primitive.(primitive.Decimal128)
+}
+
+// Decimal128OK is the same as Decimal128, except that it returns a boolean
+// instead of panicking.
+func (v Val) Decimal128OK() (primitive.Decimal128, bool) {
+	if v.t != bsontype.Decimal128 {
+		return primitive.Decimal128{}, false
+	}
+	return v.primitive.(primitive.Decimal128), true
+}
+
+// MinKey returns the BSON minkey the Value represents. It panics if the value is a BSON type
+// other than binary.
+func (v Val) MinKey() {
+	if v.t != bsontype.MinKey {
+		panic(ElementTypeError{"bson.Value.MinKey", v.t})
+	}
+	return
+}
+
+// MinKeyOK is the same as MinKey, except it returns a boolean instead of
+// panicking.
+func (v Val) MinKeyOK() bool {
+	if v.t != bsontype.MinKey {
+		return false
+	}
+	return true
+}
+
+// MaxKey returns the BSON maxkey the Value represents. It panics if the value is a BSON type
+// other than binary.
+func (v Val) MaxKey() {
+	if v.t != bsontype.MaxKey {
+		panic(ElementTypeError{"bson.Value.MaxKey", v.t})
+	}
+	return
+}
+
+// MaxKeyOK is the same as MaxKey, except it returns a boolean instead of
+// panicking.
+func (v Val) MaxKeyOK() bool {
+	if v.t != bsontype.MaxKey {
+		return false
+	}
+	return true
+}
+
+// Equal compares v to v2 and returns true if they are equal. Unknown BSON types are
+// never equal. Two empty values are equal.
+func (v Val) Equal(v2 Val) bool {
+	if v.Type() != v2.Type() {
+		return false
+	}
+	if v.IsZero() && v2.IsZero() {
+		return true
+	}
+
+	switch v.Type() {
+	case bsontype.Double, bsontype.DateTime, bsontype.Timestamp, bsontype.Int64:
+		return bytes.Equal(v.bootstrap[0:8], v2.bootstrap[0:8])
+	case bsontype.String:
+		return v.string() == v2.string()
+	case bsontype.EmbeddedDocument:
+		return v.equalDocs(v2)
+	case bsontype.Array:
+		return v.Array().Equal(v2.Array())
+	case bsontype.Binary:
+		return v.primitive.(primitive.Binary).Equal(v2.primitive.(primitive.Binary))
+	case bsontype.Undefined:
+		return true
+	case bsontype.ObjectID:
+		return bytes.Equal(v.bootstrap[0:12], v2.bootstrap[0:12])
+	case bsontype.Boolean:
+		return v.bootstrap[0] == v2.bootstrap[0]
+	case bsontype.Null:
+		return true
+	case bsontype.Regex:
+		return v.primitive.(primitive.Regex).Equal(v2.primitive.(primitive.Regex))
+	case bsontype.DBPointer:
+		return v.primitive.(primitive.DBPointer).Equal(v2.primitive.(primitive.DBPointer))
+	case bsontype.JavaScript:
+		return v.JavaScript() == v2.JavaScript()
+	case bsontype.Symbol:
+		return v.Symbol() == v2.Symbol()
+	case bsontype.CodeWithScope:
+		code1, scope1 := v.primitive.(primitive.CodeWithScope).Code, v.primitive.(primitive.CodeWithScope).Scope
+		code2, scope2 := v2.primitive.(primitive.CodeWithScope).Code, v2.primitive.(primitive.CodeWithScope).Scope
+		return code1 == code2 && v.equalInterfaceDocs(scope1, scope2)
+	case bsontype.Int32:
+		return v.Int32() == v2.Int32()
+	case bsontype.Decimal128:
+		h, l := v.Decimal128().GetBytes()
+		h2, l2 := v2.Decimal128().GetBytes()
+		return h == h2 && l == l2
+	case bsontype.MinKey:
+		return true
+	case bsontype.MaxKey:
+		return true
+	default:
+		return false
+	}
+}
+
+func (v Val) equalDocs(v2 Val) bool {
+	_, ok1 := v.primitive.(MDoc)
+	_, ok2 := v2.primitive.(MDoc)
+	if ok1 || ok2 {
+		return v.asMDoc().Equal(v2.asMDoc())
+	}
+	return v.asDoc().Equal(v2.asDoc())
+}
+
+func (Val) equalInterfaceDocs(i, i2 interface{}) bool {
+	switch d := i.(type) {
+	case MDoc:
+		d2, ok := i2.(IDoc)
+		if !ok {
+			return false
+		}
+		return d.Equal(d2)
+	case Doc:
+		d2, ok := i2.(IDoc)
+		if !ok {
+			return false
+		}
+		return d.Equal(d2)
+	case nil:
+		return i2 == nil
+	default:
+		return false
+	}
+}