mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-23 12:16:38 +00:00
891 lines
20 KiB
Go
891 lines
20 KiB
Go
// Copyright (C) MongoDB, Inc. 2017-present.
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//
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// Licensed under the Apache License, Version 2.0 (the "License"); you may
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// not use this file except in compliance with the License. You may obtain
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// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
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package bsonrw
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"io"
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"math"
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"sync"
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"go.mongodb.org/mongo-driver/bson/bsontype"
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"go.mongodb.org/mongo-driver/bson/primitive"
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)
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var _ ValueReader = (*valueReader)(nil)
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var vrPool = sync.Pool{
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New: func() interface{} {
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return new(valueReader)
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},
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}
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// BSONValueReaderPool is a pool for ValueReaders that read BSON.
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//
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// Deprecated: BSONValueReaderPool will not be supported in Go Driver 2.0.
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type BSONValueReaderPool struct {
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pool sync.Pool
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}
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// NewBSONValueReaderPool instantiates a new BSONValueReaderPool.
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//
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// Deprecated: BSONValueReaderPool will not be supported in Go Driver 2.0.
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func NewBSONValueReaderPool() *BSONValueReaderPool {
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return &BSONValueReaderPool{
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pool: sync.Pool{
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New: func() interface{} {
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return new(valueReader)
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},
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},
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}
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}
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// Get retrieves a ValueReader from the pool and uses src as the underlying BSON.
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//
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// Deprecated: BSONValueReaderPool will not be supported in Go Driver 2.0.
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func (bvrp *BSONValueReaderPool) Get(src []byte) ValueReader {
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vr := bvrp.pool.Get().(*valueReader)
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vr.reset(src)
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return vr
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}
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// Put inserts a ValueReader into the pool. If the ValueReader is not a BSON ValueReader nothing
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// is inserted into the pool and ok will be false.
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//
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// Deprecated: BSONValueReaderPool will not be supported in Go Driver 2.0.
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func (bvrp *BSONValueReaderPool) Put(vr ValueReader) (ok bool) {
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bvr, ok := vr.(*valueReader)
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if !ok {
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return false
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}
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bvr.reset(nil)
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bvrp.pool.Put(bvr)
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return true
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}
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// ErrEOA is the error returned when the end of a BSON array has been reached.
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var ErrEOA = errors.New("end of array")
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// ErrEOD is the error returned when the end of a BSON document has been reached.
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var ErrEOD = errors.New("end of document")
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type vrState struct {
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mode mode
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vType bsontype.Type
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end int64
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}
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// valueReader is for reading BSON values.
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type valueReader struct {
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offset int64
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d []byte
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stack []vrState
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frame int64
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}
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// NewBSONDocumentReader returns a ValueReader using b for the underlying BSON
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// representation. Parameter b must be a BSON Document.
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func NewBSONDocumentReader(b []byte) ValueReader {
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// TODO(skriptble): There's a lack of symmetry between the reader and writer, since the reader takes a []byte while the
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// TODO writer takes an io.Writer. We should have two versions of each, one that takes a []byte and one that takes an
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// TODO io.Reader or io.Writer. The []byte version will need to return a thing that can return the finished []byte since
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// TODO it might be reallocated when appended to.
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return newValueReader(b)
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}
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// NewBSONValueReader returns a ValueReader that starts in the Value mode instead of in top
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// level document mode. This enables the creation of a ValueReader for a single BSON value.
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func NewBSONValueReader(t bsontype.Type, val []byte) ValueReader {
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stack := make([]vrState, 1, 5)
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stack[0] = vrState{
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mode: mValue,
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vType: t,
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}
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return &valueReader{
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d: val,
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stack: stack,
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}
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}
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func newValueReader(b []byte) *valueReader {
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stack := make([]vrState, 1, 5)
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stack[0] = vrState{
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mode: mTopLevel,
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}
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return &valueReader{
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d: b,
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stack: stack,
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}
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}
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func (vr *valueReader) reset(b []byte) {
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if vr.stack == nil {
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vr.stack = make([]vrState, 1, 5)
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}
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vr.stack = vr.stack[:1]
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vr.stack[0] = vrState{mode: mTopLevel}
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vr.d = b
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vr.offset = 0
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vr.frame = 0
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}
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func (vr *valueReader) advanceFrame() {
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if vr.frame+1 >= int64(len(vr.stack)) { // We need to grow the stack
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length := len(vr.stack)
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if length+1 >= cap(vr.stack) {
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// double it
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buf := make([]vrState, 2*cap(vr.stack)+1)
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copy(buf, vr.stack)
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vr.stack = buf
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}
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vr.stack = vr.stack[:length+1]
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}
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vr.frame++
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// Clean the stack
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vr.stack[vr.frame].mode = 0
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vr.stack[vr.frame].vType = 0
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vr.stack[vr.frame].end = 0
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}
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func (vr *valueReader) pushDocument() error {
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vr.advanceFrame()
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vr.stack[vr.frame].mode = mDocument
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size, err := vr.readLength()
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if err != nil {
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return err
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}
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vr.stack[vr.frame].end = int64(size) + vr.offset - 4
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return nil
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}
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func (vr *valueReader) pushArray() error {
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vr.advanceFrame()
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vr.stack[vr.frame].mode = mArray
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size, err := vr.readLength()
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if err != nil {
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return err
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}
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vr.stack[vr.frame].end = int64(size) + vr.offset - 4
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return nil
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}
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func (vr *valueReader) pushElement(t bsontype.Type) {
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vr.advanceFrame()
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vr.stack[vr.frame].mode = mElement
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vr.stack[vr.frame].vType = t
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}
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func (vr *valueReader) pushValue(t bsontype.Type) {
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vr.advanceFrame()
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vr.stack[vr.frame].mode = mValue
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vr.stack[vr.frame].vType = t
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}
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func (vr *valueReader) pushCodeWithScope() (int64, error) {
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vr.advanceFrame()
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vr.stack[vr.frame].mode = mCodeWithScope
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size, err := vr.readLength()
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if err != nil {
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return 0, err
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}
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vr.stack[vr.frame].end = int64(size) + vr.offset - 4
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return int64(size), nil
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}
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func (vr *valueReader) pop() {
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switch vr.stack[vr.frame].mode {
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case mElement, mValue:
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vr.frame--
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case mDocument, mArray, mCodeWithScope:
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vr.frame -= 2 // we pop twice to jump over the vrElement: vrDocument -> vrElement -> vrDocument/TopLevel/etc...
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}
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}
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func (vr *valueReader) invalidTransitionErr(destination mode, name string, modes []mode) error {
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te := TransitionError{
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name: name,
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current: vr.stack[vr.frame].mode,
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destination: destination,
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modes: modes,
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action: "read",
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}
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if vr.frame != 0 {
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te.parent = vr.stack[vr.frame-1].mode
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}
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return te
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}
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func (vr *valueReader) typeError(t bsontype.Type) error {
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return fmt.Errorf("positioned on %s, but attempted to read %s", vr.stack[vr.frame].vType, t)
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}
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func (vr *valueReader) invalidDocumentLengthError() error {
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return fmt.Errorf("document is invalid, end byte is at %d, but null byte found at %d", vr.stack[vr.frame].end, vr.offset)
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}
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func (vr *valueReader) ensureElementValue(t bsontype.Type, destination mode, callerName string) error {
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switch vr.stack[vr.frame].mode {
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case mElement, mValue:
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if vr.stack[vr.frame].vType != t {
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return vr.typeError(t)
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}
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default:
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return vr.invalidTransitionErr(destination, callerName, []mode{mElement, mValue})
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}
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return nil
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}
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func (vr *valueReader) Type() bsontype.Type {
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return vr.stack[vr.frame].vType
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}
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func (vr *valueReader) nextElementLength() (int32, error) {
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var length int32
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var err error
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switch vr.stack[vr.frame].vType {
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case bsontype.Array, bsontype.EmbeddedDocument, bsontype.CodeWithScope:
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length, err = vr.peekLength()
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case bsontype.Binary:
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length, err = vr.peekLength()
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length += 4 + 1 // binary length + subtype byte
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case bsontype.Boolean:
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length = 1
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case bsontype.DBPointer:
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length, err = vr.peekLength()
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length += 4 + 12 // string length + ObjectID length
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case bsontype.DateTime, bsontype.Double, bsontype.Int64, bsontype.Timestamp:
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length = 8
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case bsontype.Decimal128:
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length = 16
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case bsontype.Int32:
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length = 4
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case bsontype.JavaScript, bsontype.String, bsontype.Symbol:
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length, err = vr.peekLength()
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length += 4
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case bsontype.MaxKey, bsontype.MinKey, bsontype.Null, bsontype.Undefined:
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length = 0
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case bsontype.ObjectID:
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length = 12
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case bsontype.Regex:
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regex := bytes.IndexByte(vr.d[vr.offset:], 0x00)
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if regex < 0 {
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err = io.EOF
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break
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}
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pattern := bytes.IndexByte(vr.d[vr.offset+int64(regex)+1:], 0x00)
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if pattern < 0 {
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err = io.EOF
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break
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}
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length = int32(int64(regex) + 1 + int64(pattern) + 1)
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default:
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return 0, fmt.Errorf("attempted to read bytes of unknown BSON type %v", vr.stack[vr.frame].vType)
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}
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return length, err
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}
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func (vr *valueReader) ReadValueBytes(dst []byte) (bsontype.Type, []byte, error) {
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switch vr.stack[vr.frame].mode {
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case mTopLevel:
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length, err := vr.peekLength()
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if err != nil {
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return bsontype.Type(0), nil, err
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}
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dst, err = vr.appendBytes(dst, length)
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if err != nil {
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return bsontype.Type(0), nil, err
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}
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return bsontype.Type(0), dst, nil
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case mElement, mValue:
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length, err := vr.nextElementLength()
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if err != nil {
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return bsontype.Type(0), dst, err
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}
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dst, err = vr.appendBytes(dst, length)
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t := vr.stack[vr.frame].vType
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vr.pop()
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return t, dst, err
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default:
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return bsontype.Type(0), nil, vr.invalidTransitionErr(0, "ReadValueBytes", []mode{mElement, mValue})
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}
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}
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func (vr *valueReader) Skip() error {
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switch vr.stack[vr.frame].mode {
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case mElement, mValue:
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default:
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return vr.invalidTransitionErr(0, "Skip", []mode{mElement, mValue})
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}
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length, err := vr.nextElementLength()
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if err != nil {
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return err
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}
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err = vr.skipBytes(length)
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vr.pop()
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return err
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}
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func (vr *valueReader) ReadArray() (ArrayReader, error) {
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if err := vr.ensureElementValue(bsontype.Array, mArray, "ReadArray"); err != nil {
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return nil, err
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}
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err := vr.pushArray()
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if err != nil {
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return nil, err
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}
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return vr, nil
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}
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func (vr *valueReader) ReadBinary() (b []byte, btype byte, err error) {
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if err := vr.ensureElementValue(bsontype.Binary, 0, "ReadBinary"); err != nil {
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return nil, 0, err
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}
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length, err := vr.readLength()
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if err != nil {
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return nil, 0, err
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}
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btype, err = vr.readByte()
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if err != nil {
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return nil, 0, err
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}
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// Check length in case it is an old binary without a length.
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if btype == 0x02 && length > 4 {
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length, err = vr.readLength()
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if err != nil {
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return nil, 0, err
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}
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}
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b, err = vr.readBytes(length)
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if err != nil {
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return nil, 0, err
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}
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// Make a copy of the returned byte slice because it's just a subslice from the valueReader's
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// buffer and is not safe to return in the unmarshaled value.
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cp := make([]byte, len(b))
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copy(cp, b)
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vr.pop()
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return cp, btype, nil
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}
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func (vr *valueReader) ReadBoolean() (bool, error) {
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if err := vr.ensureElementValue(bsontype.Boolean, 0, "ReadBoolean"); err != nil {
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return false, err
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}
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b, err := vr.readByte()
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if err != nil {
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return false, err
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}
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if b > 1 {
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return false, fmt.Errorf("invalid byte for boolean, %b", b)
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}
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vr.pop()
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return b == 1, nil
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}
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func (vr *valueReader) ReadDocument() (DocumentReader, error) {
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switch vr.stack[vr.frame].mode {
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case mTopLevel:
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// read size
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size, err := vr.readLength()
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if err != nil {
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return nil, err
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}
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if int(size) != len(vr.d) {
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return nil, fmt.Errorf("invalid document length")
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}
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vr.stack[vr.frame].end = int64(size) + vr.offset - 4
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return vr, nil
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case mElement, mValue:
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if vr.stack[vr.frame].vType != bsontype.EmbeddedDocument {
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return nil, vr.typeError(bsontype.EmbeddedDocument)
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}
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default:
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return nil, vr.invalidTransitionErr(mDocument, "ReadDocument", []mode{mTopLevel, mElement, mValue})
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}
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err := vr.pushDocument()
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if err != nil {
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return nil, err
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}
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return vr, nil
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}
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func (vr *valueReader) ReadCodeWithScope() (code string, dr DocumentReader, err error) {
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if err := vr.ensureElementValue(bsontype.CodeWithScope, 0, "ReadCodeWithScope"); err != nil {
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return "", nil, err
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}
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totalLength, err := vr.readLength()
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if err != nil {
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return "", nil, err
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}
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strLength, err := vr.readLength()
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if err != nil {
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return "", nil, err
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}
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if strLength <= 0 {
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return "", nil, fmt.Errorf("invalid string length: %d", strLength)
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}
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strBytes, err := vr.readBytes(strLength)
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if err != nil {
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return "", nil, err
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}
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code = string(strBytes[:len(strBytes)-1])
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size, err := vr.pushCodeWithScope()
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if err != nil {
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return "", nil, err
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}
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// The total length should equal:
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// 4 (total length) + strLength + 4 (the length of str itself) + (document length)
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componentsLength := int64(4+strLength+4) + size
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if int64(totalLength) != componentsLength {
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return "", nil, fmt.Errorf(
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"length of CodeWithScope does not match lengths of components; total: %d; components: %d",
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totalLength, componentsLength,
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)
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}
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return code, vr, nil
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}
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func (vr *valueReader) ReadDBPointer() (ns string, oid primitive.ObjectID, err error) {
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if err := vr.ensureElementValue(bsontype.DBPointer, 0, "ReadDBPointer"); err != nil {
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return "", oid, err
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}
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ns, err = vr.readString()
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if err != nil {
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return "", oid, err
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}
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oidbytes, err := vr.readBytes(12)
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if err != nil {
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return "", oid, err
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}
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copy(oid[:], oidbytes)
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vr.pop()
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return ns, oid, nil
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}
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func (vr *valueReader) ReadDateTime() (int64, error) {
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if err := vr.ensureElementValue(bsontype.DateTime, 0, "ReadDateTime"); err != nil {
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return 0, err
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}
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i, err := vr.readi64()
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if err != nil {
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return 0, err
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}
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vr.pop()
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return i, nil
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}
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func (vr *valueReader) ReadDecimal128() (primitive.Decimal128, error) {
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if err := vr.ensureElementValue(bsontype.Decimal128, 0, "ReadDecimal128"); err != nil {
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return primitive.Decimal128{}, err
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}
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b, err := vr.readBytes(16)
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if err != nil {
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return primitive.Decimal128{}, err
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}
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l := binary.LittleEndian.Uint64(b[0:8])
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h := binary.LittleEndian.Uint64(b[8:16])
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vr.pop()
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return primitive.NewDecimal128(h, l), nil
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}
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func (vr *valueReader) ReadDouble() (float64, error) {
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if err := vr.ensureElementValue(bsontype.Double, 0, "ReadDouble"); err != nil {
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return 0, err
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}
|
|
|
|
u, err := vr.readu64()
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
vr.pop()
|
|
return math.Float64frombits(u), nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadInt32() (int32, error) {
|
|
if err := vr.ensureElementValue(bsontype.Int32, 0, "ReadInt32"); err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
vr.pop()
|
|
return vr.readi32()
|
|
}
|
|
|
|
func (vr *valueReader) ReadInt64() (int64, error) {
|
|
if err := vr.ensureElementValue(bsontype.Int64, 0, "ReadInt64"); err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
vr.pop()
|
|
return vr.readi64()
|
|
}
|
|
|
|
func (vr *valueReader) ReadJavascript() (code string, err error) {
|
|
if err := vr.ensureElementValue(bsontype.JavaScript, 0, "ReadJavascript"); err != nil {
|
|
return "", err
|
|
}
|
|
|
|
vr.pop()
|
|
return vr.readString()
|
|
}
|
|
|
|
func (vr *valueReader) ReadMaxKey() error {
|
|
if err := vr.ensureElementValue(bsontype.MaxKey, 0, "ReadMaxKey"); err != nil {
|
|
return err
|
|
}
|
|
|
|
vr.pop()
|
|
return nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadMinKey() error {
|
|
if err := vr.ensureElementValue(bsontype.MinKey, 0, "ReadMinKey"); err != nil {
|
|
return err
|
|
}
|
|
|
|
vr.pop()
|
|
return nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadNull() error {
|
|
if err := vr.ensureElementValue(bsontype.Null, 0, "ReadNull"); err != nil {
|
|
return err
|
|
}
|
|
|
|
vr.pop()
|
|
return nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadObjectID() (primitive.ObjectID, error) {
|
|
if err := vr.ensureElementValue(bsontype.ObjectID, 0, "ReadObjectID"); err != nil {
|
|
return primitive.ObjectID{}, err
|
|
}
|
|
|
|
oidbytes, err := vr.readBytes(12)
|
|
if err != nil {
|
|
return primitive.ObjectID{}, err
|
|
}
|
|
|
|
var oid primitive.ObjectID
|
|
copy(oid[:], oidbytes)
|
|
|
|
vr.pop()
|
|
return oid, nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadRegex() (string, string, error) {
|
|
if err := vr.ensureElementValue(bsontype.Regex, 0, "ReadRegex"); err != nil {
|
|
return "", "", err
|
|
}
|
|
|
|
pattern, err := vr.readCString()
|
|
if err != nil {
|
|
return "", "", err
|
|
}
|
|
|
|
options, err := vr.readCString()
|
|
if err != nil {
|
|
return "", "", err
|
|
}
|
|
|
|
vr.pop()
|
|
return pattern, options, nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadString() (string, error) {
|
|
if err := vr.ensureElementValue(bsontype.String, 0, "ReadString"); err != nil {
|
|
return "", err
|
|
}
|
|
|
|
vr.pop()
|
|
return vr.readString()
|
|
}
|
|
|
|
func (vr *valueReader) ReadSymbol() (symbol string, err error) {
|
|
if err := vr.ensureElementValue(bsontype.Symbol, 0, "ReadSymbol"); err != nil {
|
|
return "", err
|
|
}
|
|
|
|
vr.pop()
|
|
return vr.readString()
|
|
}
|
|
|
|
func (vr *valueReader) ReadTimestamp() (t uint32, i uint32, err error) {
|
|
if err := vr.ensureElementValue(bsontype.Timestamp, 0, "ReadTimestamp"); err != nil {
|
|
return 0, 0, err
|
|
}
|
|
|
|
i, err = vr.readu32()
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
|
|
t, err = vr.readu32()
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
|
|
vr.pop()
|
|
return t, i, nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadUndefined() error {
|
|
if err := vr.ensureElementValue(bsontype.Undefined, 0, "ReadUndefined"); err != nil {
|
|
return err
|
|
}
|
|
|
|
vr.pop()
|
|
return nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadElement() (string, ValueReader, error) {
|
|
switch vr.stack[vr.frame].mode {
|
|
case mTopLevel, mDocument, mCodeWithScope:
|
|
default:
|
|
return "", nil, vr.invalidTransitionErr(mElement, "ReadElement", []mode{mTopLevel, mDocument, mCodeWithScope})
|
|
}
|
|
|
|
t, err := vr.readByte()
|
|
if err != nil {
|
|
return "", nil, err
|
|
}
|
|
|
|
if t == 0 {
|
|
if vr.offset != vr.stack[vr.frame].end {
|
|
return "", nil, vr.invalidDocumentLengthError()
|
|
}
|
|
|
|
vr.pop()
|
|
return "", nil, ErrEOD
|
|
}
|
|
|
|
name, err := vr.readCString()
|
|
if err != nil {
|
|
return "", nil, err
|
|
}
|
|
|
|
vr.pushElement(bsontype.Type(t))
|
|
return name, vr, nil
|
|
}
|
|
|
|
func (vr *valueReader) ReadValue() (ValueReader, error) {
|
|
switch vr.stack[vr.frame].mode {
|
|
case mArray:
|
|
default:
|
|
return nil, vr.invalidTransitionErr(mValue, "ReadValue", []mode{mArray})
|
|
}
|
|
|
|
t, err := vr.readByte()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if t == 0 {
|
|
if vr.offset != vr.stack[vr.frame].end {
|
|
return nil, vr.invalidDocumentLengthError()
|
|
}
|
|
|
|
vr.pop()
|
|
return nil, ErrEOA
|
|
}
|
|
|
|
if err := vr.skipCString(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
vr.pushValue(bsontype.Type(t))
|
|
return vr, nil
|
|
}
|
|
|
|
// readBytes reads length bytes from the valueReader starting at the current offset. Note that the
|
|
// returned byte slice is a subslice from the valueReader buffer and must be converted or copied
|
|
// before returning in an unmarshaled value.
|
|
func (vr *valueReader) readBytes(length int32) ([]byte, error) {
|
|
if length < 0 {
|
|
return nil, fmt.Errorf("invalid length: %d", length)
|
|
}
|
|
|
|
if vr.offset+int64(length) > int64(len(vr.d)) {
|
|
return nil, io.EOF
|
|
}
|
|
|
|
start := vr.offset
|
|
vr.offset += int64(length)
|
|
|
|
return vr.d[start : start+int64(length)], nil
|
|
}
|
|
|
|
func (vr *valueReader) appendBytes(dst []byte, length int32) ([]byte, error) {
|
|
if vr.offset+int64(length) > int64(len(vr.d)) {
|
|
return nil, io.EOF
|
|
}
|
|
|
|
start := vr.offset
|
|
vr.offset += int64(length)
|
|
return append(dst, vr.d[start:start+int64(length)]...), nil
|
|
}
|
|
|
|
func (vr *valueReader) skipBytes(length int32) error {
|
|
if vr.offset+int64(length) > int64(len(vr.d)) {
|
|
return io.EOF
|
|
}
|
|
|
|
vr.offset += int64(length)
|
|
return nil
|
|
}
|
|
|
|
func (vr *valueReader) readByte() (byte, error) {
|
|
if vr.offset+1 > int64(len(vr.d)) {
|
|
return 0x0, io.EOF
|
|
}
|
|
|
|
vr.offset++
|
|
return vr.d[vr.offset-1], nil
|
|
}
|
|
|
|
func (vr *valueReader) skipCString() error {
|
|
idx := bytes.IndexByte(vr.d[vr.offset:], 0x00)
|
|
if idx < 0 {
|
|
return io.EOF
|
|
}
|
|
vr.offset += int64(idx) + 1
|
|
return nil
|
|
}
|
|
|
|
func (vr *valueReader) readCString() (string, error) {
|
|
idx := bytes.IndexByte(vr.d[vr.offset:], 0x00)
|
|
if idx < 0 {
|
|
return "", io.EOF
|
|
}
|
|
start := vr.offset
|
|
// idx does not include the null byte
|
|
vr.offset += int64(idx) + 1
|
|
return string(vr.d[start : start+int64(idx)]), nil
|
|
}
|
|
|
|
func (vr *valueReader) readString() (string, error) {
|
|
length, err := vr.readLength()
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
if int64(length)+vr.offset > int64(len(vr.d)) {
|
|
return "", io.EOF
|
|
}
|
|
|
|
if length <= 0 {
|
|
return "", fmt.Errorf("invalid string length: %d", length)
|
|
}
|
|
|
|
if vr.d[vr.offset+int64(length)-1] != 0x00 {
|
|
return "", fmt.Errorf("string does not end with null byte, but with %v", vr.d[vr.offset+int64(length)-1])
|
|
}
|
|
|
|
start := vr.offset
|
|
vr.offset += int64(length)
|
|
return string(vr.d[start : start+int64(length)-1]), nil
|
|
}
|
|
|
|
func (vr *valueReader) peekLength() (int32, error) {
|
|
if vr.offset+4 > int64(len(vr.d)) {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
idx := vr.offset
|
|
return (int32(vr.d[idx]) | int32(vr.d[idx+1])<<8 | int32(vr.d[idx+2])<<16 | int32(vr.d[idx+3])<<24), nil
|
|
}
|
|
|
|
func (vr *valueReader) readLength() (int32, error) { return vr.readi32() }
|
|
|
|
func (vr *valueReader) readi32() (int32, error) {
|
|
if vr.offset+4 > int64(len(vr.d)) {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
idx := vr.offset
|
|
vr.offset += 4
|
|
return (int32(vr.d[idx]) | int32(vr.d[idx+1])<<8 | int32(vr.d[idx+2])<<16 | int32(vr.d[idx+3])<<24), nil
|
|
}
|
|
|
|
func (vr *valueReader) readu32() (uint32, error) {
|
|
if vr.offset+4 > int64(len(vr.d)) {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
idx := vr.offset
|
|
vr.offset += 4
|
|
return (uint32(vr.d[idx]) | uint32(vr.d[idx+1])<<8 | uint32(vr.d[idx+2])<<16 | uint32(vr.d[idx+3])<<24), nil
|
|
}
|
|
|
|
func (vr *valueReader) readi64() (int64, error) {
|
|
if vr.offset+8 > int64(len(vr.d)) {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
idx := vr.offset
|
|
vr.offset += 8
|
|
return int64(vr.d[idx]) | int64(vr.d[idx+1])<<8 | int64(vr.d[idx+2])<<16 | int64(vr.d[idx+3])<<24 |
|
|
int64(vr.d[idx+4])<<32 | int64(vr.d[idx+5])<<40 | int64(vr.d[idx+6])<<48 | int64(vr.d[idx+7])<<56, nil
|
|
}
|
|
|
|
func (vr *valueReader) readu64() (uint64, error) {
|
|
if vr.offset+8 > int64(len(vr.d)) {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
idx := vr.offset
|
|
vr.offset += 8
|
|
return uint64(vr.d[idx]) | uint64(vr.d[idx+1])<<8 | uint64(vr.d[idx+2])<<16 | uint64(vr.d[idx+3])<<24 |
|
|
uint64(vr.d[idx+4])<<32 | uint64(vr.d[idx+5])<<40 | uint64(vr.d[idx+6])<<48 | uint64(vr.d[idx+7])<<56, nil
|
|
}
|