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gitea/vendor/go.mongodb.org/mongo-driver/bson/bsonrw/extjson_reader.go
2021-02-28 18:08:33 -05:00

628 lines
14 KiB
Go
Vendored

// 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 bsonrw
import (
"fmt"
"io"
"sync"
"go.mongodb.org/mongo-driver/bson/bsontype"
"go.mongodb.org/mongo-driver/bson/primitive"
)
// ExtJSONValueReaderPool is a pool for ValueReaders that read ExtJSON.
type ExtJSONValueReaderPool struct {
pool sync.Pool
}
// NewExtJSONValueReaderPool instantiates a new ExtJSONValueReaderPool.
func NewExtJSONValueReaderPool() *ExtJSONValueReaderPool {
return &ExtJSONValueReaderPool{
pool: sync.Pool{
New: func() interface{} {
return new(extJSONValueReader)
},
},
}
}
// Get retrieves a ValueReader from the pool and uses src as the underlying ExtJSON.
func (bvrp *ExtJSONValueReaderPool) Get(r io.Reader, canonical bool) (ValueReader, error) {
vr := bvrp.pool.Get().(*extJSONValueReader)
return vr.reset(r, canonical)
}
// Put inserts a ValueReader into the pool. If the ValueReader is not a ExtJSON ValueReader nothing
// is inserted into the pool and ok will be false.
func (bvrp *ExtJSONValueReaderPool) Put(vr ValueReader) (ok bool) {
bvr, ok := vr.(*extJSONValueReader)
if !ok {
return false
}
bvr, _ = bvr.reset(nil, false)
bvrp.pool.Put(bvr)
return true
}
type ejvrState struct {
mode mode
vType bsontype.Type
depth int
}
// extJSONValueReader is for reading extended JSON.
type extJSONValueReader struct {
p *extJSONParser
stack []ejvrState
frame int
}
// NewExtJSONValueReader creates a new ValueReader from a given io.Reader
// It will interpret the JSON of r as canonical or relaxed according to the
// given canonical flag
func NewExtJSONValueReader(r io.Reader, canonical bool) (ValueReader, error) {
return newExtJSONValueReader(r, canonical)
}
func newExtJSONValueReader(r io.Reader, canonical bool) (*extJSONValueReader, error) {
ejvr := new(extJSONValueReader)
return ejvr.reset(r, canonical)
}
func (ejvr *extJSONValueReader) reset(r io.Reader, canonical bool) (*extJSONValueReader, error) {
p := newExtJSONParser(r, canonical)
typ, err := p.peekType()
if err != nil {
return nil, ErrInvalidJSON
}
var m mode
switch typ {
case bsontype.EmbeddedDocument:
m = mTopLevel
case bsontype.Array:
m = mArray
default:
m = mValue
}
stack := make([]ejvrState, 1, 5)
stack[0] = ejvrState{
mode: m,
vType: typ,
}
return &extJSONValueReader{
p: p,
stack: stack,
}, nil
}
func (ejvr *extJSONValueReader) advanceFrame() {
if ejvr.frame+1 >= len(ejvr.stack) { // We need to grow the stack
length := len(ejvr.stack)
if length+1 >= cap(ejvr.stack) {
// double it
buf := make([]ejvrState, 2*cap(ejvr.stack)+1)
copy(buf, ejvr.stack)
ejvr.stack = buf
}
ejvr.stack = ejvr.stack[:length+1]
}
ejvr.frame++
// Clean the stack
ejvr.stack[ejvr.frame].mode = 0
ejvr.stack[ejvr.frame].vType = 0
ejvr.stack[ejvr.frame].depth = 0
}
func (ejvr *extJSONValueReader) pushDocument() {
ejvr.advanceFrame()
ejvr.stack[ejvr.frame].mode = mDocument
ejvr.stack[ejvr.frame].depth = ejvr.p.depth
}
func (ejvr *extJSONValueReader) pushCodeWithScope() {
ejvr.advanceFrame()
ejvr.stack[ejvr.frame].mode = mCodeWithScope
}
func (ejvr *extJSONValueReader) pushArray() {
ejvr.advanceFrame()
ejvr.stack[ejvr.frame].mode = mArray
}
func (ejvr *extJSONValueReader) push(m mode, t bsontype.Type) {
ejvr.advanceFrame()
ejvr.stack[ejvr.frame].mode = m
ejvr.stack[ejvr.frame].vType = t
}
func (ejvr *extJSONValueReader) pop() {
switch ejvr.stack[ejvr.frame].mode {
case mElement, mValue:
ejvr.frame--
case mDocument, mArray, mCodeWithScope:
ejvr.frame -= 2 // we pop twice to jump over the vrElement: vrDocument -> vrElement -> vrDocument/TopLevel/etc...
}
}
func (ejvr *extJSONValueReader) skipObject() {
// read entire object until depth returns to 0 (last ending } or ] seen)
depth := 1
for depth > 0 {
ejvr.p.advanceState()
switch ejvr.p.s {
case jpsSawBeginObject, jpsSawBeginArray:
depth++
case jpsSawEndObject, jpsSawEndArray:
depth--
}
}
}
func (ejvr *extJSONValueReader) invalidTransitionErr(destination mode, name string, modes []mode) error {
te := TransitionError{
name: name,
current: ejvr.stack[ejvr.frame].mode,
destination: destination,
modes: modes,
action: "read",
}
if ejvr.frame != 0 {
te.parent = ejvr.stack[ejvr.frame-1].mode
}
return te
}
func (ejvr *extJSONValueReader) typeError(t bsontype.Type) error {
return fmt.Errorf("positioned on %s, but attempted to read %s", ejvr.stack[ejvr.frame].vType, t)
}
func (ejvr *extJSONValueReader) ensureElementValue(t bsontype.Type, destination mode, callerName string, addModes ...mode) error {
switch ejvr.stack[ejvr.frame].mode {
case mElement, mValue:
if ejvr.stack[ejvr.frame].vType != t {
return ejvr.typeError(t)
}
default:
modes := []mode{mElement, mValue}
if addModes != nil {
modes = append(modes, addModes...)
}
return ejvr.invalidTransitionErr(destination, callerName, modes)
}
return nil
}
func (ejvr *extJSONValueReader) Type() bsontype.Type {
return ejvr.stack[ejvr.frame].vType
}
func (ejvr *extJSONValueReader) Skip() error {
switch ejvr.stack[ejvr.frame].mode {
case mElement, mValue:
default:
return ejvr.invalidTransitionErr(0, "Skip", []mode{mElement, mValue})
}
defer ejvr.pop()
t := ejvr.stack[ejvr.frame].vType
switch t {
case bsontype.Array, bsontype.EmbeddedDocument, bsontype.CodeWithScope:
// read entire array, doc or CodeWithScope
ejvr.skipObject()
default:
_, err := ejvr.p.readValue(t)
if err != nil {
return err
}
}
return nil
}
func (ejvr *extJSONValueReader) ReadArray() (ArrayReader, error) {
switch ejvr.stack[ejvr.frame].mode {
case mTopLevel: // allow reading array from top level
case mArray:
return ejvr, nil
default:
if err := ejvr.ensureElementValue(bsontype.Array, mArray, "ReadArray", mTopLevel, mArray); err != nil {
return nil, err
}
}
ejvr.pushArray()
return ejvr, nil
}
func (ejvr *extJSONValueReader) ReadBinary() (b []byte, btype byte, err error) {
if err := ejvr.ensureElementValue(bsontype.Binary, 0, "ReadBinary"); err != nil {
return nil, 0, err
}
v, err := ejvr.p.readValue(bsontype.Binary)
if err != nil {
return nil, 0, err
}
b, btype, err = v.parseBinary()
ejvr.pop()
return b, btype, err
}
func (ejvr *extJSONValueReader) ReadBoolean() (bool, error) {
if err := ejvr.ensureElementValue(bsontype.Boolean, 0, "ReadBoolean"); err != nil {
return false, err
}
v, err := ejvr.p.readValue(bsontype.Boolean)
if err != nil {
return false, err
}
if v.t != bsontype.Boolean {
return false, fmt.Errorf("expected type bool, but got type %s", v.t)
}
ejvr.pop()
return v.v.(bool), nil
}
func (ejvr *extJSONValueReader) ReadDocument() (DocumentReader, error) {
switch ejvr.stack[ejvr.frame].mode {
case mTopLevel:
return ejvr, nil
case mElement, mValue:
if ejvr.stack[ejvr.frame].vType != bsontype.EmbeddedDocument {
return nil, ejvr.typeError(bsontype.EmbeddedDocument)
}
ejvr.pushDocument()
return ejvr, nil
default:
return nil, ejvr.invalidTransitionErr(mDocument, "ReadDocument", []mode{mTopLevel, mElement, mValue})
}
}
func (ejvr *extJSONValueReader) ReadCodeWithScope() (code string, dr DocumentReader, err error) {
if err = ejvr.ensureElementValue(bsontype.CodeWithScope, 0, "ReadCodeWithScope"); err != nil {
return "", nil, err
}
v, err := ejvr.p.readValue(bsontype.CodeWithScope)
if err != nil {
return "", nil, err
}
code, err = v.parseJavascript()
ejvr.pushCodeWithScope()
return code, ejvr, err
}
func (ejvr *extJSONValueReader) ReadDBPointer() (ns string, oid primitive.ObjectID, err error) {
if err = ejvr.ensureElementValue(bsontype.DBPointer, 0, "ReadDBPointer"); err != nil {
return "", primitive.NilObjectID, err
}
v, err := ejvr.p.readValue(bsontype.DBPointer)
if err != nil {
return "", primitive.NilObjectID, err
}
ns, oid, err = v.parseDBPointer()
ejvr.pop()
return ns, oid, err
}
func (ejvr *extJSONValueReader) ReadDateTime() (int64, error) {
if err := ejvr.ensureElementValue(bsontype.DateTime, 0, "ReadDateTime"); err != nil {
return 0, err
}
v, err := ejvr.p.readValue(bsontype.DateTime)
if err != nil {
return 0, err
}
d, err := v.parseDateTime()
ejvr.pop()
return d, err
}
func (ejvr *extJSONValueReader) ReadDecimal128() (primitive.Decimal128, error) {
if err := ejvr.ensureElementValue(bsontype.Decimal128, 0, "ReadDecimal128"); err != nil {
return primitive.Decimal128{}, err
}
v, err := ejvr.p.readValue(bsontype.Decimal128)
if err != nil {
return primitive.Decimal128{}, err
}
d, err := v.parseDecimal128()
ejvr.pop()
return d, err
}
func (ejvr *extJSONValueReader) ReadDouble() (float64, error) {
if err := ejvr.ensureElementValue(bsontype.Double, 0, "ReadDouble"); err != nil {
return 0, err
}
v, err := ejvr.p.readValue(bsontype.Double)
if err != nil {
return 0, err
}
d, err := v.parseDouble()
ejvr.pop()
return d, err
}
func (ejvr *extJSONValueReader) ReadInt32() (int32, error) {
if err := ejvr.ensureElementValue(bsontype.Int32, 0, "ReadInt32"); err != nil {
return 0, err
}
v, err := ejvr.p.readValue(bsontype.Int32)
if err != nil {
return 0, err
}
i, err := v.parseInt32()
ejvr.pop()
return i, err
}
func (ejvr *extJSONValueReader) ReadInt64() (int64, error) {
if err := ejvr.ensureElementValue(bsontype.Int64, 0, "ReadInt64"); err != nil {
return 0, err
}
v, err := ejvr.p.readValue(bsontype.Int64)
if err != nil {
return 0, err
}
i, err := v.parseInt64()
ejvr.pop()
return i, err
}
func (ejvr *extJSONValueReader) ReadJavascript() (code string, err error) {
if err = ejvr.ensureElementValue(bsontype.JavaScript, 0, "ReadJavascript"); err != nil {
return "", err
}
v, err := ejvr.p.readValue(bsontype.JavaScript)
if err != nil {
return "", err
}
code, err = v.parseJavascript()
ejvr.pop()
return code, err
}
func (ejvr *extJSONValueReader) ReadMaxKey() error {
if err := ejvr.ensureElementValue(bsontype.MaxKey, 0, "ReadMaxKey"); err != nil {
return err
}
v, err := ejvr.p.readValue(bsontype.MaxKey)
if err != nil {
return err
}
err = v.parseMinMaxKey("max")
ejvr.pop()
return err
}
func (ejvr *extJSONValueReader) ReadMinKey() error {
if err := ejvr.ensureElementValue(bsontype.MinKey, 0, "ReadMinKey"); err != nil {
return err
}
v, err := ejvr.p.readValue(bsontype.MinKey)
if err != nil {
return err
}
err = v.parseMinMaxKey("min")
ejvr.pop()
return err
}
func (ejvr *extJSONValueReader) ReadNull() error {
if err := ejvr.ensureElementValue(bsontype.Null, 0, "ReadNull"); err != nil {
return err
}
v, err := ejvr.p.readValue(bsontype.Null)
if err != nil {
return err
}
if v.t != bsontype.Null {
return fmt.Errorf("expected type null but got type %s", v.t)
}
ejvr.pop()
return nil
}
func (ejvr *extJSONValueReader) ReadObjectID() (primitive.ObjectID, error) {
if err := ejvr.ensureElementValue(bsontype.ObjectID, 0, "ReadObjectID"); err != nil {
return primitive.ObjectID{}, err
}
v, err := ejvr.p.readValue(bsontype.ObjectID)
if err != nil {
return primitive.ObjectID{}, err
}
oid, err := v.parseObjectID()
ejvr.pop()
return oid, err
}
func (ejvr *extJSONValueReader) ReadRegex() (pattern string, options string, err error) {
if err = ejvr.ensureElementValue(bsontype.Regex, 0, "ReadRegex"); err != nil {
return "", "", err
}
v, err := ejvr.p.readValue(bsontype.Regex)
if err != nil {
return "", "", err
}
pattern, options, err = v.parseRegex()
ejvr.pop()
return pattern, options, err
}
func (ejvr *extJSONValueReader) ReadString() (string, error) {
if err := ejvr.ensureElementValue(bsontype.String, 0, "ReadString"); err != nil {
return "", err
}
v, err := ejvr.p.readValue(bsontype.String)
if err != nil {
return "", err
}
if v.t != bsontype.String {
return "", fmt.Errorf("expected type string but got type %s", v.t)
}
ejvr.pop()
return v.v.(string), nil
}
func (ejvr *extJSONValueReader) ReadSymbol() (symbol string, err error) {
if err = ejvr.ensureElementValue(bsontype.Symbol, 0, "ReadSymbol"); err != nil {
return "", err
}
v, err := ejvr.p.readValue(bsontype.Symbol)
if err != nil {
return "", err
}
symbol, err = v.parseSymbol()
ejvr.pop()
return symbol, err
}
func (ejvr *extJSONValueReader) ReadTimestamp() (t uint32, i uint32, err error) {
if err = ejvr.ensureElementValue(bsontype.Timestamp, 0, "ReadTimestamp"); err != nil {
return 0, 0, err
}
v, err := ejvr.p.readValue(bsontype.Timestamp)
if err != nil {
return 0, 0, err
}
t, i, err = v.parseTimestamp()
ejvr.pop()
return t, i, err
}
func (ejvr *extJSONValueReader) ReadUndefined() error {
if err := ejvr.ensureElementValue(bsontype.Undefined, 0, "ReadUndefined"); err != nil {
return err
}
v, err := ejvr.p.readValue(bsontype.Undefined)
if err != nil {
return err
}
err = v.parseUndefined()
ejvr.pop()
return err
}
func (ejvr *extJSONValueReader) ReadElement() (string, ValueReader, error) {
switch ejvr.stack[ejvr.frame].mode {
case mTopLevel, mDocument, mCodeWithScope:
default:
return "", nil, ejvr.invalidTransitionErr(mElement, "ReadElement", []mode{mTopLevel, mDocument, mCodeWithScope})
}
name, t, err := ejvr.p.readKey()
if err != nil {
if err == ErrEOD {
if ejvr.stack[ejvr.frame].mode == mCodeWithScope {
_, err := ejvr.p.peekType()
if err != nil {
return "", nil, err
}
}
ejvr.pop()
}
return "", nil, err
}
ejvr.push(mElement, t)
return name, ejvr, nil
}
func (ejvr *extJSONValueReader) ReadValue() (ValueReader, error) {
switch ejvr.stack[ejvr.frame].mode {
case mArray:
default:
return nil, ejvr.invalidTransitionErr(mValue, "ReadValue", []mode{mArray})
}
t, err := ejvr.p.peekType()
if err != nil {
if err == ErrEOA {
ejvr.pop()
}
return nil, err
}
ejvr.push(mValue, t)
return ejvr, nil
}