gitea/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/uint_codec.go
2020-09-01 10:01:23 -04:00

151 lines
3.9 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 bsoncodec
import (
"errors"
"fmt"
"math"
"reflect"
"go.mongodb.org/mongo-driver/bson/bsonoptions"
"go.mongodb.org/mongo-driver/bson/bsonrw"
"go.mongodb.org/mongo-driver/bson/bsontype"
)
var defaultUIntCodec = NewUIntCodec()
// UIntCodec is the Codec used for uint values.
type UIntCodec struct {
EncodeToMinSize bool
}
var _ ValueCodec = &UIntCodec{}
// NewUIntCodec returns a UIntCodec with options opts.
func NewUIntCodec(opts ...*bsonoptions.UIntCodecOptions) *UIntCodec {
uintOpt := bsonoptions.MergeUIntCodecOptions(opts...)
codec := UIntCodec{}
if uintOpt.EncodeToMinSize != nil {
codec.EncodeToMinSize = *uintOpt.EncodeToMinSize
}
return &codec
}
// EncodeValue is the ValueEncoder for uint types.
func (uic *UIntCodec) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
switch val.Kind() {
case reflect.Uint8, reflect.Uint16:
return vw.WriteInt32(int32(val.Uint()))
case reflect.Uint, reflect.Uint32, reflect.Uint64:
u64 := val.Uint()
// If ec.MinSize or if encodeToMinSize is true for a non-uint64 value we should write val as an int32
useMinSize := ec.MinSize || (uic.EncodeToMinSize && val.Kind() != reflect.Uint64)
if u64 <= math.MaxInt32 && useMinSize {
return vw.WriteInt32(int32(u64))
}
if u64 > math.MaxInt64 {
return fmt.Errorf("%d overflows int64", u64)
}
return vw.WriteInt64(int64(u64))
}
return ValueEncoderError{
Name: "UintEncodeValue",
Kinds: []reflect.Kind{reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint},
Received: val,
}
}
// DecodeValue is the ValueDecoder for uint types.
func (uic *UIntCodec) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
if !val.CanSet() {
return ValueDecoderError{
Name: "UintDecodeValue",
Kinds: []reflect.Kind{reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint},
Received: val,
}
}
var i64 int64
var err error
switch vrType := vr.Type(); vrType {
case bsontype.Int32:
i32, err := vr.ReadInt32()
if err != nil {
return err
}
i64 = int64(i32)
case bsontype.Int64:
i64, err = vr.ReadInt64()
if err != nil {
return err
}
case bsontype.Double:
f64, err := vr.ReadDouble()
if err != nil {
return err
}
if !dc.Truncate && math.Floor(f64) != f64 {
return errors.New("UintDecodeValue can only truncate float64 to an integer type when truncation is enabled")
}
if f64 > float64(math.MaxInt64) {
return fmt.Errorf("%g overflows int64", f64)
}
i64 = int64(f64)
case bsontype.Boolean:
b, err := vr.ReadBoolean()
if err != nil {
return err
}
if b {
i64 = 1
}
case bsontype.Null:
if err = vr.ReadNull(); err != nil {
return err
}
default:
return fmt.Errorf("cannot decode %v into an integer type", vrType)
}
switch val.Kind() {
case reflect.Uint8:
if i64 < 0 || i64 > math.MaxUint8 {
return fmt.Errorf("%d overflows uint8", i64)
}
case reflect.Uint16:
if i64 < 0 || i64 > math.MaxUint16 {
return fmt.Errorf("%d overflows uint16", i64)
}
case reflect.Uint32:
if i64 < 0 || i64 > math.MaxUint32 {
return fmt.Errorf("%d overflows uint32", i64)
}
case reflect.Uint64:
if i64 < 0 {
return fmt.Errorf("%d overflows uint64", i64)
}
case reflect.Uint:
if i64 < 0 || int64(uint(i64)) != i64 { // Can we fit this inside of an uint
return fmt.Errorf("%d overflows uint", i64)
}
default:
return ValueDecoderError{
Name: "UintDecodeValue",
Kinds: []reflect.Kind{reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint},
Received: val,
}
}
val.SetUint(uint64(i64))
return nil
}