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mirror of https://github.com/wader/fq.git synced 2024-12-02 12:45:53 +03:00
fq/format/bson/bson.go
2022-07-19 18:33:50 +02:00

120 lines
3.4 KiB
Go

package bson
// https://bsonspec.org/spec.html
// TODO: more types
import (
"embed"
"github.com/wader/fq/format"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/interp"
"github.com/wader/fq/pkg/scalar"
)
//go:embed bson.jq
var bsonFS embed.FS
func init() {
interp.RegisterFormat(decode.Format{
Name: format.BSON,
Description: "Binary JSON",
DecodeFn: decodeBSON,
Files: bsonFS,
Functions: []string{"torepr", "_help"},
})
}
const (
elementTypeDouble = 0x01
elementTypeString = 0x02
elementTypeDocument = 0x03
elementTypeArray = 0x04
elementTypeBinary = 0x05
elementTypeUndefined = 0x06
elementTypeObjectID = 0x07
elementTypeBoolean = 0x08
elementTypeDatatime = 0x09
elementTypeNull = 0x0a
elementTypeRegexp = 0x0b
elementTypeInt32 = 0x10
elementTypeTimestamp = 0x11
elementTypeInt64 = 0x12
)
var elementTypeMap = scalar.UToScalar{
elementTypeDouble: {Sym: "double", Description: "64-bit binary floating point"},
elementTypeString: {Sym: "string", Description: "UTF-8 string"},
elementTypeDocument: {Sym: "document", Description: "Embedded document"},
elementTypeArray: {Sym: "array", Description: "Array"},
elementTypeBinary: {Sym: "binary", Description: "Binary data"},
elementTypeUndefined: {Sym: "undefined", Description: "Undefined (deprecated)"},
elementTypeObjectID: {Sym: "object_id", Description: "ObjectId"},
elementTypeBoolean: {Sym: "boolean", Description: "Boolean"},
elementTypeDatatime: {Sym: "datatime", Description: "UTC datetime"},
elementTypeNull: {Sym: "null", Description: "Null value"},
elementTypeRegexp: {Sym: "regexp", Description: "Regular expression"},
elementTypeInt32: {Sym: "int32", Description: "32-bit integer"},
elementTypeTimestamp: {Sym: "timestamp", Description: "Timestamp"},
elementTypeInt64: {Sym: "int64", Description: "64-bit integer"},
}
func decodeBSONDocument(d *decode.D) {
size := d.FieldU32("size")
d.FramedFn(int64(size-4)*8, func(d *decode.D) {
d.FieldArray("elements", func(d *decode.D) {
for d.BitsLeft() > 8 {
d.FieldStruct("element", func(d *decode.D) {
typ := d.FieldU8("type", elementTypeMap)
d.FieldUTF8Null("name")
switch typ {
case elementTypeDouble:
d.FieldF64("value")
case elementTypeString:
length := d.FieldU32("length")
d.FieldUTF8NullFixedLen("value", int(length))
case elementTypeDocument:
d.FieldStruct("value", decodeBSONDocument)
case elementTypeArray:
d.FieldStruct("value", decodeBSONDocument)
case elementTypeBinary:
length := d.FieldU32("length")
d.FieldU8("subtype")
d.FieldRawLen("value", int64(length)*8)
case elementTypeUndefined:
//deprecated
case elementTypeObjectID:
d.FieldRawLen("value", 12*8)
case elementTypeBoolean:
d.FieldU8("value")
case elementTypeDatatime:
d.FieldS32("value")
case elementTypeNull:
d.FieldValueNil("value")
case elementTypeRegexp:
d.FieldUTF8Null("value")
d.FieldUTF8Null("options")
case elementTypeInt32:
d.FieldS32("value")
case elementTypeTimestamp:
d.FieldU64("value")
case elementTypeInt64:
d.FieldS64("value")
default:
d.FieldRawLen("value", d.BitsLeft())
}
})
}
})
d.FieldU8("terminator", d.ValidateU(0))
})
}
func decodeBSON(d *decode.D, _ any) any {
d.Endian = decode.LittleEndian
decodeBSONDocument(d)
return nil
}