gopkg/pgx
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Move lowlevel binary routines into own package

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This commit is contained in:
Maxim Ivanov
2020-04-16 20:59:07 +01:00
parent a6747b513f
commit 2e13f2fe76
3 changed files with 93 additions and 68 deletions
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binary/record.go
+78
View File
@@ -0,0 +1,78 @@
package binary
import (
"encoding/binary"
"github.com/jackc/pgio"
errors "golang.org/x/xerrors"
)
type RecordFieldIter struct {
rp int
src []byte
}
// NewRecordFieldIterator creates iterator over binary representation
// of record, aka ROW(), aka Composite
func NewRecordFieldIterator(src []byte) (RecordFieldIter, int, error) {
rp := 0
if len(src[rp:]) < 4 {
return RecordFieldIter{}, 0, errors.Errorf("Record incomplete %v", src)
}
fieldCount := int(int32(binary.BigEndian.Uint32(src[rp:])))
rp += 4
return RecordFieldIter{
rp: rp,
src: src,
}, fieldCount, nil
}
// Next returns next field decoded from record. eof is returned if no
// more fields left to decode.
func (fi *RecordFieldIter) Next() (fieldOID uint32, buf []byte, eof bool, err error) {
if fi.rp == len(fi.src) {
eof = true
return
}
if len(fi.src[fi.rp:]) < 8 {
err = errors.Errorf("Record incomplete %v", fi.src)
return
}
fieldOID = binary.BigEndian.Uint32(fi.src[fi.rp:])
fi.rp += 4
fieldLen := int(int32(binary.BigEndian.Uint32(fi.src[fi.rp:])))
fi.rp += 4
if fieldLen >= 0 {
if len(fi.src[fi.rp:]) < fieldLen {
err = errors.Errorf("Record incomplete rp=%d src=%v", fi.rp, fi.src)
return
}
buf = fi.src[fi.rp : fi.rp+fieldLen]
fi.rp += fieldLen
}
return
}
// RecordStart adds record header to the buf
func RecordStart(buf []byte, fieldCount int) []byte {
return pgio.AppendUint32(buf, uint32(fieldCount))
}
// RecordAdd adds record field to the buf
func RecordAdd(buf []byte, oid uint32, fieldBytes []byte) []byte {
buf = pgio.AppendUint32(buf, oid)
buf = pgio.AppendUint32(buf, uint32(len(fieldBytes)))
buf = append(buf, fieldBytes...)
return buf
}
// RecordAddNull adds null value as a field to the buf
func RecordAddNull(buf []byte, oid uint32) []byte {
return pgio.AppendInt32(buf, int32(-1))
}
convert.go
+9 -13
View File
@@ -5,7 +5,7 @@ import (
"reflect"
"time"
"github.com/jackc/pgio"
"github.com/jackc/pgtype/binary"
errors "golang.org/x/xerrors"
)
@@ -442,16 +442,16 @@ func GetAssignToDstType(dst interface{}) (interface{}, bool) {
// Values must implement BinaryDecoder interface otherwise error is returned.
// ScanRowValue takes ownership of src, caller MUST not use it after call
func ScanRowValue(ci *ConnInfo, src []byte, dst ...Value) error {
fieldIter, err := newFieldIterator(src)
fieldIter, fieldCount, err := binary.NewRecordFieldIterator(src)
if err != nil {
return err
}
if len(dst) != fieldIter.fieldCount {
return errors.Errorf("can't scan row value, number of fields don't match: row fields count=%d desired fields count=%d", fieldIter.fieldCount, len(dst))
if len(dst) != fieldCount {
return errors.Errorf("can't scan row value, number of fields don't match: row fields count=%d desired fields count=%d", fieldCount, len(dst))
}
_, fieldBytes, eof, err := fieldIter.next()
_, fieldBytes, eof, err := fieldIter.Next()
for i := 0; !eof; i++ {
if err != nil {
return err
@@ -466,7 +466,7 @@ func ScanRowValue(ci *ConnInfo, src []byte, dst ...Value) error {
return err
}
_, fieldBytes, eof, err = fieldIter.next()
_, fieldBytes, eof, err = fieldIter.Next()
}
return nil
@@ -476,14 +476,12 @@ func ScanRowValue(ci *ConnInfo, src []byte, dst ...Value) error {
func EncodeRow(ci *ConnInfo, buf []byte, fields ...Value) (newBuf []byte, err error) {
fieldBytes := make([]byte, 0, 128)
newBuf = pgio.AppendUint32(buf, uint32(len(fields)))
newBuf = binary.RecordStart(buf, len(fields))
for _, f := range fields {
dt, ok := ci.DataTypeForValue(f)
if !ok {
return nil, errors.Errorf("Unknown OID for %s", f)
}
newBuf = pgio.AppendUint32(newBuf, dt.OID)
if f.Get() != nil {
binaryEncoder, ok := f.(BinaryEncoder)
if !ok {
@@ -493,11 +491,9 @@ func EncodeRow(ci *ConnInfo, buf []byte, fields ...Value) (newBuf []byte, err er
if err != nil {
return nil, err
}
newBuf = pgio.AppendUint32(newBuf, uint32(len(fieldBytes)))
newBuf = append(newBuf, fieldBytes...)
newBuf = binary.RecordAdd(newBuf, dt.OID, fieldBytes)
} else {
newBuf = pgio.AppendInt32(newBuf, int32(-1))
newBuf = binary.RecordAddNull(newBuf, dt.OID)
}
}
record.go
+6 -55
View File
@@ -1,9 +1,10 @@
package pgtype
import (
"encoding/binary"
"reflect"
"github.com/jackc/pgtype/binary"
errors "golang.org/x/xerrors"
)
@@ -78,56 +79,6 @@ func (src *Record) AssignTo(dst interface{}) error {
return errors.Errorf("cannot decode %#v into %T", src, dst)
}
type fieldIter struct {
rp int
fieldCount int
src []byte
}
func newFieldIterator(src []byte) (fieldIter, error) {
rp := 0
if len(src[rp:]) < 4 {
return fieldIter{}, errors.Errorf("Record incomplete %v", src)
}
fieldCount := int(int32(binary.BigEndian.Uint32(src[rp:])))
rp += 4
return fieldIter{
rp: rp,
fieldCount: fieldCount,
src: src,
}, nil
}
func (fi *fieldIter) next() (fieldOID uint32, buf []byte, eof bool, err error) {
if fi.rp == len(fi.src) {
eof = true
return
}
if len(fi.src[fi.rp:]) < 8 {
err = errors.Errorf("Record incomplete %v", fi.src)
return
}
fieldOID = binary.BigEndian.Uint32(fi.src[fi.rp:])
fi.rp += 4
fieldLen := int(int32(binary.BigEndian.Uint32(fi.src[fi.rp:])))
fi.rp += 4
if fieldLen >= 0 {
if len(fi.src[fi.rp:]) < fieldLen {
err = errors.Errorf("Record incomplete rp=%d src=%v", fi.rp, fi.src)
return
}
buf = fi.src[fi.rp : fi.rp+fieldLen]
fi.rp += fieldLen
}
return
}
func prepareNewBinaryDecoder(ci *ConnInfo, fieldOID uint32, v *Value) (BinaryDecoder, error) {
var binaryDecoder BinaryDecoder
@@ -153,13 +104,13 @@ func (dst *Record) DecodeBinary(ci *ConnInfo, src []byte) error {
return nil
}
fieldIter, err := newFieldIterator(src)
fieldIter, fieldCount, err := binary.NewRecordFieldIterator(src)
if err != nil {
return err
}
fields := make([]Value, fieldIter.fieldCount)
fieldOID, fieldBytes, eof, err := fieldIter.next()
fields := make([]Value, fieldCount)
fieldOID, fieldBytes, eof, err := fieldIter.Next()
for i := 0; !eof; i++ {
if err != nil {
@@ -175,7 +126,7 @@ func (dst *Record) DecodeBinary(ci *ConnInfo, src []byte) error {
return err
}
fieldOID, fieldBytes, eof, err = fieldIter.next()
fieldOID, fieldBytes, eof, err = fieldIter.Next()
}
*dst = Record{Fields: fields, Status: Present}