taldir

Directory service to resolve wallet mailboxes by messenger addresses
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buf.go (1946B)

      1 package pq
      2 
      3 import (
      4 	"bytes"
      5 	"encoding/binary"
      6 	"errors"
      7 	"fmt"
      8 
      9 	"github.com/lib/pq/internal/proto"
     10 	"github.com/lib/pq/oid"
     11 )
     12 
     13 type readBuf []byte
     14 
     15 func (b *readBuf) int32() (n int) {
     16 	n = int(int32(binary.BigEndian.Uint32(*b)))
     17 	*b = (*b)[4:]
     18 	return
     19 }
     20 
     21 func (b *readBuf) oid() (n oid.Oid) {
     22 	n = oid.Oid(binary.BigEndian.Uint32(*b))
     23 	*b = (*b)[4:]
     24 	return
     25 }
     26 
     27 // N.B: this is actually an unsigned 16-bit integer, unlike int32
     28 func (b *readBuf) int16() (n int) {
     29 	n = int(binary.BigEndian.Uint16(*b))
     30 	*b = (*b)[2:]
     31 	return
     32 }
     33 
     34 func (b *readBuf) string() string {
     35 	i := bytes.IndexByte(*b, 0)
     36 	if i < 0 {
     37 		panic(errors.New("pq: invalid message format; expected string terminator"))
     38 	}
     39 	s := (*b)[:i]
     40 	*b = (*b)[i+1:]
     41 	return string(s)
     42 }
     43 
     44 func (b *readBuf) next(n int) (v []byte) {
     45 	v = (*b)[:n]
     46 	*b = (*b)[n:]
     47 	return
     48 }
     49 
     50 func (b *readBuf) byte() byte {
     51 	return b.next(1)[0]
     52 }
     53 
     54 type writeBuf struct {
     55 	buf []byte
     56 	pos int
     57 }
     58 
     59 func (b *writeBuf) int32(n int) {
     60 	x := make([]byte, 4)
     61 	binary.BigEndian.PutUint32(x, uint32(n))
     62 	b.buf = append(b.buf, x...)
     63 }
     64 
     65 func (b *writeBuf) int16(n int) {
     66 	x := make([]byte, 2)
     67 	binary.BigEndian.PutUint16(x, uint16(n))
     68 	b.buf = append(b.buf, x...)
     69 }
     70 
     71 func (b *writeBuf) string(s string) {
     72 	b.buf = append(append(b.buf, s...), '\000')
     73 }
     74 
     75 func (b *writeBuf) byte(c proto.RequestCode) {
     76 	b.buf = append(b.buf, byte(c))
     77 }
     78 
     79 func (b *writeBuf) bytes(v []byte) {
     80 	b.buf = append(b.buf, v...)
     81 }
     82 
     83 func (b *writeBuf) wrap() []byte {
     84 	p := b.buf[b.pos:]
     85 	if len(p) > proto.MaxUint32 {
     86 		panic(fmt.Errorf("pq: message too large (%d > math.MaxUint32)", len(p)))
     87 	}
     88 	binary.BigEndian.PutUint32(p, uint32(len(p)))
     89 	return b.buf
     90 }
     91 
     92 func (b *writeBuf) next(c proto.RequestCode) {
     93 	p := b.buf[b.pos:]
     94 	if len(p) > proto.MaxUint32 {
     95 		panic(fmt.Errorf("pq: message too large (%d > math.MaxUint32)", len(p)))
     96 	}
     97 	binary.BigEndian.PutUint32(p, uint32(len(p)))
     98 	b.pos = len(b.buf) + 1
     99 	b.buf = append(b.buf, byte(c), 0, 0, 0, 0)
    100 }