source: code/trunk/vendor/github.com/lib/pq/buf.go@ 823

package pq

import (
        "bytes"
        "encoding/binary"

        "github.com/lib/pq/oid"
)

type readBuf []byte

func (b *readBuf) int32() (n int) {
        n = int(int32(binary.BigEndian.Uint32(*b)))
        *b = (*b)[4:]
        return
}

func (b *readBuf) oid() (n oid.Oid) {
        n = oid.Oid(binary.BigEndian.Uint32(*b))
        *b = (*b)[4:]
        return
}

// N.B: this is actually an unsigned 16-bit integer, unlike int32
func (b *readBuf) int16() (n int) {
        n = int(binary.BigEndian.Uint16(*b))
        *b = (*b)[2:]
        return
}

func (b *readBuf) string() string {
        i := bytes.IndexByte(*b, 0)
        if i < 0 {
                errorf("invalid message format; expected string terminator")
        }
        s := (*b)[:i]
        *b = (*b)[i+1:]
        return string(s)
}

func (b *readBuf) next(n int) (v []byte) {
        v = (*b)[:n]
        *b = (*b)[n:]
        return
}

func (b *readBuf) byte() byte {
        return b.next(1)[0]
}

type writeBuf struct {
        buf []byte
        pos int
}

func (b *writeBuf) int32(n int) {
        x := make([]byte, 4)
        binary.BigEndian.PutUint32(x, uint32(n))
        b.buf = append(b.buf, x...)
}

func (b *writeBuf) int16(n int) {
        x := make([]byte, 2)
        binary.BigEndian.PutUint16(x, uint16(n))
        b.buf = append(b.buf, x...)
}

func (b *writeBuf) string(s string) {
        b.buf = append(append(b.buf, s...), '\000')
}

func (b *writeBuf) byte(c byte) {
        b.buf = append(b.buf, c)
}

func (b *writeBuf) bytes(v []byte) {
        b.buf = append(b.buf, v...)
}

func (b *writeBuf) wrap() []byte {
        p := b.buf[b.pos:]
        binary.BigEndian.PutUint32(p, uint32(len(p)))
        return b.buf
}

func (b *writeBuf) next(c byte) {
        p := b.buf[b.pos:]
        binary.BigEndian.PutUint32(p, uint32(len(p)))
        b.pos = len(b.buf) + 1
        b.buf = append(b.buf, c, 0, 0, 0, 0)
}