blob: 0fbc51e9ac3a306eeaf55acb9d343b44827bb899 [file] [log] [blame]
package proto
import (
"bufio"
"fmt"
"io"
"github.com/go-redis/redis/v8/internal/util"
)
const (
ErrorReply = '-'
StatusReply = '+'
IntReply = ':'
StringReply = '$'
ArrayReply = '*'
)
//------------------------------------------------------------------------------
const Nil = RedisError("redis: nil")
type RedisError string
func (e RedisError) Error() string { return string(e) }
func (RedisError) RedisError() {}
//------------------------------------------------------------------------------
type MultiBulkParse func(*Reader, int64) (interface{}, error)
type Reader struct {
rd *bufio.Reader
_buf []byte
}
func NewReader(rd io.Reader) *Reader {
return &Reader{
rd: bufio.NewReader(rd),
_buf: make([]byte, 64),
}
}
func (r *Reader) Buffered() int {
return r.rd.Buffered()
}
func (r *Reader) Peek(n int) ([]byte, error) {
return r.rd.Peek(n)
}
func (r *Reader) Reset(rd io.Reader) {
r.rd.Reset(rd)
}
func (r *Reader) ReadLine() ([]byte, error) {
line, err := r.readLine()
if err != nil {
return nil, err
}
if isNilReply(line) {
return nil, Nil
}
return line, nil
}
// readLine that returns an error if:
// - there is a pending read error;
// - or line does not end with \r\n.
func (r *Reader) readLine() ([]byte, error) {
b, err := r.rd.ReadSlice('\n')
if err != nil {
if err != bufio.ErrBufferFull {
return nil, err
}
full := make([]byte, len(b))
copy(full, b)
b, err = r.rd.ReadBytes('\n')
if err != nil {
return nil, err
}
full = append(full, b...)
b = full
}
if len(b) <= 2 || b[len(b)-1] != '\n' || b[len(b)-2] != '\r' {
return nil, fmt.Errorf("redis: invalid reply: %q", b)
}
return b[:len(b)-2], nil
}
func (r *Reader) ReadReply(m MultiBulkParse) (interface{}, error) {
line, err := r.ReadLine()
if err != nil {
return nil, err
}
switch line[0] {
case ErrorReply:
return nil, ParseErrorReply(line)
case StatusReply:
return string(line[1:]), nil
case IntReply:
return util.ParseInt(line[1:], 10, 64)
case StringReply:
return r.readStringReply(line)
case ArrayReply:
n, err := parseArrayLen(line)
if err != nil {
return nil, err
}
if m == nil {
err := fmt.Errorf("redis: got %.100q, but multi bulk parser is nil", line)
return nil, err
}
return m(r, n)
}
return nil, fmt.Errorf("redis: can't parse %.100q", line)
}
func (r *Reader) ReadIntReply() (int64, error) {
line, err := r.ReadLine()
if err != nil {
return 0, err
}
switch line[0] {
case ErrorReply:
return 0, ParseErrorReply(line)
case IntReply:
return util.ParseInt(line[1:], 10, 64)
default:
return 0, fmt.Errorf("redis: can't parse int reply: %.100q", line)
}
}
func (r *Reader) ReadString() (string, error) {
line, err := r.ReadLine()
if err != nil {
return "", err
}
switch line[0] {
case ErrorReply:
return "", ParseErrorReply(line)
case StringReply:
return r.readStringReply(line)
case StatusReply:
return string(line[1:]), nil
case IntReply:
return string(line[1:]), nil
default:
return "", fmt.Errorf("redis: can't parse reply=%.100q reading string", line)
}
}
func (r *Reader) readStringReply(line []byte) (string, error) {
if isNilReply(line) {
return "", Nil
}
replyLen, err := util.Atoi(line[1:])
if err != nil {
return "", err
}
b := make([]byte, replyLen+2)
_, err = io.ReadFull(r.rd, b)
if err != nil {
return "", err
}
return util.BytesToString(b[:replyLen]), nil
}
func (r *Reader) ReadArrayReply(m MultiBulkParse) (interface{}, error) {
line, err := r.ReadLine()
if err != nil {
return nil, err
}
switch line[0] {
case ErrorReply:
return nil, ParseErrorReply(line)
case ArrayReply:
n, err := parseArrayLen(line)
if err != nil {
return nil, err
}
return m(r, n)
default:
return nil, fmt.Errorf("redis: can't parse array reply: %.100q", line)
}
}
func (r *Reader) ReadArrayLen() (int, error) {
line, err := r.ReadLine()
if err != nil {
return 0, err
}
switch line[0] {
case ErrorReply:
return 0, ParseErrorReply(line)
case ArrayReply:
n, err := parseArrayLen(line)
if err != nil {
return 0, err
}
return int(n), nil
default:
return 0, fmt.Errorf("redis: can't parse array reply: %.100q", line)
}
}
func (r *Reader) ReadScanReply() ([]string, uint64, error) {
n, err := r.ReadArrayLen()
if err != nil {
return nil, 0, err
}
if n != 2 {
return nil, 0, fmt.Errorf("redis: got %d elements in scan reply, expected 2", n)
}
cursor, err := r.ReadUint()
if err != nil {
return nil, 0, err
}
n, err = r.ReadArrayLen()
if err != nil {
return nil, 0, err
}
keys := make([]string, n)
for i := 0; i < n; i++ {
key, err := r.ReadString()
if err != nil {
return nil, 0, err
}
keys[i] = key
}
return keys, cursor, err
}
func (r *Reader) ReadInt() (int64, error) {
b, err := r.readTmpBytesReply()
if err != nil {
return 0, err
}
return util.ParseInt(b, 10, 64)
}
func (r *Reader) ReadUint() (uint64, error) {
b, err := r.readTmpBytesReply()
if err != nil {
return 0, err
}
return util.ParseUint(b, 10, 64)
}
func (r *Reader) ReadFloatReply() (float64, error) {
b, err := r.readTmpBytesReply()
if err != nil {
return 0, err
}
return util.ParseFloat(b, 64)
}
func (r *Reader) readTmpBytesReply() ([]byte, error) {
line, err := r.ReadLine()
if err != nil {
return nil, err
}
switch line[0] {
case ErrorReply:
return nil, ParseErrorReply(line)
case StringReply:
return r._readTmpBytesReply(line)
case StatusReply:
return line[1:], nil
default:
return nil, fmt.Errorf("redis: can't parse string reply: %.100q", line)
}
}
func (r *Reader) _readTmpBytesReply(line []byte) ([]byte, error) {
if isNilReply(line) {
return nil, Nil
}
replyLen, err := util.Atoi(line[1:])
if err != nil {
return nil, err
}
buf := r.buf(replyLen + 2)
_, err = io.ReadFull(r.rd, buf)
if err != nil {
return nil, err
}
return buf[:replyLen], nil
}
func (r *Reader) buf(n int) []byte {
if n <= cap(r._buf) {
return r._buf[:n]
}
d := n - cap(r._buf)
r._buf = append(r._buf, make([]byte, d)...)
return r._buf
}
func isNilReply(b []byte) bool {
return len(b) == 3 &&
(b[0] == StringReply || b[0] == ArrayReply) &&
b[1] == '-' && b[2] == '1'
}
func ParseErrorReply(line []byte) error {
return RedisError(string(line[1:]))
}
func parseArrayLen(line []byte) (int64, error) {
if isNilReply(line) {
return 0, Nil
}
return util.ParseInt(line[1:], 10, 64)
}