redis/parser.go

263 lines
5.3 KiB
Go

package redis
import (
"errors"
"fmt"
"strconv"
"gopkg.in/bufio.v1"
)
type multiBulkParser func(rd *bufio.Reader, n int64) (interface{}, error)
var (
errReaderTooSmall = errors.New("redis: reader is too small")
errInvalidReplyType = errors.New("redis: invalid reply type")
)
//------------------------------------------------------------------------------
func appendArgs(buf []byte, args []string) []byte {
buf = append(buf, '*')
buf = strconv.AppendUint(buf, uint64(len(args)), 10)
buf = append(buf, '\r', '\n')
for _, arg := range args {
buf = append(buf, '$')
buf = strconv.AppendUint(buf, uint64(len(arg)), 10)
buf = append(buf, '\r', '\n')
buf = append(buf, arg...)
buf = append(buf, '\r', '\n')
}
return buf
}
//------------------------------------------------------------------------------
func readLine(rd *bufio.Reader) ([]byte, error) {
line, isPrefix, err := rd.ReadLine()
if err != nil {
return line, err
}
if isPrefix {
return line, errReaderTooSmall
}
return line, nil
}
func readN(rd *bufio.Reader, n int) ([]byte, error) {
b, err := rd.ReadN(n)
if err == bufio.ErrBufferFull {
tmp := make([]byte, n)
r := copy(tmp, b)
b = tmp
for {
nn, err := rd.Read(b[r:])
r += nn
if r >= n {
// Ignore error if we read enough.
break
}
if err != nil {
return nil, err
}
}
} else if err != nil {
return nil, err
}
return b, nil
}
//------------------------------------------------------------------------------
func parseReq(rd *bufio.Reader) ([]string, error) {
line, err := readLine(rd)
if err != nil {
return nil, err
}
if line[0] != '*' {
return []string{string(line)}, nil
}
numReplies, err := strconv.ParseInt(string(line[1:]), 10, 64)
if err != nil {
return nil, err
}
args := make([]string, 0, numReplies)
for i := int64(0); i < numReplies; i++ {
line, err = readLine(rd)
if err != nil {
return nil, err
}
if line[0] != '$' {
return nil, fmt.Errorf("redis: expected '$', but got %q", line)
}
argLen, err := strconv.ParseInt(string(line[1:]), 10, 32)
if err != nil {
return nil, err
}
arg, err := readN(rd, int(argLen)+2)
if err != nil {
return nil, err
}
args = append(args, string(arg[:argLen]))
}
return args, nil
}
//------------------------------------------------------------------------------
func parseReply(rd *bufio.Reader, p multiBulkParser) (interface{}, error) {
line, err := readLine(rd)
if err != nil {
return nil, err
}
switch line[0] {
case '-':
return nil, errorf(string(line[1:]))
case '+':
return string(line[1:]), nil
case ':':
v, err := strconv.ParseInt(string(line[1:]), 10, 64)
if err != nil {
return nil, err
}
return v, nil
case '$':
if len(line) == 3 && line[1] == '-' && line[2] == '1' {
return nil, Nil
}
replyLenInt32, err := strconv.ParseInt(string(line[1:]), 10, 32)
if err != nil {
return nil, err
}
replyLen := int(replyLenInt32) + 2
line, err = readN(rd, replyLen)
if err != nil {
return nil, err
}
return string(line[:len(line)-2]), nil
case '*':
if len(line) == 3 && line[1] == '-' && line[2] == '1' {
return nil, Nil
}
repliesNum, err := strconv.ParseInt(string(line[1:]), 10, 64)
if err != nil {
return nil, err
}
return p(rd, repliesNum)
}
return nil, fmt.Errorf("redis: can't parse %q", line)
}
func parseSlice(rd *bufio.Reader, n int64) (interface{}, error) {
vals := make([]interface{}, 0, n)
for i := int64(0); i < n; i++ {
v, err := parseReply(rd, parseSlice)
if err == Nil {
vals = append(vals, nil)
} else if err != nil {
return nil, err
} else {
vals = append(vals, v)
}
}
return vals, nil
}
func parseStringSlice(rd *bufio.Reader, n int64) (interface{}, error) {
vals := make([]string, 0, n)
for i := int64(0); i < n; i++ {
vi, err := parseReply(rd, nil)
if err != nil {
return nil, err
}
if v, ok := vi.(string); ok {
vals = append(vals, v)
} else {
return nil, errInvalidReplyType
}
}
return vals, nil
}
func parseBoolSlice(rd *bufio.Reader, n int64) (interface{}, error) {
vals := make([]bool, 0, n)
for i := int64(0); i < n; i++ {
vi, err := parseReply(rd, nil)
if err != nil {
return nil, err
}
if v, ok := vi.(int64); ok {
vals = append(vals, v == 1)
} else {
return nil, errInvalidReplyType
}
}
return vals, nil
}
func parseStringStringMap(rd *bufio.Reader, n int64) (interface{}, error) {
m := make(map[string]string, n/2)
for i := int64(0); i < n; i += 2 {
keyI, err := parseReply(rd, nil)
if err != nil {
return nil, err
}
key, ok := keyI.(string)
if !ok {
return nil, errInvalidReplyType
}
valueI, err := parseReply(rd, nil)
if err != nil {
return nil, err
}
value, ok := valueI.(string)
if !ok {
return nil, errInvalidReplyType
}
m[key] = value
}
return m, nil
}
func parseStringFloatMap(rd *bufio.Reader, n int64) (interface{}, error) {
m := make(map[string]float64, n/2)
for i := int64(0); i < n; i += 2 {
keyI, err := parseReply(rd, nil)
if err != nil {
return nil, err
}
key, ok := keyI.(string)
if !ok {
return nil, errInvalidReplyType
}
valueI, err := parseReply(rd, nil)
if err != nil {
return nil, err
}
valueS, ok := valueI.(string)
if !ok {
return nil, errInvalidReplyType
}
value, err := strconv.ParseFloat(valueS, 64)
if err != nil {
return nil, err
}
m[key] = value
}
return m, nil
}