refactor return value

This commit is contained in:
Josh Baker 2017-07-03 05:45:30 -07:00
parent 52545603e4
commit e095da84ca
2 changed files with 45 additions and 50 deletions

View File

@ -18,21 +18,20 @@ const (
)
var errInvalidMessage = &errProtocol{"invalid message"}
var errIncompletePacket = &errProtocol{"incomplete packet"}
// ReadNextCommand reads the next command from the provided packet. It's
// possible that the packet contains multiple commands, or zero commands
// when the packet is incomplete.
// 'args' is an optional reusable buffer and it can be nil.
// 'argsout' are the output arguments for the command. 'kind' is the type of
// command that was read.
// 'stop' indicates that there are no more possible commands in the packet.
// 'err' is returned when a protocol error was encountered.
// 'argsbuf' is an optional reusable buffer and it can be nil.
// 'complete' indicates that a command was read. false means no more commands.
// 'args' are the output arguments for the command.
// 'kind' is the type of command that was read.
// 'leftover' is any remaining unused bytes which belong to the next command.
func ReadNextCommand(packet []byte, args [][]byte) (
leftover []byte, argsout [][]byte, kind Kind, stop bool, err error,
// 'err' is returned when a protocol error was encountered.
func ReadNextCommand(packet []byte, argsbuf [][]byte) (
complete bool, args [][]byte, kind Kind, leftover []byte, err error,
) {
args = args[:0]
args = argsbuf[:0]
if len(packet) > 0 {
if packet[0] != '*' {
if packet[0] == '$' {
@ -44,17 +43,15 @@ func ReadNextCommand(packet []byte, args [][]byte) (
for s, i := 1, 1; i < len(packet); i++ {
if packet[i] == '\n' {
if packet[i-1] != '\r' {
println("here", i)
return packet, args[:0], Redis, true, errInvalidMultiBulkLength
return false, args[:0], Redis, packet, errInvalidMultiBulkLength
}
count, ok := parseInt(packet[s : i-1])
if !ok || count < 0 {
println("there", i, count, ok, "["+string(packet[s:i-1])+"]")
return packet, args[:0], Redis, true, errInvalidMultiBulkLength
return false, args[:0], Redis, packet, errInvalidMultiBulkLength
}
i++
if count == 0 {
return packet[i:], args[:0], Redis, i == len(packet), nil
return true, args[:0], Redis, packet[i:], nil
}
nextArg:
for j := 0; j < count; j++ {
@ -62,29 +59,29 @@ func ReadNextCommand(packet []byte, args [][]byte) (
break
}
if packet[i] != '$' {
return packet, args[:0], Redis, true,
return false, args[:0], Redis, packet,
&errProtocol{"expected '$', got '" +
string(packet[i]) + "'"}
}
for s := i + 1; i < len(packet); i++ {
if packet[i] == '\n' {
if packet[i-1] != '\r' {
return packet, args[:0], Redis, true, errInvalidBulkLength
return false, args[:0], Redis, packet, errInvalidBulkLength
}
n, ok := parseInt(packet[s : i-1])
if !ok || count <= 0 {
return packet, args[:0], Redis, true, errInvalidBulkLength
return false, args[:0], Redis, packet, errInvalidBulkLength
}
i++
if len(packet)-i >= n+2 {
if packet[i+n] != '\r' || packet[i+n+1] != '\n' {
return packet, args[:0], Redis, true, errInvalidBulkLength
return false, args[:0], Redis, packet, errInvalidBulkLength
}
args = append(args, packet[i:i+n])
i += n + 2
if j == count-1 {
// done reading
return packet[i:], args, Redis, i == len(packet), nil
return true, args, Redis, packet[i:], nil
}
continue nextArg
}
@ -97,24 +94,24 @@ func ReadNextCommand(packet []byte, args [][]byte) (
}
}
}
return packet, args[:0], Redis, true, errIncompletePacket
return false, args[:0], Redis, packet, nil
}
func readTile38Command(b []byte, argsbuf [][]byte) (
leftover []byte, args [][]byte, kind Kind, stop bool, err error,
func readTile38Command(packet []byte, argsbuf [][]byte) (
complete bool, args [][]byte, kind Kind, leftover []byte, err error,
) {
for i := 1; i < len(b); i++ {
if b[i] == ' ' {
n, ok := parseInt(b[1:i])
for i := 1; i < len(packet); i++ {
if packet[i] == ' ' {
n, ok := parseInt(packet[1:i])
if !ok || n < 0 {
return b, args[:0], Tile38, true, errInvalidMessage
return false, args[:0], Tile38, packet, errInvalidMessage
}
i++
if len(b) >= i+n+2 {
if b[i+n] != '\r' || b[i+n+1] != '\n' {
return b, args[:0], Tile38, true, errInvalidMessage
if len(packet) >= i+n+2 {
if packet[i+n] != '\r' || packet[i+n+1] != '\n' {
return false, args[:0], Tile38, packet, errInvalidMessage
}
line := b[i : i+n]
line := packet[i : i+n]
reading:
for len(line) != 0 {
if line[0] == '{' {
@ -147,24 +144,24 @@ func readTile38Command(b []byte, argsbuf [][]byte) (
args = append(args, line)
break
}
return b[i+n+2:], args, Tile38, i == len(b), nil
return true, args, Tile38, packet[i+n+2:], nil
}
break
}
}
return b, args[:0], Tile38, true, errIncompletePacket
return false, args[:0], Tile38, packet, nil
}
func readTelnetCommand(b []byte, argsbuf [][]byte) (
leftover []byte, args [][]byte, kind Kind, stop bool, err error,
func readTelnetCommand(packet []byte, argsbuf [][]byte) (
complete bool, args [][]byte, kind Kind, leftover []byte, err error,
) {
// just a plain text command
for i := 0; i < len(b); i++ {
if b[i] == '\n' {
for i := 0; i < len(packet); i++ {
if packet[i] == '\n' {
var line []byte
if i > 0 && b[i-1] == '\r' {
line = b[:i-1]
if i > 0 && packet[i-1] == '\r' {
line = packet[:i-1]
} else {
line = b[:i]
line = packet[:i]
}
var quote bool
var quotech byte
@ -184,7 +181,7 @@ func readTelnetCommand(b []byte, argsbuf [][]byte) (
}
if c == '"' || c == '\'' {
if i != 0 {
return b, args[:0], Telnet, true, errUnbalancedQuotes
return false, args[:0], Telnet, packet, errUnbalancedQuotes
}
quotech = c
quote = true
@ -208,7 +205,7 @@ func readTelnetCommand(b []byte, argsbuf [][]byte) (
args = append(args, nline)
line = line[i+1:]
if len(line) > 0 && line[0] != ' ' {
return b, args[:0], Telnet, true, errUnbalancedQuotes
return false, args[:0], Telnet, packet, errUnbalancedQuotes
}
continue outer
} else if c == '\\' {
@ -219,17 +216,17 @@ func readTelnetCommand(b []byte, argsbuf [][]byte) (
nline = append(nline, c)
}
if quote {
return b, args[:0], Telnet, true, errUnbalancedQuotes
return false, args[:0], Telnet, packet, errUnbalancedQuotes
}
if len(line) > 0 {
args = append(args, line)
}
break
}
return b[i+1:], args, Telnet, i == len(b), nil
return true, args, Telnet, packet[i+1:], nil
}
}
return b, args[:0], Telnet, true, errIncompletePacket
return false, args[:0], Telnet, packet, nil
}
// AppendUint appends a Redis protocol uint64 to the input bytes.

View File

@ -64,17 +64,15 @@ func TestNextCommand(t *testing.T) {
data = chunk
}
for {
leftover, args, _, stop, err := ReadNextCommand(data, nil)
complete, args, _, leftover, err := ReadNextCommand(data, nil)
data = leftover
if err != nil && err != errIncompletePacket {
if err != nil {
t.Fatal(err)
}
if err != errIncompletePacket {
fargs = append(fargs, args)
}
if stop {
if !complete {
break
}
fargs = append(fargs, args)
}
rbuf = append(rbuf[:0], data...)
}