Files
mesh-delivery/modules/mesh-delivery-view/vendor/github.com/nats-io/nats.go/parser.go
T
jschoubben 0dbe8f9a32 Derive the delivery view's rows from the have, assignments and builds buckets (issue 1134)
The operator sees per module and node what is assigned, what the node reports and what it waits on; a have with no open assignment is left behind, never running.
2026-10-18 19:31:50 +02:00

556 lines
11 KiB
Go

// Copyright 2012-2023 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package nats
import (
"fmt"
)
type msgArg struct {
subject []byte
reply []byte
sid int64
hdr int
size int
}
const MAX_CONTROL_LINE_SIZE = 4096
type parseState struct {
state int
as int
drop int
hdr int
ma msgArg
argBuf []byte
msgBuf []byte
msgCopied bool
scratch [MAX_CONTROL_LINE_SIZE]byte
}
const (
OP_START = iota
OP_PLUS
OP_PLUS_O
OP_PLUS_OK
OP_MINUS
OP_MINUS_E
OP_MINUS_ER
OP_MINUS_ERR
OP_MINUS_ERR_SPC
MINUS_ERR_ARG
OP_M
OP_MS
OP_MSG
OP_MSG_SPC
MSG_ARG
MSG_PAYLOAD
MSG_END
OP_H
OP_P
OP_PI
OP_PIN
OP_PING
OP_PO
OP_PON
OP_PONG
OP_I
OP_IN
OP_INF
OP_INFO
OP_INFO_SPC
INFO_ARG
)
// parse is the fast protocol parser engine.
func (nc *Conn) parse(buf []byte) error {
var i int
var b byte
// Move to loop instead of range syntax to allow jumping of i
for i = 0; i < len(buf); i++ {
b = buf[i]
switch nc.ps.state {
case OP_START:
switch b {
case 'M', 'm':
nc.ps.state = OP_M
nc.ps.hdr = -1
nc.ps.ma.hdr = -1
case 'H', 'h':
nc.ps.state = OP_H
nc.ps.hdr = 0
nc.ps.ma.hdr = 0
case 'P', 'p':
nc.ps.state = OP_P
case '+':
nc.ps.state = OP_PLUS
case '-':
nc.ps.state = OP_MINUS
case 'I', 'i':
nc.ps.state = OP_I
default:
goto parseErr
}
case OP_H:
switch b {
case 'M', 'm':
nc.ps.state = OP_M
default:
goto parseErr
}
case OP_M:
switch b {
case 'S', 's':
nc.ps.state = OP_MS
default:
goto parseErr
}
case OP_MS:
switch b {
case 'G', 'g':
nc.ps.state = OP_MSG
default:
goto parseErr
}
case OP_MSG:
switch b {
case ' ', '\t':
nc.ps.state = OP_MSG_SPC
default:
goto parseErr
}
case OP_MSG_SPC:
switch b {
case ' ', '\t':
continue
default:
nc.ps.state = MSG_ARG
nc.ps.as = i
}
case MSG_ARG:
switch b {
case '\r':
nc.ps.drop = 1
case '\n':
var arg []byte
if nc.ps.argBuf != nil {
arg = nc.ps.argBuf
} else {
arg = buf[nc.ps.as : i-nc.ps.drop]
}
if err := nc.processMsgArgs(arg); err != nil {
return err
}
nc.ps.drop, nc.ps.as, nc.ps.state = 0, i+1, MSG_PAYLOAD
// jump ahead with the index. If this overruns
// what is left we fall out and process a split buffer.
i = nc.ps.as + nc.ps.ma.size - 1
default:
if nc.ps.argBuf != nil {
nc.ps.argBuf = append(nc.ps.argBuf, b)
}
}
case MSG_PAYLOAD:
if nc.ps.msgBuf != nil {
if len(nc.ps.msgBuf) >= nc.ps.ma.size {
nc.processMsg(nc.ps.msgBuf)
nc.ps.argBuf, nc.ps.msgBuf, nc.ps.msgCopied, nc.ps.state = nil, nil, false, MSG_END
} else {
// copy as much as we can to the buffer and skip ahead.
toCopy := nc.ps.ma.size - len(nc.ps.msgBuf)
avail := len(buf) - i
if avail < toCopy {
toCopy = avail
}
if toCopy > 0 {
start := len(nc.ps.msgBuf)
// This is needed for copy to work.
nc.ps.msgBuf = nc.ps.msgBuf[:start+toCopy]
copy(nc.ps.msgBuf[start:], buf[i:i+toCopy])
// Update our index
i = (i + toCopy) - 1
} else {
nc.ps.msgBuf = append(nc.ps.msgBuf, b)
}
}
} else if i-nc.ps.as >= nc.ps.ma.size {
nc.processMsg(buf[nc.ps.as:i])
nc.ps.argBuf, nc.ps.msgBuf, nc.ps.msgCopied, nc.ps.state = nil, nil, false, MSG_END
}
case MSG_END:
switch b {
case '\n':
nc.ps.drop, nc.ps.as, nc.ps.state = 0, i+1, OP_START
default:
continue
}
case OP_PLUS:
switch b {
case 'O', 'o':
nc.ps.state = OP_PLUS_O
default:
goto parseErr
}
case OP_PLUS_O:
switch b {
case 'K', 'k':
nc.ps.state = OP_PLUS_OK
default:
goto parseErr
}
case OP_PLUS_OK:
switch b {
case '\n':
nc.processOK()
nc.ps.drop, nc.ps.state = 0, OP_START
}
case OP_MINUS:
switch b {
case 'E', 'e':
nc.ps.state = OP_MINUS_E
default:
goto parseErr
}
case OP_MINUS_E:
switch b {
case 'R', 'r':
nc.ps.state = OP_MINUS_ER
default:
goto parseErr
}
case OP_MINUS_ER:
switch b {
case 'R', 'r':
nc.ps.state = OP_MINUS_ERR
default:
goto parseErr
}
case OP_MINUS_ERR:
switch b {
case ' ', '\t':
nc.ps.state = OP_MINUS_ERR_SPC
default:
goto parseErr
}
case OP_MINUS_ERR_SPC:
switch b {
case ' ', '\t':
continue
default:
nc.ps.state = MINUS_ERR_ARG
nc.ps.as = i
}
case MINUS_ERR_ARG:
switch b {
case '\r':
nc.ps.drop = 1
case '\n':
var arg []byte
if nc.ps.argBuf != nil {
arg = nc.ps.argBuf
nc.ps.argBuf = nil
} else {
arg = buf[nc.ps.as : i-nc.ps.drop]
}
nc.processErr(string(arg))
nc.ps.drop, nc.ps.as, nc.ps.state = 0, i+1, OP_START
default:
if nc.ps.argBuf != nil {
nc.ps.argBuf = append(nc.ps.argBuf, b)
}
}
case OP_P:
switch b {
case 'I', 'i':
nc.ps.state = OP_PI
case 'O', 'o':
nc.ps.state = OP_PO
default:
goto parseErr
}
case OP_PO:
switch b {
case 'N', 'n':
nc.ps.state = OP_PON
default:
goto parseErr
}
case OP_PON:
switch b {
case 'G', 'g':
nc.ps.state = OP_PONG
default:
goto parseErr
}
case OP_PONG:
switch b {
case '\n':
nc.processPong()
nc.ps.drop, nc.ps.state = 0, OP_START
}
case OP_PI:
switch b {
case 'N', 'n':
nc.ps.state = OP_PIN
default:
goto parseErr
}
case OP_PIN:
switch b {
case 'G', 'g':
nc.ps.state = OP_PING
default:
goto parseErr
}
case OP_PING:
switch b {
case '\n':
nc.processPing()
nc.ps.drop, nc.ps.state = 0, OP_START
}
case OP_I:
switch b {
case 'N', 'n':
nc.ps.state = OP_IN
default:
goto parseErr
}
case OP_IN:
switch b {
case 'F', 'f':
nc.ps.state = OP_INF
default:
goto parseErr
}
case OP_INF:
switch b {
case 'O', 'o':
nc.ps.state = OP_INFO
default:
goto parseErr
}
case OP_INFO:
switch b {
case ' ', '\t':
nc.ps.state = OP_INFO_SPC
default:
goto parseErr
}
case OP_INFO_SPC:
switch b {
case ' ', '\t':
continue
default:
nc.ps.state = INFO_ARG
nc.ps.as = i
}
case INFO_ARG:
switch b {
case '\r':
nc.ps.drop = 1
case '\n':
var arg []byte
if nc.ps.argBuf != nil {
arg = nc.ps.argBuf
nc.ps.argBuf = nil
} else {
arg = buf[nc.ps.as : i-nc.ps.drop]
}
nc.processAsyncInfo(arg)
nc.ps.drop, nc.ps.as, nc.ps.state = 0, i+1, OP_START
default:
if nc.ps.argBuf != nil {
nc.ps.argBuf = append(nc.ps.argBuf, b)
}
}
default:
goto parseErr
}
}
// Check for split buffer scenarios
if (nc.ps.state == MSG_ARG || nc.ps.state == MINUS_ERR_ARG || nc.ps.state == INFO_ARG) && nc.ps.argBuf == nil {
nc.ps.argBuf = nc.ps.scratch[:0]
nc.ps.argBuf = append(nc.ps.argBuf, buf[nc.ps.as:i-nc.ps.drop]...)
// FIXME, check max len
}
// Check for split msg
if nc.ps.state == MSG_PAYLOAD && nc.ps.msgBuf == nil {
// We need to clone the msgArg if it is still referencing the
// read buffer and we are not able to process the msg.
if nc.ps.argBuf == nil {
nc.cloneMsgArg()
}
// If we will overflow the scratch buffer, just create a
// new buffer to hold the split message.
if nc.ps.ma.size > cap(nc.ps.scratch)-len(nc.ps.argBuf) {
lrem := len(buf[nc.ps.as:])
nc.ps.msgBuf = make([]byte, lrem, nc.ps.ma.size)
copy(nc.ps.msgBuf, buf[nc.ps.as:])
nc.ps.msgCopied = true
} else {
nc.ps.msgBuf = nc.ps.scratch[len(nc.ps.argBuf):len(nc.ps.argBuf)]
nc.ps.msgBuf = append(nc.ps.msgBuf, (buf[nc.ps.as:])...)
}
}
return nil
parseErr:
return fmt.Errorf("nats: Parse Error [%d]: '%s'", nc.ps.state, buf[i:])
}
// cloneMsgArg is used when the split buffer scenario has the pubArg in the existing read buffer, but
// we need to hold onto it into the next read.
func (nc *Conn) cloneMsgArg() {
nc.ps.argBuf = nc.ps.scratch[:0]
nc.ps.argBuf = append(nc.ps.argBuf, nc.ps.ma.subject...)
nc.ps.argBuf = append(nc.ps.argBuf, nc.ps.ma.reply...)
nc.ps.ma.subject = nc.ps.argBuf[:len(nc.ps.ma.subject)]
if nc.ps.ma.reply != nil {
nc.ps.ma.reply = nc.ps.argBuf[len(nc.ps.ma.subject):]
}
}
const argsLenMax = 4
const hdrArgsLenMax = 5
func (nc *Conn) processMsgArgs(arg []byte) error {
// Use separate function for header based messages.
if nc.ps.hdr >= 0 {
return nc.processHeaderMsgArgs(arg)
}
// Unroll splitArgs to avoid runtime/heap issues
a := [argsLenMax][]byte{}
args := a[:0]
start := -1
for i, b := range arg {
switch b {
case ' ', '\t', '\r', '\n':
if start >= 0 {
args = append(args, arg[start:i])
start = -1
}
default:
if start < 0 {
start = i
}
}
}
if start >= 0 {
args = append(args, arg[start:])
}
switch len(args) {
case 3:
nc.ps.ma.subject = args[0]
nc.ps.ma.sid = parseInt64(args[1])
nc.ps.ma.reply = nil
nc.ps.ma.size = int(parseInt64(args[2]))
case 4:
nc.ps.ma.subject = args[0]
nc.ps.ma.sid = parseInt64(args[1])
nc.ps.ma.reply = args[2]
nc.ps.ma.size = int(parseInt64(args[3]))
default:
return fmt.Errorf("nats: processMsgArgs Parse Error: '%s'", arg)
}
if nc.ps.ma.sid < 0 {
return fmt.Errorf("nats: processMsgArgs Bad or Missing Sid: '%s'", arg)
}
if nc.ps.ma.size < 0 {
return fmt.Errorf("nats: processMsgArgs Bad or Missing Size: '%s'", arg)
}
return nil
}
// processHeaderMsgArgs is for a header based message.
func (nc *Conn) processHeaderMsgArgs(arg []byte) error {
// Unroll splitArgs to avoid runtime/heap issues
a := [hdrArgsLenMax][]byte{}
args := a[:0]
start := -1
for i, b := range arg {
switch b {
case ' ', '\t', '\r', '\n':
if start >= 0 {
args = append(args, arg[start:i])
start = -1
}
default:
if start < 0 {
start = i
}
}
}
if start >= 0 {
args = append(args, arg[start:])
}
switch len(args) {
case 4:
nc.ps.ma.subject = args[0]
nc.ps.ma.sid = parseInt64(args[1])
nc.ps.ma.reply = nil
nc.ps.ma.hdr = int(parseInt64(args[2]))
nc.ps.ma.size = int(parseInt64(args[3]))
case 5:
nc.ps.ma.subject = args[0]
nc.ps.ma.sid = parseInt64(args[1])
nc.ps.ma.reply = args[2]
nc.ps.ma.hdr = int(parseInt64(args[3]))
nc.ps.ma.size = int(parseInt64(args[4]))
default:
return fmt.Errorf("nats: processHeaderMsgArgs Parse Error: '%s'", arg)
}
if nc.ps.ma.sid < 0 {
return fmt.Errorf("nats: processHeaderMsgArgs Bad or Missing Sid: '%s'", arg)
}
if nc.ps.ma.hdr < 0 || nc.ps.ma.hdr > nc.ps.ma.size {
return fmt.Errorf("nats: processHeaderMsgArgs Bad or Missing Header Size: '%s'", arg)
}
if nc.ps.ma.size < 0 {
return fmt.Errorf("nats: processHeaderMsgArgs Bad or Missing Size: '%s'", arg)
}
return nil
}
// ASCII numbers 0-9
const (
ascii_0 = 48
ascii_9 = 57
)
// parseInt64 expects decimal positive numbers. We
// return -1 to signal error
func parseInt64(d []byte) (n int64) {
if len(d) == 0 {
return -1
}
for _, dec := range d {
if dec < ascii_0 || dec > ascii_9 {
return -1
}
n = n*10 + (int64(dec) - ascii_0)
}
return n
}