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generally faster javascript parser

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commit 7ec1815188fafa9764e8b1494692f28ff3cfd549 1 parent a798cc0
Jerry Sievert JerrySievert authored
Showing with 193 additions and 281 deletions.
  1. +193 −281 lib/parser/javascript.js
474 lib/parser/javascript.js
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@@ -1,317 +1,229 @@
-/*global Buffer require exports console setTimeout */
-
-// TODO - incorporate these V8 pro tips:
-// pre-allocate Arrays if length is known in advance
-// do not use delete
-// use numbers for parser state
-
var events = require("events"),
- util = require("../util");
+ util = require('../util');
+
+function Packet (type, size) {
+ this.type = type;
+ this.size = +size;
+}
+exports.name = 'faster';
exports.debug_mode = false;
-exports.name = "javascript";
-function RedisReplyParser(options) {
+function FasterReplyParser (options) {
this.name = exports.name;
- this.options = options || {};
- this.reset();
- events.EventEmitter.call(this);
+ this.options = options || { };
+
+ this._buffer = null;
+ this._offset = 0;
+ this._encoding = 'utf-8';
+ this._debug_mode = options.debug_mode;
+ this._reply_type = null;
}
-util.inherits(RedisReplyParser, events.EventEmitter);
+util.inherits(FasterReplyParser, events.EventEmitter);
-exports.Parser = RedisReplyParser;
+exports.Parser = FasterReplyParser;
-// Buffer.toString() is quite slow for small strings
-function small_toString(buf, len) {
- var tmp = "", i;
+FasterReplyParser.prototype._parseResult = function (type) {
+ var start, end, offset, packetHeader;
+
+ if (type === 43 || type === 45) { // +
+ end = this._packetEndOffset() - 1;
+ start = this._offset;
- for (i = 0; i < len; i += 1) {
- tmp += String.fromCharCode(buf[i]);
- }
+ this._offset = end + 2;
- return tmp;
-}
+ if (this.options.return_buffers) {
+ return this._buffer.slice(start, end);
+ } else {
+ return this._buffer.slice(start, end).toString(this._encoding);
+ }
+ } else if (type === 58) { // :
+ end = this._packetEndOffset() - 1;
+ start = this._offset;
-// Reset parser to it's original state.
-RedisReplyParser.prototype.reset = function () {
- this.return_buffer = new Buffer(16384); // for holding replies, might grow
- this.return_string = "";
- this.tmp_string = ""; // for holding size fields
-
- this.multi_bulk_length = 0;
- this.multi_bulk_replies = null;
- this.multi_bulk_pos = 0;
- this.multi_bulk_nested_length = 0;
- this.multi_bulk_nested_replies = null;
-
- this.states = {
- TYPE: 1,
- SINGLE_LINE: 2,
- MULTI_BULK_COUNT: 3,
- INTEGER_LINE: 4,
- BULK_LENGTH: 5,
- ERROR_LINE: 6,
- BULK_DATA: 7,
- UNKNOWN_TYPE: 8,
- FINAL_CR: 9,
- FINAL_LF: 10,
- MULTI_BULK_COUNT_LF: 11,
- BULK_LF: 12
- };
-
- this.state = this.states.TYPE;
-};
+ this._offset = end + 2;
-RedisReplyParser.prototype.parser_error = function (message) {
- this.emit("error", message);
- this.reset();
+ return +this._buffer.toString(this._encoding, start, end);
+ } else if (type === 36) { // $
+ offset = this._offset - 1;
+
+ packetHeader = new Packet(type, this.parseHeader());
+
+ if (packetHeader.size === null) {
+ this._offset++;
+
+ return null;
+ }
+
+ if (packetHeader.size === -1) {
+ return null;
+ }
+
+ end = this._offset + packetHeader.size;
+ start = this._offset;
+
+ this._offset = end + 2;
+
+ if (end > this._buffer.length) {
+ this._offset = offset;
+ return null;
+ }
+
+ if (this.options.return_buffers) {
+ return this._buffer.slice(start, end);
+ } else {
+ return this._buffer.slice(start, end).toString(this._encoding);
+ }
+ } else if (type === 42) { // *
+ offset = this._offset;
+ packetHeader = new Packet(type, this.parseHeader());
+
+ if (packetHeader.size > this._bytesRemaining()) {
+ this._offset = offset - 1;
+ return -1;
+ }
+
+ if (packetHeader.size < 0) {
+ this._offset += 2;
+ return null;
+ }
+
+ var reply = [ ];
+ offset = this._offset - 1;
+
+ for (var i = 0; i < packetHeader.size; i++) {
+ var ntype = this._buffer[this._offset++];
+
+ if (this._offset === this._buffer.length) {
+ throw new Error('too far');
+ }
+ reply.push(this._parseResult(ntype));
+ }
+
+ return reply;
+ }
};
-RedisReplyParser.prototype.execute = function (incoming_buf) {
- var pos = 0, bd_tmp, bd_str, i, il, states = this.states;
- //, state_times = {}, start_execute = new Date(), start_switch, end_switch, old_state;
- //start_switch = new Date();
-
- while (pos < incoming_buf.length) {
- // old_state = this.state;
- // console.log("execute: " + this.state + ", " + pos + "/" + incoming_buf.length + ", " + String.fromCharCode(incoming_buf[pos]));
-
- switch (this.state) {
- case 1: // states.TYPE
- this.type = incoming_buf[pos];
- pos += 1;
-
- switch (this.type) {
- case 43: // +
- this.state = states.SINGLE_LINE;
- this.return_buffer.end = 0;
- this.return_string = "";
- break;
- case 42: // *
- this.state = states.MULTI_BULK_COUNT;
- this.tmp_string = "";
- break;
- case 58: // :
- this.state = states.INTEGER_LINE;
- this.return_buffer.end = 0;
- this.return_string = "";
- break;
- case 36: // $
- this.state = states.BULK_LENGTH;
- this.tmp_string = "";
- break;
- case 45: // -
- this.state = states.ERROR_LINE;
- this.return_buffer.end = 0;
- this.return_string = "";
+FasterReplyParser.prototype.execute = function (buffer) {
+ this.append(buffer);
+
+ while (true) {
+ var offset = this._offset;
+ try {
+ var ret;
+
+ // at least 4 bytes: *1\r\n
+ if (this._bytesRemaining() < 4) {
break;
- default:
- this.state = states.UNKNOWN_TYPE;
}
- break;
- case 4: // states.INTEGER_LINE
- if (incoming_buf[pos] === 13) {
- this.send_reply(+small_toString(this.return_buffer, this.return_buffer.end));
- this.state = states.FINAL_LF;
- } else {
- this.return_buffer[this.return_buffer.end] = incoming_buf[pos];
- this.return_buffer.end += 1;
- }
- pos += 1;
- break;
- case 6: // states.ERROR_LINE
- if (incoming_buf[pos] === 13) {
- this.send_error(this.return_buffer.toString("ascii", 0, this.return_buffer.end));
- this.state = states.FINAL_LF;
- } else {
- this.return_buffer[this.return_buffer.end] = incoming_buf[pos];
- this.return_buffer.end += 1;
- }
- pos += 1;
- break;
- case 2: // states.SINGLE_LINE
- if (incoming_buf[pos] === 13) {
- this.send_reply(this.return_string);
- this.state = states.FINAL_LF;
- } else {
- this.return_string += String.fromCharCode(incoming_buf[pos]);
- }
- pos += 1;
- break;
- case 3: // states.MULTI_BULK_COUNT
- if (incoming_buf[pos] === 13) { // \r
- this.state = states.MULTI_BULK_COUNT_LF;
- } else {
- this.tmp_string += String.fromCharCode(incoming_buf[pos]);
- }
- pos += 1;
- break;
- case 11: // states.MULTI_BULK_COUNT_LF
- if (incoming_buf[pos] === 10) { // \n
- if (this.multi_bulk_length) { // nested multi-bulk
- this.multi_bulk_nested_length = this.multi_bulk_length;
- this.multi_bulk_nested_replies = this.multi_bulk_replies;
- this.multi_bulk_nested_pos = this.multi_bulk_pos;
- }
- this.multi_bulk_length = +this.tmp_string;
- this.multi_bulk_pos = 0;
- this.state = states.TYPE;
- if (this.multi_bulk_length < 0) {
- this.send_reply(null);
- this.multi_bulk_length = 0;
- } else if (this.multi_bulk_length === 0) {
- this.multi_bulk_pos = 0;
- this.multi_bulk_replies = null;
- this.send_reply([]);
- } else {
- this.multi_bulk_replies = new Array(this.multi_bulk_length);
+
+ var type = this._buffer[this._offset++];
+
+ if (type === 43) { // +
+ ret = this._parseResult(type);
+ this.send_reply(ret);
+ } else if (type === 45) {
+ ret = this._parseResult(type);
+ this.send_error(ret);
+ } else if (type === 58) { // :
+ ret = this._parseResult(type);
+ this.send_reply(+ret);
+ } else if (type === 36) { // $
+ ret = this._parseResult(type);
+
+ if (ret === null) {
+ break;
}
- } else {
- this.parser_error(new Error("didn't see LF after NL reading multi bulk count"));
- return;
- }
- pos += 1;
- break;
- case 5: // states.BULK_LENGTH
- if (incoming_buf[pos] === 13) { // \r
- this.state = states.BULK_LF;
- } else {
- this.tmp_string += String.fromCharCode(incoming_buf[pos]);
- }
- pos += 1;
- break;
- case 12: // states.BULK_LF
- if (incoming_buf[pos] === 10) { // \n
- this.bulk_length = +this.tmp_string;
- if (this.bulk_length === -1) {
- this.send_reply(null);
- this.state = states.TYPE;
- } else if (this.bulk_length === 0) {
- this.send_reply(new Buffer(""));
- this.state = states.FINAL_CR;
- } else {
- this.state = states.BULK_DATA;
- if (this.bulk_length > this.return_buffer.length) {
- if (exports.debug_mode) {
- console.log("Growing return_buffer from " + this.return_buffer.length + " to " + this.bulk_length);
- }
- this.return_buffer = new Buffer(this.bulk_length);
- }
- this.return_buffer.end = 0;
+ this.send_reply(ret);
+ } else if (type === 42) { // *
+ offset = this._offset - 1;
+ ret = this._parseResult(type);
+ if (ret === -1) {
+ this._offset = offset;
+ break;
}
- } else {
- this.parser_error(new Error("didn't see LF after NL while reading bulk length"));
- return;
- }
- pos += 1;
- break;
- case 7: // states.BULK_DATA
- this.return_buffer[this.return_buffer.end] = incoming_buf[pos];
- this.return_buffer.end += 1;
- pos += 1;
- if (this.return_buffer.end === this.bulk_length) {
- bd_tmp = new Buffer(this.bulk_length);
- // When the response is small, Buffer.copy() is a lot slower.
- if (this.bulk_length > 10) {
- this.return_buffer.copy(bd_tmp, 0, 0, this.bulk_length);
- } else {
- for (i = 0, il = this.bulk_length; i < il; i += 1) {
- bd_tmp[i] = this.return_buffer[i];
- }
- }
- this.send_reply(bd_tmp);
- this.state = states.FINAL_CR;
- }
- break;
- case 9: // states.FINAL_CR
- if (incoming_buf[pos] === 13) { // \r
- this.state = states.FINAL_LF;
- pos += 1;
- } else {
- this.parser_error(new Error("saw " + incoming_buf[pos] + " when expecting final CR"));
- return;
- }
- break;
- case 10: // states.FINAL_LF
- if (incoming_buf[pos] === 10) { // \n
- this.state = states.TYPE;
- pos += 1;
- } else {
- this.parser_error(new Error("saw " + incoming_buf[pos] + " when expecting final LF"));
- return;
+
+ this.send_reply(ret);
}
+ } catch(err) {
+ this._offset = offset;
break;
- default:
- this.parser_error(new Error("invalid state " + this.state));
}
- // end_switch = new Date();
- // if (state_times[old_state] === undefined) {
- // state_times[old_state] = 0;
- // }
- // state_times[old_state] += (end_switch - start_switch);
- // start_switch = end_switch;
}
- // console.log("execute ran for " + (Date.now() - start_execute) + " ms, on " + incoming_buf.length + " Bytes. ");
- // Object.keys(state_times).forEach(function (state) {
- // console.log(" " + state + ": " + state_times[state]);
- // });
};
-RedisReplyParser.prototype.send_error = function (reply) {
- if (this.multi_bulk_length > 0 || this.multi_bulk_nested_length > 0) {
- // TODO - can this happen? Seems like maybe not.
- this.add_multi_bulk_reply(reply);
- } else {
- this.emit("reply error", reply);
+FasterReplyParser.prototype.append = function(newBuffer) {
+ if (!newBuffer) {
+ return;
}
-};
-RedisReplyParser.prototype.send_reply = function (reply) {
- if (this.multi_bulk_length > 0 || this.multi_bulk_nested_length > 0) {
- if (!this.options.return_buffers && Buffer.isBuffer(reply)) {
- this.add_multi_bulk_reply(reply.toString("utf8"));
- } else {
- this.add_multi_bulk_reply(reply);
- }
- } else {
- if (!this.options.return_buffers && Buffer.isBuffer(reply)) {
- this.emit("reply", reply.toString("utf8"));
- } else {
- this.emit("reply", reply);
- }
+ var oldBuffer = this._buffer;
+ if (!oldBuffer) {
+ this._buffer = newBuffer;
+
+ return;
}
-};
-RedisReplyParser.prototype.add_multi_bulk_reply = function (reply) {
- if (this.multi_bulk_replies) {
- this.multi_bulk_replies[this.multi_bulk_pos] = reply;
- this.multi_bulk_pos += 1;
- if (this.multi_bulk_pos < this.multi_bulk_length) {
- return;
- }
- } else {
- this.multi_bulk_replies = reply;
+ var bytesRemaining = this._bytesRemaining();
+
+ var newLength = bytesRemaining + newBuffer.length;
+
+ if (bytesRemaining === 0) {
+ this._buffer = newBuffer;
+ this._offset = 0;
+
+ return;
}
- if (this.multi_bulk_nested_length > 0) {
- this.multi_bulk_nested_replies[this.multi_bulk_nested_pos] = this.multi_bulk_replies;
- this.multi_bulk_nested_pos += 1;
+ this._buffer = Buffer.concat([this._buffer.slice(this._offset), newBuffer]);
+
+ this._offset = 0;
+};
+
+FasterReplyParser.prototype.parseHeader = function () {
+ var end = this._packetEndOffset(),
+ value = this._buffer.toString(this._encoding, this._offset, end - 1);
+
+ this._offset = end + 1;
+
+ return value;
+};
+
+FasterReplyParser.prototype.parseBuffer = function(length) {
+ var buffer = this._buffer.slice(this._offset, this._offset + length);
- this.multi_bulk_length = 0;
- this.multi_bulk_replies = null;
- this.multi_bulk_pos = 0;
+ this._offset += length;
+ return buffer;
+};
+
+FasterReplyParser.prototype._packetEndOffset = function () {
+ var offset = this._offset;
- if (this.multi_bulk_nested_length === this.multi_bulk_nested_pos) {
- this.emit("reply", this.multi_bulk_nested_replies);
- this.multi_bulk_nested_length = 0;
- this.multi_bulk_nested_pos = 0;
- this.multi_bulk_nested_replies = null;
+ while (this._buffer[offset] !== 0x0d && this._buffer[offset + 1] !== 0x0a) {
+ offset++;
+
+ if (offset >= this._buffer.length) {
+ throw new Error("didn't see LF after NL reading multi bulk count (" + offset + " => " + this._buffer.length + ", " + this._offset + ")");
}
- } else {
- this.emit("reply", this.multi_bulk_replies);
- this.multi_bulk_length = 0;
- this.multi_bulk_replies = null;
- this.multi_bulk_pos = 0;
}
+
+ offset++;
+ return offset;
};
+
+FasterReplyParser.prototype._bytesRemaining = function() {
+ return (this._buffer.length - this._offset) < 0 ? 0 : (this._buffer.length - this._offset);
+};
+
+FasterReplyParser.prototype.parser_error = function (message) {
+ this.emit("error", message);
+};
+
+FasterReplyParser.prototype.send_error = function (reply) {
+ this.emit("reply error", reply);
+};
+
+FasterReplyParser.prototype.send_reply = function (reply) {
+ this.emit("reply", reply);
+};
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