metamaps--metamaps/realtime/node_modules/redis/lib/parser/javascript.js

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/*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");
exports.debug_mode = false;
exports.name = "javascript";
function RedisReplyParser(options) {
this.name = exports.name;
this.options = options || {};
this.reset();
events.EventEmitter.call(this);
}
util.inherits(RedisReplyParser, events.EventEmitter);
exports.Parser = RedisReplyParser;
// Buffer.toString() is quite slow for small strings
function small_toString(buf, len) {
var tmp = "", i;
for (i = 0; i < len; i += 1) {
tmp += String.fromCharCode(buf[i]);
}
return tmp;
}
// 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;
};
RedisReplyParser.prototype.parser_error = function (message) {
this.emit("error", message);
this.reset();
};
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 = "";
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);
}
} 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;
}
} 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;
}
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);
}
};
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);
}
}
};
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;
}
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.multi_bulk_length = 0;
this.multi_bulk_replies = null;
this.multi_bulk_pos = 0;
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;
}
} else {
this.emit("reply", this.multi_bulk_replies);
this.multi_bulk_length = 0;
this.multi_bulk_replies = null;
this.multi_bulk_pos = 0;
}
};