Commit d4bf9f50 authored by Zhai Zirun's avatar Zhai Zirun

connected node.js to database

parent c2315b35
......@@ -4,6 +4,29 @@ var MOUSE_VISITED_CLASSNAME = 'crx_mouse_visited';
var srcName;
var dietNum;
//Querying database on heroku
const { Client } = require('pg');
const client = new Client({
connectionString: process.env.DATABASE_URL, //default name for main database is DATABASE_URL
ssl: {
rejectUnauthorized: false
}
});
client.connect();
client.query('SELECT table_schema,table_name FROM information_schema.tables;', (err, res) => {
if (err) throw err;
for (let row of res.rows) {
console.log(JSON.stringify(row));
}
client.end();
});
//https://www.w3schools.com/nodejs/nodejs_mysql_select.asp
// Previous dom, that we want to track, so we can remove the previous styling.
//var prevDOM = null;
......
../semver/bin/semver
\ No newline at end of file
language: node_js
node_js:
- 4
- 6
- 8
- 10
- 11
The MIT License (MIT)
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
# buffer-writer
[![Build Status](https://secure.travis-ci.org/brianc/node-buffer-writer.png?branch=master)](http://travis-ci.org/brianc/node-buffer-writer)
Fast & efficient buffer writer used to keep memory usage low by internally recycling a single large buffer.
Used as the binary protocol writer in [node-postgres](https://github.com/brianc/node-postgres)
Since postgres requires big endian encoding, this only writes big endian numbers for now, but can & probably will easily be extended to write little endian as well.
I'll admit this has a few postgres specific things I might need to take out in the future, such as `addHeader`
## api
`var writer = new (require('buffer-writer')());`
### writer.addInt32(num)
Writes a 4-byte big endian binary encoded number to the end of the buffer.
### writer.addInt16(num)
Writes a 2-byte big endian binary encoded number to the end of the buffer.
### writer.addCString(string)
Writes a string to the buffer `utf8` encoded and adds a null character (`\0`) at the end.
### var buffer = writer.addHeader(char)
Writes the 5 byte PostgreSQL required header to the beginning of the buffer. (1 byte for character, 1 BE Int32 for length of the buffer)
### var buffer = writer.join()
Collects all data in the writer and joins it into a single, new buffer.
### var buffer = writer.flush(char)
Writes the 5 byte postgres required message header, collects all data in the writer and joins it into a single, new buffer, and then resets the writer.
## thoughts
This is kind of node-postgres specific. If you're interested in using this for a more general purpose thing, lemme know.
I would love to work with you on getting this more reusable for your needs.
## license
MIT
//binary data writer tuned for creating
//postgres message packets as effeciently as possible by reusing the
//same buffer to avoid memcpy and limit memory allocations
var Writer = module.exports = function (size) {
this.size = size || 1024;
this.buffer = Buffer.alloc(this.size + 5);
this.offset = 5;
this.headerPosition = 0;
};
//resizes internal buffer if not enough size left
Writer.prototype._ensure = function (size) {
var remaining = this.buffer.length - this.offset;
if (remaining < size) {
var oldBuffer = this.buffer;
// exponential growth factor of around ~ 1.5
// https://stackoverflow.com/questions/2269063/buffer-growth-strategy
var newSize = oldBuffer.length + (oldBuffer.length >> 1) + size;
this.buffer = Buffer.alloc(newSize);
oldBuffer.copy(this.buffer);
}
};
Writer.prototype.addInt32 = function (num) {
this._ensure(4);
this.buffer[this.offset++] = (num >>> 24 & 0xFF);
this.buffer[this.offset++] = (num >>> 16 & 0xFF);
this.buffer[this.offset++] = (num >>> 8 & 0xFF);
this.buffer[this.offset++] = (num >>> 0 & 0xFF);
return this;
};
Writer.prototype.addInt16 = function (num) {
this._ensure(2);
this.buffer[this.offset++] = (num >>> 8 & 0xFF);
this.buffer[this.offset++] = (num >>> 0 & 0xFF);
return this;
};
//for versions of node requiring 'length' as 3rd argument to buffer.write
var writeString = function (buffer, string, offset, len) {
buffer.write(string, offset, len);
};
//overwrite function for older versions of node
if (Buffer.prototype.write.length === 3) {
writeString = function (buffer, string, offset, len) {
buffer.write(string, offset);
};
}
Writer.prototype.addCString = function (string) {
//just write a 0 for empty or null strings
if (!string) {
this._ensure(1);
} else {
var len = Buffer.byteLength(string);
this._ensure(len + 1); //+1 for null terminator
writeString(this.buffer, string, this.offset, len);
this.offset += len;
}
this.buffer[this.offset++] = 0; // null terminator
return this;
};
Writer.prototype.addChar = function (c) {
this._ensure(1);
writeString(this.buffer, c, this.offset, 1);
this.offset++;
return this;
};
Writer.prototype.addString = function (string) {
string = string || "";
var len = Buffer.byteLength(string);
this._ensure(len);
this.buffer.write(string, this.offset);
this.offset += len;
return this;
};
Writer.prototype.getByteLength = function () {
return this.offset - 5;
};
Writer.prototype.add = function (otherBuffer) {
this._ensure(otherBuffer.length);
otherBuffer.copy(this.buffer, this.offset);
this.offset += otherBuffer.length;
return this;
};
Writer.prototype.clear = function () {
this.offset = 5;
this.headerPosition = 0;
this.lastEnd = 0;
};
//appends a header block to all the written data since the last
//subsequent header or to the beginning if there is only one data block
Writer.prototype.addHeader = function (code, last) {
var origOffset = this.offset;
this.offset = this.headerPosition;
this.buffer[this.offset++] = code;
//length is everything in this packet minus the code
this.addInt32(origOffset - (this.headerPosition + 1));
//set next header position
this.headerPosition = origOffset;
//make space for next header
this.offset = origOffset;
if (!last) {
this._ensure(5);
this.offset += 5;
}
};
Writer.prototype.join = function (code) {
if (code) {
this.addHeader(code, true);
}
return this.buffer.slice(code ? 0 : 5, this.offset);
};
Writer.prototype.flush = function (code) {
var result = this.join(code);
this.clear();
return result;
};
{
"_from": "buffer-writer@2.0.0",
"_id": "buffer-writer@2.0.0",
"_inBundle": false,
"_integrity": "sha512-a7ZpuTZU1TRtnwyCNW3I5dc0wWNC3VR9S++Ewyk2HHZdrO3CQJqSpd+95Us590V6AL7JqUAH2IwZ/398PmNFgw==",
"_location": "/buffer-writer",
"_phantomChildren": {},
"_requested": {
"type": "version",
"registry": true,
"raw": "buffer-writer@2.0.0",
"name": "buffer-writer",
"escapedName": "buffer-writer",
"rawSpec": "2.0.0",
"saveSpec": null,
"fetchSpec": "2.0.0"
},
"_requiredBy": [
"/pg"
],
"_resolved": "https://registry.npmjs.org/buffer-writer/-/buffer-writer-2.0.0.tgz",
"_shasum": "ce7eb81a38f7829db09c873f2fbb792c0c98ec04",
"_spec": "buffer-writer@2.0.0",
"_where": "/Users/zirun/Documents/chrome-groceries-extension/node_modules/pg",
"author": {
"name": "Brian M. Carlson"
},
"bugs": {
"url": "https://github.com/brianc/node-buffer-writer/issues"
},
"bundleDependencies": false,
"deprecated": false,
"description": "a fast, efficient buffer writer",
"devDependencies": {
"mocha": "5.2.0"
},
"engines": {
"node": ">=4"
},
"homepage": "https://github.com/brianc/node-buffer-writer#readme",
"keywords": [
"buffer",
"writer",
"builder"
],
"license": "MIT",
"main": "index.js",
"name": "buffer-writer",
"repository": {
"type": "git",
"url": "git://github.com/brianc/node-buffer-writer.git"
},
"scripts": {
"test": "mocha --throw-deprecation"
},
"version": "2.0.0"
}
var Writer = require(__dirname + "/../");
var assert = require('assert');
var util = require('util');
assert.equalBuffers = function (actual, expected) {
var spit = function (actual, expected) {
console.log("");
console.log("actual " + util.inspect(actual));
console.log("expect " + util.inspect(expected));
console.log("");
};
if (actual.length != expected.length) {
spit(actual, expected);
assert.strictEqual(actual.length, expected.length);
}
for (var i = 0; i < actual.length; i++) {
if (actual[i] != expected[i]) {
spit(actual, expected);
}
assert.strictEqual(actual[i], expected[i]);
}
};
suite('adding int32', function () {
var testAddingInt32 = function (int, expectedBuffer) {
test('writes ' + int, function () {
var subject = new Writer();
var result = subject.addInt32(int).join();
assert.equalBuffers(result, expectedBuffer);
});
};
testAddingInt32(0, [0, 0, 0, 0]);
testAddingInt32(1, [0, 0, 0, 1]);
testAddingInt32(256, [0, 0, 1, 0]);
test('writes largest int32', function () {
//todo need to find largest int32 when I have internet access
return false;
});
test('writing multiple int32s', function () {
var subject = new Writer();
var result = subject.addInt32(1).addInt32(10).addInt32(0).join();
assert.equalBuffers(result, [0, 0, 0, 1, 0, 0, 0, 0x0a, 0, 0, 0, 0]);
});
suite('having to resize the buffer', function () {
test('after resize correct result returned', function () {
var subject = new Writer(10);
subject.addInt32(1).addInt32(1).addInt32(1);
assert.equalBuffers(subject.join(), [0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1]);
});
});
});
suite('int16', function () {
test('writes 0', function () {
var subject = new Writer();
var result = subject.addInt16(0).join();
assert.equalBuffers(result, [0, 0]);
});
test('writes 400', function () {
var subject = new Writer();
var result = subject.addInt16(400).join();
assert.equalBuffers(result, [1, 0x90]);
});
test('writes many', function () {
var subject = new Writer();
var result = subject.addInt16(0).addInt16(1).addInt16(2).join();
assert.equalBuffers(result, [0, 0, 0, 1, 0, 2]);
});
test('resizes if internal buffer fills up', function () {
var subject = new Writer(3);
var result = subject.addInt16(2).addInt16(3).join();
assert.equalBuffers(result, [0, 2, 0, 3]);
});
});
suite('cString', function () {
test('writes empty cstring', function () {
var subject = new Writer();
var result = subject.addCString().join();
assert.equalBuffers(result, [0]);
});
test('writes two empty cstrings', function () {
var subject = new Writer();
var result = subject.addCString("").addCString("").join();
assert.equalBuffers(result, [0, 0]);
});
test('writes non-empty cstring', function () {
var subject = new Writer();
var result = subject.addCString("!!!").join();
assert.equalBuffers(result, [33, 33, 33, 0]);
});
test('resizes if reached end', function () {
var subject = new Writer(3);
var result = subject.addCString("!!!").join();
assert.equalBuffers(result, [33, 33, 33, 0]);
});
test('writes multiple cstrings', function () {
var subject = new Writer();
var result = subject.addCString("!").addCString("!").join();
assert.equalBuffers(result, [33, 0, 33, 0]);
});
});
test('writes char', function () {
var subject = new Writer(2);
var result = subject.addChar('a').addChar('b').addChar('c').join();
assert.equalBuffers(result, [0x61, 0x62, 0x63]);
});
test('gets correct byte length', function () {
var subject = new Writer(5);
assert.strictEqual(subject.getByteLength(), 0);
subject.addInt32(0);
assert.strictEqual(subject.getByteLength(), 4);
subject.addCString("!");
assert.strictEqual(subject.getByteLength(), 6);
});
test('can add arbitrary buffer to the end', function () {
var subject = new Writer(4);
subject.addCString("!!!")
var result = subject.add(Buffer.from("@@@")).join();
assert.equalBuffers(result, [33, 33, 33, 0, 0x40, 0x40, 0x40]);
});
suite('can write normal string', function () {
var subject = new Writer(4);
var result = subject.addString("!").join();
assert.equalBuffers(result, [33]);
test('can write cString too', function () {
var result = subject.addCString("!").join();
assert.equalBuffers(result, [33, 33, 0]);
});
test('can resize', function () {
var result = subject.addString("!!").join();
assert.equalBuffers(result, [33, 33, 0, 33, 33]);
});
});
suite('clearing', function () {
var subject = new Writer();
subject.addCString("@!!#!#");
subject.addInt32(10401);
test('clears', function () {
subject.clear();
assert.equalBuffers(subject.join(), []);
});
test('writing more', function () {
var joinedResult = subject.addCString("!").addInt32(9).addInt16(2).join();
assert.equalBuffers(joinedResult, [33, 0, 0, 0, 0, 9, 0, 2]);
});
test('returns result', function () {
var flushedResult = subject.flush();
assert.equalBuffers(flushedResult, [33, 0, 0, 0, 0, 9, 0, 2])
});
test('clears the writer', function () {
assert.equalBuffers(subject.join(), [])
assert.equalBuffers(subject.flush(), [])
});
});
test("resizing to much larger", function () {
var subject = new Writer(2);
var string = "!!!!!!!!";
var result = subject.addCString(string).flush();
assert.equalBuffers(result, [33, 33, 33, 33, 33, 33, 33, 33, 0]);
});
suite("flush", function () {
test('added as a hex code to a full writer', function () {
var subject = new Writer(2);
var result = subject.addCString("!").flush(0x50);
assert.equalBuffers(result, [0x50, 0, 0, 0, 6, 33, 0]);
});
test('added as a hex code to a non-full writer', function () {
var subject = new Writer(10).addCString("!");
var joinedResult = subject.join(0x50);
var result = subject.flush(0x50);
assert.equalBuffers(result, [0x50, 0, 0, 0, 6, 33, 0]);
});
test('added as a hex code to a buffer which requires resizing', function () {
var result = new Writer(2).addCString("!!!!!!!!").flush(0x50);
assert.equalBuffers(result, [0x50, 0, 0, 0, 0x0D, 33, 33, 33, 33, 33, 33, 33, 33, 0]);
});
});
suite("header", function () {
test('adding two packets with headers', function () {
var subject = new Writer(10).addCString("!");
subject.addHeader(0x50);
subject.addCString("!!");
subject.addHeader(0x40);
subject.addCString("!");
var result = subject.flush(0x10);
assert.equalBuffers(result, [0x50, 0, 0, 0, 6, 33, 0, 0x40, 0, 0, 0, 7, 33, 33, 0, 0x10, 0, 0, 0, 6, 33, 0]);
});
});
language: node_js
node_js: "10"
matrix:
include:
- node_js: "4"
- node_js: "6"
- node_js: "8"
node-packet-reader
==================