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uBlock/src/js/utils.js

737 lines
24 KiB
JavaScript

/*******************************************************************************
uBlock Origin - a browser extension to block requests.
Copyright (C) 2014-present Raymond Hill
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see {http://www.gnu.org/licenses/}.
Home: https://github.com/gorhill/uBlock
*/
'use strict';
/******************************************************************************/
// A standalone URL tokenizer will allow us to use URL tokens in more than
// just static filtering engine. This opens the door to optimize other
// filtering engine parts aside static filtering. This also allows:
// - Tokenize only on demand.
// - To potentially avoid tokenizing when same URL is fed to tokenizer.
// - Benchmarking shows this to be a common occurrence.
//
// https://github.com/gorhill/uBlock/issues/2630
// Slice input URL into a list of safe-integer token values, instead of a list
// of substrings. The assumption is that with dealing only with numeric
// values, less underlying memory allocations, and also as a consequence
// less work for the garbage collector down the road.
// Another assumption is that using a numeric-based key value for Map() is
// more efficient than string-based key value (but that is something I would
// have to benchmark).
// Benchmark for string-based tokens vs. safe-integer token values:
// https://gorhill.github.io/obj-vs-set-vs-map/tokenize-to-str-vs-to-int.html
µBlock.urlTokenizer = new (class {
constructor() {
this._chars = '0123456789%abcdefghijklmnopqrstuvwxyz';
this._validTokenChars = new Uint8Array(128);
for ( let i = 0, n = this._chars.length; i < n; i++ ) {
this._validTokenChars[this._chars.charCodeAt(i)] = i + 1;
}
// Four upper bits of token hash are reserved for built-in predefined
// token hashes, which should never end up being used when tokenizing
// any arbitrary string.
this.dotTokenHash = 0x10000000;
this.anyTokenHash = 0x20000000;
this.anyHTTPSTokenHash = 0x30000000;
this.anyHTTPTokenHash = 0x40000000;
this.noTokenHash = 0x50000000;
this.emptyTokenHash = 0xF0000000;
this._urlIn = '';
this._urlOut = '';
this._tokenized = false;
this._tokens = [ 0 ];
this.knownTokens = new Uint8Array(65536);
this.resetKnownTokens();
}
setURL(url) {
if ( url !== this._urlIn ) {
this._urlIn = url;
this._urlOut = url.toLowerCase();
this._tokenized = false;
}
return this._urlOut;
}
resetKnownTokens() {
this.knownTokens.fill(0);
this.addKnownToken(this.dotTokenHash);
this.addKnownToken(this.anyTokenHash);
this.addKnownToken(this.anyHTTPSTokenHash);
this.addKnownToken(this.anyHTTPTokenHash);
this.addKnownToken(this.noTokenHash);
}
addKnownToken(th) {
this.knownTokens[th & 0xFFFF ^ th >>> 16] = 1;
}
// Tokenize on demand.
getTokens() {
if ( this._tokenized ) { return this._tokens; }
let i = this._tokenize();
i = this._appendTokenAt(i, this.anyTokenHash, 0);
if ( this._urlOut.startsWith('https://') ) {
i = this._appendTokenAt(i, this.anyHTTPSTokenHash, 0);
} else if ( this._urlOut.startsWith('http://') ) {
i = this._appendTokenAt(i, this.anyHTTPTokenHash, 0);
}
i = this._appendTokenAt(i, this.noTokenHash, 0);
this._tokens[i] = 0;
this._tokenized = true;
return this._tokens;
}
tokenHashFromString(s) {
const l = s.length;
if ( l === 0 ) { return this.emptyTokenHash; }
const vtc = this._validTokenChars;
let th = vtc[s.charCodeAt(0)];
for ( let i = 1; i !== 7 && i !== l; i++ ) {
th = th << 4 ^ vtc[s.charCodeAt(i)];
}
return th;
}
stringFromTokenHash(th) {
if ( th === 0 ) { return ''; }
return th.toString(16);
}
toSelfie() {
return µBlock.base64.encode(
this.knownTokens.buffer,
this.knownTokens.byteLength
);
}
fromSelfie(selfie) {
return µBlock.base64.decode(selfie, this.knownTokens.buffer);
}
// https://github.com/chrisaljoudi/uBlock/issues/1118
// We limit to a maximum number of tokens.
_appendTokenAt(i, th, ti) {
this._tokens[i+0] = th;
this._tokens[i+1] = ti;
return i + 2;
}
_tokenize() {
const tokens = this._tokens;
let url = this._urlOut;
let l = url.length;
if ( l === 0 ) { return this.emptyTokenHash; }
if ( l > 2048 ) {
url = url.slice(0, 2048);
l = 2048;
}
const knownTokens = this.knownTokens;
const vtc = this._validTokenChars;
let i = 0, j = 0, v, n, ti, th;
for (;;) {
for (;;) {
if ( i === l ) { return j; }
v = vtc[url.charCodeAt(i++)];
if ( v !== 0 ) { break; }
}
th = v; ti = i - 1; n = 1;
for (;;) {
if ( i === l ) { break; }
v = vtc[url.charCodeAt(i++)];
if ( v === 0 ) { break; }
if ( n === 7 ) { continue; }
th = th << 4 ^ v;
n += 1;
}
if ( knownTokens[th & 0xFFFF ^ th >>> 16] !== 0 ) {
tokens[j+0] = th;
tokens[j+1] = ti;
j += 2;
}
}
}
})();
/******************************************************************************/
µBlock.formatCount = function(count) {
if ( typeof count !== 'number' ) {
return '';
}
var s = count.toFixed(0);
if ( count >= 1000 ) {
if ( count < 10000 ) {
s = '>' + s.slice(0,1) + 'k';
} else if ( count < 100000 ) {
s = s.slice(0,2) + 'k';
} else if ( count < 1000000 ) {
s = s.slice(0,3) + 'k';
} else if ( count < 10000000 ) {
s = s.slice(0,1) + 'M';
} else {
s = s.slice(0,-6) + 'M';
}
}
return s;
};
// https://www.youtube.com/watch?v=DyvzfyqYm_s
/******************************************************************************/
µBlock.dateNowToSensibleString = function() {
var now = new Date(Date.now() - (new Date()).getTimezoneOffset() * 60000);
return now.toISOString().replace(/\.\d+Z$/, '')
.replace(/:/g, '.')
.replace('T', '_');
};
/******************************************************************************/
µBlock.LineIterator = function(text, offset) {
this.text = text;
this.textLen = this.text.length;
this.offset = offset || 0;
};
µBlock.LineIterator.prototype.next = function(offset) {
if ( offset !== undefined ) {
this.offset += offset;
}
var lineEnd = this.text.indexOf('\n', this.offset);
if ( lineEnd === -1 ) {
lineEnd = this.text.indexOf('\r', this.offset);
if ( lineEnd === -1 ) {
lineEnd = this.textLen;
}
}
var line = this.text.slice(this.offset, lineEnd);
this.offset = lineEnd + 1;
return line;
};
µBlock.LineIterator.prototype.charCodeAt = function(offset) {
return this.text.charCodeAt(this.offset + offset);
};
µBlock.LineIterator.prototype.eot = function() {
return this.offset >= this.textLen;
};
/******************************************************************************/
// The field iterator is less CPU-intensive than when using native
// String.split().
µBlock.FieldIterator = function(sep) {
this.text = '';
this.sep = sep;
this.sepLen = sep.length;
this.offset = 0;
};
µBlock.FieldIterator.prototype.first = function(text) {
this.text = text;
this.offset = 0;
return this.next();
};
µBlock.FieldIterator.prototype.next = function() {
var end = this.text.indexOf(this.sep, this.offset);
if ( end === -1 ) {
end = this.text.length;
}
var field = this.text.slice(this.offset, end);
this.offset = end + this.sepLen;
return field;
};
µBlock.FieldIterator.prototype.remainder = function() {
return this.text.slice(this.offset);
};
/******************************************************************************/
µBlock.CompiledLineIO = {
serialize: JSON.stringify,
unserialize: JSON.parse,
blockStartPrefix: '#block-start-', // ensure no special regex characters
blockEndPrefix: '#block-end-', // ensure no special regex characters
Writer: function() {
this.io = µBlock.CompiledLineIO;
this.blockId = undefined;
this.block = undefined;
this.stringifier = this.io.serialize;
this.blocks = new Map();
this.properties = new Map();
},
Reader: function(raw, blockId) {
this.io = µBlock.CompiledLineIO;
this.block = '';
this.len = 0;
this.offset = 0;
this.line = '';
this.parser = this.io.unserialize;
this.blocks = new Map();
this.properties = new Map();
let reBlockStart = new RegExp(
'^' + this.io.blockStartPrefix + '(\\d+)\\n',
'gm'
);
let match = reBlockStart.exec(raw);
while ( match !== null ) {
let beg = match.index + match[0].length;
let end = raw.indexOf(this.io.blockEndPrefix + match[1], beg);
this.blocks.set(parseInt(match[1], 10), raw.slice(beg, end));
reBlockStart.lastIndex = end;
match = reBlockStart.exec(raw);
}
if ( blockId !== undefined ) {
this.select(blockId);
}
}
};
µBlock.CompiledLineIO.Writer.prototype = {
push: function(args) {
this.block[this.block.length] = this.stringifier(args);
},
select: function(blockId) {
if ( blockId === this.blockId ) { return; }
this.blockId = blockId;
this.block = this.blocks.get(blockId);
if ( this.block === undefined ) {
this.blocks.set(blockId, (this.block = []));
}
},
toString: function() {
let result = [];
for ( let [ id, lines ] of this.blocks ) {
if ( lines.length === 0 ) { continue; }
result.push(
this.io.blockStartPrefix + id,
lines.join('\n'),
this.io.blockEndPrefix + id
);
}
return result.join('\n');
}
};
µBlock.CompiledLineIO.Reader.prototype = {
next: function() {
if ( this.offset === this.len ) {
this.line = '';
return false;
}
let pos = this.block.indexOf('\n', this.offset);
if ( pos !== -1 ) {
this.line = this.block.slice(this.offset, pos);
this.offset = pos + 1;
} else {
this.line = this.block.slice(this.offset);
this.offset = this.len;
}
return true;
},
select: function(blockId) {
this.block = this.blocks.get(blockId) || '';
this.len = this.block.length;
this.offset = 0;
return this;
},
fingerprint: function() {
return this.line;
},
args: function() {
return this.parser(this.line);
}
};
/******************************************************************************/
// I want this helper to be self-maintained, callers must not worry about
// this helper cleaning after itself by asking them to reset it when it is no
// longer needed. A timer will be used for self-garbage-collect.
// Cleaning up 10s after last hit sounds reasonable.
µBlock.stringDeduplicater = {
strings: new Map(),
timer: undefined,
last: 0,
lookup: function(s) {
let t = this.strings.get(s);
if ( t === undefined ) {
t = this.strings.set(s, s).get(s);
if ( this.timer === undefined ) {
this.timer = vAPI.setTimeout(() => { this.cleanup(); }, 10000);
}
}
this.last = Date.now();
return t;
},
cleanup: function() {
if ( (Date.now() - this.last) < 10000 ) {
this.timer = vAPI.setTimeout(() => { this.cleanup(); }, 10000);
} else {
this.timer = undefined;
this.strings.clear();
}
}
};
/******************************************************************************/
µBlock.openNewTab = function(details) {
if ( details.url.startsWith('logger-ui.html') ) {
if ( details.shiftKey ) {
this.changeUserSettings(
'alwaysDetachLogger',
!this.userSettings.alwaysDetachLogger
);
}
details.popup = this.userSettings.alwaysDetachLogger;
if ( details.popup ) {
const url = new URL(vAPI.getURL(details.url));
url.searchParams.set('popup', '1');
details.url = url.href;
let popupLoggerBox;
try {
popupLoggerBox = JSON.parse(
vAPI.localStorage.getItem('popupLoggerBox')
);
} catch(ex) {
}
if ( popupLoggerBox !== undefined ) {
details.box = popupLoggerBox;
}
}
}
vAPI.tabs.open(details);
};
/******************************************************************************/
µBlock.MRUCache = function(size) {
this.size = size;
this.array = [];
this.map = new Map();
this.resetTime = Date.now();
};
µBlock.MRUCache.prototype = {
add: function(key, value) {
var found = this.map.has(key);
this.map.set(key, value);
if ( !found ) {
if ( this.array.length === this.size ) {
this.map.delete(this.array.pop());
}
this.array.unshift(key);
}
},
remove: function(key) {
if ( this.map.has(key) ) {
this.array.splice(this.array.indexOf(key), 1);
}
},
lookup: function(key) {
var value = this.map.get(key);
if ( value !== undefined && this.array[0] !== key ) {
var i = this.array.indexOf(key);
do {
this.array[i] = this.array[i-1];
} while ( --i );
this.array[0] = key;
}
return value;
},
reset: function() {
this.array = [];
this.map.clear();
this.resetTime = Date.now();
}
};
/******************************************************************************/
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
µBlock.escapeRegex = function(s) {
return s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
};
/******************************************************************************/
µBlock.decomposeHostname = (function() {
// For performance purpose, as simple tests as possible
let reHostnameVeryCoarse = /[g-z_-]/;
let reIPv4VeryCoarse = /\.\d+$/;
let toBroaderHostname = function(hostname) {
let pos = hostname.indexOf('.');
if ( pos !== -1 ) {
return hostname.slice(pos + 1);
}
return hostname !== '*' && hostname !== '' ? '*' : '';
};
let toBroaderIPv4Address = function(ipaddress) {
if ( ipaddress === '*' || ipaddress === '' ) { return ''; }
let pos = ipaddress.lastIndexOf('.');
if ( pos === -1 ) { return '*'; }
return ipaddress.slice(0, pos);
};
let toBroaderIPv6Address = function(ipaddress) {
return ipaddress !== '*' && ipaddress !== '' ? '*' : '';
};
return function decomposeHostname(hostname, decomposed) {
if ( decomposed.length === 0 || decomposed[0] !== hostname ) {
let broaden;
if ( reHostnameVeryCoarse.test(hostname) === false ) {
if ( reIPv4VeryCoarse.test(hostname) ) {
broaden = toBroaderIPv4Address;
} else if ( hostname.startsWith('[') ) {
broaden = toBroaderIPv6Address;
}
}
if ( broaden === undefined ) {
broaden = toBroaderHostname;
}
decomposed[0] = hostname;
let i = 1;
for (;;) {
hostname = broaden(hostname);
if ( hostname === '' ) { break; }
decomposed[i++] = hostname;
}
decomposed.length = i;
}
return decomposed;
};
})();
/******************************************************************************/
// TODO: evaluate using TextEncoder/TextDecoder
µBlock.orphanizeString = function(s) {
return JSON.parse(JSON.stringify(s));
};
/******************************************************************************/
// Custom base64 encoder/decoder
//
// TODO:
// Could expand the LZ4 codec API to be able to return UTF8-safe string
// representation of a compressed buffer, and thus the code below could be
// moved LZ4 codec-side.
// https://github.com/uBlockOrigin/uBlock-issues/issues/461
// Provide a fallback encoding for Chromium 59 and less by issuing a plain
// JSON string. The fallback can be removed once min supported version is
// above 59.
µBlock.base64 = new (class {
constructor() {
this.valToDigit = new Uint8Array(64);
this.digitToVal = new Uint8Array(128);
const chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz@%";
for ( let i = 0, n = chars.length; i < n; i++ ) {
const c = chars.charCodeAt(i);
this.valToDigit[i] = c;
this.digitToVal[c] = i;
}
this.magic = 'Base64_1';
}
encode(arrbuf, arrlen) {
const inputLength = arrlen >>> 2;
const inbuf = new Uint32Array(arrbuf, 0, inputLength);
const outputLength = this.magic.length + 7 + inputLength * 7;
const outbuf = new Uint8Array(outputLength);
let j = 0;
for ( let i = 0; i < this.magic.length; i++ ) {
outbuf[j++] = this.magic.charCodeAt(i);
}
let v = inputLength;
do {
outbuf[j++] = this.valToDigit[v & 0b111111];
v >>>= 6;
} while ( v !== 0 );
outbuf[j++] = 0x20 /* ' ' */;
for ( let i = 0; i < inputLength; i++ ) {
v = inbuf[i];
do {
outbuf[j++] = this.valToDigit[v & 0b111111];
v >>>= 6;
} while ( v !== 0 );
outbuf[j++] = 0x20 /* ' ' */;
}
if ( typeof TextDecoder === 'undefined' ) {
return JSON.stringify(
Array.from(new Uint32Array(outbuf.buffer, 0, j >>> 2))
);
}
const textDecoder = new TextDecoder();
return textDecoder.decode(new Uint8Array(outbuf.buffer, 0, j));
}
decode(instr, arrbuf) {
if ( instr.charCodeAt(0) === 0x5B /* '[' */ ) {
const inbuf = JSON.parse(instr);
if ( arrbuf instanceof ArrayBuffer === false ) {
return new Uint32Array(inbuf);
}
const outbuf = new Uint32Array(arrbuf);
outbuf.set(inbuf);
return outbuf;
}
if ( instr.startsWith(this.magic) === false ) {
throw new Error('Invalid µBlock.base64 encoding');
}
const inputLength = instr.length;
const outbuf = arrbuf instanceof ArrayBuffer === false
? new Uint32Array(this.decodeSize(instr))
: new Uint32Array(arrbuf);
let i = instr.indexOf(' ', this.magic.length) + 1;
if ( i === -1 ) {
throw new Error('Invalid µBlock.base64 encoding');
}
let j = 0;
for (;;) {
if ( i === inputLength ) { break; }
let v = 0, l = 0;
for (;;) {
const c = instr.charCodeAt(i++);
if ( c === 0x20 /* ' ' */ ) { break; }
v += this.digitToVal[c] << l;
l += 6;
}
outbuf[j++] = v;
}
return outbuf;
}
decodeSize(instr) {
if ( instr.startsWith(this.magic) === false ) { return 0; }
let v = 0, l = 0, i = this.magic.length;
for (;;) {
const c = instr.charCodeAt(i++);
if ( c === 0x20 /* ' ' */ ) { break; }
v += this.digitToVal[c] << l;
l += 6;
}
return v << 2;
}
})();
/******************************************************************************/
// The requests.json.gz file can be downloaded from:
// https://cdn.cliqz.com/adblocking/requests_top500.json.gz
//
// Which is linked from:
// https://whotracks.me/blog/adblockers_performance_study.html
//
// Copy the file into ./tmp/requests.json.gz
//
// If the file is present when you build uBO using `make-[target].sh` from
// the shell, the resulting package will have `./assets/requests.json`, which
// will be looked-up by the method below to launch a benchmark session.
//
// From uBO's dev console, launch the benchmark:
// µBlock.staticNetFilteringEngine.benchmark();
//
// The advanced setting `consoleLogLevel` must be set to `info` to see the
// results in uBO's dev console, see:
// https://github.com/gorhill/uBlock/wiki/Advanced-settings#consoleloglevel
//
// The usual browser dev tools can be used to obtain useful profiling
// data, i.e. start the profiler, call the benchmark method from the
// console, then stop the profiler when it completes.
//
// Keep in mind that the measurements at the blog post above where obtained
// with ONLY EasyList. The CPU reportedly used was:
// https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-6600U+%40+2.60GHz&id=2608
//
// Rename ./tmp/requests.json.gz to something else if you no longer want
// ./assets/requests.json in the build.
µBlock.loadBenchmarkDataset = (function() {
let datasetPromise;
let ttlTimer;
return function() {
if ( ttlTimer !== undefined ) {
clearTimeout(ttlTimer);
ttlTimer = undefined;
}
vAPI.setTimeout(( ) => {
ttlTimer = undefined;
datasetPromise = undefined;
}, 60000);
if ( datasetPromise !== undefined ) {
return datasetPromise;
}
console.info(`Loading benchmark dataset...`);
const url = vAPI.getURL('/assets/requests.json');
datasetPromise = µBlock.assets.fetchText(url).then(details => {
console.info(`Parsing benchmark dataset...`);
const requests = [];
const lineIter = new µBlock.LineIterator(details.content);
while ( lineIter.eot() === false ) {
let request;
try {
request = JSON.parse(lineIter.next());
} catch(ex) {
}
if ( request instanceof Object === false ) { continue; }
if ( !request.frameUrl || !request.url ) { continue; }
requests.push(request);
}
return requests;
}).catch(details => {
console.info(`Not found: ${details.url}`);
datasetPromise = undefined;
});
return datasetPromise;
};
})();