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mirror of https://github.com/gorhill/uBlock.git synced 2024-11-17 16:02:33 +01:00
uBlock/src/js/utils.js
Raymond Hill a9f68fe02f
Fix #3069, and consequently #3374, #3378.
A new filtering class has been created: "static extended filtering".
This new class is an umbrella class for more specialized filtering
engines:
- Cosmetic filtering
- Scriptlet filtering
- HTML filtering

HTML filtering is available only on platforms which support modifying
the response body on the fly, so only Firefox 57+ at the moment.

With the ability to modify the response body, HTML filtering has
been introduced: removing elements from the DOM before the source
data has been parsed by the browser.

A consequence of HTML filtering ability is to bring back script tag
filtering feature.
2017-12-28 13:49:02 -05:00

437 lines
13 KiB
JavaScript

/*******************************************************************************
uBlock Origin - a browser extension to block requests.
Copyright (C) 2014-2017 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 = {
setURL: function(url) {
if ( url !== this._urlIn ) {
this._urlIn = url;
this._urlOut = url.toLowerCase();
this._tokenized = false;
}
return this._urlOut;
},
// Tokenize on demand.
getTokens: function() {
if ( this._tokenized === false ) {
this._tokenize();
this._tokenized = true;
}
return this._tokens;
},
tokenHashFromString: function(s) {
var l = s.length;
if ( l === 0 ) { return 0; }
if ( l === 1 ) {
if ( s === '*' ) { return 63; }
if ( s === '.' ) { return 62; }
}
var vtc = this._validTokenChars,
th = vtc[s.charCodeAt(0)];
for ( var i = 1; i !== 8 && i !== l; i++ ) {
th = th * 64 + vtc[s.charCodeAt(i)];
}
return th;
},
// https://github.com/chrisaljoudi/uBlock/issues/1118
// We limit to a maximum number of tokens.
_tokenize: function() {
var tokens = this._tokens,
url = this._urlOut,
l = url.length;
if ( l === 0 ) { tokens[0] = 0; return; }
if ( l > 2048 ) {
url = url.slice(0, 2048);
l = 2048;
}
var i = 0, j = 0, v, n, ti, th,
vtc = this._validTokenChars;
for (;;) {
for (;;) {
if ( i === l ) { tokens[j] = 0; return; }
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 === 8 ) { continue; }
th = th * 64 + v;
n += 1;
}
tokens[j++] = th;
tokens[j++] = ti;
}
},
_urlIn: '',
_urlOut: '',
_tokenized: false,
_tokens: [ 0 ],
_validTokenChars: (function() {
var vtc = new Uint8Array(128),
chars = '0123456789%abcdefghijklmnopqrstuvwxyz',
i = chars.length;
while ( i-- ) {
vtc[chars.charCodeAt(i)] = i + 1;
}
return vtc;
})()
};
/******************************************************************************/
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.CompiledLineWriter = function() {
this.blockId = undefined;
this.block = undefined;
this.blocks = new Map();
this.stringifier = JSON.stringify;
};
µBlock.CompiledLineWriter.fingerprint = function(args) {
return JSON.stringify(args);
};
µBlock.CompiledLineWriter.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() {
var result = [];
for ( var entry of this.blocks ) {
if ( entry[1].length === 0 ) { continue; }
result.push(
'#block-start-' + entry[0],
entry[1].join('\n'),
'#block-end-' + entry[0]
);
}
return result.join('\n');
}
};
/******************************************************************************/
µBlock.CompiledLineReader = function(raw, blockId) {
this.block = '';
this.len = 0;
this.offset = 0;
this.line = '';
this.parser = JSON.parse;
this.blocks = new Map();
var reBlockStart = /^#block-start-(\d+)\n/gm,
match = reBlockStart.exec(raw),
beg, end;
while ( match !== null ) {
beg = match.index + match[0].length;
end = raw.indexOf('#block-end-' + 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.CompiledLineReader.prototype = {
next: function() {
if ( this.offset === this.len ) {
this.line = '';
return false;
}
var 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.
// https://github.com/gorhill/uBlock/issues/2656
// Can't use chained calls if we want to support legacy Map().
µBlock.stringDeduplicater = {
strings: new Map(),
timer: undefined,
last: 0,
lookup: function(s) {
var t = this.strings.get(s);
if ( t === undefined ) {
this.strings.set(s, s);
t = this.strings.get(s);
if ( this.timer === undefined ) { this.cleanupAsync(); }
}
this.last = Date.now();
return t;
},
cleanupAsync: function() {
this.timer = vAPI.setTimeout(this.cleanup.bind(this), 10000);
},
cleanup: function() {
if ( (Date.now() - this.last) < 10000 ) {
this.timer = vAPI.setTimeout(this.cleanup.bind(this), 10000);
} else {
this.timer = undefined;
this.strings.clear();
}
}
};
/******************************************************************************/
µBlock.arrayFrom = typeof Array.from === 'function'
? Array.from
: function(iterable) {
var out = [], i = 0;
for ( var value of iterable ) {
out[i++] = value;
}
return out;
};
/******************************************************************************/
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;
}
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, '\\$&');
};
/******************************************************************************/