uBlock/src/js/html-filtering.js

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/*******************************************************************************
uBlock Origin - a browser extension to block requests.
Copyright (C) 2017-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';
/******************************************************************************/
µBlock.htmlFilteringEngine = (function() {
const µb = µBlock;
const pselectors = new Map();
const duplicates = new Set();
let filterDB = new µb.staticExtFilteringEngine.HostnameBasedDB(2),
acceptedCount = 0,
discardedCount = 0,
docRegister;
const api = {
get acceptedCount() {
return acceptedCount;
},
get discardedCount() {
return discardedCount;
}
};
const PSelectorHasTextTask = class {
constructor(task) {
let arg0 = task[1], arg1;
if ( Array.isArray(task[1]) ) {
arg1 = arg0[1]; arg0 = arg0[0];
}
this.needle = new RegExp(arg0, arg1);
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}
exec(input) {
const output = [];
for ( const node of input ) {
if ( this.needle.test(node.textContent) ) {
output.push(node);
}
}
return output;
}
};
const PSelectorIfTask = class {
constructor(task) {
this.pselector = new PSelector(task[1]);
}
exec(input) {
const output = [];
for ( const node of input ) {
if ( this.pselector.test(node) === this.target ) {
output.push(node);
}
}
return output;
}
get invalid() {
return this.pselector.invalid;
}
};
PSelectorIfTask.prototype.target = true;
const PSelectorIfNotTask = class extends PSelectorIfTask {
constructor(task) {
super(task);
this.target = false;
}
};
const PSelectorMinTextLengthTask = class {
constructor(task) {
this.min = task[1];
}
exec(input) {
const output = [];
for ( const node of input ) {
if ( node.textContent.length >= this.min ) {
output.push(node);
}
}
return output;
}
};
const PSelectorNthAncestorTask = class {
constructor(task) {
this.nth = task[1];
}
exec(input) {
const output = [];
for ( let node of input ) {
let nth = this.nth;
for (;;) {
node = node.parentElement;
if ( node === null ) { break; }
nth -= 1;
if ( nth !== 0 ) { continue; }
output.push(node);
break;
}
}
return output;
}
};
const PSelectorXpathTask = class {
constructor(task) {
this.xpe = task[1];
}
exec(input) {
const output = [];
const xpe = docRegister.createExpression(this.xpe, null);
let xpr = null;
for ( const node of input ) {
xpr = xpe.evaluate(
node,
XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
xpr
);
let j = xpr.snapshotLength;
while ( j-- ) {
const node = xpr.snapshotItem(j);
if ( node.nodeType === 1 ) {
output.push(node);
}
}
}
return output;
}
};
const PSelector = class {
constructor(o) {
this.raw = o.raw;
this.selector = o.selector;
this.tasks = [];
if ( !o.tasks ) { return; }
for ( const task of o.tasks ) {
const ctor = this.operatorToTaskMap.get(task[0]);
if ( ctor === undefined ) {
this.invalid = true;
break;
}
const pselector = new ctor(task);
if ( pselector instanceof PSelectorIfTask && pselector.invalid ) {
this.invalid = true;
break;
}
this.tasks.push(pselector);
}
}
prime(input) {
const root = input || docRegister;
if ( this.selector !== '' ) {
return root.querySelectorAll(this.selector);
}
return [ root ];
}
exec(input) {
if ( this.invalid ) { return []; }
let nodes = this.prime(input);
for ( const task of this.tasks ) {
if ( nodes.length === 0 ) { break; }
nodes = task.exec(nodes);
}
return nodes;
}
test(input) {
if ( this.invalid ) { return false; }
const nodes = this.prime(input);
const AA = [ null ];
for ( const node of nodes ) {
AA[0] = node;
let aa = AA;
for ( const task of this.tasks ) {
aa = task.exec(aa);
if ( aa.length === 0 ) { break; }
}
if ( aa.length !== 0 ) { return true; }
}
return false;
}
};
PSelector.prototype.operatorToTaskMap = new Map([
[ ':has', PSelectorIfTask ],
[ ':has-text', PSelectorHasTextTask ],
[ ':if', PSelectorIfTask ],
[ ':if-not', PSelectorIfNotTask ],
[ ':min-text-length', PSelectorMinTextLengthTask ],
[ ':not', PSelectorIfNotTask ],
[ ':nth-ancestor', PSelectorNthAncestorTask ],
[ ':xpath', PSelectorXpathTask ]
]);
PSelector.prototype.invalid = false;
const logOne = function(details, exception, selector) {
µBlock.filteringContext
.duplicate()
.fromTabId(details.tabId)
.setRealm('cosmetic')
.setType('dom')
.setURL(details.url)
.setDocOriginFromURL(details.url)
.setFilter({
source: 'cosmetic',
raw: `${exception === 0 ? '##' : '#@#'}^${selector}`
})
.toLogger();
};
const applyProceduralSelector = function(details, selector) {
let pselector = pselectors.get(selector);
if ( pselector === undefined ) {
pselector = new PSelector(JSON.parse(selector));
pselectors.set(selector, pselector);
}
const nodes = pselector.exec();
let i = nodes.length,
modified = false;
while ( i-- ) {
const node = nodes[i];
if ( node.parentNode !== null ) {
node.parentNode.removeChild(node);
modified = true;
}
}
if ( modified && µb.logger.enabled ) {
logOne(details, 0, pselector.raw);
}
return modified;
};
const applyCSSSelector = function(details, selector) {
const nodes = docRegister.querySelectorAll(selector);
let i = nodes.length,
modified = false;
while ( i-- ) {
const node = nodes[i];
if ( node.parentNode !== null ) {
node.parentNode.removeChild(node);
modified = true;
}
}
if ( modified && µb.logger.enabled ) {
logOne(details, 0, selector);
}
return modified;
};
api.reset = function() {
filterDB.clear();
pselectors.clear();
duplicates.clear();
acceptedCount = 0;
discardedCount = 0;
};
api.freeze = function() {
duplicates.clear();
filterDB.collectGarbage();
};
api.compile = function(parsed, writer) {
const selector = parsed.suffix.slice(1).trim();
const compiled = µb.staticExtFilteringEngine.compileSelector(selector);
if ( compiled === undefined ) {
const who = writer.properties.get('assetKey') || '?';
µb.logger.writeOne({
realm: 'message',
type: 'error',
text: `Invalid HTML filter in ${who}: ##${selector}`
});
return;
}
// 1002 = html filtering
writer.select(1002);
// TODO: Mind negated hostnames, they are currently discarded.
for ( const hn of parsed.hostnames ) {
if ( hn.charCodeAt(0) === 0x7E /* '~' */ ) { continue; }
let kind = 0;
if ( parsed.exception ) {
kind |= 0b01;
}
if ( compiled.charCodeAt(0) === 0x7B /* '{' */ ) {
kind |= 0b10;
}
writer.push([ 64, hn, kind, compiled ]);
}
};
api.fromCompiledContent = function(reader) {
// Don't bother loading filters if stream filtering is not supported.
if ( µb.canFilterResponseData === false ) { return; }
// 1002 = html filtering
reader.select(1002);
while ( reader.next() ) {
acceptedCount += 1;
const fingerprint = reader.fingerprint();
if ( duplicates.has(fingerprint) ) {
discardedCount += 1;
continue;
}
duplicates.add(fingerprint);
const args = reader.args();
filterDB.store(args[1], args[2], args[3]);
}
};
api.retrieve = function(details) {
const hostname = details.hostname;
// https://github.com/gorhill/uBlock/issues/2835
// Do not filter if the site is under an `allow` rule.
if (
µb.userSettings.advancedUserEnabled &&
µb.sessionFirewall.evaluateCellZY(hostname, hostname, '*') === 2
) {
return;
}
const plains = new Set();
const procedurals = new Set();
const exceptions = new Set();
filterDB.retrieve(
hostname,
[ plains, exceptions, procedurals, exceptions ]
);
if ( details.entity !== '' ) {
filterDB.retrieve(
`${hostname.slice(0, -details.domain)}${details.entity}`,
[ plains, exceptions, procedurals, exceptions ]
);
}
if ( plains.size === 0 && procedurals.size === 0 ) { return; }
const out = { plains, procedurals };
if ( exceptions.size === 0 ) {
return out;
}
for ( const selector of exceptions ) {
if ( plains.has(selector) ) {
plains.delete(selector);
logOne(details, 1, selector);
continue;
}
if ( procedurals.has(selector) ) {
procedurals.delete(selector);
logOne(details, 1, JSON.parse(selector).raw);
continue;
}
}
if ( plains.size !== 0 || procedurals.size !== 0 ) {
return out;
}
};
api.apply = function(doc, details) {
docRegister = doc;
let modified = false;
for ( const selector of details.selectors.plains ) {
if ( applyCSSSelector(details, selector) ) {
modified = true;
}
}
for ( const selector of details.selectors.procedurals ) {
if ( applyProceduralSelector(details, selector) ) {
modified = true;
}
}
docRegister = undefined;
return modified;
};
api.toSelfie = function() {
return filterDB.toSelfie();
};
api.fromSelfie = function(selfie) {
filterDB = new µb.staticExtFilteringEngine.HostnameBasedDB(2, selfie);
pselectors.clear();
};
return api;
})();
/******************************************************************************/