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Replace exec with transpose in procedural filters
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The purpose is to avoid having to iterate through
all input nodes at each operator implementation
level. The `transpose` method deals with only one
input node, and the iteration is performed by the
main procedural filtering entry points.

Additionally:
- Add `:spath` to HTML filtering
- Rename `:watch-attrs` to `:watch-attr`
  - `:watch=attrs` is deprecated and will be kept around
    until it is safe to remove it completely
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@gorhill
gorhill committed Jun 23, 2019
1 parent 4956a16 commit 41685f4
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Showing 3 changed files with 140 additions and 169 deletions.
172 changes: 68 additions & 104 deletions src/js/contentscript.js
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Original file line number Diff line number Diff line change
Expand Up @@ -469,39 +469,28 @@ vAPI.DOMFilterer = (function() {
}
this.needle = new RegExp(arg0, arg1);
}
exec(input) {
const output = [];
for ( const node of input ) {
if ( this.needle.test(node.textContent) ) {
output.push(node);
}
transpose(node, output) {
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);
}
transpose(node, output) {
if ( this.pselector.test(node) === this.target ) {
output.push(node);
}
return output;
}
};
PSelectorIfTask.prototype.target = true;

const PSelectorIfNotTask = class extends PSelectorIfTask {
constructor(task) {
super(task);
this.target = false;
}
};
PSelectorIfNotTask.prototype.target = false;

const PSelectorMatchesCSSTask = class {
constructor(task) {
Expand All @@ -512,93 +501,69 @@ vAPI.DOMFilterer = (function() {
}
this.value = new RegExp(arg0, arg1);
}
exec(input) {
const output = [];
for ( const node of input ) {
const style = window.getComputedStyle(node, this.pseudo);
if ( style === null ) { return null; } /* FF */
if ( this.value.test(style[this.name]) ) {
output.push(node);
}
transpose(node, output) {
const style = window.getComputedStyle(node, this.pseudo);
if ( style !== null && this.value.test(style[this.name]) ) {
output.push(node);
}
return output;
}
};
PSelectorMatchesCSSTask.prototype.pseudo = null;

const PSelectorMatchesCSSAfterTask = class extends PSelectorMatchesCSSTask {
constructor(task) {
super(task);
this.pseudo = ':after';
}
};
PSelectorMatchesCSSAfterTask.prototype.pseudo = ':after';

const PSelectorMatchesCSSBeforeTask = class extends PSelectorMatchesCSSTask {
constructor(task) {
super(task);
this.pseudo = ':before';
}
};
PSelectorMatchesCSSBeforeTask.prototype.pseudo = ':before';

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);
}
transpose(node, output) {
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;
}
transpose(node, output) {
let nth = this.nth;
for (;;) {
node = node.parentElement;
if ( node === null ) { return; }
nth -= 1;
if ( nth === 0 ) { break; }
}
return output;
output.push(node);
}
};

const PSelectorSpathTask = class {
constructor(task) {
this.spath = task[1];
}
exec(input) {
const output = [];
for ( let node of input ) {
const parent = node.parentElement;
if ( parent === null ) { continue; }
let pos = 1;
for (;;) {
node = node.previousElementSibling;
if ( node === null ) { break; }
pos += 1;
}
const nodes = parent.querySelectorAll(
':scope > :nth-child(' + pos + ')' + this.spath
);
for ( const node of nodes ) {
output.push(node);
}
transpose(node, output) {
const parent = node.parentElement;
if ( parent === null ) { return; }
let pos = 1;
for (;;) {
node = node.previousElementSibling;
if ( node === null ) { break; }
pos += 1;
}
const nodes = parent.querySelectorAll(
`:scope > :nth-child(${pos})${this.spath}`
);
for ( const node of nodes ) {
output.push(node);
}
return output;
}
};

Expand All @@ -623,17 +588,14 @@ vAPI.DOMFilterer = (function() {
filterer.onDOMChanged([ null ]);
}
}
exec(input) {
if ( input.length === 0 ) { return input; }
transpose(node, output) {
output.push(node);
if ( this.observed.has(node) ) { return; }
if ( this.observer === null ) {
this.observer = new MutationObserver(this.handler);
}
for ( const node of input ) {
if ( this.observed.has(node) ) { continue; }
this.observer.observe(node, this.observerOptions);
this.observed.add(node);
}
return input;
this.observer.observe(node, this.observerOptions);
this.observed.add(node);
}
};

Expand All @@ -642,23 +604,19 @@ vAPI.DOMFilterer = (function() {
this.xpe = document.createExpression(task[1], null);
this.xpr = null;
}
exec(input) {
const output = [];
for ( const node of input ) {
this.xpr = this.xpe.evaluate(
node,
XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
this.xpr
);
let j = this.xpr.snapshotLength;
while ( j-- ) {
const node = this.xpr.snapshotItem(j);
if ( node.nodeType === 1 ) {
output.push(node);
}
transpose(node, output) {
this.xpr = this.xpe.evaluate(
node,
XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
this.xpr
);
let j = this.xpr.snapshotLength;
while ( j-- ) {
const node = this.xpr.snapshotItem(j);
if ( node.nodeType === 1 ) {
output.push(node);
}
}
return output;
}
};

Expand All @@ -677,7 +635,7 @@ vAPI.DOMFilterer = (function() {
[ ':not', PSelectorIfNotTask ],
[ ':nth-ancestor', PSelectorNthAncestorTask ],
[ ':spath', PSelectorSpathTask ],
[ ':watch-attrs', PSelectorWatchAttrs ],
[ ':watch-attr', PSelectorWatchAttrs ],
[ ':xpath', PSelectorXpathTask ],
]);
}
Expand All @@ -704,21 +662,27 @@ vAPI.DOMFilterer = (function() {
let nodes = this.prime(input);
for ( const task of this.tasks ) {
if ( nodes.length === 0 ) { break; }
nodes = task.exec(nodes);
const transposed = [];
for ( const node of nodes ) {
task.transpose(node, transposed);
}
nodes = transposed;
}
return nodes;
}
test(input) {
const nodes = this.prime(input);
const AA = [ null ];
for ( const node of nodes ) {
AA[0] = node;
let aa = AA;
let output = [ node ];
for ( const task of this.tasks ) {
aa = task.exec(aa);
if ( aa.length === 0 ) { break; }
const transposed = [];
for ( const node of output ) {
task.transpose(node, transposed);
}
output = transposed;
if ( output.length === 0 ) { break; }
}
if ( aa.length !== 0 ) { return true; }
if ( output.length !== 0 ) { return true; }
}
return false;
}
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