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Merge pull request #107 from tophf/iframe-observer-speedup

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Make iframe observer 10-100 times faster
This commit is contained in:
Jason Barnabe 2015-05-21 09:25:55 -05:00
commit a7cb548f92
1 changed files with 119 additions and 45 deletions
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120
apply.js
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@ -1,3 +1,8 @@
var g_disableAll = false;
var g_styleElements = {};
var iframeObserver;
initObserver();
requestStyles();
function requestStyles() {
@ -45,12 +50,21 @@ chrome.extension.onMessage.addListener(function(request, sender, sendResponse) {
}
});
var g_disableAll = false;
function disableAll(disable) {
if (!disable === !g_disableAll) return;
if (!disable === !g_disableAll) {
return;
}
g_disableAll = disable;
if (g_disableAll) {
iframeObserver.disconnect();
}
disableSheets(g_disableAll, document);
if (!g_disableAll && document.readyState != "loading") {
iframeObserver.start();
}
function disableSheets(disable, doc) {
Array.prototype.forEach.call(doc.styleSheets, function(stylesheet) {
if (stylesheet.ownerNode.classList.contains("stylish")) {
@ -58,6 +72,10 @@ function disableAll(disable) {
}
});
getDynamicIFrames(doc).forEach(function(iframe) {
if (!disable) {
// update the IFRAME if it was created while the observer was disconnected
addDocumentStylesToIFrame(iframe);
}
disableSheets(disable, iframe.contentDocument);
});
}
@ -65,8 +83,12 @@ function disableAll(disable) {
function removeStyle(id, doc) {
var e = doc.getElementById("stylish-" + id);
delete g_styleElements["stylish-" + id];
if (e) {
e.parentNode.removeChild(e);
e.remove();
}
if (doc == document && Object.keys(g_styleElements).length == 0) {
iframeObserver.disconnect();
}
getDynamicIFrames(doc).forEach(function(iframe) {
removeStyle(id, iframe.contentDocument);
@ -86,6 +108,13 @@ function applyStyles(styleHash) {
for (var styleId in styleHash) {
applySections(styleId, styleHash[styleId]);
}
if (Object.keys(g_styleElements).length) {
document.addEventListener("DOMContentLoaded", function() {
getDynamicIFrames(document).forEach(addDocumentStylesToIFrame);
});
iframeObserver.start();
}
}
function applySections(styleId, sections) {
@ -108,16 +137,36 @@ function applySections(styleId, sections) {
return section.code;
}).join("\n")));
addStyleElement(styleElement, document);
g_styleElements[styleElement.id] = styleElement;
}
function addStyleElement(styleElement, doc) {
if (!doc.documentElement || doc.getElementById(styleElement.id)) {
return;
}
doc.documentElement.appendChild(doc.importNode(styleElement, true))
.disabled = g_disableAll;
getDynamicIFrames(doc).forEach(function(iframe) {
addStyleElement(styleElement, iframe.contentDocument);
if (iframeIsLoadingSrcDoc(iframe)) {
addStyleToIFrameSrcDoc(iframe, styleElement);
} else {
addStyleElement(styleElement, iframe.contentDocument);
}
});
}
function addDocumentStylesToIFrame(iframe) {
var doc = iframe.contentDocument;
var srcDocIsLoading = iframeIsLoadingSrcDoc(iframe);
for (var id in g_styleElements) {
if (srcDocIsLoading) {
addStyleToIFrameSrcDoc(iframe, g_styleElements[id]);
} else {
addStyleElement(g_styleElements[id], doc);
}
}
}
// Only dynamic iframes get the parent document's styles. Other ones should get styles based on their own URLs.
function getDynamicIFrames(doc) {
return Array.prototype.filter.call(doc.getElementsByTagName('iframe'), iframeIsDynamic);
@ -134,32 +183,57 @@ function iframeIsDynamic(f) {
return href == document.location.href || href.indexOf("about:") == 0;
}
function iframeIsLoadingSrcDoc(f) {
return f.srcdoc && f.contentDocument.all.length <= 3;
// 3 nodes or less in total (html, head, body) == new empty iframe about to be overwritten by its 'srcdoc'
}
function addStyleToIFrameSrcDoc(iframe, styleElement) {
if (g_disableAll) {
return;
}
iframe.srcdoc += styleElement.outerHTML;
// make sure the style is added in case srcdoc was malformed
setTimeout(addStyleElement.bind(null, styleElement, iframe.contentDocument), 100);
}
function replaceAll(newStyles, doc) {
Array.prototype.forEach.call(doc.querySelectorAll("STYLE.stylish"), function(style) {
style.parentNode.removeChild(style);
style.remove();
});
applyStyles(newStyles);
if (doc == document) {
g_styleElements = {};
applyStyles(newStyles);
}
getDynamicIFrames(doc).forEach(function(iframe) {
replaceAll(newStyles, iframe.contentDocument);
});
}
// Observe dynamic IFRAMEs being added
var iframeObserver = new MutationObserver(function(mutations) {
var styles = Array.prototype.slice.call(document.querySelectorAll('STYLE.stylish'));
if (styles.length == 0) {
return;
}
mutations.filter(function(mutation) {
return "childList" === mutation.type;
}).forEach(function(mutation) {
Array.prototype.filter.call(mutation.addedNodes, function(node) { return "IFRAME" === node.tagName; }).filter(iframeIsDynamic).forEach(function(iframe) {
var doc = iframe.contentDocument;
styles.forEach(function(style) {
doc.documentElement.appendChild(doc.importNode(style, true))
.disabled = g_disableAll;
});
});
function initObserver() {
iframeObserver = new MutationObserver(function(mutations) {
if (mutations.length > 1000) {
// use a much faster method for very complex pages with 100,000 mutations
// (observer usually receives 1k-10k mutations per call)
getDynamicIFrames(document).forEach(addDocumentStylesToIFrame);
return;
}
for (var m = 0, ml = mutations.length; m < ml; m++) {
var mutation = mutations[m];
if (mutation.type === "childList") {
for (var n = 0, nodes = mutation.addedNodes, nl = nodes.length; n < nl; n++) {
var node = nodes[n];
if (node.localName === "iframe" && iframeIsDynamic(node)) {
addDocumentStylesToIFrame(node);
}
}
}
}
});
});
iframeObserver.observe(document, {childList: true, subtree: true});
iframeObserver.start = function() {
// will be ignored by browser if already observing
iframeObserver.observe(document, {childList: true, subtree: true});
}
}