gecko/browser/components/thumbnails/PageThumbsWorker.js

74 lines
1.9 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* A worker dedicated for the I/O component of PageThumbs storage.
*
* Do not rely on the API of this worker. In a future version, it might be
* fully replaced by a OS.File global I/O worker.
*/
"use strict";
importScripts("resource://gre/modules/osfile.jsm");
let PageThumbsWorker = {
handleMessage: function Worker_handleMessage(aEvent) {
let msg = aEvent.data;
let data = {result: null, data: null};
switch (msg.type) {
case "removeFile":
data.result = this.removeFile(msg);
break;
case "expireFilesInDirectory":
data.result = this.expireFilesInDirectory(msg);
break;
default:
data.result = false;
data.detail = "message not understood";
break;
}
self.postMessage(data);
},
removeFile: function Worker_removeFile(msg) {
try {
OS.File.remove(msg.path);
return true;
} catch (e) {
return false;
}
},
expireFilesInDirectory: function Worker_expireFilesInDirectory(msg) {
let entries = this.getFileEntriesInDirectory(msg.path, msg.filesToKeep);
let limit = Math.max(msg.minChunkSize, Math.round(entries.length / 2));
for (let entry of entries) {
this.removeFile(entry);
// Check if we reached the limit of files to remove.
if (--limit <= 0) {
break;
}
}
return true;
},
getFileEntriesInDirectory:
function Worker_getFileEntriesInDirectory(aPath, aSkipFiles) {
let skip = new Set(aSkipFiles);
let iter = new OS.File.DirectoryIterator(aPath);
return [entry
for (entry in iter)
if (!entry.isDir && !entry.isSymLink && !skip.has(entry.name))];
}
};
self.onmessage = PageThumbsWorker.handleMessage.bind(PageThumbsWorker);