gecko-dev/toolkit/components/thumbnails/PageThumbsStorageService.js

66 строки
1.9 KiB
JavaScript

const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
const THUMBNAIL_DIRECTORY = "thumbnails";
Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
Cu.import("resource://gre/modules/osfile.jsm", this);
XPCOMUtils.defineLazyGetter(this, "gCryptoHash", function() {
return Cc["@mozilla.org/security/hash;1"].createInstance(Ci.nsICryptoHash);
});
XPCOMUtils.defineLazyGetter(this, "gUnicodeConverter", function() {
let converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"]
.createInstance(Ci.nsIScriptableUnicodeConverter);
converter.charset = "utf8";
return converter;
});
function PageThumbsStorageService() {}
PageThumbsStorageService.prototype = {
classID: Components.ID("{97943eec-0e48-49ef-b7b7-cf4aa0109bb6}"),
QueryInterface: XPCOMUtils.generateQI([Ci.nsIPageThumbsStorageService]),
_xpcom_categories: [{
service: true
}],
// The path for the storage
_path: null,
get path() {
if (!this._path) {
this._path = OS.Path.join(OS.Constants.Path.localProfileDir, THUMBNAIL_DIRECTORY);
}
return this._path;
},
getLeafNameForURL(aURL) {
if (typeof aURL != "string") {
throw new TypeError("Expecting a string");
}
let hash = this._calculateMD5Hash(aURL);
return hash + ".png";
},
getFilePathForURL(aURL) {
return OS.Path.join(this.path, this.getLeafNameForURL(aURL));
},
_calculateMD5Hash(aValue) {
let hash = gCryptoHash;
let value = gUnicodeConverter.convertToByteArray(aValue);
hash.init(hash.MD5);
hash.update(value, value.length);
return this._convertToHexString(hash.finish(false));
},
_convertToHexString(aData) {
let hex = "";
for (let i = 0; i < aData.length; i++)
hex += ("0" + aData.charCodeAt(i).toString(16)).slice(-2);
return hex;
},
};
this.NSGetFactory = XPCOMUtils.generateNSGetFactory([PageThumbsStorageService]);