michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * A worker dedicated for the I/O component of PageThumbs storage.
michael@0:  *
michael@0:  * Do not rely on the API of this worker. In a future version, it might be
michael@0:  * fully replaced by a OS.File global I/O worker.
michael@0:  */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: importScripts("resource://gre/modules/osfile.jsm");
michael@0: 
michael@0: let File = OS.File;
michael@0: let Type = OS.Shared.Type;
michael@0: 
michael@0: /**
michael@0:  * Communications with the controller.
michael@0:  *
michael@0:  * Accepts messages:
michael@0:  * {fun:function_name, args:array_of_arguments_or_null}
michael@0:  *
michael@0:  * Sends messages:
michael@0:  * {ok: result} / {fail: serialized_form_of_OS.File.Error}
michael@0:  */
michael@0: self.onmessage = function onmessage(msg) {
michael@0:   let data = msg.data;
michael@0:   let id = data.id;
michael@0:   let result;
michael@0:   if (!(data.fun in Agent)) {
michael@0:     throw new Error("Cannot find method " + data.fun);
michael@0:   }
michael@0:   try {
michael@0:     result = Agent[data.fun].apply(Agent, data.args);
michael@0:   } catch (ex if ex instanceof StopIteration) {
michael@0:     // StopIteration cannot be serialized automatically
michael@0:     self.postMessage({StopIteration: true, id: id});
michael@0:     return;
michael@0:   } catch (ex if ex instanceof OS.File.Error) {
michael@0:     // Instances of OS.File.Error know how to serialize themselves
michael@0:     // (deserialization ensures that we end up with OS-specific
michael@0:     // instances of |OS.File.Error|)
michael@0:     self.postMessage({fail: OS.File.Error.toMsg(ex), id:id});
michael@0:     return;
michael@0:   }
michael@0:   // Other exceptions do not, and should be propagated through DOM's
michael@0:   // built-in mechanism for uncaught errors, although this mechanism
michael@0:   // may lose interesting information.
michael@0:   self.postMessage({ok: result, id:id});
michael@0: };
michael@0: 
michael@0: 
michael@0: let Agent = {
michael@0:   // Checks if the specified file exists and has an age less than as
michael@0:   // specifed (in seconds).
michael@0:   isFileRecent: function Agent_isFileRecent(path, maxAge) {
michael@0:     try {
michael@0:       let stat = OS.File.stat(path);
michael@0:       let maxDate = new Date();
michael@0:       maxDate.setSeconds(maxDate.getSeconds() - maxAge);
michael@0:       return stat.lastModificationDate > maxDate;
michael@0:     } catch (ex if ex instanceof OS.File.Error) {
michael@0:       // file doesn't exist (or can't be stat'd) - must be stale.
michael@0:       return false;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   remove: function Agent_removeFile(path) {
michael@0:     try {
michael@0:       OS.File.remove(path);
michael@0:       return true;
michael@0:     } catch (e) {
michael@0:       return false;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   expireFilesInDirectory:
michael@0:   function Agent_expireFilesInDirectory(path, filesToKeep, minChunkSize) {
michael@0:     let entries = this.getFileEntriesInDirectory(path, filesToKeep);
michael@0:     let limit = Math.max(minChunkSize, Math.round(entries.length / 2));
michael@0: 
michael@0:     for (let entry of entries) {
michael@0:       this.remove(entry.path);
michael@0: 
michael@0:       // Check if we reached the limit of files to remove.
michael@0:       if (--limit <= 0) {
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0:   },
michael@0: 
michael@0:   getFileEntriesInDirectory:
michael@0:   function Agent_getFileEntriesInDirectory(path, skipFiles) {
michael@0:     let iter = new OS.File.DirectoryIterator(path);
michael@0:     if (!iter.exists()) {
michael@0:       return [];
michael@0:     }
michael@0: 
michael@0:     let skip = new Set(skipFiles);
michael@0: 
michael@0:     return [entry
michael@0:             for (entry in iter)
michael@0:             if (!entry.isDir && !entry.isSymLink && !skip.has(entry.name))];
michael@0:   },
michael@0: 
michael@0:   moveOrDeleteAllThumbnails:
michael@0:   function Agent_moveOrDeleteAllThumbnails(pathFrom, pathTo) {
michael@0:     OS.File.makeDir(pathTo, {ignoreExisting: true});
michael@0:     if (pathFrom == pathTo) {
michael@0:       return true;
michael@0:     }
michael@0:     let iter = new OS.File.DirectoryIterator(pathFrom);
michael@0:     if (iter.exists()) {
michael@0:       for (let entry in iter) {
michael@0:         if (entry.isDir || entry.isSymLink) {
michael@0:           continue;
michael@0:         }
michael@0: 
michael@0: 
michael@0:         let from = OS.Path.join(pathFrom, entry.name);
michael@0:         let to = OS.Path.join(pathTo, entry.name);
michael@0: 
michael@0:         try {
michael@0:           OS.File.move(from, to, {noOverwrite: true, noCopy: true});
michael@0:         } catch (e) {
michael@0:           OS.File.remove(from);
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:     iter.close();
michael@0: 
michael@0:     try {
michael@0:       OS.File.removeEmptyDir(pathFrom);
michael@0:     } catch (e) {
michael@0:       // This could fail if there's something in
michael@0:       // the folder we're not permitted to remove.
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0:   },
michael@0: 
michael@0:   writeAtomic: function Agent_writeAtomic(path, buffer, options) {
michael@0:     return File.writeAtomic(path,
michael@0:       buffer,
michael@0:       options);
michael@0:   },
michael@0: 
michael@0:   makeDir: function Agent_makeDir(path, options) {
michael@0:     return File.makeDir(path, options);
michael@0:   },
michael@0: 
michael@0:   copy: function Agent_copy(source, dest, options) {
michael@0:     return File.copy(source, dest, options);
michael@0:   },
michael@0: 
michael@0:   wipe: function Agent_wipe(path) {
michael@0:     let iterator = new File.DirectoryIterator(path);
michael@0:     try {
michael@0:       for (let entry in iterator) {
michael@0:         try {
michael@0:           File.remove(entry.path);
michael@0:         } catch (ex) {
michael@0:           // If a file cannot be removed, we should still continue.
michael@0:           // This can happen at least for any of the following reasons:
michael@0:           // - access denied;
michael@0:           // - file has been removed recently during a previous wipe
michael@0:           //  and the file system has not flushed that yet (yes, this
michael@0:           //  can happen under Windows);
michael@0:           // - file has been removed by the user or another process.
michael@0:         }
michael@0:       }
michael@0:     } finally {
michael@0:       iterator.close();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   exists: function Agent_exists(path) {
michael@0:     return File.exists(path);
michael@0:   },
michael@0: };
michael@0: