diff options
Diffstat (limited to 'src/library_idbfs.js')
| -rw-r--r-- | src/library_idbfs.js | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/library_idbfs.js b/src/library_idbfs.js new file mode 100644 index 00000000..9031bad8 --- /dev/null +++ b/src/library_idbfs.js @@ -0,0 +1,216 @@ +mergeInto(LibraryManager.library, { + $IDBFS__deps: ['$FS', '$MEMFS', '$PATH'], + $IDBFS: { + dbs: {}, + indexedDB: function() { + return window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB; + }, + DB_VERSION: 20, + DB_STORE_NAME: 'FILE_DATA', + // reuse all of the core MEMFS functionality + mount: function(mount) { + return MEMFS.mount.apply(null, arguments); + }, + // the only custom function IDBFS implements is to handle + // synchronizing the wrapped MEMFS with a backing IDB instance + syncfs: function(mount, populate, callback) { + IDBFS.getLocalSet(mount, function(err, local) { + if (err) return callback(err); + + IDBFS.getRemoteSet(mount, function(err, remote) { + if (err) return callback(err); + + var src = populate ? remote : local; + var dst = populate ? local : remote; + + IDBFS.reconcile(src, dst, callback); + }); + }); + }, + reconcile: function(src, dst, callback) { + var total = 0; + + var create = {}; + for (var key in src.files) { + if (!src.files.hasOwnProperty(key)) continue; + var e = src.files[key]; + var e2 = dst.files[key]; + if (!e2 || e.timestamp > e2.timestamp) { + create[key] = e; + total++; + } + } + + var remove = {}; + for (var key in dst.files) { + if (!dst.files.hasOwnProperty(key)) continue; + var e = dst.files[key]; + var e2 = src.files[key]; + if (!e2) { + remove[key] = e; + total++; + } + } + + if (!total) { + // early out + return callback(null); + } + + var completed = 0; + var done = function(err) { + if (err) return callback(err); + if (++completed >= total) { + return callback(null); + } + }; + + // create a single transaction to handle and IDB reads / writes we'll need to do + var db = src.type === 'remote' ? src.db : dst.db; + var transaction = db.transaction([IDBFS.DB_STORE_NAME], 'readwrite'); + transaction.onerror = function() { callback(this.error); }; + var store = transaction.objectStore(IDBFS.DB_STORE_NAME); + + for (var path in create) { + if (!create.hasOwnProperty(path)) continue; + var entry = create[path]; + + if (dst.type === 'local') { + // save file to local + try { + if (FS.isDir(entry.mode)) { + FS.mkdir(path, entry.mode); + } else if (FS.isFile(entry.mode)) { + var stream = FS.open(path, 'w+', 0666); + FS.write(stream, entry.contents, 0, entry.contents.length, 0, true /* canOwn */); + FS.close(stream); + } + done(null); + } catch (e) { + return done(e); + } + } else { + // save file to IDB + var req = store.put(entry, path); + req.onsuccess = function() { done(null); }; + req.onerror = function() { done(this.error); }; + } + } + + for (var path in remove) { + if (!remove.hasOwnProperty(path)) continue; + var entry = remove[path]; + + if (dst.type === 'local') { + // delete file from local + try { + if (FS.isDir(entry.mode)) { + // TODO recursive delete? + FS.rmdir(path); + } else if (FS.isFile(entry.mode)) { + FS.unlink(path); + } + done(null); + } catch (e) { + return done(e); + } + } else { + // delete file from IDB + var req = store.delete(path); + req.onsuccess = function() { done(null); }; + req.onerror = function() { done(this.error); }; + } + } + }, + getLocalSet: function(mount, callback) { + var files = {}; + + var isRealDir = function(p) { + return p !== '.' && p !== '..'; + }; + var toAbsolute = function(root) { + return function(p) { + return PATH.join(root, p); + } + }; + + var check = FS.readdir(mount.mountpoint) + .filter(isRealDir) + .map(toAbsolute(mount.mountpoint)); + + while (check.length) { + var path = check.pop(); + var stat, node; + + try { + var lookup = FS.lookupPath(path); + node = lookup.node; + stat = FS.stat(path); + } catch (e) { + return callback(e); + } + + if (FS.isDir(stat.mode)) { + check.push.apply(check, FS.readdir(path) + .filter(isRealDir) + .map(toAbsolute(path))); + + files[path] = { mode: stat.mode, timestamp: stat.mtime }; + } else if (FS.isFile(stat.mode)) { + files[path] = { contents: node.contents, mode: stat.mode, timestamp: stat.mtime }; + } else { + return callback(new Error('node type not supported')); + } + } + + return callback(null, { type: 'local', files: files }); + }, + getDB: function(name, callback) { + // look it up in the cache + var db = IDBFS.dbs[name]; + if (db) { + return callback(null, db); + } + var req; + try { + req = IDBFS.indexedDB().open(name, IDBFS.DB_VERSION); + } catch (e) { + return onerror(e); + } + req.onupgradeneeded = function() { + db = req.result; + db.createObjectStore(IDBFS.DB_STORE_NAME); + }; + req.onsuccess = function() { + db = req.result; + // add to the cache + IDBFS.dbs[name] = db; + callback(null, db); + }; + req.onerror = function() { + callback(this.error); + }; + }, + getRemoteSet: function(mount, callback) { + var files = {}; + + IDBFS.getDB(mount.mountpoint, function(err, db) { + if (err) return callback(err); + + var transaction = db.transaction([IDBFS.DB_STORE_NAME], 'readonly'); + transaction.onerror = function() { callback(this.error); }; + + var store = transaction.objectStore(IDBFS.DB_STORE_NAME); + store.openCursor().onsuccess = function(event) { + var cursor = event.target.result; + if (!cursor) { + return callback(null, { type: 'remote', db: db, files: files }); + } + + files[cursor.key] = cursor.value; + cursor.continue(); + }; + }); + } + } +}); |