Issue #1499 - Re-import ExtensionStorage.jsm

1 files changed, 241 insertions, 0 deletions

diff --git a/toolkit/modules/ExtensionStorage.jsm b/toolkit/modules/ExtensionStorage.jsm
new file mode 100644
index 000000000..0b0ffb000
--- /dev/null
+++ b/toolkit/modules/ExtensionStorage.jsm
@@ -0,0 +1,241 @@
+/* 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/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["ExtensionStorage"];
+
+const Ci = Components.interfaces;
+const Cc = Components.classes;
+const Cu = Components.utils;
+const Cr = Components.results;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+                                  "resource://gre/modules/osfile.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "AsyncShutdown",
+                                  "resource://gre/modules/AsyncShutdown.jsm");
+
+function jsonReplacer(key, value) {
+  switch (typeof(value)) {
+    // Serialize primitive types as-is.
+    case "string":
+    case "number":
+    case "boolean":
+      return value;
+
+    case "object":
+      if (value === null) {
+        return value;
+      }
+
+      switch (Cu.getClassName(value, true)) {
+        // Serialize arrays and ordinary objects as-is.
+        case "Array":
+        case "Object":
+          return value;
+
+        // Serialize Date objects and regular expressions as their
+        // string representations.
+        case "Date":
+        case "RegExp":
+          return String(value);
+      }
+      break;
+  }
+
+  if (!key) {
+    // If this is the root object, and we can't serialize it, serialize
+    // the value to an empty object.
+    return {};
+  }
+
+  // Everything else, omit entirely.
+  return undefined;
+}
+
+this.ExtensionStorage = {
+  cache: new Map(),
+  listeners: new Map(),
+
+  /**
+   * Sanitizes the given value, and returns a JSON-compatible
+   * representation of it, based on the privileges of the given global.
+   *
+   * @param {value} value
+   *        The value to sanitize.
+   * @param {Context} context
+   *        The extension context in which to sanitize the value
+   * @returns {value}
+   *        The sanitized value.
+   */
+  sanitize(value, context) {
+    let json = context.jsonStringify(value, jsonReplacer);
+    return JSON.parse(json);
+  },
+
+  getExtensionDir(extensionId) {
+    return OS.Path.join(this.extensionDir, extensionId);
+  },
+
+  getStorageFile(extensionId) {
+    return OS.Path.join(this.extensionDir, extensionId, "storage.js");
+  },
+
+  read(extensionId) {
+    if (this.cache.has(extensionId)) {
+      return this.cache.get(extensionId);
+    }
+
+    let path = this.getStorageFile(extensionId);
+    let decoder = new TextDecoder();
+    let promise = OS.File.read(path);
+    promise = promise.then(array => {
+      return JSON.parse(decoder.decode(array));
+    }).catch((error) => {
+      if (!error.becauseNoSuchFile) {
+        Cu.reportError("Unable to parse JSON data for extension storage.");
+      }
+      return {};
+    });
+    this.cache.set(extensionId, promise);
+    return promise;
+  },
+
+  write(extensionId) {
+    let promise = this.read(extensionId).then(extData => {
+      let encoder = new TextEncoder();
+      let array = encoder.encode(JSON.stringify(extData));
+      let path = this.getStorageFile(extensionId);
+      OS.File.makeDir(this.getExtensionDir(extensionId), {
+        ignoreExisting: true,
+        from: OS.Constants.Path.profileDir,
+      });
+      let promise = OS.File.writeAtomic(path, array);
+      return promise;
+    }).catch(() => {
+      // Make sure this promise is never rejected.
+      Cu.reportError("Unable to write JSON data for extension storage.");
+    });
+
+    AsyncShutdown.profileBeforeChange.addBlocker(
+      "ExtensionStorage: Finish writing extension data",
+      promise);
+
+    return promise.then(() => {
+      AsyncShutdown.profileBeforeChange.removeBlocker(promise);
+    });
+  },
+
+  set(extensionId, items, context) {
+    return this.read(extensionId).then(extData => {
+      let changes = {};
+      for (let prop in items) {
+        let item = this.sanitize(items[prop], context);
+        changes[prop] = {oldValue: extData[prop], newValue: item};
+        extData[prop] = item;
+      }
+
+      this.notifyListeners(extensionId, changes);
+
+      return this.write(extensionId);
+    });
+  },
+
+  remove(extensionId, items) {
+    return this.read(extensionId).then(extData => {
+      let changes = {};
+      for (let prop of [].concat(items)) {
+        changes[prop] = {oldValue: extData[prop]};
+        delete extData[prop];
+      }
+
+      this.notifyListeners(extensionId, changes);
+
+      return this.write(extensionId);
+    });
+  },
+
+  clear(extensionId) {
+    return this.read(extensionId).then(extData => {
+      let changes = {};
+      for (let prop of Object.keys(extData)) {
+        changes[prop] = {oldValue: extData[prop]};
+        delete extData[prop];
+      }
+
+      this.notifyListeners(extensionId, changes);
+
+      return this.write(extensionId);
+    });
+  },
+
+  get(extensionId, keys) {
+    return this.read(extensionId).then(extData => {
+      let result = {};
+      if (keys === null) {
+        Object.assign(result, extData);
+      } else if (typeof(keys) == "object" && !Array.isArray(keys)) {
+        for (let prop in keys) {
+          if (prop in extData) {
+            result[prop] = extData[prop];
+          } else {
+            result[prop] = keys[prop];
+          }
+        }
+      } else {
+        for (let prop of [].concat(keys)) {
+          if (prop in extData) {
+            result[prop] = extData[prop];
+          }
+        }
+      }
+
+      return result;
+    });
+  },
+
+  addOnChangedListener(extensionId, listener) {
+    let listeners = this.listeners.get(extensionId) || new Set();
+    listeners.add(listener);
+    this.listeners.set(extensionId, listeners);
+  },
+
+  removeOnChangedListener(extensionId, listener) {
+    let listeners = this.listeners.get(extensionId);
+    listeners.delete(listener);
+  },
+
+  notifyListeners(extensionId, changes) {
+    let listeners = this.listeners.get(extensionId);
+    if (listeners) {
+      for (let listener of listeners) {
+        listener(changes);
+      }
+    }
+  },
+
+  init() {
+    if (Services.appinfo.processType != Services.appinfo.PROCESS_TYPE_DEFAULT) {
+      return;
+    }
+    Services.obs.addObserver(this, "extension-invalidate-storage-cache", false);
+    Services.obs.addObserver(this, "xpcom-shutdown", false);
+  },
+
+  observe(subject, topic, data) {
+    if (topic == "xpcom-shutdown") {
+      Services.obs.removeObserver(this, "extension-invalidate-storage-cache");
+      Services.obs.removeObserver(this, "xpcom-shutdown");
+    } else if (topic == "extension-invalidate-storage-cache") {
+      this.cache.clear();
+    }
+  },
+};
+
+XPCOMUtils.defineLazyGetter(ExtensionStorage, "extensionDir",
+  () => OS.Path.join(OS.Constants.Path.profileDir, "browser-extension-data"));
+
+ExtensionStorage.init();