Bug 865387 - Changes to |options| and |clone| in OS.File. r=Yoric

toolkit/components/osfile/modules/osfile_async_front.jsm

@@ -93,48 +93,10 @@ if (!("localProfileDir" in OS.Constants.Path)) {
   });
 }
 
-/**
- * A global constant used as a default refs parameter value when cloning.
- */
-const noRefs = [];
-
 /**
  * Return a shallow clone of the enumerable properties of an object.
- *
- * Utility used whenever normalizing options requires making (shallow)
- * changes to an option object. The copy ensures that we do not modify
- * a client-provided object by accident.
- *
- * Note: to reference and not copy specific fields, provide an optional
- * |refs| argument containing their names.
- *
- * @param {JSON} object Options to be cloned.
- * @param {Array} refs An optional array of field names to be passed by
- * reference instead of copying.
  */
-let clone = function clone(object, refs = noRefs) {
-  let result = {};
-  // Make a reference between result[key] and object[key].
-  let refer = function refer(result, key, object) {
-    Object.defineProperty(result, key, {
-        enumerable: true,
-        get: function() {
-            return object[key];
-        },
-        set: function(value) {
-            object[key] = value;
-        }
-    });
-  };
-  for (let k in object) {
-    if (refs.indexOf(k) < 0) {
-      result[k] = object[k];
-    } else {
-      refer(result, k, object);
-    }
-  }
-  return result;
-};
+let clone = SharedAll.clone;
 
 let worker = new PromiseWorker(
   "resource://gre/modules/osfile/osfile_async_worker.js", LOG);
@@ -367,9 +329,8 @@ File.prototype = {
     // If |buffer| is a typed array and there is no |bytes| options, we
     // need to extract the |byteLength| now, as it will be lost by
     // communication
-    if (isTypedArray(buffer) && (!options || !("bytes" in options))) {
-      // Preserve the reference to |outExecutionDuration| option if it is
-      // passed.
+    if (isTypedArray(buffer) && !("bytes" in options)) {
+      // Preserve reference to option |outExecutionDuration|, if it is passed.
       options = clone(options, ["outExecutionDuration"]);
       options.bytes = buffer.byteLength;
     }
@@ -405,9 +366,8 @@ File.prototype = {
     // If |buffer| is a typed array and there is no |bytes| options,
     // we need to extract the |byteLength| now, as it will be lost
     // by communication
-    if (isTypedArray(buffer) && (!options || !("bytes" in options))) {
-      // Preserve the reference to |outExecutionDuration| option if it is
-      // passed.
+    if (isTypedArray(buffer)) {
+      // Preserve reference to option |outExecutionDuration|, if it is passed.
       options = clone(options, ["outExecutionDuration"]);
       options.bytes = buffer.byteLength;
     }
@@ -428,13 +388,14 @@ File.prototype = {
    * @param {number=} bytes If unspecified, read all the remaining bytes from
    * this file. If specified, read |bytes| bytes, or less if the file does not
    * contain that many bytes.
+   * @param {JSON} options
    * @return {promise}
    * @resolves {Uint8Array} An array containing the bytes read.
    */
-  read: function read(nbytes) {
+  read: function read(nbytes, options = {}) {
     let promise = Scheduler.post("File_prototype_read",
       [this._fdmsg,
-       nbytes]);
+       nbytes, options]);
     return promise.then(
       function onSuccess(data) {
         return new Uint8Array(data.buffer, data.byteOffset, data.byteLength);
@@ -639,6 +600,11 @@ File.makeDir = function makeDir(path, options) {
  * @param {number=} bytes Optionally, an upper bound to the number of bytes
  * to read.
  * @param {JSON} options Additional options.
+ * - {boolean} sequential A flag that triggers a population of the page cache
+ * with data from a file so that subsequent reads from that file would not
+ * block on disk I/O. If |true| or unspecified, inform the system that the
+ * contents of the file will be read in order. Otherwise, make no such
+ * assumption. |true| by default.
  *
  * @resolves {Uint8Array} A buffer holding the bytes
  * read from the file.

toolkit/components/osfile/modules/osfile_async_worker.js

@@ -272,7 +272,7 @@ if (this.Components) {
          });
        },
        read: function read(path, bytes, options) {
-         let data = File.read(Type.path.fromMsg(path), bytes);
+         let data = File.read(Type.path.fromMsg(path), bytes, options);
          return new Transfer({buffer: data.buffer, byteOffset: data.byteOffset, byteLength: data.byteLength}, [data.buffer]);
        },
        exists: function exists(path) {

toolkit/components/osfile/modules/osfile_shared_allthreads.jsm

@@ -34,6 +34,7 @@ if (typeof Components != "undefined") {
 
 let EXPORTED_SYMBOLS = [
   "LOG",
+  "clone",
   "Config",
   "Constants",
   "Type",
@@ -162,6 +163,46 @@ let LOG = function (...args) {
 
 exports.LOG = LOG;
 
+/**
+ * Return a shallow clone of the enumerable properties of an object.
+ *
+ * Utility used whenever normalizing options requires making (shallow)
+ * changes to an option object. The copy ensures that we do not modify
+ * a client-provided object by accident.
+ *
+ * Note: to reference and not copy specific fields, provide an optional
+ * |refs| argument containing their names.
+ *
+ * @param {JSON} object Options to be cloned.
+ * @param {Array} refs An optional array of field names to be passed by
+ * reference instead of copying.
+ */
+let clone = function (object, refs = []) {
+  let result = {};
+  // Make a reference between result[key] and object[key].
+  let refer = function refer(result, key, object) {
+    Object.defineProperty(result, key, {
+      enumerable: true,
+      get: function() {
+        return object[key];
+      },
+      set: function(value) {
+        object[key] = value;
+      }
+    });
+  };
+  for (let k in object) {
+    if (refs.indexOf(k) < 0) {
+      result[k] = object[k];
+    } else {
+      refer(result, k, object);
+    }
+  }
+  return result;
+};
+
+exports.clone = clone;
+
 ///////////////////// Abstractions above js-ctypes
 
 /**
@@ -974,6 +1015,7 @@ exports.OS = {
   Constants: exports.Constants,
   Shared: {
     LOG: LOG,
+    clone: clone,
     Type: Type,
     HollowStructure: HollowStructure,
     Error: OSError,
@@ -1015,4 +1057,3 @@ if (typeof Components != "undefined") {
     this[symbol] = exports[symbol];
   }
 }
-

toolkit/components/osfile/modules/osfile_shared_front.jsm

@@ -17,6 +17,7 @@ if (typeof Components != "undefined") {
 exports.OS = require("resource://gre/modules/osfile/osfile_shared_allthreads.jsm").OS;
 
 let LOG = exports.OS.Shared.LOG.bind(OS.Shared, "Shared front-end");
+let clone = exports.OS.Shared.clone;
 
 /**
  * Code shared by implementations of File.
@@ -44,17 +45,17 @@ AbstractFile.prototype = {
    * Read bytes from this file to a new buffer.
    *
    * @param {number=} bytes If unspecified, read all the remaining bytes from
-   * this file. If specified, read |bytes| bytes, or less if the file does not
+   * this file. If specified, read |bytes| bytes, or less if the file does notclone
    * contain that many bytes.
+   * @param {JSON} options
    * @return {Uint8Array} An array containing the bytes read.
    */
-  read: function read(bytes) {
-    if (bytes == null) {
-      bytes = this.stat().size;
-    }
-    let buffer = new Uint8Array(bytes);
-    let size = this.readTo(buffer, {bytes: bytes});
-    if (size == bytes) {
+  read: function read(bytes, options = {}) {
+    options = clone(options);
+    options.bytes = bytes == null ? this.stat().size : bytes;
+    let buffer = new Uint8Array(options.bytes);
+    let size = this.readTo(buffer, options);
+    if (size == options.bytes) {
       return buffer;
     } else {
       return buffer.subarray(0, size);
@@ -291,14 +292,15 @@ AbstractFile.normalizeOpenMode = function normalizeOpenMode(mode) {
  * @param {string} path The path to the file.
  * @param {number=} bytes Optionally, an upper bound to the number of bytes
  * to read.
+ * @param {JSON} options Optionally contains additional options.
  *
  * @return {Uint8Array} A buffer holding the bytes
  * and the number of bytes read from the file.
  */
-AbstractFile.read = function read(path, bytes) {
+AbstractFile.read = function read(path, bytes, options = {}) {
   let file = exports.OS.File.open(path);
   try {
-    return file.read(bytes);
+    return file.read(bytes, options);
   } finally {
     file.close();
   }