test_seek_multiplex.js

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/* 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/. */

// The string we use as data.

const data = "0123456789";

// Number of streams in the multiplex stream.

const count = 10;

function test_multiplex_streams() {

  var MultiplexStream = CC(

    "@mozilla.org/io/multiplex-input-stream;1",

    "nsIMultiplexInputStream"

);

  Assert.equal(1, 1);

  var multiplex = new MultiplexStream();

  for (var i = 0; i < count; ++i) {

    let s = Cc["@mozilla.org/io/string-input-stream;1"].createInstance(

      Ci.nsIStringInputStream

);

    s.setData(data, data.length);

    multiplex.appendStream(s);

  var seekable = multiplex.QueryInterface(Ci.nsISeekableStream);

  var sis = Cc["@mozilla.org/scriptableinputstream;1"].createInstance(

    Ci.nsIScriptableInputStream

);

  sis.init(seekable);

  // Read some data.

  var readData = sis.read(20);

  Assert.equal(readData, data + data);

  // -- Tests for NS_SEEK_SET

  // Seek to a non-zero, non-stream-boundary offset.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 2);

  Assert.equal(seekable.tell(), 2);

  Assert.equal(seekable.available(), 98);

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 9);

  Assert.equal(seekable.tell(), 9);

  Assert.equal(seekable.available(), 91);

  // Seek across stream boundary.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 35);

  Assert.equal(seekable.tell(), 35);

  Assert.equal(seekable.available(), 65);

  readData = sis.read(5);

  Assert.equal(readData, data.slice(5));

  Assert.equal(seekable.available(), 60);

  // Seek at stream boundaries.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 40);

  Assert.equal(seekable.tell(), 40);

  Assert.equal(seekable.available(), 60);

  readData = sis.read(10);

  Assert.equal(readData, data);

  Assert.equal(seekable.tell(), 50);

  Assert.equal(seekable.available(), 50);

  // Rewind and read across streams.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 39);

  Assert.equal(seekable.tell(), 39);

  Assert.equal(seekable.available(), 61);

  readData = sis.read(11);

  Assert.equal(readData, data.slice(9) + data);

  Assert.equal(seekable.tell(), 50);

  Assert.equal(seekable.available(), 50);

  // Rewind to the beginning.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 0);

  Assert.equal(seekable.tell(), 0);

  Assert.equal(seekable.available(), 100);

  // Seek to some random location

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 50);

  // -- Tests for NS_SEEK_CUR

  // Positive seek.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_CUR, 15);

  Assert.equal(seekable.tell(), 65);

  Assert.equal(seekable.available(), 35);

  readData = sis.read(10);

  Assert.equal(readData, data.slice(5) + data.slice(0, 5));

  Assert.equal(seekable.tell(), 75);

  Assert.equal(seekable.available(), 25);

  // Negative seek.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_CUR, -15);

  Assert.equal(seekable.tell(), 60);

  Assert.equal(seekable.available(), 40);

  readData = sis.read(10);

  Assert.equal(readData, data);

  Assert.equal(seekable.tell(), 70);

  Assert.equal(seekable.available(), 30);

  // -- Tests for NS_SEEK_END

  // Normal read.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_END, -5);

  Assert.equal(seekable.tell(), data.length * count - 5);

  readData = sis.read(5);

  Assert.equal(readData, data.slice(5));

  Assert.equal(seekable.tell(), data.length * count);

  // Read across streams.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_END, -15);

  Assert.equal(seekable.tell(), data.length * count - 15);

  readData = sis.read(15);

  Assert.equal(readData, data.slice(5) + data);

  Assert.equal(seekable.tell(), data.length * count);

  // -- Try to do various edge cases

  // Forward seek from the end, should throw.

  var caught = false;

  try {

    seekable.seek(Ci.nsISeekableStream.NS_SEEK_END, 15);

  } catch (e) {

    caught = true;

  Assert.equal(caught, true);

  Assert.equal(seekable.tell(), data.length * count);

  // Backward seek from the beginning, should be clamped.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 0);

  Assert.equal(seekable.tell(), 0);

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_CUR, -15);

  Assert.equal(seekable.tell(), 0);

  // Seek too far: should be clamped.

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 0);

  Assert.equal(seekable.tell(), 0);

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_CUR, 3 * data.length * count);

  Assert.equal(seekable.tell(), 100);

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, data.length * count);

  Assert.equal(seekable.tell(), 100);

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_CUR, -2 * data.length * count);

  Assert.equal(seekable.tell(), 0);

function test_multiplex_bug797871() {

  var data2 = "1234567890123456789012345678901234567890";

  var MultiplexStream = CC(

    "@mozilla.org/io/multiplex-input-stream;1",

    "nsIMultiplexInputStream"

);

  Assert.equal(1, 1);

  var multiplex = new MultiplexStream();

  let s = Cc["@mozilla.org/io/string-input-stream;1"].createInstance(

    Ci.nsIStringInputStream

);

  s.setData(data2, data2.length);

  multiplex.appendStream(s);

  var seekable = multiplex.QueryInterface(Ci.nsISeekableStream);

  var sis = Cc["@mozilla.org/scriptableinputstream;1"].createInstance(

    Ci.nsIScriptableInputStream

);

  sis.init(seekable);

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 8);

  Assert.equal(seekable.tell(), 8);

  sis.read(2);

  Assert.equal(seekable.tell(), 10);

  seekable.seek(Ci.nsISeekableStream.NS_SEEK_SET, 20);

  Assert.equal(seekable.tell(), 20);

function run_test() {

  test_multiplex_streams();

  test_multiplex_bug797871();