1 files changed, 164 insertions, 0 deletions
diff --git a/xpcom/tests/unit/test_seek_multiplex.js b/xpcom/tests/unit/test_seek_multiplex.js
new file mode 100644
index 0000000000..7a469d9f48
--- /dev/null
+++ b/xpcom/tests/unit/test_seek_multiplex.js
@@ -0,0 +1,164 @@
+/* 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();
+}