1 files changed, 129 insertions, 0 deletions
diff --git a/Source/WebCore/Modules/streams/StreamInternals.js b/Source/WebCore/Modules/streams/StreamInternals.js
new file mode 100644
index 000000000..94a96e396
--- /dev/null
+++ b/Source/WebCore/Modules/streams/StreamInternals.js
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2015 Canon Inc.
+ * Copyright (C) 2015 Igalia.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+// @conditional=ENABLE(READABLE_STREAM_API) || ENABLE(WRITABLE_STREAM_API)
+// @internal
+
+function shieldingPromiseResolve(result)
+{
+    const promise = @Promise.@resolve(result);
+    if (promise.@then === @undefined)
+        promise.@then = @Promise.prototype.@then;
+    return promise;
+}
+
+function promiseInvokeOrNoopNoCatch(object, key, args)
+{
+    "use strict";
+
+    const method = object[key];
+    if (method === @undefined)
+        return @Promise.@resolve();
+    return @shieldingPromiseResolve(method.@apply(object, args));
+}
+
+function promiseInvokeOrNoop(object, key, args)
+{
+    "use strict";
+
+    try {
+        return @promiseInvokeOrNoopNoCatch(object, key, args);
+    }
+    catch(error) {
+        return @Promise.@reject(error);
+    }
+
+}
+
+function promiseInvokeOrFallbackOrNoop(object, key1, args1, key2, args2)
+{
+    "use strict";
+
+    try {
+        const method = object[key1];
+        if (method === @undefined)
+            return @promiseInvokeOrNoopNoCatch(object, key2, args2);
+        return @shieldingPromiseResolve(method.@apply(object, args1));
+    }
+    catch(error) {
+        return @Promise.@reject(error);
+    }
+}
+
+function validateAndNormalizeQueuingStrategy(size, highWaterMark)
+{
+    "use strict";
+
+    if (size !== @undefined && typeof size !== "function")
+        @throwTypeError("size parameter must be a function");
+
+    const normalizedStrategy = { };
+
+    normalizedStrategy.size = size;
+    normalizedStrategy.highWaterMark = @Number(highWaterMark);
+
+    if (@isNaN(normalizedStrategy.highWaterMark) || normalizedStrategy.highWaterMark < 0)
+        @throwRangeError("highWaterMark value is negative or not a number");
+
+    return normalizedStrategy;
+}
+
+function newQueue()
+{
+    "use strict";
+
+    return { content: [], size: 0 };
+}
+
+function dequeueValue(queue)
+{
+    "use strict";
+
+    const record = queue.content.@shift();
+    queue.size -= record.size;
+    return record.value;
+}
+
+function enqueueValueWithSize(queue, value, size)
+{
+    "use strict";
+
+    size = @Number(size);
+    if (!@isFinite(size) || size < 0)
+        @throwRangeError("size has an incorrect value");
+    queue.content.@push({ value: value, size: size });
+    queue.size += size;
+}
+
+function peekQueueValue(queue)
+{
+    "use strict";
+
+    @assert(queue.content.length > 0);
+
+    return queue.content[0].value;
+}