ReadableStreamReader.js   [plain text]

/*
 * Copyright (C) 2015 Canon Inc.
 *
 * 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(STREAMS_API)

function cancel(reason)
{
    "use strict";

    if (!@isReadableStreamReader(this))
        return @Promise.@reject(new @TypeError("Function should be called on a ReadableStreamReader"));

    if (!this.@ownerReadableStream)
        return @Promise.@reject(new @TypeError("cancel() called on a reader owned by no readable stream"));

    return @cancelReadableStream(this.@ownerReadableStream, reason);
}

function read()
{
    "use strict";

    if (!@isReadableStreamReader(this))
        return @Promise.@reject(new @TypeError("Function should be called on a ReadableStreamReader"));
    if (!this.@ownerReadableStream)
        return @Promise.@reject(new @TypeError("read() called on a reader owned by no readable stream"));

    return @readFromReadableStreamReader(this);
}

function releaseLock()
{
    "use strict";

    if (!@isReadableStreamReader(this))
        throw new @TypeError("Function should be called on a ReadableStreamReader");

    const stream = this.@ownerReadableStream;
    if (!stream)
         return;

    if (this.@readRequests.length)
        throw new @TypeError("There are still pending read requests, cannot release the lock");

    if (stream.@state === @streamReadable)
        this.@closedPromiseCapability.@reject.@call(@undefined, new @TypeError("releasing lock of reader whose stream is still in readable state"));
    else
        this.@closedPromiseCapability = { @promise: @Promise.@reject(new @TypeError("reader released lock")) };

    stream.@reader = @undefined;
    this.@ownerReadableStream = null;
}

function closed()
{
    "use strict";

    if (!@isReadableStreamReader(this))
        return @Promise.@reject(new @TypeError("Callee of closed is not a ReadableStreamReader"));

    return this.@closedPromiseCapability.@promise;
}