bun.sh/src/bun.js/builtins/js/ReadableStreamDefaultReader.js

/*
 * 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.
 */

function initializeReadableStreamDefaultReader(stream)
{
    "use strict";

    if (!@isReadableStream(stream))
        @throwTypeError("ReadableStreamDefaultReader needs a ReadableStream");
    if (@isReadableStreamLocked(stream))
        @throwTypeError("ReadableStream is locked");

    @readableStreamReaderGenericInitialize(this, stream);
    @putByIdDirectPrivate(this, "readRequests", @createFIFO());

    return this;
}

function cancel(reason)
{
    "use strict";

    if (!@isReadableStreamDefaultReader(this))
        return @Promise.@reject(@makeThisTypeError("ReadableStreamDefaultReader", "cancel"));

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

    return @readableStreamReaderGenericCancel(this, reason);
}

function readMany()
{
    "use strict";

    if (!@isReadableStreamDefaultReader(this))
        @throwTypeError("ReadableStreamDefaultReader.readMany() should not be called directly");

    const stream = @getByIdDirectPrivate(this, "ownerReadableStream");
    if (!stream)
        @throwTypeError("readMany() called on a reader owned by no readable stream");

    const state = @getByIdDirectPrivate(stream, "state");
    @putByIdDirectPrivate(stream, "disturbed", true);
    if (state === @streamClosed)
        return {value: [], size: 0, done: true};
    else if (state === @streamErrored) {
        throw @getByIdDirectPrivate(stream, "storedError");
    }

    
    var controller = @getByIdDirectPrivate(stream, "readableStreamController");
    var queue  = @getByIdDirectPrivate(controller, "queue");
    
    if (!queue) {
        // This is a ReadableStream direct controller implemented in JS
        // It hasn't been started yet.
        return controller.@pull(
            controller
        ).@then(
            function({done, value}) {
                return (
                    done ? 
                        { done: true, value: [], size: 0 } : 
                        { value: [value], size: 1, done: false }
                );
            }
        );
    }

    const content = queue.content;
    var size = queue.size;
    var values = content.toArray(false);
    
    var length = values.length;

    if (length > 0) {
        var outValues = @newArrayWithSize(length);
        if (@isReadableByteStreamController(controller)) {

            {
                const buf = values[0];
                if (!(@ArrayBuffer.@isView(buf) || buf instanceof @ArrayBuffer)) {
                    @putByValDirect(outValues, 0, new @Uint8Array(buf.buffer, buf.byteOffset, buf.byteLength));
                } else {
                    @putByValDirect(outValues, 0, buf);
                }
            }

            for (var i = 1; i < length; i++) {
                const buf = values[i];
                if (!(@ArrayBuffer.@isView(buf) || buf instanceof @ArrayBuffer)) {
                    @putByValDirect(outValues, i, new @Uint8Array(buf.buffer, buf.byteOffset, buf.byteLength));
                } else {
                    @putByValDirect(outValues, i, buf);
                }
            }

        } else {
            @putByValDirect(outValues, 0, values[0].value);
            for (var i = 1; i < length; i++) {
                @putByValDirect(outValues, i, values[i].value);
            }
        }
        
        @resetQueue(@getByIdDirectPrivate(controller, "queue"));

        if (@getByIdDirectPrivate(controller, "closeRequested"))
            @readableStreamClose(@getByIdDirectPrivate(controller, "controlledReadableStream"));
        else if (@isReadableStreamDefaultController(controller)) 
            @readableStreamDefaultControllerCallPullIfNeeded(controller);
        else if (@isReadableByteStreamController(controller))
            @readableByteStreamControllerCallPullIfNeeded(controller);

        return {value: outValues, size, done: false};
    }

    var onPullMany = (result) => {
        if (result.done) {
            return {value: [], size: 0, done: true};
        }
        var controller = @getByIdDirectPrivate(stream, "readableStreamController");
        
        var queue = @getByIdDirectPrivate(controller, "queue");
        var value = [result.value].concat(queue.content.toArray(false));
        var length = value.length;

        if (@isReadableByteStreamController(controller)) {
            for (var i = 0; i < length; i++) {
                const buf = value[i];
                if (!(@ArrayBuffer.@isView(buf) || buf instanceof @ArrayBuffer)) {
                    const {buffer, byteOffset, byteLength} = buf;
                    @putByValDirect(value, i, new @Uint8Array(buffer, byteOffset, byteLength));
                }
            }
        } else {
            for (var i = 1; i < length; i++) {
                @putByValDirect(value, i, value[i].value);
            }
        }
        
        var size = queue.size;
        @resetQueue(queue);

        if (@getByIdDirectPrivate(controller, "closeRequested"))
            @readableStreamClose(@getByIdDirectPrivate(controller, "controlledReadableStream"));
        else if (@isReadableStreamDefaultController(controller)) 
            @readableStreamDefaultControllerCallPullIfNeeded(controller);
        else if (@isReadableByteStreamController(controller))
            @readableByteStreamControllerCallPullIfNeeded(controller);
        

        
        return {value: value, size: size, done: false};
    };
    
    var pullResult = controller.@pull(controller);
    if (pullResult && @isPromise(pullResult)) {
        return pullResult.@then(onPullMany);
    }

    return onPullMany(pullResult);
}

function read()
{
    "use strict";

    if (!@isReadableStreamDefaultReader(this))
        return @Promise.@reject(@makeThisTypeError("ReadableStreamDefaultReader", "read"));
    if (!@getByIdDirectPrivate(this, "ownerReadableStream"))
        return @Promise.@reject(@makeTypeError("read() called on a reader owned by no readable stream"));

    return @readableStreamDefaultReaderRead(this);
}

function releaseLock()
{
    "use strict";

    if (!@isReadableStreamDefaultReader(this))
        throw @makeThisTypeError("ReadableStreamDefaultReader", "releaseLock");

    if (!@getByIdDirectPrivate(this, "ownerReadableStream"))
        return;

    if (@getByIdDirectPrivate(this, "readRequests")?.isNotEmpty())
        @throwTypeError("There are still pending read requests, cannot release the lock");

    @readableStreamReaderGenericRelease(this);
}

@getter
function closed()
{
    "use strict";

    if (!@isReadableStreamDefaultReader(this))
        return @Promise.@reject(@makeGetterTypeError("ReadableStreamDefaultReader", "closed"));

    return @getByIdDirectPrivate(this, "closedPromiseCapability").@promise;
}