netwerk/base/nsSyncStreamListener.cpp
author Andrew Osmond <aosmond@mozilla.com>
Fri, 17 Nov 2017 06:45:28 -0500
changeset 392351 b9a29d94ccac646c9336fa75e084bbc8581501ad
parent 367749 6a629adbb62a299d7208373d1c6f375149d2afdb
child 442673 89474459aeb8d21854d18c26822069d94625ea16
permissions -rw-r--r--
Bug 1368776 - Part 15. Cache flags passed to ImageResource::GetImageContainerImpl for consistency. r=tnikkel When FLAG_HIGH_QUALITY_SCALING is used, we need to make sure we continue using that flag when we update the container. We should also use it for comparing whether or not an existing image container is equivalent.

/* 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/. */

#include "nsIOService.h"
#include "nsSyncStreamListener.h"
#include "nsIPipe.h"
#include "nsThreadUtils.h"
#include <algorithm>

using namespace mozilla::net;

nsresult
nsSyncStreamListener::Init()
{
    return NS_NewPipe(getter_AddRefs(mPipeIn),
                      getter_AddRefs(mPipeOut),
                      mozilla::net::nsIOService::gDefaultSegmentSize,
                      UINT32_MAX, // no size limit
                      false,
                      false);
}

nsresult
nsSyncStreamListener::WaitForData()
{
    mKeepWaiting = true;

    if (!mozilla::SpinEventLoopUntil([&]() { return !mKeepWaiting; })) {
      return NS_ERROR_FAILURE;
    }

    return NS_OK;
}

//-----------------------------------------------------------------------------
// nsSyncStreamListener::nsISupports
//-----------------------------------------------------------------------------

NS_IMPL_ISUPPORTS(nsSyncStreamListener,
                  nsIStreamListener,
                  nsIRequestObserver,
                  nsIInputStream,
                  nsISyncStreamListener)

//-----------------------------------------------------------------------------
// nsSyncStreamListener::nsISyncStreamListener
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsSyncStreamListener::GetInputStream(nsIInputStream **result)
{
    NS_ADDREF(*result = this);
    return NS_OK;
}

//-----------------------------------------------------------------------------
// nsSyncStreamListener::nsIStreamListener
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsSyncStreamListener::OnStartRequest(nsIRequest  *request,
                                     nsISupports *context)
{
    return NS_OK;
}

NS_IMETHODIMP
nsSyncStreamListener::OnDataAvailable(nsIRequest     *request,
                                      nsISupports    *context,
                                      nsIInputStream *stream,
                                      uint64_t        offset,
                                      uint32_t        count)
{
    uint32_t bytesWritten;

    nsresult rv = mPipeOut->WriteFrom(stream, count, &bytesWritten);

    // if we get an error, then return failure.  this will cause the
    // channel to be canceled, and as a result our OnStopRequest method
    // will be called immediately.  because of this we do not need to
    // set mStatus or mKeepWaiting here.
    if (NS_FAILED(rv))
        return rv;

    // we expect that all data will be written to the pipe because
    // the pipe was created to have "infinite" room.
    NS_ASSERTION(bytesWritten == count, "did not write all data");

    mKeepWaiting = false; // unblock Read
    return NS_OK;
}

NS_IMETHODIMP
nsSyncStreamListener::OnStopRequest(nsIRequest  *request,
                                    nsISupports *context,
                                    nsresult     status)
{
    mStatus = status;
    mKeepWaiting = false; // unblock Read
    mDone = true;
    return NS_OK;
}

//-----------------------------------------------------------------------------
// nsSyncStreamListener::nsIInputStream
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsSyncStreamListener::Close()
{
    mStatus = NS_BASE_STREAM_CLOSED;
    mDone = true;

    // It'd be nice if we could explicitly cancel the request at this point,
    // but we don't have a reference to it, so the best we can do is close the
    // pipe so that the next OnDataAvailable event will fail.
    if (mPipeIn) {
        mPipeIn->Close();
        mPipeIn = nullptr;
    }
    return NS_OK;
}

NS_IMETHODIMP
nsSyncStreamListener::Available(uint64_t *result)
{
    if (NS_FAILED(mStatus))
        return mStatus;

    mStatus = mPipeIn->Available(result);
    if (NS_SUCCEEDED(mStatus) && (*result == 0) && !mDone) {
        mStatus = WaitForData();
        if (NS_SUCCEEDED(mStatus))
            mStatus = mPipeIn->Available(result);
    }
    return mStatus;
}

NS_IMETHODIMP
nsSyncStreamListener::Read(char     *buf,
                           uint32_t  bufLen,
                           uint32_t *result)
{
    if (mStatus == NS_BASE_STREAM_CLOSED) {
        *result = 0;
        return NS_OK;
    }

    uint64_t avail64;
    if (NS_FAILED(Available(&avail64)))
        return mStatus;

    uint32_t avail = (uint32_t)std::min(avail64, (uint64_t)bufLen);
    mStatus = mPipeIn->Read(buf, avail, result);
    return mStatus;
}

NS_IMETHODIMP
nsSyncStreamListener::ReadSegments(nsWriteSegmentFun  writer,
                                   void              *closure,
                                   uint32_t           count,
                                   uint32_t          *result)
{
    if (mStatus == NS_BASE_STREAM_CLOSED) {
        *result = 0;
        return NS_OK;
    }

    uint64_t avail64;
    if (NS_FAILED(Available(&avail64)))
        return mStatus;

    uint32_t avail = (uint32_t)std::min(avail64, (uint64_t)count);
    mStatus = mPipeIn->ReadSegments(writer, closure, avail, result);
    return mStatus;
}

NS_IMETHODIMP
nsSyncStreamListener::IsNonBlocking(bool *result)
{
    *result = false;
    return NS_OK;
}