RetroZilla/netwerk/base/src/nsTransportUtils.cpp

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
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 *
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 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla.
 *
 * The Initial Developer of the Original Code is IBM Corporation.
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 * IBM Corporation. All Rights Reserved.
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 *   IBM Corp.
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 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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#include "nsTransportUtils.h"
#include "nsITransport.h"
#include "nsIEventTarget.h"
#include "nsProxyRelease.h"
#include "nsAutoLock.h"
#include "nsCOMPtr.h"
#include "plevent.h"

//-----------------------------------------------------------------------------

class nsTransportStatusEvent;

class nsTransportEventSinkProxy : public nsITransportEventSink
{
public:
    NS_DECL_ISUPPORTS
    NS_DECL_NSITRANSPORTEVENTSINK

    nsTransportEventSinkProxy(nsITransportEventSink *sink,
                              nsIEventTarget *target,
                              PRBool coalesceAll)
        : mSink(sink)
        , mTarget(target)
        , mLock(PR_NewLock())
        , mLastEvent(nsnull)
        , mCoalesceAll(coalesceAll)
    {
        NS_ADDREF(mSink);
    }

    virtual ~nsTransportEventSinkProxy()
    {
        if (mLock)
            PR_DestroyLock(mLock);
    
        // our reference to mSink could be the last, so be sure to release
        // it on the target thread.  otherwise, we could get into trouble.
        NS_ProxyRelease(mTarget, mSink);
    }

    nsITransportEventSink           *mSink;
    nsCOMPtr<nsIEventTarget>         mTarget;
    PRLock                          *mLock;
    nsTransportStatusEvent          *mLastEvent;
    PRBool                           mCoalesceAll;
};

class nsTransportStatusEvent : public PLEvent
{
public:
    nsTransportStatusEvent(nsTransportEventSinkProxy *proxy,
                           nsITransport *transport,
                           nsresult status,
                           PRUint64 progress,
                           PRUint64 progressMax)
        : mTransport(transport)
        , mStatus(status)
        , mProgress(progress)
        , mProgressMax(progressMax)
    {
        NS_ADDREF(proxy); 
        PL_InitEvent(this, proxy, HandleEvent, DestroyEvent);
    }

   ~nsTransportStatusEvent()
    {
        nsTransportEventSinkProxy *proxy =
                (nsTransportEventSinkProxy *) owner;
        NS_RELEASE(proxy);
    }

    PR_STATIC_CALLBACK(void*) HandleEvent(PLEvent *event)
    {
        nsTransportStatusEvent *self = (nsTransportStatusEvent *) event;
        nsTransportEventSinkProxy *proxy = (nsTransportEventSinkProxy *) event->owner;

        // since this event is being handled, we need to clear the proxy's ref.
        // if not coalescing all, then last event may not equal self!
        {
            nsAutoLock lock(proxy->mLock);
            if (proxy->mLastEvent == self)
                proxy->mLastEvent = nsnull;
        }

        proxy->mSink->OnTransportStatus(self->mTransport,
                                        self->mStatus,
                                        self->mProgress,
                                        self->mProgressMax);
        return nsnull;
    }

    PR_STATIC_CALLBACK(void) DestroyEvent(PLEvent *event)
    {
        delete (nsTransportStatusEvent *) event;
    }

    // parameters to OnTransportStatus
    nsCOMPtr<nsITransport> mTransport;
    nsresult               mStatus;
    PRUint64               mProgress;
    PRUint64               mProgressMax;
};

NS_IMPL_THREADSAFE_ISUPPORTS1(nsTransportEventSinkProxy, nsITransportEventSink)

NS_IMETHODIMP
nsTransportEventSinkProxy::OnTransportStatus(nsITransport *transport,
                                             nsresult status,
                                             PRUint64 progress,
                                             PRUint64 progressMax)
{
    nsresult rv = NS_OK;
    PLEvent *event;
    {
        nsAutoLock lock(mLock);

        // try to coalesce events! ;-)
        if (mLastEvent && (mCoalesceAll || mLastEvent->mStatus == status)) {
            mLastEvent->mStatus = status;
            mLastEvent->mProgress = progress;
            mLastEvent->mProgressMax = progressMax;
            event = nsnull;
        }
        else {
            event = new nsTransportStatusEvent(this, transport, status,
                                               progress, progressMax);
            if (!event)
                rv = NS_ERROR_OUT_OF_MEMORY;
            mLastEvent = (nsTransportStatusEvent *) event;
        }
    }
    if (event) {
        rv = mTarget->PostEvent(event);
        if (NS_FAILED(rv)) {
            NS_WARNING("unable to post transport status event");
            PL_DestroyEvent(event);

            nsAutoLock lock(mLock); // cleanup.. don't reference anymore!
            mLastEvent = nsnull;
        }
    }
    return rv;
}

//-----------------------------------------------------------------------------

nsresult
net_NewTransportEventSinkProxy(nsITransportEventSink **result,
                               nsITransportEventSink *sink,
                               nsIEventTarget *target,
                               PRBool coalesceAll)
{
    *result = new nsTransportEventSinkProxy(sink, target, coalesceAll);
    if (!*result)
        return NS_ERROR_OUT_OF_MEMORY;
    NS_ADDREF(*result);
    return NS_OK;
}