michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * This file defines two implementations of the nsIBackgroundFileSaver
michael@0:  * interface.  See the "test_backgroundfilesaver.js" file for usage examples.
michael@0:  */
michael@0: 
michael@0: #ifndef BackgroundFileSaver_h__
michael@0: #define BackgroundFileSaver_h__
michael@0: 
michael@0: #include "mozilla/Mutex.h"
michael@0: #include "nsCOMArray.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsNSSShutDown.h"
michael@0: #include "nsIAsyncOutputStream.h"
michael@0: #include "nsIBackgroundFileSaver.h"
michael@0: #include "nsIStreamListener.h"
michael@0: #include "nsStreamUtils.h"
michael@0: #include "ScopedNSSTypes.h"
michael@0: 
michael@0: class nsIAsyncInputStream;
michael@0: class nsIThread;
michael@0: class nsIX509CertList;
michael@0: class PRLogModuleInfo;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace net {
michael@0: 
michael@0: class DigestOutputStream;
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: //// BackgroundFileSaver
michael@0: 
michael@0: class BackgroundFileSaver : public nsIBackgroundFileSaver,
michael@0:                             public nsNSSShutDownObject
michael@0: {
michael@0: public:
michael@0:   NS_DECL_NSIBACKGROUNDFILESAVER
michael@0: 
michael@0:   BackgroundFileSaver();
michael@0: 
michael@0:   /**
michael@0:    * Initializes the pipe and the worker thread on XPCOM construction.
michael@0:    *
michael@0:    * This is called automatically by the XPCOM infrastructure, and if this
michael@0:    * fails, the factory will delete this object without returning a reference.
michael@0:    */
michael@0:   nsresult Init();
michael@0: 
michael@0:   /**
michael@0:    * Used by nsNSSShutDownList to manage nsNSSShutDownObjects.
michael@0:    */
michael@0:   void virtualDestroyNSSReference();
michael@0: 
michael@0:   /**
michael@0:    * Number of worker threads that are currently running.
michael@0:    */
michael@0:   static uint32_t sThreadCount;
michael@0: 
michael@0:   /**
michael@0:    * Maximum number of worker threads reached during the current download session,
michael@0:    * used for telemetry.
michael@0:    *
michael@0:    * When there are no more worker threads running, we consider the download
michael@0:    * session finished, and this counter is reset.
michael@0:    */
michael@0:   static uint32_t sTelemetryMaxThreadCount;
michael@0: 
michael@0: 
michael@0: protected:
michael@0:   virtual ~BackgroundFileSaver();
michael@0: 
michael@0:   static PRLogModuleInfo *prlog;
michael@0: 
michael@0:   /**
michael@0:    * Helper function for managing NSS objects (mDigestContext).
michael@0:    */
michael@0:   void destructorSafeDestroyNSSReference();
michael@0: 
michael@0:   /**
michael@0:    * Thread that constructed this object.
michael@0:    */
michael@0:   nsCOMPtr<nsIThread> mControlThread;
michael@0: 
michael@0:   /**
michael@0:    * Thread to which the actual input/output is delegated.
michael@0:    */
michael@0:   nsCOMPtr<nsIThread> mWorkerThread;
michael@0: 
michael@0:   /**
michael@0:    * Stream that receives data from derived classes.  The received data will be
michael@0:    * available to the worker thread through mPipeInputStream. This is an
michael@0:    * instance of nsPipeOutputStream, not BackgroundFileSaverOutputStream.
michael@0:    */
michael@0:   nsCOMPtr<nsIAsyncOutputStream> mPipeOutputStream;
michael@0: 
michael@0:   /**
michael@0:    * Used during initialization, determines if the pipe is created with an
michael@0:    * infinite buffer.  An infinite buffer is required if the derived class
michael@0:    * implements nsIStreamListener, because this interface requires all the
michael@0:    * provided data to be consumed synchronously.
michael@0:    */
michael@0:   virtual bool HasInfiniteBuffer() = 0;
michael@0: 
michael@0:   /**
michael@0:    * Used by derived classes if they need to be called back while copying.
michael@0:    */
michael@0:   virtual nsAsyncCopyProgressFun GetProgressCallback() = 0;
michael@0: 
michael@0:   /**
michael@0:    * Stream used by the worker thread to read the data to be saved.
michael@0:    */
michael@0:   nsCOMPtr<nsIAsyncInputStream> mPipeInputStream;
michael@0: 
michael@0: private:
michael@0:   friend class NotifyTargetChangeRunnable;
michael@0: 
michael@0:   /**
michael@0:    * Matches the nsIBackgroundFileSaver::observer property.
michael@0:    *
michael@0:    * @remarks This is a strong reference so that JavaScript callers don't need
michael@0:    *          to worry about keeping another reference to the observer.
michael@0:    */
michael@0:   nsCOMPtr<nsIBackgroundFileSaverObserver> mObserver;
michael@0: 
michael@0:   //////////////////////////////////////////////////////////////////////////////
michael@0:   //// Shared state between control and worker threads
michael@0: 
michael@0:   /**
michael@0:    * Protects the shared state between control and worker threads.  This mutex
michael@0:    * is always locked for a very short time, never during input/output.
michael@0:    */
michael@0:   mozilla::Mutex mLock;
michael@0: 
michael@0:   /**
michael@0:    * True if the worker thread is already waiting to process a change in state.
michael@0:    */
michael@0:   bool mWorkerThreadAttentionRequested;
michael@0: 
michael@0:   /**
michael@0:    * True if the operation should finish as soon as possibile.
michael@0:    */
michael@0:   bool mFinishRequested;
michael@0: 
michael@0:   /**
michael@0:    * True if the operation completed, with either success or failure.
michael@0:    */
michael@0:   bool mComplete;
michael@0: 
michael@0:   /**
michael@0:    * Holds the current file saver status.  This is a success status while the
michael@0:    * object is working correctly, and remains such if the operation completes
michael@0:    * successfully.  This becomes an error status when an error occurs on the
michael@0:    * worker thread, or when the operation is canceled.
michael@0:    */
michael@0:   nsresult mStatus;
michael@0: 
michael@0:   /**
michael@0:    * True if we should append data to the initial target file, instead of
michael@0:    * overwriting it.
michael@0:    */
michael@0:   bool mAppend;
michael@0: 
michael@0:   /**
michael@0:    * This is set by the first SetTarget call on the control thread, and contains
michael@0:    * the target file name that will be used by the worker thread, as soon as it
michael@0:    * is possible to update mActualTarget and open the file.  This is null if no
michael@0:    * target was ever assigned to this object.
michael@0:    */
michael@0:   nsCOMPtr<nsIFile> mInitialTarget;
michael@0: 
michael@0:   /**
michael@0:    * This is set by the first SetTarget call on the control thread, and
michael@0:    * indicates whether mInitialTarget should be kept as partially completed,
michael@0:    * rather than deleted, if the operation fails or is canceled.
michael@0:    */
michael@0:   bool mInitialTargetKeepPartial;
michael@0: 
michael@0:   /**
michael@0:    * This is set by subsequent SetTarget calls on the control thread, and
michael@0:    * contains the new target file name to which the worker thread will move the
michael@0:    * target file, as soon as it can be done.  This is null if SetTarget was
michael@0:    * called only once, or no target was ever assigned to this object.
michael@0:    *
michael@0:    * The target file can be renamed multiple times, though only the most recent
michael@0:    * rename is guaranteed to be processed by the worker thread.
michael@0:    */
michael@0:   nsCOMPtr<nsIFile> mRenamedTarget;
michael@0: 
michael@0:   /**
michael@0:    * This is set by subsequent SetTarget calls on the control thread, and
michael@0:    * indicates whether mRenamedTarget should be kept as partially completed,
michael@0:    * rather than deleted, if the operation fails or is canceled.
michael@0:    */
michael@0:   bool mRenamedTargetKeepPartial;
michael@0: 
michael@0:   /**
michael@0:    * While NS_AsyncCopy is in progress, allows canceling it.  Null otherwise.
michael@0:    * This is read by both threads but only written by the worker thread.
michael@0:    */
michael@0:   nsCOMPtr<nsISupports> mAsyncCopyContext;
michael@0: 
michael@0:   /**
michael@0:    * The SHA 256 hash in raw bytes of the downloaded file. This is written
michael@0:    * by the worker thread but can be read on the main thread.
michael@0:    */
michael@0:   nsAutoCString mSha256;
michael@0: 
michael@0:   /**
michael@0:    * Whether or not to compute the hash. Must be set on the main thread before
michael@0:    * setTarget is called.
michael@0:    */
michael@0:   bool mSha256Enabled;
michael@0: 
michael@0:   /**
michael@0:    * Store the signature info.
michael@0:    */
michael@0:   nsCOMArray<nsIX509CertList> mSignatureInfo;
michael@0: 
michael@0:   /**
michael@0:    * Whether or not to extract the signature. Must be set on the main thread
michael@0:    * before setTarget is called.
michael@0:    */
michael@0:   bool mSignatureInfoEnabled;
michael@0: 
michael@0:   //////////////////////////////////////////////////////////////////////////////
michael@0:   //// State handled exclusively by the worker thread
michael@0: 
michael@0:   /**
michael@0:    * Current target file associated to the input and output streams.
michael@0:    */
michael@0:   nsCOMPtr<nsIFile> mActualTarget;
michael@0: 
michael@0:   /**
michael@0:    * Indicates whether mActualTarget should be kept as partially completed,
michael@0:    * rather than deleted, if the operation fails or is canceled.
michael@0:    */
michael@0:   bool mActualTargetKeepPartial;
michael@0: 
michael@0:   /**
michael@0:    * Used to calculate the file hash. This keeps state across file renames and
michael@0:    * is lazily initialized in ProcessStateChange.
michael@0:    */
michael@0:   ScopedPK11Context mDigestContext;
michael@0: 
michael@0:   //////////////////////////////////////////////////////////////////////////////
michael@0:   //// Private methods
michael@0: 
michael@0:   /**
michael@0:    * Called when NS_AsyncCopy completes.
michael@0:    *
michael@0:    * @param aClosure
michael@0:    *        Populated with a raw pointer to the BackgroundFileSaver object.
michael@0:    * @param aStatus
michael@0:    *        Success or failure status specified when the copy was interrupted.
michael@0:    */
michael@0:   static void AsyncCopyCallback(void *aClosure, nsresult aStatus);
michael@0: 
michael@0:   /**
michael@0:    * Called on the control thread after state changes, to ensure that the worker
michael@0:    * thread will process the state change appropriately.
michael@0:    *
michael@0:    * @param aShouldInterruptCopy
michael@0:    *        If true, the current NS_AsyncCopy, if any, is canceled.
michael@0:    */
michael@0:   nsresult GetWorkerThreadAttention(bool aShouldInterruptCopy);
michael@0: 
michael@0:   /**
michael@0:    * Event called on the worker thread to begin processing a state change.
michael@0:    */
michael@0:   nsresult ProcessAttention();
michael@0: 
michael@0:   /**
michael@0:    * Called by ProcessAttention to execute the operations corresponding to the
michael@0:    * state change.  If this results in an error, ProcessAttention will force the
michael@0:    * entire operation to be aborted.
michael@0:    */
michael@0:   nsresult ProcessStateChange();
michael@0: 
michael@0:   /**
michael@0:    * Returns true if completion conditions are met on the worker thread.  The
michael@0:    * first time this happens, posts the completion event to the control thread.
michael@0:    */
michael@0:   bool CheckCompletion();
michael@0: 
michael@0:   /**
michael@0:    * Event called on the control thread to indicate that file contents will now
michael@0:    * be saved to the specified file.
michael@0:    */
michael@0:   nsresult NotifyTargetChange(nsIFile *aTarget);
michael@0: 
michael@0:   /**
michael@0:    * Event called on the control thread to send the final notification.
michael@0:    */
michael@0:   nsresult NotifySaveComplete();
michael@0: 
michael@0:   /**
michael@0:    * Verifies the signature of the binary at the specified file path and stores
michael@0:    * the signature data in mSignatureInfo. We extract only X.509 certificates,
michael@0:    * since that is what Google's Safebrowsing protocol specifies.
michael@0:    */
michael@0:   nsresult ExtractSignatureInfo(const nsAString& filePath);
michael@0: };
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: //// BackgroundFileSaverOutputStream
michael@0: 
michael@0: class BackgroundFileSaverOutputStream : public BackgroundFileSaver
michael@0:                                       , public nsIAsyncOutputStream
michael@0:                                       , public nsIOutputStreamCallback
michael@0: {
michael@0: public:
michael@0:   NS_DECL_THREADSAFE_ISUPPORTS
michael@0:   NS_DECL_NSIOUTPUTSTREAM
michael@0:   NS_DECL_NSIASYNCOUTPUTSTREAM
michael@0:   NS_DECL_NSIOUTPUTSTREAMCALLBACK
michael@0: 
michael@0:   BackgroundFileSaverOutputStream();
michael@0: 
michael@0: protected:
michael@0:   virtual bool HasInfiniteBuffer() MOZ_OVERRIDE;
michael@0:   virtual nsAsyncCopyProgressFun GetProgressCallback() MOZ_OVERRIDE;
michael@0: 
michael@0: private:
michael@0:   ~BackgroundFileSaverOutputStream();
michael@0: 
michael@0:   /**
michael@0:    * Original callback provided to our AsyncWait wrapper.
michael@0:    */
michael@0:   nsCOMPtr<nsIOutputStreamCallback> mAsyncWaitCallback;
michael@0: };
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: //// BackgroundFileSaverStreamListener. This class is instantiated by
michael@0: // nsExternalHelperAppService, DownloadCore.jsm, and possibly others.
michael@0: 
michael@0: class BackgroundFileSaverStreamListener : public BackgroundFileSaver
michael@0:                                         , public nsIStreamListener
michael@0: {
michael@0: public:
michael@0:   NS_DECL_THREADSAFE_ISUPPORTS
michael@0:   NS_DECL_NSIREQUESTOBSERVER
michael@0:   NS_DECL_NSISTREAMLISTENER
michael@0: 
michael@0:   BackgroundFileSaverStreamListener();
michael@0: 
michael@0: protected:
michael@0:   virtual bool HasInfiniteBuffer() MOZ_OVERRIDE;
michael@0:   virtual nsAsyncCopyProgressFun GetProgressCallback() MOZ_OVERRIDE;
michael@0: 
michael@0: private:
michael@0:   ~BackgroundFileSaverStreamListener();
michael@0: 
michael@0:   /**
michael@0:    * Protects the state related to whether the request should be suspended.
michael@0:    */
michael@0:   mozilla::Mutex mSuspensionLock;
michael@0: 
michael@0:   /**
michael@0:    * Whether we should suspend the request because we received too much data.
michael@0:    */
michael@0:   bool mReceivedTooMuchData;
michael@0: 
michael@0:   /**
michael@0:    * Request for which we received too much data.  This is populated when
michael@0:    * mReceivedTooMuchData becomes true for the first time.
michael@0:    */
michael@0:   nsCOMPtr<nsIRequest> mRequest;
michael@0: 
michael@0:   /**
michael@0:    * Whether mRequest is currently suspended.
michael@0:    */
michael@0:   bool mRequestSuspended;
michael@0: 
michael@0:   /**
michael@0:    * Called while NS_AsyncCopy is copying data.
michael@0:    */
michael@0:   static void AsyncCopyProgressCallback(void *aClosure, uint32_t aCount);
michael@0: 
michael@0:   /**
michael@0:    * Called on the control thread to suspend or resume the request.
michael@0:    */
michael@0:   nsresult NotifySuspendOrResume();
michael@0: };
michael@0: 
michael@0: // A wrapper around nsIOutputStream, so that we can compute hashes on the
michael@0: // stream without copying and without polluting pristine NSS code with XPCOM
michael@0: // interfaces.
michael@0: class DigestOutputStream : public nsNSSShutDownObject,
michael@0:                            public nsIOutputStream
michael@0: {
michael@0: public:
michael@0:   NS_DECL_THREADSAFE_ISUPPORTS
michael@0:   NS_DECL_NSIOUTPUTSTREAM
michael@0:   // Constructor. Neither parameter may be null. The caller owns both.
michael@0:   DigestOutputStream(nsIOutputStream* outputStream, PK11Context* aContext);
michael@0:   ~DigestOutputStream();
michael@0: 
michael@0:   // We don't own any NSS objects here, so no need to clean up
michael@0:   void virtualDestroyNSSReference() { }
michael@0: 
michael@0: private:
michael@0:   // Calls to write are passed to this stream.
michael@0:   nsCOMPtr<nsIOutputStream> mOutputStream;
michael@0:   // Digest context used to compute the hash, owned by the caller.
michael@0:   PK11Context* mDigestContext;
michael@0: 
michael@0:   // Don't accidentally copy construct.
michael@0:   DigestOutputStream(const DigestOutputStream& d);
michael@0: };
michael@0: } // namespace net
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif