netwerk/base/nsPACMan.h
author Andrew Osmond <aosmond@mozilla.com>
Fri, 17 Nov 2017 06:45:28 -0500
changeset 392351 b9a29d94ccac646c9336fa75e084bbc8581501ad
parent 367354 beaf8abcee0b004f02d2daf88c082efe496bd97c
child 399220 3d28ca7c05d8f9ba3ba6ff1cd5449dce42ae95c1
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.

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */

#ifndef nsPACMan_h__
#define nsPACMan_h__

#include "nsIStreamLoader.h"
#include "nsIInterfaceRequestor.h"
#include "nsIChannelEventSink.h"
#include "ProxyAutoConfig.h"
#include "nsThreadUtils.h"
#include "nsIURI.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "mozilla/Attributes.h"
#include "mozilla/LinkedList.h"
#include "nsAutoPtr.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/Logging.h"
#include "mozilla/Atomics.h"
#include "mozilla/net/NeckoTargetHolder.h"

class nsISystemProxySettings;
class nsIThread;

namespace mozilla {
namespace net {

class nsPACMan;
class WaitForThreadShutdown;

/**
 * This class defines a callback interface used by AsyncGetProxyForURI.
 */
class NS_NO_VTABLE nsPACManCallback : public nsISupports
{
public:
  /**
   * This method is invoked on the same thread that called AsyncGetProxyForURI.
   *
   * @param status
   *        This parameter indicates whether or not the PAC query succeeded.
   * @param pacString
   *        This parameter holds the value of the PAC string.  It is empty when
   *        status is a failure code.
   * @param newPACURL
   *        This parameter holds the URL of a new PAC file that should be loaded
   *        before the query is evaluated again. At least one of pacString and
   *        newPACURL should be 0 length.
   */
  virtual void OnQueryComplete(nsresult status,
                               const nsCString &pacString,
                               const nsCString &newPACURL) = 0;
};

class PendingPACQuery final : public Runnable,
                              public LinkedListElement<PendingPACQuery>
{
public:
  PendingPACQuery(nsPACMan *pacMan, nsIURI *uri,
                  nsPACManCallback *callback,
                  bool mainThreadResponse);

  // can be called from either thread
  void Complete(nsresult status, const nsCString &pacString);
  void UseAlternatePACFile(const nsCString &pacURL);

  nsCString                  mSpec;
  nsCString                  mScheme;
  nsCString                  mHost;
  int32_t                    mPort;

  NS_IMETHOD Run(void);     /* Runnable */

private:
  nsPACMan                  *mPACMan;  // weak reference

private:
  RefPtr<nsPACManCallback> mCallback;
  bool                       mOnMainThreadOnly;
};

/**
 * This class provides an abstraction layer above the PAC thread.  The methods
 * defined on this class are intended to be called on the main thread only.
 */

class nsPACMan final : public nsIStreamLoaderObserver
                     , public nsIInterfaceRequestor
                     , public nsIChannelEventSink
                     , public NeckoTargetHolder
{
public:
  NS_DECL_THREADSAFE_ISUPPORTS

  explicit nsPACMan(nsIEventTarget *mainThreadEventTarget);

  /**
   * This method may be called to shutdown the PAC manager.  Any async queries
   * that have not yet completed will either finish normally or be canceled by
   * the time this method returns.
   */
  void Shutdown();

  /**
   * This method queries a PAC result asynchronously.  The callback runs on the
   * calling thread.  If the PAC file has not yet been loaded, then this method
   * will queue up the request, and complete it once the PAC file has been
   * loaded.
   *
   * @param uri
   *        The URI to query.
   * @param callback
   *        The callback to run once the PAC result is available.
   * @param mustCallbackOnMainThread
   *        If set to false the callback can be made from the PAC thread
   */
  nsresult AsyncGetProxyForURI(nsIURI *uri,
                               nsPACManCallback *callback,
                               bool mustCallbackOnMainThread);

  /**
   * This method may be called to reload the PAC file.  While we are loading
   * the PAC file, any asynchronous PAC queries will be queued up to be
   * processed once the PAC file finishes loading.
   *
   * @param pacSpec
   *        The non normalized uri spec of this URI used for comparison with
   *        system proxy settings to determine if the PAC uri has changed.
   */
  nsresult LoadPACFromURI(const nsCString &pacSpec);

  /**
   * Returns true if we are currently loading the PAC file.
   */
  bool IsLoading() { return mLoader != nullptr; }

  /**
   * Returns true if the given URI matches the URI of our PAC file or the
   * URI it has been redirected to. In the case of a chain of redirections
   * only the current one being followed and the original are considered
   * becuase this information is used, respectively, to determine if we
   * should bypass the proxy (to fetch the pac file) or if the pac
   * configuration has changed (and we should reload the pac file)
   */
  bool IsPACURI(const nsACString &spec)
  {
    return mPACURISpec.Equals(spec) || mPACURIRedirectSpec.Equals(spec) ||
      mNormalPACURISpec.Equals(spec);
  }

  bool IsPACURI(nsIURI *uri) {
    if (mPACURISpec.IsEmpty() && mPACURIRedirectSpec.IsEmpty()) {
      return false;
    }

    nsAutoCString tmp;
    nsresult rv = uri->GetSpec(tmp);
    if (NS_FAILED(rv)) {
      return false;
    }

    return IsPACURI(tmp);
  }

  nsresult Init(nsISystemProxySettings *);
  static nsPACMan *sInstance;

  // PAC thread operations only
  void ProcessPendingQ();
  void CancelPendingQ(nsresult);

private:
  NS_DECL_NSISTREAMLOADEROBSERVER
  NS_DECL_NSIINTERFACEREQUESTOR
  NS_DECL_NSICHANNELEVENTSINK

  friend class PendingPACQuery;
  friend class PACLoadComplete;
  friend class ExecutePACThreadAction;
  friend class WaitForThreadShutdown;

  ~nsPACMan();

  /**
   * Cancel any existing load if any.
   */
  void CancelExistingLoad();

  /**
   * Start loading the PAC file.
   */
  void StartLoading();

  /**
   * Reload the PAC file if there is reason to.
   */
  void MaybeReloadPAC();

  /**
   * Called when we fail to load the PAC file.
   */
  void OnLoadFailure();

  /**
   * PostQuery() only runs on the PAC thread and it is used to
   * place a pendingPACQuery into the queue and potentially
   * execute the queue if it was otherwise empty
   */
  nsresult PostQuery(PendingPACQuery *query);

  // PAC thread operations only
  void PostProcessPendingQ();
  void PostCancelPendingQ(nsresult);
  bool ProcessPending();

private:
  ProxyAutoConfig mPAC;
  nsCOMPtr<nsIThread>           mPACThread;
  nsCOMPtr<nsISystemProxySettings> mSystemProxySettings;

  LinkedList<PendingPACQuery> mPendingQ; /* pac thread only */

  // These specs are not nsIURI so that they can be used off the main thread.
  // The non-normalized versions are directly from the configuration, the
  // normalized version has been extracted from an nsIURI
  nsCString                    mPACURISpec;
  nsCString                    mPACURIRedirectSpec;
  nsCString                    mNormalPACURISpec;

  nsCOMPtr<nsIStreamLoader>    mLoader;
  bool                         mLoadPending;
  Atomic<bool, Relaxed>        mShutdown;
  TimeStamp                    mScheduledReload;
  uint32_t                     mLoadFailureCount;

  bool                         mInProgress;
  bool                         mIncludePath;
};

extern LazyLogModule gProxyLog;

} // namespace net
} // namespace mozilla

#endif  // nsPACMan_h__