chrome/nsChromeRegistry.h
author Andrew Osmond <aosmond@mozilla.com>
Tue, 24 Apr 2018 13:51:35 -0400
changeset 415325 1173dccd114e1c86047a6f01e341cf1c4ea8fe9c
parent 405487 26dc46bd3cccc934f5d8070cd8ba9a33d7a60cdf
child 421882 0673137d307f3878d4cf48160cfa16efb66c25b6
permissions -rw-r--r--
Bug 1444537 - Part 3. Fix how redecode errors could cause animated image state inconsistencies. r=tnikkel We can discard frames from an animated image if the memory footprint exceeds the threshold. This will cause us to redecode frames on demand instead. However decoders can fail to produce the same results on subsequent runs due to differences in memory pressure, etc. If this happens our state can get inconsistent. In particular, if we keep failing on the first frame, we end up in an infinite loop on the decoder thread. Since we don't have the owning image to signal, as we had to release our reference to it after the first pass, we can do little but stop decoding. From the user's perspective, the animation will come to a stop.

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 nsChromeRegistry_h
#define nsChromeRegistry_h

#include "nsIToolkitChromeRegistry.h"
#include "nsIObserver.h"
#include "nsWeakReference.h"

#ifdef MOZ_XUL
#include "nsIXULOverlayProvider.h"
#endif

#include "nsString.h"
#include "nsURIHashKey.h"
#include "nsInterfaceHashtable.h"
#include "nsXULAppAPI.h"

#include "mozilla/FileLocation.h"

class nsPIDOMWindowOuter;
class nsIPrefBranch;
class nsIURL;

// The chrome registry is actually split between nsChromeRegistryChrome and
// nsChromeRegistryContent. The work/data that is common to both resides in
// the shared nsChromeRegistry implementation, with operations that only make
// sense for one side erroring out in the other.

// for component registration
// {47049e42-1d87-482a-984d-56ae185e367a}
#define NS_CHROMEREGISTRY_CID \
{ 0x47049e42, 0x1d87, 0x482a, { 0x98, 0x4d, 0x56, 0xae, 0x18, 0x5e, 0x36, 0x7a } }

class nsChromeRegistry : public nsIToolkitChromeRegistry,
#ifdef MOZ_XUL
                         public nsIXULOverlayProvider,
#endif
                         public nsIObserver,
                         public nsSupportsWeakReference
{
public:
  NS_DECL_ISUPPORTS

  // nsIXULChromeRegistry methods:
  NS_IMETHOD ReloadChrome() override;
  NS_IMETHOD RefreshSkins() override;
  NS_IMETHOD AllowScriptsForPackage(nsIURI* url,
                                    bool* _retval) override;
  NS_IMETHOD AllowContentToAccess(nsIURI* url,
                                  bool* _retval) override;
  NS_IMETHOD CanLoadURLRemotely(nsIURI* url,
                                bool* _retval) override;
  NS_IMETHOD MustLoadURLRemotely(nsIURI* url,
                                 bool* _retval) override;

  // nsIChromeRegistry methods:
  NS_IMETHOD_(bool) WrappersEnabled(nsIURI *aURI) override;
  NS_IMETHOD ConvertChromeURL(nsIURI* aChromeURI, nsIURI* *aResult) override;

  // nsChromeRegistry methods:
  nsChromeRegistry() : mInitialized(false) { }

  virtual nsresult Init();

  static already_AddRefed<nsIChromeRegistry> GetService();

  static nsChromeRegistry* gChromeRegistry;

  // This method can change its parameter, so due to thread safety issues
  // it should only be called for nsCOMPtr<nsIURI> that is on the stack,
  // unless you know what you are doing.
  static nsresult Canonify(nsCOMPtr<nsIURI>& aChromeURL);

protected:
  virtual ~nsChromeRegistry();

  void FlushSkinCaches();
  void FlushAllCaches();

  static void LogMessage(const char* aMsg, ...)
    MOZ_FORMAT_PRINTF(1, 2);
  static void LogMessageWithContext(nsIURI* aURL, uint32_t aLineNumber, uint32_t flags,
                                    const char* aMsg, ...)
    MOZ_FORMAT_PRINTF(4, 5);

  virtual nsIURI* GetBaseURIFromPackage(const nsCString& aPackage,
                                        const nsCString& aProvider,
                                        const nsCString& aPath) = 0;
  virtual nsresult GetFlagsFromPackage(const nsCString& aPackage,
                                       uint32_t* aFlags) = 0;

  static nsresult RefreshWindow(nsPIDOMWindowOuter* aWindow);
  static nsresult GetProviderAndPath(nsIURI* aChromeURL,
                                     nsACString& aProvider, nsACString& aPath);

  bool GetDirectionForLocale(const nsACString& aLocale);

  void SanitizeForBCP47(nsACString& aLocale);

public:
  static already_AddRefed<nsChromeRegistry> GetSingleton();

  struct ManifestProcessingContext
  {
    ManifestProcessingContext(NSLocationType aType, mozilla::FileLocation &aFile)
      : mType(aType)
      , mFile(aFile)
    { }

    ~ManifestProcessingContext()
    { }

    nsIURI* GetManifestURI();
    already_AddRefed<nsIURI> ResolveURI(const char* uri);

    NSLocationType mType;
    mozilla::FileLocation mFile;
    nsCOMPtr<nsIURI> mManifestURI;
  };

  virtual void ManifestContent(ManifestProcessingContext& cx, int lineno,
                               char *const * argv, int flags) = 0;
  virtual void ManifestLocale(ManifestProcessingContext& cx, int lineno,
                              char *const * argv, int flags) = 0;
  virtual void ManifestSkin(ManifestProcessingContext& cx, int lineno,
                            char *const * argv, int flags) = 0;
  virtual void ManifestOverlay(ManifestProcessingContext& cx, int lineno,
                               char *const * argv, int flags) = 0;
  virtual void ManifestStyle(ManifestProcessingContext& cx, int lineno,
                             char *const * argv, int flags) = 0;
  virtual void ManifestOverride(ManifestProcessingContext& cx, int lineno,
                                char *const * argv, int flags) = 0;
  virtual void ManifestResource(ManifestProcessingContext& cx, int lineno,
                                char *const * argv, int flags) = 0;

  // Available flags
  enum {
    // This package should use the new XPCNativeWrappers to separate
    // content from chrome. This flag is currently unused (because we call
    // into xpconnect at registration time).
    XPCNATIVEWRAPPERS = 1 << 1,

    // Content script may access files in this package
    CONTENT_ACCESSIBLE = 1 << 2,

    // Package may be loaded remotely
    REMOTE_ALLOWED = 1 << 3,

    // Package must be loaded remotely
    REMOTE_REQUIRED = 1 << 4,
  };

  bool mInitialized;

  // "Override" table (chrome URI string -> real URI)
  nsInterfaceHashtable<nsURIHashKey, nsIURI> mOverrideTable;
};

#endif // nsChromeRegistry_h