dom/xul/nsXULPrototypeCache.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef nsXULPrototypeCache_h__
   7 #define nsXULPrototypeCache_h__
   8
   9 #include "nsBaseHashtable.h"
  10 #include "nsCOMPtr.h"
  11 #include "nsIObserver.h"
  12 #include "nsInterfaceHashtable.h"
  13 #include "nsRefPtrHashtable.h"
  14 #include "nsURIHashKey.h"
  15 #include "nsXULPrototypeDocument.h"
  16 #include "nsIStorageStream.h"
  17
  18 #include "mozilla/scache/StartupCache.h"
  19 #include "js/experimental/JSStencil.h"
  20 #include "mozilla/RefPtr.h"
  21
  22 class nsIHandleReportCallback;
  23 namespace mozilla {
  24 class StyleSheet;
  25 }  // namespace mozilla
  26
  27 /**
  28  * The XUL prototype cache can be used to store and retrieve shared data for
  29  * XUL documents, style sheets, XBL, and scripts.
  30  *
  31  * The cache has two levels:
  32  *  1. In-memory hashtables
  33  *  2. The on-disk cache file.
  34  */
  35 class nsXULPrototypeCache : public nsIObserver {
  36  public:
  37   enum class CacheType { Prototype, Script };
  38
  39   // nsISupports
  40   NS_DECL_THREADSAFE_ISUPPORTS
  41   NS_DECL_NSIOBSERVER
  42
  43   bool IsCached(nsIURI* aURI) { return GetPrototype(aURI) != nullptr; }
  44   void AbortCaching();
  45
  46   /**
  47    * Whether the prototype cache is enabled.
  48    */
  49   bool IsEnabled();
  50
  51   /**
  52    * Flush the cache; remove all XUL prototype documents, style
  53    * sheets, and scripts.
  54    */
  55   void Flush();
  56
  57   // The following methods are used to put and retrive various items into and
  58   // from the cache.
  59
  60   nsXULPrototypeDocument* GetPrototype(nsIURI* aURI);
  61   nsresult PutPrototype(nsXULPrototypeDocument* aDocument);
  62   void RemovePrototype(nsIURI* aURI) { mPrototypeTable.Remove(aURI); }
  63
  64   JS::Stencil* GetStencil(nsIURI* aURI);
  65   nsresult PutStencil(nsIURI* aURI, JS::Stencil* aStencil);
  66
  67   /**
  68    * Write the XUL prototype document to a cache file. The proto must be
  69    * fully loaded.
  70    */
  71   nsresult WritePrototype(nsXULPrototypeDocument* aPrototypeDocument);
  72
  73   /**
  74    * This interface allows partial reads and writes from the buffers in the
  75    * startupCache.
  76    */
  77
  78   inline nsresult GetPrototypeInputStream(nsIURI* aURI,
  79                                           nsIObjectInputStream** objectInput) {
  80     return GetInputStream(CacheType::Prototype, aURI, objectInput);
  81   }
  82   inline nsresult GetScriptInputStream(nsIURI* aURI,
  83                                        nsIObjectInputStream** objectInput) {
  84     return GetInputStream(CacheType::Script, aURI, objectInput);
  85   }
  86   inline nsresult FinishScriptInputStream(nsIURI* aURI) {
  87     return FinishInputStream(aURI);
  88   }
  89
  90   inline nsresult GetPrototypeOutputStream(
  91       nsIURI* aURI, nsIObjectOutputStream** objectOutput) {
  92     return GetOutputStream(aURI, objectOutput);
  93   }
  94   inline nsresult GetScriptOutputStream(nsIURI* aURI,
  95                                         nsIObjectOutputStream** objectOutput) {
  96     return GetOutputStream(aURI, objectOutput);
  97   }
  98
  99   inline nsresult FinishPrototypeOutputStream(nsIURI* aURI) {
 100     return FinishOutputStream(CacheType::Prototype, aURI);
 101   }
 102   inline nsresult FinishScriptOutputStream(nsIURI* aURI) {
 103     return FinishOutputStream(CacheType::Script, aURI);
 104   }
 105
 106   inline nsresult HasPrototype(nsIURI* aURI, bool* exists) {
 107     return HasData(CacheType::Prototype, aURI, exists);
 108   }
 109   inline nsresult HasScript(nsIURI* aURI, bool* exists) {
 110     return HasData(CacheType::Script, aURI, exists);
 111   }
 112
 113  private:
 114   nsresult GetInputStream(CacheType cacheType, nsIURI* uri,
 115                           nsIObjectInputStream** stream);
 116   nsresult FinishInputStream(nsIURI* aURI);
 117
 118   nsresult GetOutputStream(nsIURI* aURI, nsIObjectOutputStream** objectOutput);
 119   nsresult FinishOutputStream(CacheType cacheType, nsIURI* aURI);
 120   nsresult HasData(CacheType cacheType, nsIURI* aURI, bool* exists);
 121
 122  public:
 123   static nsXULPrototypeCache* GetInstance();
 124   static nsXULPrototypeCache* MaybeGetInstance() { return sInstance; }
 125
 126   static void ReleaseGlobals() { NS_IF_RELEASE(sInstance); }
 127
 128   void MarkInCCGeneration(uint32_t aGeneration);
 129
 130   static void CollectMemoryReports(nsIHandleReportCallback* aHandleReport,
 131                                    nsISupports* aData);
 132
 133  protected:
 134   friend nsresult NS_NewXULPrototypeCache(REFNSIID aIID, void** aResult);
 135
 136   nsXULPrototypeCache();
 137   virtual ~nsXULPrototypeCache() = default;
 138
 139   static nsXULPrototypeCache* sInstance;
 140
 141   nsRefPtrHashtable<nsURIHashKey, nsXULPrototypeDocument>
 142       mPrototypeTable;  // owns the prototypes
 143
 144   class StencilHashKey : public nsURIHashKey {
 145    public:
 146     explicit StencilHashKey(const nsIURI* aKey) : nsURIHashKey(aKey) {}
 147     StencilHashKey(StencilHashKey&&) = default;
 148
 149     RefPtr<JS::Stencil> mStencil;
 150   };
 151
 152   nsTHashtable<StencilHashKey> mStencilTable;
 153
 154   // URIs already written to the startup cache, to prevent double-caching.
 155   nsTHashtable<nsURIHashKey> mStartupCacheURITable;
 156
 157   nsInterfaceHashtable<nsURIHashKey, nsIStorageStream> mOutputStreamTable;
 158   nsInterfaceHashtable<nsURIHashKey, nsIObjectInputStream> mInputStreamTable;
 159
 160   // Bootstrap caching service
 161   nsresult BeginCaching(nsIURI* aDocumentURI);
 162 };
 163
 164 #endif  // nsXULPrototypeCache_h__