Bug 377995 - "Move nsCategoryCache to the XPCOM Glue". nsCategoryCache was initially created as part of Bug 315598 by Christian Biesinger <cbiesinger@gmx.at>. r=bsmedberg.

xpcom/components/Makefile.in

@@ -53,7 +53,6 @@ REQUIRES	= string \
 
 CPPSRCS		= \
 		nsCategoryManager.cpp \
-		nsCategoryCache.cpp \
 		nsComponentManager.cpp \
 		nsNativeComponentLoader.cpp \
 		nsStaticComponentLoader.cpp \
@@ -62,7 +61,6 @@ CPPSRCS		= \
 
 EXPORTS		= \
 		nsCategoryManagerUtils.h \
-		nsCategoryCache.h \
 		nsIServiceManagerObsolete.h \
 		nsModule.h \
 		nsObsoleteModuleLoading.h \

xpcom/ds/nsObserverService.h

@@ -42,7 +42,6 @@
 #include "nsObserverList.h"
 #include "nsTHashtable.h"
 
-#define NS_OBSERVERSERVICE_CONTRACTID "@mozilla.org/observer-service;1"
 #define NS_OBSERVERSERVICE_CLASSNAME "Observer Service"
 
 // {D07F5195-E3D1-11d2-8ACD-00105A1B8860}

xpcom/glue/Makefile.in

@@ -74,6 +74,7 @@ SDK_HEADERS = \
 		nsArrayUtils.h \
 		nsAutoLock.h \
 		nsBaseHashtable.h \
+		nsCategoryCache.h \
 		nsCOMArray.h \
 		nsCRTGlue.h \
 		nsClassHashtable.h \

xpcom/glue/nsCategoryCache.cpp

@@ -0,0 +1,167 @@
+/* vim:set st=2 sts=2 ts=2 et cin: */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * 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
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is a cache for services in a category.
+ *
+ * The Initial Developer of the Original Code is
+ * Christian Biesinger <cbiesinger@web.de>.
+ * Portions created by the Initial Developer are Copyright (C) 2005
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "nsIObserverService.h"
+#include "nsISupportsPrimitives.h"
+
+#include "nsXPCOMCID.h"
+
+#include "nsCategoryCache.h"
+
+nsCategoryObserver::nsCategoryObserver(const char* aCategory,
+                                       nsCategoryListener* aListener)
+  : mListener(nsnull), mCategory(aCategory)
+{
+  if (!mHash.Init()) {
+    // OOM
+    return;
+  }
+
+  mListener = aListener;
+
+  // First, enumerate the currently existing entries
+  nsCOMPtr<nsICategoryManager> catMan =
+    do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
+  if (!catMan)
+    return;
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  nsresult rv = catMan->EnumerateCategory(aCategory,
+                                          getter_AddRefs(enumerator));
+  if (NS_FAILED(rv))
+    return;
+
+  nsCOMPtr<nsISupports> entry;
+  while (NS_SUCCEEDED(enumerator->GetNext(getter_AddRefs(entry)))) {
+    nsCOMPtr<nsISupportsCString> entryName = do_QueryInterface(entry, &rv);
+
+    if (NS_SUCCEEDED(rv)) {
+      nsCAutoString categoryEntry;
+      rv = entryName->GetData(categoryEntry);
+
+      nsCString entryValue;
+      catMan->GetCategoryEntry(aCategory,
+                               categoryEntry.get(),
+                               getter_Copies(entryValue));
+
+      if (NS_SUCCEEDED(rv)) {
+        mHash.Put(categoryEntry, entryValue);
+        mListener->EntryAdded(entryValue);
+      }
+    }
+  }
+
+  // Now, listen for changes
+  nsCOMPtr<nsIObserverService> serv =
+    do_GetService(NS_OBSERVERSERVICE_CONTRACTID);
+  if (!serv)
+    return;
+
+  serv->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, PR_FALSE);
+
+  serv->AddObserver(this, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID, PR_FALSE);
+  serv->AddObserver(this, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID, PR_FALSE);
+  serv->AddObserver(this, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID, PR_FALSE);
+}
+
+nsCategoryObserver::~nsCategoryObserver() {
+}
+
+NS_IMPL_ISUPPORTS1(nsCategoryObserver, nsIObserver)
+
+void
+nsCategoryObserver::ListenerDied() {
+  mListener = nsnull;
+
+  nsCOMPtr<nsIObserverService> serv =
+    do_GetService(NS_OBSERVERSERVICE_CONTRACTID);
+  if (!serv)
+    return;
+
+  serv->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
+
+  serv->RemoveObserver(this, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID);
+  serv->RemoveObserver(this, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID);
+  serv->RemoveObserver(this, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID);
+}
+
+NS_IMETHODIMP
+nsCategoryObserver::Observe(nsISupports* aSubject, const char* aTopic,
+                            const PRUnichar* aData) {
+  if (!mListener)
+    return NS_OK;
+
+  if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
+    mHash.Clear();
+    mListener->CategoryCleared();
+    return NS_OK;
+  }
+
+  if (!aData ||
+      !nsDependentString(aData).Equals(NS_ConvertASCIItoUTF16(mCategory)))
+    return NS_OK;
+
+  nsCAutoString str;
+  nsCOMPtr<nsISupportsCString> strWrapper(do_QueryInterface(aSubject));
+  if (strWrapper)
+    strWrapper->GetData(str);
+
+  if (strcmp(aTopic, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID) == 0) {
+    nsCOMPtr<nsICategoryManager> catMan =
+      do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
+    if (!catMan)
+      return NS_OK;
+
+    nsCString entryValue;
+    catMan->GetCategoryEntry(mCategory.get(),
+                             str.get(),
+                             getter_Copies(entryValue));
+
+    mHash.Put(str, entryValue);
+    mListener->EntryAdded(entryValue);
+  } else if (strcmp(aTopic, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID) == 0) {
+    nsCAutoString val;
+    if (mHash.Get(str, &val)) {
+      mHash.Remove(str);
+      mListener->EntryRemoved(val);
+    }
+  } else if (strcmp(aTopic, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID) == 0) {
+    mHash.Clear();
+    mListener->CategoryCleared();
+  }
+  return NS_OK;
+}

xpcom/glue/nsCategoryCache.h

@@ -0,0 +1,137 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * 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
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is a cache for services in a category.
+ *
+ * The Initial Developer of the Original Code is
+ * Christian Biesinger <cbiesinger@web.de>.
+ * Portions created by the Initial Developer are Copyright (C) 2005
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef nsCategoryCache_h_
+#define nsCategoryCache_h_
+
+#include "nsICategoryManager.h"
+#include "nsIObserver.h"
+#include "nsISimpleEnumerator.h"
+#include "nsISupportsPrimitives.h"
+
+#include "nsServiceManagerUtils.h"
+
+#include "nsAutoPtr.h"
+#include "nsCOMArray.h"
+#include "nsDataHashtable.h"
+
+#include "nsXPCOM.h"
+
+class NS_NO_VTABLE nsCategoryListener {
+  protected:
+    // no virtual destructor (people shouldn't delete through an
+    // nsCategoryListener pointer)
+    ~nsCategoryListener() {}
+
+  public:
+    virtual void EntryAdded(const nsCString& aValue) = 0;
+    virtual void EntryRemoved(const nsCString& aValue) = 0;
+    virtual void CategoryCleared() = 0;
+};
+
+class NS_COM_GLUE nsCategoryObserver : public nsIObserver {
+  public:
+    nsCategoryObserver(const char* aCategory,
+                       nsCategoryListener* aCategoryListener);
+    ~nsCategoryObserver();
+
+    void ListenerDied();
+
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIOBSERVER
+  private:
+    nsDataHashtable<nsCStringHashKey, nsCString> mHash;
+    nsCategoryListener*                          mListener;
+    nsCString                                    mCategory;
+};
+
+/**
+ * This is a helper class that caches services that are registered in a certain
+ * category. The intended usage is that a service stores a variable of type
+ * nsCategoryCache<nsIFoo> in a member variable, where nsIFoo is the interface
+ * that these services should implement. The constructor of this class should
+ * then get the name of the category.
+ */
+template<class T>
+class nsCategoryCache : protected nsCategoryListener {
+  public:
+    explicit nsCategoryCache(const char* aCategory);
+    ~nsCategoryCache() { if (mObserver) mObserver->ListenerDied(); }
+
+    const nsCOMArray<T>& GetEntries() const { return mEntries; }
+  protected:
+    virtual void EntryAdded(const nsCString& aValue);
+    virtual void EntryRemoved(const nsCString& aValue);
+    virtual void CategoryCleared();
+  private:
+    friend class CategoryObserver;
+
+    // Not to be implemented
+    nsCategoryCache(const nsCategoryCache<T>&);
+
+    nsCOMArray<T> mEntries;
+    nsRefPtr<nsCategoryObserver> mObserver;
+};
+
+// -----------------------------------
+// Implementation
+
+template<class T>
+nsCategoryCache<T>::nsCategoryCache(const char* aCategory)
+{
+  mObserver = new nsCategoryObserver(aCategory, this);
+}
+
+template<class T>
+void nsCategoryCache<T>::EntryAdded(const nsCString& aValue) {
+  nsCOMPtr<T> catEntry = do_GetService(aValue.get());
+  if (catEntry)
+    mEntries.AppendObject(catEntry);
+}
+
+template<class T>
+void nsCategoryCache<T>::EntryRemoved(const nsCString& aValue) {
+  nsCOMPtr<T> catEntry = do_GetService(aValue.get());
+  if (catEntry)
+    mEntries.RemoveObject(catEntry);
+}
+
+template<class T>
+void nsCategoryCache<T>::CategoryCleared() {
+  mEntries.Clear();
+}
+
+#endif

xpcom/glue/objs.mk

@@ -43,6 +43,7 @@ XPCOM_GLUE_SRC_CSRCS = $(addprefix $(topsrcdir)/xpcom/glue/, $(XPCOM_GLUE_SRC_LC
 XPCOM_GLUE_SRC_LCPPSRCS =        \
   nsArrayEnumerator.cpp          \
   nsArrayUtils.cpp               \
+  nsCategoryCache.cpp            \
   nsCOMPtr.cpp                   \
   nsCOMArray.cpp                 \
   nsCRTGlue.cpp                  \