1 : /* vim:set st=2 sts=2 ts=2 et cin: */
2 : /* ***** BEGIN LICENSE BLOCK *****
3 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 : *
5 : * The contents of this file are subject to the Mozilla Public License Version
6 : * 1.1 (the "License"); you may not use this file except in compliance with
7 : * the License. You may obtain a copy of the License at
8 : * http://www.mozilla.org/MPL/
9 : *
10 : * Software distributed under the License is distributed on an "AS IS" basis,
11 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 : * for the specific language governing rights and limitations under the
13 : * License.
14 : *
15 : * The Original Code is a cache for services in a category.
16 : *
17 : * The Initial Developer of the Original Code is
18 : * Christian Biesinger <cbiesinger@web.de>.
19 : * Portions created by the Initial Developer are Copyright (C) 2005
20 : * the Initial Developer. All Rights Reserved.
21 : *
22 : * Contributor(s):
23 : *
24 : * Alternatively, the contents of this file may be used under the terms of
25 : * either the GNU General Public License Version 2 or later (the "GPL"), or
26 : * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
27 : * in which case the provisions of the GPL or the LGPL are applicable instead
28 : * of those above. If you wish to allow use of your version of this file only
29 : * under the terms of either the GPL or the LGPL, and not to allow others to
30 : * use your version of this file under the terms of the MPL, indicate your
31 : * decision by deleting the provisions above and replace them with the notice
32 : * and other provisions required by the GPL or the LGPL. If you do not delete
33 : * the provisions above, a recipient may use your version of this file under
34 : * the terms of any one of the MPL, the GPL or the LGPL.
35 : *
36 : * ***** END LICENSE BLOCK ***** */
37 :
38 : #include "nsIObserverService.h"
39 : #include "mozilla/Services.h"
40 : #include "nsISupportsPrimitives.h"
41 :
42 : #include "nsXPCOMCID.h"
43 :
44 : #include "nsCategoryCache.h"
45 :
46 389 : nsCategoryObserver::nsCategoryObserver(const char* aCategory,
47 : nsCategoryListener* aListener)
48 389 : : mListener(nsnull), mCategory(aCategory), mObserversRemoved(false)
49 : {
50 389 : if (!mHash.Init()) {
51 : // OOM
52 0 : return;
53 : }
54 :
55 389 : mListener = aListener;
56 :
57 : // First, enumerate the currently existing entries
58 : nsCOMPtr<nsICategoryManager> catMan =
59 778 : do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
60 389 : if (!catMan)
61 : return;
62 :
63 778 : nsCOMPtr<nsISimpleEnumerator> enumerator;
64 389 : nsresult rv = catMan->EnumerateCategory(aCategory,
65 389 : getter_AddRefs(enumerator));
66 389 : if (NS_FAILED(rv))
67 : return;
68 :
69 1167 : nsTArray<nsCString> entries;
70 778 : nsCOMPtr<nsISupports> entry;
71 1178 : while (NS_SUCCEEDED(enumerator->GetNext(getter_AddRefs(entry)))) {
72 800 : nsCOMPtr<nsISupportsCString> entryName = do_QueryInterface(entry, &rv);
73 :
74 400 : if (NS_SUCCEEDED(rv)) {
75 800 : nsCAutoString categoryEntry;
76 400 : rv = entryName->GetData(categoryEntry);
77 :
78 800 : nsCString entryValue;
79 400 : catMan->GetCategoryEntry(aCategory,
80 : categoryEntry.get(),
81 400 : getter_Copies(entryValue));
82 :
83 400 : if (NS_SUCCEEDED(rv)) {
84 400 : mHash.Put(categoryEntry, entryValue);
85 400 : entries.AppendElement(entryValue);
86 : }
87 : }
88 : }
89 :
90 : // Now, listen for changes
91 : nsCOMPtr<nsIObserverService> serv =
92 778 : mozilla::services::GetObserverService();
93 389 : if (serv) {
94 389 : serv->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
95 389 : serv->AddObserver(this, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID, false);
96 389 : serv->AddObserver(this, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID, false);
97 389 : serv->AddObserver(this, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID, false);
98 : }
99 :
100 789 : for (PRInt32 i = entries.Length() - 1; i >= 0; --i)
101 400 : mListener->EntryAdded(entries[i]);
102 : }
103 :
104 389 : nsCategoryObserver::~nsCategoryObserver() {
105 389 : }
106 :
107 13655 : NS_IMPL_ISUPPORTS1(nsCategoryObserver, nsIObserver)
108 :
109 : void
110 389 : nsCategoryObserver::ListenerDied() {
111 389 : mListener = nsnull;
112 389 : RemoveObservers();
113 389 : }
114 :
115 : NS_HIDDEN_(void)
116 774 : nsCategoryObserver::RemoveObservers() {
117 774 : if (mObserversRemoved)
118 385 : return;
119 :
120 389 : mObserversRemoved = true;
121 : nsCOMPtr<nsIObserverService> obsSvc =
122 778 : mozilla::services::GetObserverService();
123 389 : if (obsSvc) {
124 389 : obsSvc->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
125 389 : obsSvc->RemoveObserver(this, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID);
126 389 : obsSvc->RemoveObserver(this, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID);
127 389 : obsSvc->RemoveObserver(this, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID);
128 : }
129 : }
130 :
131 : NS_IMETHODIMP
132 399 : nsCategoryObserver::Observe(nsISupports* aSubject, const char* aTopic,
133 : const PRUnichar* aData) {
134 399 : if (!mListener)
135 0 : return NS_OK;
136 :
137 399 : if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
138 385 : mHash.Clear();
139 385 : mListener->CategoryCleared();
140 385 : RemoveObservers();
141 :
142 385 : return NS_OK;
143 : }
144 :
145 70 : if (!aData ||
146 56 : !nsDependentString(aData).Equals(NS_ConvertASCIItoUTF16(mCategory)))
147 9 : return NS_OK;
148 :
149 10 : nsCAutoString str;
150 10 : nsCOMPtr<nsISupportsCString> strWrapper(do_QueryInterface(aSubject));
151 5 : if (strWrapper)
152 5 : strWrapper->GetData(str);
153 :
154 5 : if (strcmp(aTopic, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID) == 0) {
155 : // We may get an add notification even when we already have an entry. This
156 : // is due to the notification happening asynchronously, so if the entry gets
157 : // added and an nsCategoryObserver gets instantiated before events get
158 : // processed, we'd get the notification for an existing entry.
159 : // Do nothing in that case.
160 4 : if (mHash.Get(str, nsnull))
161 2 : return NS_OK;
162 :
163 : nsCOMPtr<nsICategoryManager> catMan =
164 4 : do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
165 2 : if (!catMan)
166 0 : return NS_OK;
167 :
168 6 : nsCString entryValue;
169 2 : catMan->GetCategoryEntry(mCategory.get(),
170 : str.get(),
171 2 : getter_Copies(entryValue));
172 :
173 2 : mHash.Put(str, entryValue);
174 2 : mListener->EntryAdded(entryValue);
175 1 : } else if (strcmp(aTopic, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID) == 0) {
176 2 : nsCAutoString val;
177 1 : if (mHash.Get(str, &val)) {
178 1 : mHash.Remove(str);
179 1 : mListener->EntryRemoved(val);
180 : }
181 0 : } else if (strcmp(aTopic, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID) == 0) {
182 0 : mHash.Clear();
183 0 : mListener->CategoryCleared();
184 : }
185 3 : return NS_OK;
186 : }
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