Fix DCHECK, memory leak, and refactor PasswordStore to use CancelableRequest

chrome/browser/password_manager/password_store.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/password_manager/password_store.h"
 
 #include "base/message_loop.h"
 #include "base/scoped_ptr.h"
+#include "base/stl_util-inl.h"
 #include "base/task.h"
 #include "content/browser/browser_thread.h"
 
 using std::vector;
 using webkit_glue::PasswordForm;
 
-PasswordStore::PasswordStore() : handle_(0) {
+PasswordStore::PasswordStore() {
 }
 
 bool PasswordStore::Init() {
   ReportMetrics();
   return true;
 }
 
 void PasswordStore::ScheduleTask(Task* task) {
   BrowserThread::PostTask(BrowserThread::DB, FROM_HERE, task);
 }
@@ skipping 16 matching lines @@
   ScheduleTask(NewRunnableMethod(this, &PasswordStore::RemoveLoginImpl, form));
 }
 
 void PasswordStore::RemoveLoginsCreatedBetween(const base::Time& delete_begin,
                                                const base::Time& delete_end) {
   ScheduleTask(NewRunnableMethod(this,
                                  &PasswordStore::RemoveLoginsCreatedBetweenImpl,
                                  delete_begin, delete_end));
 }
 
-int PasswordStore::GetLogins(const PasswordForm& form,
-                             PasswordStoreConsumer* consumer) {
-  int handle = GetNewRequestHandle();
-  GetLoginsRequest* request = new GetLoginsRequest(consumer, handle);
-  ScheduleTask(NewRunnableMethod(this, &PasswordStore::GetLoginsImpl, request,
-                                 form));
-  return handle;
+PasswordStore::Handle PasswordStore::GetLogins(
+    const PasswordForm& form, PasswordStoreConsumer* consumer) {
+  return Schedule(&PasswordStore::GetLoginsImpl, consumer, form);
 }
 
-int PasswordStore::GetAutofillableLogins(PasswordStoreConsumer* consumer) {
-  int handle = GetNewRequestHandle();
-  GetLoginsRequest* request = new GetLoginsRequest(consumer, handle);
-  ScheduleTask(NewRunnableMethod(this,
-                                 &PasswordStore::GetAutofillableLoginsImpl,
-                                 request));
-  return handle;
+PasswordStore::Handle PasswordStore::GetAutofillableLogins(
+    PasswordStoreConsumer* consumer) {
+  return Schedule(&PasswordStore::GetAutofillableLoginsImpl, consumer);
 }
 
-int PasswordStore::GetBlacklistLogins(PasswordStoreConsumer* consumer) {
-  int handle = GetNewRequestHandle();
-  GetLoginsRequest* request = new GetLoginsRequest(consumer, handle);
-  ScheduleTask(NewRunnableMethod(this,
-                                 &PasswordStore::GetBlacklistLoginsImpl,
-                                 request));
-  return handle;
+PasswordStore::Handle PasswordStore::GetBlacklistLogins(
+    PasswordStoreConsumer* consumer) {
+  return Schedule(&PasswordStore::GetBlacklistLoginsImpl, consumer);
 }
 
-void PasswordStore::NotifyConsumer(GetLoginsRequest* request,
-                                   const vector<PasswordForm*>& forms) {
-  scoped_ptr<GetLoginsRequest> request_ptr(request);
-
-#if !defined(OS_MACOSX)
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
-#endif
-  request->message_loop->PostTask(FROM_HERE,
-      NewRunnableMethod(this,
-                        &PasswordStore::NotifyConsumerImpl,
-                        request->consumer, request->handle, forms));
+void PasswordStore::ForwardLoginsResult(GetLoginsRequest* request) {
+  request->ForwardResult(GetLoginsRequest::TupleType(request->handle(),
+                                                     request->value));
 }
 
-void PasswordStore::NotifyConsumerImpl(PasswordStoreConsumer* consumer,
-                                       int handle,
-                                       const vector<PasswordForm*>& forms) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  // Don't notify the consumer if the request was canceled.
-  if (pending_requests_.find(handle) == pending_requests_.end()) {
-    // |forms| is const so we iterate rather than use STLDeleteElements().
-    for (size_t i = 0; i < forms.size(); ++i)
-      delete forms[i];
-    return;
+PasswordStore::GetLoginsRequest::~GetLoginsRequest() {
+  if (canceled()) {
+    STLDeleteElements(&value);
   }
-  pending_requests_.erase(handle);
-
-  consumer->OnPasswordStoreRequestDone(handle, forms);
 }
-
-int PasswordStore::GetNewRequestHandle() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  int handle = handle_++;
-  pending_requests_.insert(handle);
-  return handle;
-}
-
-void PasswordStore::CancelLoginsQuery(int handle) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  pending_requests_.erase(handle);
-}
-
-PasswordStore::GetLoginsRequest::GetLoginsRequest(
-    PasswordStoreConsumer* consumer, int handle)
-    : consumer(consumer), handle(handle), message_loop(MessageLoop::current()) {
-}