Downloads: Avoid some redundant map lookups in DownloadMangerImpl.

content/browser/download/download_manager_impl.cc

 // Copyright (c) 2012 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 "content/browser/download/download_manager_impl.h"
 
 #include <iterator>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 53 matching lines @@
         net::UploadOwnedBytesElementReader::CreateWithString(body));
     request->set_upload(make_scoped_ptr(
         net::UploadDataStream::CreateWithReader(reader.Pass(), 0)));
   }
   if (params->post_id() >= 0) {
     // The POST in this case does not have an actual body, and only works
     // when retrieving data from cache. This is done because we don't want
     // to do a re-POST without user consent, and currently don't have a good
     // plan on how to display the UI for that.
     DCHECK(params->prefer_cache());
-    DCHECK(params->method() == "POST");
+    DCHECK_EQ("POST", params->method());
     ScopedVector<net::UploadElementReader> element_readers;
     request->set_upload(make_scoped_ptr(
         new net::UploadDataStream(element_readers.Pass(), params->post_id())));
   }
 
   // If we're not at the beginning of the file, retrieve only the remaining
   // portion.
   bool has_last_modified = !params->last_modified().empty();
   bool has_etag = !params->etag().empty();
 
@@ skipping 16 matching lines @@
     if (has_etag) {
       request->SetExtraRequestHeaderByName("If-Match", params->etag(), true);
     }
   }
 
   for (DownloadUrlParameters::RequestHeadersType::const_iterator iter
            = params->request_headers_begin();
        iter != params->request_headers_end();
        ++iter) {
     request->SetExtraRequestHeaderByName(
-        iter->first, iter->second, false/*overwrite*/);
+        iter->first, iter->second, false /*overwrite*/);
   }
 
   scoped_ptr<DownloadSaveInfo> save_info(new DownloadSaveInfo());
   save_info->file_path = params->file_path();
   save_info->suggested_name = params->suggested_name();
   save_info->offset = params->offset();
   save_info->hash_state = params->hash_state();
   save_info->prompt_for_save_location = params->prompt();
   save_info->file_stream = params->GetFileStream();
 
@@ skipping 432 matching lines @@
 
 DownloadFileFactory* DownloadManagerImpl::GetDownloadFileFactoryForTesting() {
   return file_factory_.get();
 }
 
 void DownloadManagerImpl::DownloadRemoved(DownloadItemImpl* download) {
   if (!download)
     return;
 
   uint32 download_id = download->GetId();
-  if (downloads_.find(download_id) == downloads_.end())
+  if (downloads_.erase(download_id) == 0)
     return;
-
   delete download;
-  downloads_.erase(download_id);
 }
 
 int DownloadManagerImpl::RemoveDownloadsBetween(base::Time remove_begin,
                                                 base::Time remove_end) {
   int count = 0;
   DownloadMap::const_iterator it = downloads_.begin();
   while (it != downloads_.end()) {
     DownloadItemImpl* download = it->second;
 
     // Increment done here to protect against invalidation below.
@@ skipping 19 matching lines @@
   int num_deleted = RemoveDownloadsBetween(base::Time(), base::Time());
   RecordClearAllSize(num_deleted);
   return num_deleted;
 }
 
 void DownloadManagerImpl::DownloadUrl(
     scoped_ptr<DownloadUrlParameters> params) {
   if (params->post_id() >= 0) {
     // Check this here so that the traceback is more useful.
     DCHECK(params->prefer_cache());
-    DCHECK(params->method() == "POST");
+    DCHECK_EQ("POST", params->method());
   }
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
       &BeginDownload, base::Passed(&params),
       content::DownloadItem::kInvalidId));
 }
 
 void DownloadManagerImpl::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
 
@@ skipping 10 matching lines @@
     const base::Time& start_time,
     const base::Time& end_time,
     const std::string& etag,
     const std::string& last_modified,
     int64 received_bytes,
     int64 total_bytes,
     DownloadItem::DownloadState state,
     DownloadDangerType danger_type,
     DownloadInterruptReason interrupt_reason,
     bool opened) {
-  DCHECK(!ContainsKey(downloads_, id));
-  if (ContainsKey(downloads_, id))
+  if (ContainsKey(downloads_, id)) {
+    NOTREACHED();
     return NULL;
+  }
   DownloadItemImpl* item = item_factory_->CreatePersistedItem(
       this,
       id,
       current_path,
       target_path,
       url_chain,
       referrer_url,
       start_time,
       end_time,
       etag,
@@ skipping 60 matching lines @@
   if (delegate_)
     delegate_->OpenDownload(download);
 }
 
 void DownloadManagerImpl::ShowDownloadInShell(DownloadItemImpl* download) {
   if (delegate_)
     delegate_->ShowDownloadInShell(download);
 }
 
 }  // namespace content