[Resumption 6/11] Add a RESUMING_INTERNAL state to DownloadItem.

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 229 matching lines @@
       browser_context_(browser_context),
       delegate_(NULL),
       net_log_(net_log) {
   DCHECK(browser_context);
 }
 
 DownloadManagerImpl::~DownloadManagerImpl() {
   DCHECK(!shutdown_needed_);
 }
 
-void DownloadManagerImpl::CreateActiveItem(
-    DownloadId id, const DownloadCreateInfo& info) {
-  net::BoundNetLog bound_net_log =
-      net::BoundNetLog::Make(net_log_, net::NetLog::SOURCE_DOWNLOAD);
-  downloads_[id.local()] =
-      item_factory_->CreateActiveItem(this, id, info, bound_net_log);
-}
-
 DownloadId DownloadManagerImpl::GetNextId() {
   DownloadId id;
   if (delegate_)
    id = delegate_->GetNextId();
   if (!id.IsValid()) {
     static int next_id;
     id = DownloadId(browser_context_, ++next_id);
   }
 
   return id;
@@ skipping 102 matching lines @@
   if (delegate_)
     delegate_->Shutdown();
   delegate_ = NULL;
 }
 
 DownloadItem* DownloadManagerImpl::StartDownload(
     scoped_ptr<DownloadCreateInfo> info,
     scoped_ptr<ByteStreamReader> stream) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  DownloadId id(info->download_id);
+  bool new_download = !id.IsValid();
+  DownloadItemImpl* download = NULL;
+
+  if (new_download) {
+    id = GetNextId();
+    net::BoundNetLog bound_net_log =
+        net::BoundNetLog::Make(net_log_, net::NetLog::SOURCE_DOWNLOAD);
+    download = item_factory_->CreateActiveItem(this, id, *info, bound_net_log);
+    downloads_[id.local()] = download;
+  } else {
+    // Trying to resume an interrupted download.
+    if (!ContainsKey(downloads_, id.local())) {
+      // If the download is no longer known to the DownloadManager, then it was
+      // removed after it was resumed. Ignore.
+      info->request_handle.CancelRequest();
+      return NULL;
+    }
+    download = downloads_[id.local()];

[Randy Smith (Not in Mondays), 2013/05/13 15:59:26]

I'm tempted to suggest you explicitly look up the iterator, test against end()
to check if the key is there, then dereference to get the download, to avoid the
double lookup.  But I'm good with this code; just wanted to raise the option.

[asanka, 2013/05/13 19:19:01]

Done.

+    DCHECK(download->IsInterrupted());
+  }
+
   base::FilePath default_download_directory;
   if (delegate_) {
     base::FilePath website_save_directory;  // Unused
     bool skip_dir_check = false;            // Unused
     delegate_->GetSaveDir(GetBrowserContext(), &website_save_directory,
                           &default_download_directory, &skip_dir_check);
   }
 
-  // If we don't have a valid id, that's a signal to generate one.
-  DownloadId id(info->download_id);
-  if (!id.IsValid())
-    id = GetNextId();
-
-  // Create a new download item if this isn't a resumption.
-  bool new_download(!ContainsKey(downloads_, id.local()));
-  if (new_download)
-    CreateActiveItem(id, *info);
-
-  DownloadItemImpl* download(downloads_[id.local()]);
-  DCHECK(download);
-  DCHECK(new_download || download->IsInterrupted());
-
   // Create the download file and start the download.
   scoped_ptr<DownloadFile> download_file(
       file_factory_->CreateFile(
           info->save_info.Pass(), default_download_directory,
           info->url(), info->referrer_url,
           delegate_->GenerateFileHash(),
           stream.Pass(), download->GetBoundNetLog(),
           download->DestinationObserverAsWeakPtr()));
   scoped_ptr<DownloadRequestHandleInterface> req_handle(
       new DownloadRequestHandle(info->request_handle));
@@ skipping 243 matching lines @@
   if (delegate_)
     delegate_->OpenDownload(download);
 }
 
 void DownloadManagerImpl::ShowDownloadInShell(DownloadItemImpl* download) {
   if (delegate_)
     delegate_->ShowDownloadInShell(download);
 }
 
 }  // namespace content