Initial CL for Downloads resumption.

content/browser/download/download_manager_impl.cc

Index: content/browser/download/download_manager_impl.cc
diff --git a/content/browser/download/download_manager_impl.cc b/content/browser/download/download_manager_impl.cc
index 83c68747c42c06bcfbefc09d5d22680b45ebfcb6..2d4ec522fb24c11243a278fd657943ad808c42c7 100644
--- a/content/browser/download/download_manager_impl.cc
+++ b/content/browser/download/download_manager_impl.cc
@@ -39,6 +39,7 @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/web_contents_delegate.h"
+#include "content/public/common/referrer.h"
 #include "net/base/load_flags.h"
 #include "net/base/upload_bytes_element_reader.h"
 #include "net/base/upload_data_stream.h"
@@ -48,7 +49,8 @@
 namespace content {
 namespace {
 
-void BeginDownload(scoped_ptr<DownloadUrlParameters> params) {
+void BeginDownload(scoped_ptr<DownloadUrlParameters> params,
+                   DownloadId download_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   // ResourceDispatcherHost{Base} is-not-a URLRequest::Delegate, and
   // DownloadUrlParameters can-not include resource_dispatcher_host_impl.h, so
@@ -103,6 +105,9 @@ void BeginDownload(scoped_ptr<DownloadUrlParameters> params) {
       params->render_view_host_routing_id(),
       params->prefer_cache(),
       save_info.Pass(),
+      params->last_modified(),
+      params->etag(),
+      download_id,
       params->callback());
 }
 
@@ -173,10 +178,8 @@ class DownloadItemFactoryImpl : public DownloadItemFactory {
     virtual DownloadItemImpl* CreateActiveItem(
         DownloadItemImplDelegate* delegate,
         const DownloadCreateInfo& info,
-        scoped_ptr<DownloadRequestHandleInterface> request_handle,
         const net::BoundNetLog& bound_net_log) OVERRIDE {
-      return new DownloadItemImpl(delegate, info, request_handle.Pass(),
-                                  bound_net_log);
+      return new DownloadItemImpl(delegate, info, bound_net_log);
     }
 
     virtual DownloadItemImpl* CreateSavePageItem(
@@ -339,9 +342,6 @@ DownloadItem* DownloadManagerImpl::StartDownload(
     scoped_ptr<ByteStreamReader> stream) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  net::BoundNetLog bound_net_log =
-      net::BoundNetLog::Make(net_log_, net::NetLog::SOURCE_DOWNLOAD);
-
   FilePath default_download_directory;
   if (delegate_) {
     FilePath website_save_directory;      // Unused
@@ -353,16 +353,17 @@ DownloadItem* DownloadManagerImpl::StartDownload(
   // We create the DownloadItem before the DownloadFile because the
   // DownloadItem already needs to handle a state in which there is
   // no associated DownloadFile (history downloads, !IN_PROGRESS downloads)
-  DownloadItemImpl* download =
-      CreateDownloadItem(info.get(), bound_net_log);
+  DownloadItemImpl* download = GetOrCreateDownloadItem(info.get());
   scoped_ptr<DownloadFile> download_file(
       file_factory_->CreateFile(
           info->save_info.Pass(), default_download_directory,
           info->url(), info->referrer_url,
           delegate_->GenerateFileHash(),
-          stream.Pass(), bound_net_log,
+          stream.Pass(), download->GetBoundNetLog(),
           download->DestinationObserverAsWeakPtr()));
-  download->Start(download_file.Pass());
+  scoped_ptr<DownloadRequestHandleInterface> req_handle(
+      new DownloadRequestHandle(info->request_handle));
+  download->Start(download_file.Pass(), req_handle.Pass());
 
   // Delay notification until after Start() so that download_file is bound
   // to download and all the usual setters (e.g. Cancel) work.
@@ -414,20 +415,26 @@ BrowserContext* DownloadManagerImpl::GetBrowserContext() const {
   return browser_context_;
 }
 
-DownloadItemImpl* DownloadManagerImpl::CreateDownloadItem(
-    DownloadCreateInfo* info, const net::BoundNetLog& bound_net_log) {
+DownloadItemImpl* DownloadManagerImpl::GetOrCreateDownloadItem(
+    DownloadCreateInfo* info) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (!info->download_id.IsValid())

[asanka, 2012/12/28 22:01:42]

Under what circumstances would download_id.IsValid() and there's no
corresponding download in downloads_?

[Randy Smith (Not in Mondays), 2012/12/29 17:16:16]

Possibly I shouldn't allow for the possibility in this CL, but I've wanted to be
able to allocate download ids on the UI thread for programmatic downloads (and
return them to the caller) for a long time.  Happy to put that off to it's own
CL if you'd prefer, though.

     info->download_id = GetNextId();
-  DownloadItemImpl* download = item_factory_->CreateActiveItem(
-      this, *info,
-      scoped_ptr<DownloadRequestHandleInterface>(
-          new DownloadRequestHandle(info->request_handle)).Pass(),
-      bound_net_log);
 
-  DCHECK(!ContainsKey(downloads_, download->GetId()));
-  downloads_[download->GetId()] = download;
+  DownloadItemImpl* download = NULL;
+  if (ContainsKey(downloads_, info->download_id.local())) {
+    // Resuming an existing download.
+    download = downloads_[info->download_id.local()];
+    DCHECK(download->IsInterrupted());
+  } else {
+    // New download
+    net::BoundNetLog bound_net_log =
+        net::BoundNetLog::Make(net_log_, net::NetLog::SOURCE_DOWNLOAD);
+    download = item_factory_->CreateActiveItem(this, *info, bound_net_log);
+    downloads_[download->GetId()] = download;
+  }
+
   return download;
 }
 
@@ -465,6 +472,18 @@ void DownloadManagerImpl::CancelDownload(int32 download_id) {
   download->Cancel(true);
 }
 
+// Resume a download of a specific URL. We send the request to the
+// ResourceDispatcherHost, and let it send us responses like a regular
+// download.
+void DownloadManagerImpl::ResumeInterruptedDownload(
+    scoped_ptr<content::DownloadUrlParameters> params,
+    content::DownloadId id) {
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&BeginDownload, base::Passed(params.Pass()), id));
+}
+
 void DownloadManagerImpl::SetDownloadItemFactoryForTesting(
     scoped_ptr<DownloadItemFactory> item_factory) {
   item_factory_ = item_factory.Pass();
@@ -544,7 +563,7 @@ void DownloadManagerImpl::DownloadUrl(
     DCHECK(params->method() == "POST");
   }
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
-      &BeginDownload, base::Passed(&params)));
+      &BeginDownload, base::Passed(&params), DownloadId()));
 }
 
 void DownloadManagerImpl::AddObserver(Observer* observer) {