Replace the DownloadFileManager with direct ownership

content/browser/download/download_item_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_item_impl.h"
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/format_macros.h"
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/string_search.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_file.h"
-#include "content/browser/download/download_file_manager.h"
 #include "content/browser/download/download_interrupt_reasons_impl.h"
 #include "content/browser/download/download_item_impl_delegate.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/download_persistent_store_info.h"
 #include "net/base/net_util.h"
 
@@ skipping 79 matching lines @@
     return NULL;
   }
   virtual void PauseRequest() const OVERRIDE {}
   virtual void ResumeRequest() const OVERRIDE {}
   virtual void CancelRequest() const OVERRIDE {}
   virtual std::string DebugString() const OVERRIDE {
     return "Null DownloadRequestHandle";
   }
 };
 
+// Detach the specified download file, then invoke the callback on the
+// UI thread.  Note that this will also delete the DownloadFile object,
+// as the function accepts ownership and does not transfer it on.
+//
+// This is effectively a "PostTaskAndReply" targeted at
+// download_file->Detach(), with the difference that the destruction of the
+// task arguments is done on the target thread rather than the originating
+// thread.  If |ui_callback| wasn't needed, we could have just used
+// PostTask transferring ownership of download_file, and if download_file
+// FILE thread destruction wasn't needed, we could have used PostTaskAndReply.
+static void ReleaseDownloadFile(scoped_ptr<DownloadFile> download_file,
+                                const base::Closure& ui_callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  download_file->Detach();
+
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, ui_callback);
+}
+
 }  // namespace
 
 namespace content {
 
 // Our download table ID starts at 1, so we use 0 to represent a download that
 // has started, but has not yet had its data persisted in the table. We use fake
 // database handles in incognito mode starting at -1 and progressively getting
 // more negative.
 // static
 const int DownloadItem::kUninitializedHandle = 0;
@@ skipping 158 matching lines @@
       delegate_delayed_complete_(false),
       bound_net_log_(bound_net_log),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {
   delegate_->Attach();
   Init(true /* actively downloading */,
        download_net_logs::SRC_SAVE_PAGE_AS);
 }
 
 DownloadItemImpl::~DownloadItemImpl() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  // Should always have been nuked before now, at worst in
+  // DownloadManager shutdown.
+  DCHECK(!download_file_.get());
+
   FOR_EACH_OBSERVER(Observer, observers_, OnDownloadDestroyed(this));
   STLDeleteContainerPairSecondPointers(
       external_data_map_.begin(), external_data_map_.end());
   delegate_->AssertStateConsistent(this);
   delegate_->Detach();
 }
 
+base::WeakPtr<content::DownloadDestinationObserver>
+DownloadItemImpl::DestinationObserverAsWeakPtr() {
+  // Return does private downcast.
+  return weak_ptr_factory_.GetWeakPtr();
+}
+
 void DownloadItemImpl::AddObserver(Observer* observer) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   observers_.AddObserver(observer);
 }
 
 void DownloadItemImpl::RemoveObserver(Observer* observer) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   observers_.RemoveObserver(observer);
@@ skipping 68 matching lines @@
   bound_net_log_.AddEvent(
       net::NetLog::TYPE_DOWNLOAD_ITEM_SAFETY_STATE_UPDATED,
       base::Bind(&download_net_logs::ItemCheckedCallback,
                  GetDangerType(), GetSafetyState()));
 
   UpdateObservers();
 
   delegate_->MaybeCompleteDownload(this);
 }
 
-void DownloadItemImpl::ProgressComplete(int64 bytes_so_far,
-                                        const std::string& final_hash) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  hash_ = final_hash;
-  hash_state_ = "";
-
-  received_bytes_ = bytes_so_far;
-
-  // If we've received more data than we were expecting (bad server info?),
-  // revert to 'unknown size mode'.
-  if (received_bytes_ > total_bytes_)
-    total_bytes_ = 0;
-}
-
 // Updates from the download thread may have been posted while this download
 // was being cancelled in the UI thread, so we'll accept them unless we're
 // complete.
 void DownloadItemImpl::UpdateProgress(int64 bytes_so_far,
                                       int64 bytes_per_sec,
                                       const std::string& hash_state) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (!IsInProgress()) {
     // Ignore if we're no longer in-progress.  This can happen if we race a
@@ skipping 36 matching lines @@
   VLOG(20) << __FUNCTION__ << "() download = " << DebugString(true);
   if (!IsPartialDownload()) {
     // Small downloads might be complete before this method has
     // a chance to run.
     return;
   }
 
   download_stats::RecordDownloadCount(download_stats::CANCELLED_COUNT);
 
   TransitionTo(CANCELLED);
+
+  // Cancel and remove the download file.
+  DCHECK(download_file_.get());
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      // Will be deleted at end of task execution.
+      base::Bind(&DownloadFile::Cancel, base::Owned(download_file_.release())));
+
+  // Cancel the originating URL request.
+  request_handle_->CancelRequest();
+
   if (user_cancel)
     delegate_->DownloadStopped(this);
 }
 
+// We're starting the download.
+void DownloadItemImpl::Start(scoped_ptr<content::DownloadFile> download_file) {
+  DCHECK(!download_file_.get());
+  download_file_ = download_file.Pass();
+
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&DownloadFile::Initialize,
+                 // Safe because we control download file lifetime.
+                 base::Unretained(download_file_.get()),
+                 base::Bind(&DownloadItemImpl::OnDownloadFileInitialized,
+                            weak_ptr_factory_.GetWeakPtr())));
+}
+
 // An error occurred somewhere.
 void DownloadItemImpl::Interrupt(content::DownloadInterruptReason reason) {
   // Somewhat counter-intuitively, it is possible for us to receive an
   // interrupt after we've already been interrupted.  The generation of
   // interrupts from the file thread Renames and the generation of
   // interrupts from disk writes go through two different mechanisms (driven
   // by rename requests from UI thread and by write requests from IO thread,
   // respectively), and since we choose not to keep state on the File thread,
   // this is the place where the races collide.  It's also possible for
   // interrupts to race with cancels.
 
   // Whatever happens, the first one to hit the UI thread wins.
   if (!IsInProgress())
     return;
 
   last_reason_ = reason;
   TransitionTo(INTERRUPTED);
+
+  // Cancel and remove the download file.
+  DCHECK(download_file_.get());
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      // Will be deleted at end of task execution.
+      base::Bind(&DownloadFile::Cancel, base::Owned(download_file_.release())));
+
+  // Cancel the originating URL request.
+  request_handle_->CancelRequest();
+
   download_stats::RecordDownloadInterrupted(
       reason, received_bytes_, total_bytes_);
   delegate_->DownloadStopped(this);
 }
 
 void DownloadItemImpl::MarkAsComplete() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   DCHECK(all_data_saved_);
   end_time_ = base::Time::Now();
   TransitionTo(COMPLETE);
 }
 
 void DownloadItemImpl::DelayedDownloadOpened(bool auto_opened) {
   auto_opened_ = auto_opened;
   Completed();
 }
 
 void DownloadItemImpl::OnAllDataSaved(
-    int64 size, const std::string& final_hash) {
+    const std::string& final_hash) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  DCHECK_EQ(IN_PROGRESS, state_);
   DCHECK(!all_data_saved_);
   all_data_saved_ = true;
-  ProgressComplete(size, final_hash);
+
+  // Store final hash and null out intermediate serialized hash state.
+  hash_ = final_hash;
+  hash_state_ = "";
+
   UpdateObservers();
 }
 
 void DownloadItemImpl::OnDownloadedFileRemoved() {
   file_externally_removed_ = true;
   UpdateObservers();
 }
 
 void DownloadItemImpl::MaybeCompleteDownload() {
   // TODO(rdsmith): Move logic for this function here.
@@ skipping 174 matching lines @@
     request_handle_->ResumeRequest();
   else
     request_handle_->PauseRequest();
   is_paused_ = !is_paused_;
   UpdateObservers();
 }
 
 void DownloadItemImpl::OnDownloadCompleting() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  if (!IsInProgress())
+    return;
+
   VLOG(20) << __FUNCTION__ << "()"
            << " needs rename = " << NeedsRename()
            << " " << DebugString(true);
   DCHECK(!GetTargetName().empty());
   DCHECK_NE(DANGEROUS, GetSafetyState());
 
+  DCHECK(download_file_.get());
   if (NeedsRename()) {
-    DownloadFileManager::RenameCompletionCallback callback =
+    content::DownloadFile::RenameCompletionCallback callback =
         base::Bind(&DownloadItemImpl::OnDownloadRenamedToFinalName,
                    weak_ptr_factory_.GetWeakPtr());
     BrowserThread::PostTask(
         BrowserThread::FILE, FROM_HERE,
-        base::Bind(&DownloadFileManager::RenameDownloadFile,
-                   delegate_->GetDownloadFileManager(), GetGlobalId(),
+        base::Bind(&DownloadFile::Rename,
+                   base::Unretained(download_file_.get()),
                    GetTargetFilePath(), true, callback));
   } else {
     // Complete the download and release the DownloadFile.
     BrowserThread::PostTask(
         BrowserThread::FILE, FROM_HERE,
-        base::Bind(&DownloadFileManager::CompleteDownload,
-                   delegate_->GetDownloadFileManager(), GetGlobalId(),
+        base::Bind(&ReleaseDownloadFile, base::Passed(download_file_.Pass()),
                    base::Bind(&DownloadItemImpl::OnDownloadFileReleased,
                               weak_ptr_factory_.GetWeakPtr())));
   }
 }
 
 void DownloadItemImpl::OnDownloadRenamedToFinalName(
     content::DownloadInterruptReason reason,
     const FilePath& full_path) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  if (!IsInProgress())
+    return;
+
   VLOG(20) << __FUNCTION__ << "()"
            << " full_path = \"" << full_path.value() << "\""
            << " needed rename = " << NeedsRename()
            << " " << DebugString(false);
   DCHECK(NeedsRename());
 
   if (content::DOWNLOAD_INTERRUPT_REASON_NONE != reason) {
     Interrupt(reason);
     return;
   }
 
   // full_path is now the current and target file path.
   DCHECK(!full_path.empty());
   target_path_ = full_path;
   SetFullPath(full_path);
   delegate_->DownloadRenamedToFinalName(this);
 
   // Complete the download and release the DownloadFile.
+  // TODO(rdsmith): Unify this path with the !NeedsRename() path in
+  // OnDownloadCompleting above.  This can happen easily after history
+  // is made into an observer and the path accessors are cleaned up;
+  // that should allow OnDownloadCompleting to simply call
+  // OnDownloadRenamedToFinalName directly.
+  DCHECK(download_file_.get());
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
-      base::Bind(&DownloadFileManager::CompleteDownload,
-                 delegate_->GetDownloadFileManager(), GetGlobalId(),
+      base::Bind(&ReleaseDownloadFile, base::Passed(download_file_.Pass()),
                  base::Bind(&DownloadItemImpl::OnDownloadFileReleased,
                             weak_ptr_factory_.GetWeakPtr())));
 }
 
+void DownloadItemImpl::OnDownloadFileInitialized(
+    content::DownloadInterruptReason result) {
+  if (result != content::DOWNLOAD_INTERRUPT_REASON_NONE) {
+    Interrupt(result);
+    // TODO(rdsmith): It makes no sense to continue along the
+    // regular download path after we've gotten an error.  But it's
+    // the way the code has historically worked, and this allows us
+    // to get the download persisted and observers of the download manager
+    // notified, so tests work.  When we execute all side effects of cancel
+    // (including queue removal) immedately rather than waiting for
+    // persistence we should replace this comment with a "return;".
+  }
+
+  delegate_->DelegateStart(this);
+}
+
 void DownloadItemImpl::OnDownloadFileReleased() {
   if (delegate_->ShouldOpenDownload(this))
     Completed();
   else
     delegate_delayed_complete_ = true;
 }
 
 void DownloadItemImpl::OnDownloadRenamedToIntermediateName(
     content::DownloadInterruptReason reason,
     const FilePath& full_path) {
@@ skipping 108 matching lines @@
   target_path_ = target_path;
   target_disposition_ = disposition;
   SetDangerType(danger_type);
   // TODO(asanka): SetDangerType() doesn't need to send a notification here.
 
   // We want the intermediate and target paths to refer to the same directory so
   // that they are both on the same device and subject to same
   // space/permission/availability constraints.
   DCHECK(intermediate_path.DirName() == target_path.DirName());
 
+  if (!IsInProgress()) {
+    // If we've been cancelled or interrupted while the target was being
+    // determined, continue the cascade with a null name.
+    // The error doesn't matter as the cause of download stoppaged
+    // will already have been recorded.
+    OnDownloadRenamedToIntermediateName(
+        content::DOWNLOAD_INTERRUPT_REASON_FILE_FAILED, FilePath());
+    return;
+  }
+
   // Rename to intermediate name.
   // TODO(asanka): Skip this rename if AllDataSaved() is true. This avoids a
   //               spurious rename when we can just rename to the final
   //               filename. Unnecessary renames may cause bugs like
   //               http://crbug.com/74187.
-  DownloadFileManager::RenameCompletionCallback callback =
+  DCHECK(download_file_.get());
+  DownloadFile::RenameCompletionCallback callback =
       base::Bind(&DownloadItemImpl::OnDownloadRenamedToIntermediateName,
                  weak_ptr_factory_.GetWeakPtr());
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
-      base::Bind(&DownloadFileManager::RenameDownloadFile,
-                 delegate_->GetDownloadFileManager(), GetGlobalId(),
+      base::Bind(&DownloadFile::Rename,
+                 // Safe because we control download file lifetime.
+                 base::Unretained(download_file_.get()),
                  intermediate_path, false, callback));
 }
 
 void DownloadItemImpl::OnContentCheckCompleted(
     content::DownloadDangerType danger_type) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(AllDataSaved());
   SetDangerType(danger_type);
   UpdateObservers();
 }
@@ skipping 10 matching lines @@
 
 void DownloadItemImpl::SetDisplayName(const FilePath& name) {
   display_name_ = name;
 }
 
 FilePath DownloadItemImpl::GetUserVerifiedFilePath() const {
   return (safety_state_ == DownloadItem::SAFE) ?
       GetTargetFilePath() : GetFullPath();
 }
 
-void DownloadItemImpl::OffThreadCancel() {
+void DownloadItemImpl::DestinationUpdate(int64 bytes_so_far,
+                                         int64 bytes_per_sec,
+                                         const std::string& hash_state) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  request_handle_->CancelRequest();
 
-  BrowserThread::PostTask(
-      BrowserThread::FILE, FROM_HERE,
-      base::Bind(&DownloadFileManager::CancelDownload,
-                 delegate_->GetDownloadFileManager(), download_id_));
+  if (!IsInProgress()) {
+    // Ignore if we're no longer in-progress.  This can happen if we race a
+    // Cancel on the UI thread with an update on the FILE thread.
+    //
+    // TODO(rdsmith): Arguably we should let this go through, as this means
+    // the download really did get further than we know before it was
+    // cancelled.  But the gain isn't very large, and the code is more
+    // fragile if it has to support in progress updates in a non-in-progress
+    // state.  This issue should be readdressed when we revamp performance
+    // reporting.
+    return;
+  }
+  bytes_per_sec_ = bytes_per_sec;
+  hash_state_ = hash_state;
+  received_bytes_ = bytes_so_far;
+
+  // If we've received more data than we were expecting (bad server info?),
+  // revert to 'unknown size mode'.
+  if (received_bytes_ > total_bytes_)
+    total_bytes_ = 0;
+
+  if (bound_net_log_.IsLoggingAllEvents()) {
+    bound_net_log_.AddEvent(
+        net::NetLog::TYPE_DOWNLOAD_ITEM_UPDATED,
+        net::NetLog::Int64Callback("bytes_so_far", received_bytes_));
+  }
+
+  UpdateObservers();
+}
+
+void DownloadItemImpl::DestinationError(
+    content::DownloadInterruptReason reason) {
+  // The DestinationError and Interrupt routines are being kept separate
+  // to allow for a future merging of the Cancel and Interrupt routines..
+  Interrupt(reason);
+}
+
+void DownloadItemImpl::DestinationCompleted(const std::string& final_hash) {
+  if (!IsInProgress())
+    return;
+  OnAllDataSaved(final_hash);
+  delegate_->MaybeCompleteDownload(this);
 }
 
 void DownloadItemImpl::Init(bool active,
                             download_net_logs::DownloadType download_type) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (active)
     download_stats::RecordDownloadCount(download_stats::START_COUNT);
 
   if (target_path_.empty())
@@ skipping 90 matching lines @@
         " total = %" PRId64
         " received = %" PRId64
         " reason = %s"
         " paused = %c"
         " otr = %c"
         " safety = %s"
         " last_modified = '%s'"
         " etag = '%s'"
         " url_chain = \n\t\"%s\"\n\t"
         " full_path = \"%" PRFilePath "\""
-        " target_path = \"%" PRFilePath "\"",
+        " target_path = \"%" PRFilePath "\""
+        " has download file = %s",
         GetDbHandle(),
         GetTotalBytes(),
         GetReceivedBytes(),
         InterruptReasonDebugString(last_reason_).c_str(),
         IsPaused() ? 'T' : 'F',
         IsOtr() ? 'T' : 'F',
         DebugSafetyStateString(GetSafetyState()),
         GetLastModifiedTime().c_str(),
         GetETag().c_str(),
         url_list.c_str(),
         GetFullPath().value().c_str(),
-        GetTargetFilePath().value().c_str());
+        GetTargetFilePath().value().c_str(),
+        download_file_.get() ? "true" : "false");
   } else {
     description += base::StringPrintf(" url = \"%s\"", url_list.c_str());
   }
 
   description += " }";
 
   return description;
 }
 
 bool DownloadItemImpl::AllDataSaved() const { return all_data_saved_; }
@@ skipping 118 matching lines @@
   std::map<const void*, ExternalData*>::iterator it =
       external_data_map_.find(key);
 
   if (it == external_data_map_.end()) {
     external_data_map_[key] = data;
   } else if (it->second != data) {
     delete it->second;
     it->second = data;
   }
 }