[Downloads] Rework how hashes are calculated for download files.

content/browser/download/download_file_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_file_impl.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/time/time.h"
 #include "base/values.h"
 #include "content/browser/byte_stream.h"
 #include "content/browser/download/download_create_info.h"
+#include "content/browser/download/download_destination_observer.h"
 #include "content/browser/download/download_interrupt_reasons_impl.h"
 #include "content/browser/download/download_net_log_parameters.h"
 #include "content/browser/download/download_stats.h"
 #include "content/public/browser/browser_thread.h"
-#include "content/public/browser/download_destination_observer.h"
+#include "crypto/secure_hash.h"
+#include "crypto/sha2.h"
 #include "net/base/io_buffer.h"
 
 namespace content {
 
 const int kUpdatePeriodMs = 500;
 const int kMaxTimeBlockingFileThreadMs = 1000;
 
 // These constants control the default retry behavior for failing renames. Each
 // retry is performed after a delay that is twice the previous delay. The
 // initial delay is specified by kInitialRenameRetryDelayMs.
-const int kMaxRenameRetries = 3;
 const int kInitialRenameRetryDelayMs = 200;
 
-int DownloadFile::number_active_objects_ = 0;
+// Number of times a failing rename is retried before giving up.
+const int kMaxRenameRetries = 3;
 
 DownloadFileImpl::DownloadFileImpl(
-    const DownloadSaveInfo& save_info,
+    scoped_ptr<DownloadSaveInfo> save_info,
     const base::FilePath& default_download_directory,
-    const GURL& url,
-    const GURL& referrer_url,
-    bool calculate_hash,
-    base::File file,
     scoped_ptr<ByteStreamReader> stream,
     const net::BoundNetLog& bound_net_log,
     base::WeakPtr<DownloadDestinationObserver> observer)
-    : file_(save_info.file_path,
-            url,
-            referrer_url,
-            save_info.offset,
-            calculate_hash,
-            save_info.hash_state,
-            std::move(file),
-            bound_net_log),
+    : file_(bound_net_log),
+      save_info_(std::move(save_info)),
       default_download_directory_(default_download_directory),
       stream_reader_(std::move(stream)),
       bytes_seen_(0),
       bound_net_log_(bound_net_log),
       observer_(observer),
       weak_factory_(this) {}
 
 DownloadFileImpl::~DownloadFileImpl() {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
-  --number_active_objects_;
 }
 
 void DownloadFileImpl::Initialize(const InitializeCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 
   update_timer_.reset(new base::RepeatingTimer());
   DownloadInterruptReason result =
-      file_.Initialize(default_download_directory_);
+      file_.Initialize(save_info_->file_path,
+                       default_download_directory_,
+                       std::move(save_info_->file),
+                       save_info_->offset,
+                       save_info_->hash_of_partial_file,
+                       std::move(save_info_->hash_state));
   if (result != DOWNLOAD_INTERRUPT_REASON_NONE) {
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE, base::Bind(callback, result));
     return;
   }
 
   stream_reader_->RegisterCallback(
       base::Bind(&DownloadFileImpl::StreamActive, weak_factory_.GetWeakPtr()));
 
   download_start_ = base::TimeTicks::Now();
 
   // Primarily to make reset to zero in restart visible to owner.
   SendUpdate();
 
   // Initial pull from the straw.
   StreamActive();
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE, base::Bind(
           callback, DOWNLOAD_INTERRUPT_REASON_NONE));
-
-  ++number_active_objects_;
 }
 
 DownloadInterruptReason DownloadFileImpl::AppendDataToFile(
     const char* data, size_t data_len) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 
   if (!update_timer_->IsRunning()) {
     update_timer_->Start(FROM_HERE,
                          base::TimeDelta::FromMilliseconds(kUpdatePeriodMs),
                          this, &DownloadFileImpl::SendUpdate);
   }
   rate_estimator_.Increment(data_len);
   return file_.AppendDataToFile(data, data_len);
 }
 
 void DownloadFileImpl::RenameAndUniquify(
     const base::FilePath& full_path,
     const RenameCompletionCallback& callback) {
-  RenameWithRetryInternal(
-      full_path, UNIQUIFY, kMaxRenameRetries, base::TimeTicks(), callback);
+  scoped_ptr<RenameParameters> parameters(
+      new RenameParameters(UNIQUIFY, full_path, callback));
+  RenameWithRetryInternal(std::move(parameters));
 }
 
 void DownloadFileImpl::RenameAndAnnotate(
     const base::FilePath& full_path,
+    const std::string& client_guid,
+    const GURL& source_url,
+    const GURL& referrer_url,
     const RenameCompletionCallback& callback) {
-  RenameWithRetryInternal(full_path,
-                          ANNOTATE_WITH_SOURCE_INFORMATION,
-                          kMaxRenameRetries,
-                          base::TimeTicks(),
-                          callback);
+  scoped_ptr<RenameParameters> parameters(new RenameParameters(
+      ANNOTATE_WITH_SOURCE_INFORMATION, full_path, callback));
+  parameters->client_guid = client_guid;
+  parameters->source_url = source_url;
+  parameters->referrer_url = referrer_url;
+  RenameWithRetryInternal(std::move(parameters));
 }
 
 base::TimeDelta DownloadFileImpl::GetRetryDelayForFailedRename(
     int attempt_number) {
   DCHECK_GE(attempt_number, 0);
   // |delay| starts at kInitialRenameRetryDelayMs and increases by a factor of
   // 2 at each subsequent retry. Assumes that |retries_left| starts at
   // kMaxRenameRetries. Also assumes that kMaxRenameRetries is less than the
   // number of bits in an int.
   return base::TimeDelta::FromMilliseconds(kInitialRenameRetryDelayMs) *
          (1 << attempt_number);
 }
 
 bool DownloadFileImpl::ShouldRetryFailedRename(DownloadInterruptReason reason) {
   return reason == DOWNLOAD_INTERRUPT_REASON_FILE_TRANSIENT_ERROR;
 }
 
 void DownloadFileImpl::RenameWithRetryInternal(
-    const base::FilePath& full_path,
-    RenameOption option,
-    int retries_left,
-    base::TimeTicks time_of_first_failure,
-    const RenameCompletionCallback& callback) {
+    scoped_ptr<RenameParameters> parameters) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 
-  base::FilePath new_path(full_path);
+  base::FilePath new_path = parameters->new_path;
 
-  if ((option & UNIQUIFY) && full_path != file_.full_path()) {
+  if ((parameters->option & UNIQUIFY) && new_path != file_.full_path()) {
     int uniquifier =
         base::GetUniquePathNumber(new_path, base::FilePath::StringType());
     if (uniquifier > 0)
       new_path = new_path.InsertBeforeExtensionASCII(
           base::StringPrintf(" (%d)", uniquifier));
   }
 
   DownloadInterruptReason reason = file_.Rename(new_path);
 
   // Attempt to retry the rename if possible. If the rename failed and the
   // subsequent open also failed, then in_progress() would be false. We don't
   // try to retry renames if the in_progress() was false to begin with since we
   // have less assurance that the file at file_.full_path() was the one we were
   // working with.
   if (ShouldRetryFailedRename(reason) && file_.in_progress() &&
-      retries_left > 0) {
-    int attempt_number = kMaxRenameRetries - retries_left;
+      parameters->retries_left > 0) {
+    int attempt_number = kMaxRenameRetries - parameters->retries_left;
+    --parameters->retries_left;
+    if (parameters->time_of_first_failure.is_null())
+      parameters->time_of_first_failure = base::TimeTicks::Now();
     BrowserThread::PostDelayedTask(
         BrowserThread::FILE,
         FROM_HERE,
         base::Bind(&DownloadFileImpl::RenameWithRetryInternal,
                    weak_factory_.GetWeakPtr(),
-                   full_path,
-                   option,
-                   --retries_left,
-                   time_of_first_failure.is_null() ? base::TimeTicks::Now()
-                                                   : time_of_first_failure,
-                   callback),
+                   base::Passed(std::move(parameters))),
         GetRetryDelayForFailedRename(attempt_number));
     return;
   }
 
-  if (!time_of_first_failure.is_null())
+  if (!parameters->time_of_first_failure.is_null())
     RecordDownloadFileRenameResultAfterRetry(
-        base::TimeTicks::Now() - time_of_first_failure, reason);
+        base::TimeTicks::Now() - parameters->time_of_first_failure, reason);
 
   if (reason == DOWNLOAD_INTERRUPT_REASON_NONE &&
-      (option & ANNOTATE_WITH_SOURCE_INFORMATION)) {
+      (parameters->option & ANNOTATE_WITH_SOURCE_INFORMATION)) {
     // Doing the annotation after the rename rather than before leaves
     // a very small window during which the file has the final name but
     // hasn't been marked with the Mark Of The Web.  However, it allows
     // anti-virus scanners on Windows to actually see the data
     // (http://crbug.com/127999) under the correct name (which is information
     // it uses).
-    reason = file_.AnnotateWithSourceInformation();
+    reason = file_.AnnotateWithSourceInformation(parameters->client_guid,
+                                                 parameters->source_url,
+                                                 parameters->referrer_url);
   }
 
   if (reason != DOWNLOAD_INTERRUPT_REASON_NONE) {
     // Make sure our information is updated, since we're about to
     // error out.
     SendUpdate();
 
     // Null out callback so that we don't do any more stream processing.
     stream_reader_->RegisterCallback(base::Closure());
 
     new_path.clear();
   }
 
   BrowserThread::PostTask(
-      BrowserThread::UI, FROM_HERE,
-      base::Bind(callback, reason, new_path));
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(parameters->completion_callback, reason, new_path));
 }
 
 void DownloadFileImpl::Detach() {
   file_.Detach();
 }
 
 void DownloadFileImpl::Cancel() {
   file_.Cancel();
 }
 
-base::FilePath DownloadFileImpl::FullPath() const {
+const base::FilePath& DownloadFileImpl::FullPath() const {
   return file_.full_path();
 }
 
 bool DownloadFileImpl::InProgress() const {
   return file_.in_progress();
 }
 
-int64_t DownloadFileImpl::CurrentSpeed() const {
-  return rate_estimator_.GetCountPerSecond();
-}
-
-bool DownloadFileImpl::GetHash(std::string* hash) {
-  return file_.GetHash(hash);
-}
-
-std::string DownloadFileImpl::GetHashState() {
-  return file_.GetHashState();
-}
-
-void DownloadFileImpl::SetClientGuid(const std::string& guid) {
-  file_.SetClientGuid(guid);
-}
-
 void DownloadFileImpl::StreamActive() {
   base::TimeTicks start(base::TimeTicks::Now());
   base::TimeTicks now;
   scoped_refptr<net::IOBuffer> incoming_data;
   size_t incoming_data_size = 0;
   size_t total_incoming_data_size = 0;
   size_t num_buffers = 0;
   ByteStreamReader::StreamState state(ByteStreamReader::STREAM_EMPTY);
   DownloadInterruptReason reason = DOWNLOAD_INTERRUPT_REASON_NONE;
   base::TimeDelta delta(
@@ skipping 16 matching lines @@
           bytes_seen_ += incoming_data_size;
           total_incoming_data_size += incoming_data_size;
         }
         break;
       case ByteStreamReader::STREAM_COMPLETE:
         {
           reason = static_cast<DownloadInterruptReason>(
               stream_reader_->GetStatus());
           SendUpdate();
           base::TimeTicks close_start(base::TimeTicks::Now());
-          if (reason == DOWNLOAD_INTERRUPT_REASON_NONE)
-            file_.Finish();
-          else
-            file_.FinishWithError();
           base::TimeTicks now(base::TimeTicks::Now());
           disk_writes_time_ += (now - close_start);
           RecordFileBandwidth(
               bytes_seen_, disk_writes_time_, now - download_start_);
           update_timer_.reset();
         }
         break;
       default:
         NOTREACHED();
         break;
@@ skipping 17 matching lines @@
 
   RecordContiguousWriteTime(now - start);
 
   // Take care of communication with our observer.
   if (reason != DOWNLOAD_INTERRUPT_REASON_NONE) {
     // Error case for both upstream source and file write.
     // Shut down processing and signal an error to our observer.
     // Our observer will clean us up.
     stream_reader_->RegisterCallback(base::Closure());
     weak_factory_.InvalidateWeakPtrs();
-    SendUpdate();                       // Make info up to date before error.
+    SendUpdate();  // Make info up to date before error.
+    scoped_ptr<crypto::SecureHash> hash_state = file_.Finish();
     BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE,
+        BrowserThread::UI,
+        FROM_HERE,
         base::Bind(&DownloadDestinationObserver::DestinationError,
-                   observer_, reason));
+                   observer_,
+                   reason,
+                   file_.bytes_so_far(),
+                   base::Passed(&hash_state)));
   } else if (state == ByteStreamReader::STREAM_COMPLETE) {
     // Signal successful completion and shut down processing.
     stream_reader_->RegisterCallback(base::Closure());
     weak_factory_.InvalidateWeakPtrs();
-    std::string hash;
-    if (!GetHash(&hash) || file_.IsEmptyHash(hash))
-      hash.clear();
     SendUpdate();
+    scoped_ptr<crypto::SecureHash> hash_state = file_.Finish();
     BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE,
-        base::Bind(
-            &DownloadDestinationObserver::DestinationCompleted,
-            observer_, hash));
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(&DownloadDestinationObserver::DestinationCompleted,
+                   observer_,
+                   file_.bytes_so_far(),
+                   base::Passed(&hash_state)));
   }
   if (bound_net_log_.IsCapturing()) {
     bound_net_log_.AddEvent(
         net::NetLog::TYPE_DOWNLOAD_STREAM_DRAINED,
         base::Bind(&FileStreamDrainedNetLogCallback, total_incoming_data_size,
                    num_buffers));
   }
 }
 
 void DownloadFileImpl::SendUpdate() {
   BrowserThread::PostTask(
-      BrowserThread::UI, FROM_HERE,
+      BrowserThread::UI,
+      FROM_HERE,
       base::Bind(&DownloadDestinationObserver::DestinationUpdate,
-                 observer_, file_.bytes_so_far(), CurrentSpeed(),
-                 GetHashState()));
+                 observer_,
+                 file_.bytes_so_far(),
+                 rate_estimator_.GetCountPerSecond()));
 }
 
-// static
-int DownloadFile::GetNumberOfDownloadFiles() {
-  return number_active_objects_;
-}
+DownloadFileImpl::RenameParameters::RenameParameters(
+    RenameOption option,
+    const base::FilePath& new_path,
+    const RenameCompletionCallback& completion_callback)
+    : option(option),
+      new_path(new_path),
+      retries_left(kMaxRenameRetries),
+      completion_callback(completion_callback) {}
+
+DownloadFileImpl::RenameParameters::~RenameParameters() {}
 
 }  // namespace content