root/content/browser/download/save_file_manager.cc

DEFINITIONS

1. Shutdown
2. OnShutdown
3. LookupSaveFile
4. GetNextId
5. RegisterStartingRequest
6. UnregisterStartingRequest
7. LookupPackage
8. SaveURL
9. RemoveSaveFile
10. GetSavePackageFromRenderIds
11. DeleteDirectoryOrFile
12. SendCancelRequest
13. StartSave
14. UpdateSaveProgress
15. SaveFinished
16. OnStartSave
17. OnUpdateSaveProgress
18. OnSaveFinished
19. OnErrorFinished
20. OnSaveURL
21. OnRequireSaveJobFromOtherSource
22. ExecuteCancelSaveRequest
23. CancelSave
24. SaveLocalFile
25. OnDeleteDirectoryOrFile
26. RenameAllFiles
27. OnFinishSavePageJob
28. RemoveSavedFileFromFileMap

// 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 "build/build_config.h"

#include "content/browser/download/save_file_manager.h"

#include "base/bind.h"
#include "base/file_util.h"
#include "base/logging.h"
#include "base/stl_util.h"
#include "base/strings/string_util.h"
#include "base/threading/thread.h"
#include "content/browser/download/save_file.h"
#include "content/browser/download/save_package.h"
#include "content/browser/loader/resource_dispatcher_host_impl.h"
#include "content/browser/renderer_host/render_view_host_impl.h"
#include "content/browser/web_contents/web_contents_impl.h"
#include "content/public/browser/browser_thread.h"
#include "net/base/io_buffer.h"
#include "net/base/net_util.h"
#include "url/gurl.h"

namespace content {

SaveFileManager::SaveFileManager()
    : next_id_(0) {
}

SaveFileManager::~SaveFileManager() {
  // Check for clean shutdown.
  DCHECK(save_file_map_.empty());
}

// Called during the browser shutdown process to clean up any state (open files,
// timers) that live on the saving thread (file thread).
void SaveFileManager::Shutdown() {
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&SaveFileManager::OnShutdown, this));
}

// Stop file thread operations.
void SaveFileManager::OnShutdown() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  STLDeleteValues(&save_file_map_);
}

SaveFile* SaveFileManager::LookupSaveFile(int save_id) {
  SaveFileMap::iterator it = save_file_map_.find(save_id);
  return it == save_file_map_.end() ? NULL : it->second;
}

// Called on the IO thread when
// a) The ResourceDispatcherHostImpl has decided that a request is savable.
// b) The resource does not come from the network, but we still need a
// save ID for for managing the status of the saving operation. So we
// file a request from the file thread to the IO thread to generate a
// unique save ID.
int SaveFileManager::GetNextId() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  return next_id_++;
}

void SaveFileManager::RegisterStartingRequest(const GURL& save_url,
                                              SavePackage* save_package) {
  // Make sure it runs in the UI thread.
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  int contents_id = save_package->contents_id();

  // Register this starting request.
  StartingRequestsMap& starting_requests =
      contents_starting_requests_[contents_id];
  bool never_present = starting_requests.insert(
      StartingRequestsMap::value_type(save_url.spec(), save_package)).second;
  DCHECK(never_present);
}

SavePackage* SaveFileManager::UnregisterStartingRequest(
    const GURL& save_url, int contents_id) {
  // Make sure it runs in UI thread.
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  ContentsToStartingRequestsMap::iterator it =
      contents_starting_requests_.find(contents_id);
  if (it != contents_starting_requests_.end()) {
    StartingRequestsMap& requests = it->second;
    StartingRequestsMap::iterator sit = requests.find(save_url.spec());
    if (sit == requests.end())
      return NULL;

    // Found, erase it from starting list and return SavePackage.
    SavePackage* save_package = sit->second;
    requests.erase(sit);
    // If there is no element in requests, remove it
    if (requests.empty())
      contents_starting_requests_.erase(it);
    return save_package;
  }

  return NULL;
}

// Look up a SavePackage according to a save id.
SavePackage* SaveFileManager::LookupPackage(int save_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackageMap::iterator it = packages_.find(save_id);
  if (it != packages_.end())
    return it->second;
  return NULL;
}

// Call from SavePackage for starting a saving job
void SaveFileManager::SaveURL(
    const GURL& url,
    const Referrer& referrer,
    int render_process_host_id,
    int render_view_id,
    SaveFileCreateInfo::SaveFileSource save_source,
    const base::FilePath& file_full_path,
    ResourceContext* context,
    SavePackage* save_package) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  // Register a saving job.
  RegisterStartingRequest(url, save_package);
  if (save_source == SaveFileCreateInfo::SAVE_FILE_FROM_NET) {
    DCHECK(url.is_valid());

    BrowserThread::PostTask(
        BrowserThread::IO, FROM_HERE,
        base::Bind(&SaveFileManager::OnSaveURL, this, url, referrer,
            render_process_host_id, render_view_id, context));
  } else {
    // We manually start the save job.
    SaveFileCreateInfo* info = new SaveFileCreateInfo(file_full_path,
         url,
         save_source,
         -1);
    info->render_process_id = render_process_host_id;
    info->render_view_id = render_view_id;

    // Since the data will come from render process, so we need to start
    // this kind of save job by ourself.
    BrowserThread::PostTask(
        BrowserThread::IO, FROM_HERE,
        base::Bind(&SaveFileManager::OnRequireSaveJobFromOtherSource,
            this, info));
  }
}

// Utility function for look up table maintenance, called on the UI thread.
// A manager may have multiple save page job (SavePackage) in progress,
// so we just look up the save id and remove it from the tracking table.
// If the save id is -1, it means we just send a request to save, but the
// saving action has still not happened, need to call UnregisterStartingRequest
// to remove it from the tracking map.
void SaveFileManager::RemoveSaveFile(int save_id, const GURL& save_url,
                                     SavePackage* package) {
  DCHECK(package);
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  // A save page job (SavePackage) can only have one manager,
  // so remove it if it exists.
  if (save_id == -1) {
    SavePackage* old_package =
        UnregisterStartingRequest(save_url, package->contents_id());
    DCHECK_EQ(old_package, package);
  } else {
    SavePackageMap::iterator it = packages_.find(save_id);
    if (it != packages_.end())
      packages_.erase(it);
  }
}

// Static
SavePackage* SaveFileManager::GetSavePackageFromRenderIds(
    int render_process_id, int render_view_id) {
  RenderViewHostImpl* render_view_host =
      RenderViewHostImpl::FromID(render_process_id, render_view_id);
  if (!render_view_host)
    return NULL;

  WebContentsImpl* contents = static_cast<WebContentsImpl*>(
      render_view_host->GetDelegate()->GetAsWebContents());
  if (!contents)
    return NULL;

  return contents->save_package();
}

void SaveFileManager::DeleteDirectoryOrFile(const base::FilePath& full_path,
                                            bool is_dir) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&SaveFileManager::OnDeleteDirectoryOrFile,
          this, full_path, is_dir));
}

void SaveFileManager::SendCancelRequest(int save_id) {
  // Cancel the request which has specific save id.
  DCHECK_GT(save_id, -1);
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&SaveFileManager::CancelSave, this, save_id));
}

// Notifications sent from the IO thread and run on the file thread:

// The IO thread created |info|, but the file thread (this method) uses it
// to create a SaveFile which will hold and finally destroy |info|. It will
// then passes |info| to the UI thread for reporting saving status.
void SaveFileManager::StartSave(SaveFileCreateInfo* info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  DCHECK(info);
  // No need to calculate hash.
  SaveFile* save_file = new SaveFile(info, false);

  // TODO(phajdan.jr): We should check the return value and handle errors here.
  save_file->Initialize();

  DCHECK(!LookupSaveFile(info->save_id));
  save_file_map_[info->save_id] = save_file;
  info->path = save_file->FullPath();

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&SaveFileManager::OnStartSave, this, info));
}

// We do forward an update to the UI thread here, since we do not use timer to
// update the UI. If the user has canceled the saving action (in the UI
// thread). We may receive a few more updates before the IO thread gets the
// cancel message. We just delete the data since the SaveFile has been deleted.
void SaveFileManager::UpdateSaveProgress(int save_id,
                                         net::IOBuffer* data,
                                         int data_len) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFile* save_file = LookupSaveFile(save_id);
  if (save_file) {
    DCHECK(save_file->InProgress());

    DownloadInterruptReason reason =
        save_file->AppendDataToFile(data->data(), data_len);
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&SaveFileManager::OnUpdateSaveProgress,
                   this,
                   save_file->save_id(),
                   save_file->BytesSoFar(),
                   reason == DOWNLOAD_INTERRUPT_REASON_NONE));
  }
}

// The IO thread will call this when saving is completed or it got error when
// fetching data. In the former case, we forward the message to OnSaveFinished
// in UI thread. In the latter case, the save ID will be -1, which means the
// saving action did not even start, so we need to call OnErrorFinished in UI
// thread, which will use the save URL to find corresponding request record and
// delete it.
void SaveFileManager::SaveFinished(int save_id,
                                   const GURL& save_url,
                                   int render_process_id,
                                   bool is_success) {
  VLOG(20) << " " << __FUNCTION__ << "()"
           << " save_id = " << save_id
           << " save_url = \"" << save_url.spec() << "\""
           << " is_success = " << is_success;
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFileMap::iterator it = save_file_map_.find(save_id);
  if (it != save_file_map_.end()) {
    SaveFile* save_file = it->second;
    // This routine may be called twice for the same from from
    // SaveePackage::OnReceivedSerializedHtmlData, once for the file
    // itself, and once when all frames have been serialized.
    // So we can't assert that the file is InProgress() here.
    // TODO(rdsmith): Fix this logic and put the DCHECK below back in.
    // DCHECK(save_file->InProgress());

    VLOG(20) << " " << __FUNCTION__ << "()"
             << " save_file = " << save_file->DebugString();
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&SaveFileManager::OnSaveFinished, this, save_id,
            save_file->BytesSoFar(), is_success));

    save_file->Finish();
    save_file->Detach();
  } else if (save_id == -1) {
    // Before saving started, we got error. We still call finish process.
    DCHECK(!save_url.is_empty());
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&SaveFileManager::OnErrorFinished, this, save_url,
            render_process_id));
  }
}

// Notifications sent from the file thread and run on the UI thread.

void SaveFileManager::OnStartSave(const SaveFileCreateInfo* info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* save_package =
      GetSavePackageFromRenderIds(info->render_process_id,
                                  info->render_view_id);
  if (!save_package) {
    // Cancel this request.
    SendCancelRequest(info->save_id);
    return;
  }

  // Insert started saving job to tracking list.
  SavePackageMap::iterator sit = packages_.find(info->save_id);
  if (sit == packages_.end()) {
    // Find the registered request. If we can not find, it means we have
    // canceled the job before.
    SavePackage* old_save_package = UnregisterStartingRequest(info->url,
        info->render_process_id);
    if (!old_save_package) {
      // Cancel this request.
      SendCancelRequest(info->save_id);
      return;
    }
    DCHECK_EQ(old_save_package, save_package);
    packages_[info->save_id] = save_package;
  } else {
    NOTREACHED();
  }

  // Forward this message to SavePackage.
  save_package->StartSave(info);
}

void SaveFileManager::OnUpdateSaveProgress(int save_id, int64 bytes_so_far,
                                           bool write_success) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* package = LookupPackage(save_id);
  if (package)
    package->UpdateSaveProgress(save_id, bytes_so_far, write_success);
  else
    SendCancelRequest(save_id);
}

void SaveFileManager::OnSaveFinished(int save_id,
                                     int64 bytes_so_far,
                                     bool is_success) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* package = LookupPackage(save_id);
  if (package)
    package->SaveFinished(save_id, bytes_so_far, is_success);
}

void SaveFileManager::OnErrorFinished(const GURL& save_url, int contents_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* save_package = UnregisterStartingRequest(save_url, contents_id);
  if (save_package)
    save_package->SaveFailed(save_url);
}

// Notifications sent from the UI thread and run on the IO thread.

void SaveFileManager::OnSaveURL(
    const GURL& url,
    const Referrer& referrer,
    int render_process_host_id,
    int render_view_id,
    ResourceContext* context) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  ResourceDispatcherHostImpl::Get()->BeginSaveFile(url,
                                                   referrer,
                                                   render_process_host_id,
                                                   render_view_id,
                                                   context);
}

void SaveFileManager::OnRequireSaveJobFromOtherSource(
    SaveFileCreateInfo* info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK_EQ(info->save_id, -1);
  // Generate a unique save id.
  info->save_id = GetNextId();
  // Start real saving action.
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&SaveFileManager::StartSave, this, info));
}

void SaveFileManager::ExecuteCancelSaveRequest(int render_process_id,
                                               int request_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  ResourceDispatcherHostImpl::Get()->CancelRequest(
      render_process_id, request_id);
}

// Notifications sent from the UI thread and run on the file thread.

// This method will be sent via a user action, or shutdown on the UI thread,
// and run on the file thread. We don't post a message back for cancels,
// but we do forward the cancel to the IO thread. Since this message has been
// sent from the UI thread, the saving job may have already completed and
// won't exist in our map.
void SaveFileManager::CancelSave(int save_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFileMap::iterator it = save_file_map_.find(save_id);
  if (it != save_file_map_.end()) {
    SaveFile* save_file = it->second;

    if (!save_file->InProgress()) {
      // We've won a race with the UI thread--we finished the file before
      // the UI thread cancelled it on us.  Unfortunately, in this situation
      // the cancel wins, so we need to delete the now detached file.
      base::DeleteFile(save_file->FullPath(), false);
    } else if (save_file->save_source() ==
               SaveFileCreateInfo::SAVE_FILE_FROM_NET) {
      // If the data comes from the net IO thread and hasn't completed
      // yet, then forward the cancel message to IO thread & cancel the
      // save locally.  If the data doesn't come from the IO thread,
      // we can ignore the message.
      BrowserThread::PostTask(
          BrowserThread::IO, FROM_HERE,
          base::Bind(&SaveFileManager::ExecuteCancelSaveRequest, this,
              save_file->render_process_id(), save_file->request_id()));
    }

    // Whatever the save file is complete or not, just delete it.  This
    // will delete the underlying file if InProgress() is true.
    save_file_map_.erase(it);
    delete save_file;
  }
}

// It is possible that SaveItem which has specified save_id has been canceled
// before this function runs. So if we can not find corresponding SaveFile by
// using specified save_id, just return.
void SaveFileManager::SaveLocalFile(const GURL& original_file_url,
                                    int save_id,
                                    int render_process_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFile* save_file = LookupSaveFile(save_id);
  if (!save_file)
    return;
  // If it has finished, just return.
  if (!save_file->InProgress())
    return;

  // Close the save file before the copy operation.
  save_file->Finish();
  save_file->Detach();

  DCHECK(original_file_url.SchemeIsFile());
  base::FilePath file_path;
  net::FileURLToFilePath(original_file_url, &file_path);
  // If we can not get valid file path from original URL, treat it as
  // disk error.
  if (file_path.empty())
    SaveFinished(save_id, original_file_url, render_process_id, false);

  // Copy the local file to the temporary file. It will be renamed to its
  // final name later.
  bool success = base::CopyFile(file_path, save_file->FullPath());
  if (!success)
    base::DeleteFile(save_file->FullPath(), false);
  SaveFinished(save_id, original_file_url, render_process_id, success);
}

void SaveFileManager::OnDeleteDirectoryOrFile(const base::FilePath& full_path,
                                              bool is_dir) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  DCHECK(!full_path.empty());

  base::DeleteFile(full_path, is_dir);
}

void SaveFileManager::RenameAllFiles(
    const FinalNameList& final_names,
    const base::FilePath& resource_dir,
    int render_process_id,
    int render_view_id,
    int save_package_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));

  if (!resource_dir.empty() && !base::PathExists(resource_dir))
    base::CreateDirectory(resource_dir);

  for (FinalNameList::const_iterator i = final_names.begin();
      i != final_names.end(); ++i) {
    SaveFileMap::iterator it = save_file_map_.find(i->first);
    if (it != save_file_map_.end()) {
      SaveFile* save_file = it->second;
      DCHECK(!save_file->InProgress());
      save_file->Rename(i->second);
      delete save_file;
      save_file_map_.erase(it);
    }
  }

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&SaveFileManager::OnFinishSavePageJob, this,
          render_process_id, render_view_id, save_package_id));
}

void SaveFileManager::OnFinishSavePageJob(int render_process_id,
                                          int render_view_id,
                                          int save_package_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  SavePackage* save_package =
      GetSavePackageFromRenderIds(render_process_id, render_view_id);

  if (save_package && save_package->id() == save_package_id)
    save_package->Finish();
}

void SaveFileManager::RemoveSavedFileFromFileMap(
    const SaveIDList& save_ids) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));

  for (SaveIDList::const_iterator i = save_ids.begin();
      i != save_ids.end(); ++i) {
    SaveFileMap::iterator it = save_file_map_.find(*i);
    if (it != save_file_map_.end()) {
      SaveFile* save_file = it->second;
      DCHECK(!save_file->InProgress());
      base::DeleteFile(save_file->FullPath(), false);
      delete save_file;
      save_file_map_.erase(it);
    }
  }
}

}  // namespace content