Use ExternalFileSystemBackend in the DriveURLRequestJob.

chrome/browser/chromeos/drive/drive_url_request_job.cc

 // Copyright 2013 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 "chrome/browser/chromeos/drive/drive_url_request_job.h"
 
+#include <algorithm>
 #include <string>
+#include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "chrome/browser/chromeos/drive/drive.pb.h"
-#include "chrome/browser/chromeos/drive/drive_file_stream_reader.h"
-#include "chrome/browser/chromeos/drive/file_system_interface.h"
+#include "base/memory/ref_counted.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/drive/file_system_util.h"
+#include "chrome/browser/extensions/api/file_handlers/mime_util.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/storage_partition.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_byte_range.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_response_info.h"
 #include "net/http/http_util.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_status.h"
+#include "storage/browser/fileapi/file_system_backend.h"
+#include "storage/browser/fileapi/file_system_context.h"
+#include "storage/browser/fileapi/file_system_operation_runner.h"
 
 using content::BrowserThread;
 
 namespace drive {
 namespace {
 
 struct MimeTypeReplacement {
   const char* original_type;
   const char* new_type;
 };
 
 const MimeTypeReplacement kMimeTypeReplacements[] = {
   {"message/rfc822", "multipart/related"}  // Fixes MHTML
 };
 
-std::string FixupMimeType(const std::string& type) {
-  for (size_t i = 0; i < arraysize(kMimeTypeReplacements); i++) {
-    if (type == kMimeTypeReplacements[i].original_type)
-      return kMimeTypeReplacements[i].new_type;
+// Check if the |url| points a valid location or not.
+bool IsValidURL(const storage::FileSystemURL& url) {
+  switch (url.type()) {
+    case storage::kFileSystemTypeDrive: {
+      const base::FilePath my_drive_path = util::GetDriveMyDriveRootPath();
+      const base::FilePath drive_other_path =
+          util::GetDriveGrandRootPath().Append(util::kDriveOtherDirName);
+      const base::FilePath url_drive_path =
+          util::ExtractDrivePathFromFileSystemUrl(url);
+      return my_drive_path == url_drive_path ||
+             my_drive_path.IsParent(url_drive_path) ||
+             drive_other_path.IsParent(url_drive_path);
+    }
+    default:
+      return false;
   }
-  return type;
 }
 
+// Delegate for obtaining FileSystemContext, FileSystemURL, and mime type on

[mtomasz, 2014/09/19 00:43:49]

I think this is not a delegate. It's more like a helper. Also mime type seems to
be not related to context, so I'm not sure if GetFileSystemContextDelegate is a
correct name.

It seems that this class does three different things. Maybe UrlParser would be a
better name, or just UrlHelper? The key responsibility of this class is to
provide information (FileSystemURL, mime type and related context) for the input
url.

[hirono, 2014/09/19 03:46:52]

I prefer URLHepler (Parser does not sound to access external resources).
Done!

+// the UI thread.
+class GetFileSystemContextDelegate {
+ public:
+  GetFileSystemContextDelegate(
+      void* profile_id,
+      const GURL& url,
+      const DriveURLRequestJob::DelegateCallback& callback)
+      : profile_id_(profile_id), url_(url), callback_(callback) {
+    DCHECK_CURRENTLY_ON(BrowserThread::IO);
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(&GetFileSystemContextDelegate::RunOnUIThread,
+                   base::Unretained(this)));
+  }
+
+ private:
+  void RunOnUIThread() {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    Profile* const profile = reinterpret_cast<Profile*>(profile_id_);
+    if (!g_browser_process->profile_manager()->IsValidProfile(profile)) {
+      ReplyResult(net::ERR_FAILED);
+      return;
+    }
+    content::StoragePartition* const storage =
+        content::BrowserContext::GetStoragePartitionForSite(profile, url_);
+    DCHECK(storage);
+
+    scoped_refptr<storage::FileSystemContext> context =
+        storage->GetFileSystemContext();
+    DCHECK(context.get());
+
+    // Obtain the absolute path in the file system.
+    base::FilePath path = drive::util::GetDriveMountPointPath(profile);
+    drive::util::GetDriveGrandRootPath().AppendRelativePath(
+        util::DriveURLToFilePath(url_), &path);
+
+    storage::ExternalFileSystemBackend* const backend =
+        context->external_backend();
+    DCHECK(backend);
+
+    // Obtain the virtual path.
+    base::FilePath virtual_path;
+    if (!backend->GetVirtualPath(path, &virtual_path)) {
+      ReplyResult(net::ERR_FILE_NOT_FOUND);
+      return;
+    }
+
+    // Obtain the file system URL.
+    // TODO(hirono): After removing MHTML support, stop to use the special
+    // drive: scheme and use filesystem: URL directly.  crbug.com/415455
+    file_system_url_ = context->CreateCrackedFileSystemURL(
+        GURL(std::string(chrome::kDriveScheme) + ":"),
+        storage::kFileSystemTypeExternal,
+        virtual_path);
+    if (!IsValidURL(file_system_url_)) {
+      ReplyResult(net::ERR_INVALID_URL);
+      return;
+    }
+
+    file_system_context_ = context;
+
+    extensions::app_file_handler_util::GetMimeTypeForLocalPath(
+        profile,
+        file_system_url_.path(),
+        base::Bind(&GetFileSystemContextDelegate::OnGotMimeTypeOnUIThread,

[mtomasz, 2014/09/19 00:43:48]

Is it safe for shutdown? During shutdown the callback may not be called, because
message loops maybe closed. As a result, we would never reach #157 and hence we
would have a memory leak. I'm not 100% sure, but could you double check?

To avoid that I used to keep an instance to "this" in a scoped_ptr and bind to a
callback.

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/chr...

But it would only make sense, if we theoretically can have a leak on shutdown
here. WDYT?

[hirono, 2014/09/19 03:46:52]

Let me do a safer way. Done.
 

+                   base::Unretained(this)));
+  }
+
+  void OnGotMimeTypeOnUIThread(const std::string& mime_type) {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    mime_type_ = mime_type;
+    for (size_t i = 0; i < arraysize(kMimeTypeReplacements); i++) {
+      if (mime_type_ == kMimeTypeReplacements[i].original_type) {
+        mime_type_ = kMimeTypeReplacements[i].new_type;
+        break;
+      }
+    }
+    ReplyResult(net::OK);
+  }
+
+  void ReplyResult(net::Error error) {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+    BrowserThread::PostTask(
+        BrowserThread::IO,
+        FROM_HERE,
+        base::Bind(callback_,
+                   error,
+                   file_system_context_,
+                   file_system_url_,
+                   mime_type_));
+    delete this;
+  }
+
+  void* const profile_id_;
+  const GURL url_;
+  const DriveURLRequestJob::DelegateCallback callback_;
+  scoped_refptr<storage::FileSystemContext> file_system_context_;
+  storage::FileSystemURL file_system_url_;
+  std::string mime_type_;
+
+  DISALLOW_COPY_AND_ASSIGN(GetFileSystemContextDelegate);
+};
+
 }  // namespace
 
-DriveURLRequestJob::DriveURLRequestJob(
-    const FileSystemGetter& file_system_getter,
-    base::SequencedTaskRunner* file_task_runner,
-    net::URLRequest* request,
-    net::NetworkDelegate* network_delegate)
+DriveURLRequestJob::DriveURLRequestJob(void* profile_id,
+                                       net::URLRequest* request,
+                                       net::NetworkDelegate* network_delegate)
     : net::URLRequestJob(request, network_delegate),
-      file_system_getter_(file_system_getter),
-      file_task_runner_(file_task_runner),
+      profile_id_(profile_id),
+      remaining_bytes_(0),
       weak_ptr_factory_(this) {
 }
 
 void DriveURLRequestJob::SetExtraRequestHeaders(
     const net::HttpRequestHeaders& headers) {
   std::string range_header;
   if (headers.GetHeader(net::HttpRequestHeaders::kRange, &range_header)) {
     // Note: We only support single range requests.
     std::vector<net::HttpByteRange> ranges;
     if (net::HttpUtil::ParseRangeHeader(range_header, &ranges) &&
         ranges.size() == 1) {
       byte_range_ = ranges[0];
     } else {
       // Failed to parse Range: header, so notify the error.
       NotifyDone(
           net::URLRequestStatus(net::URLRequestStatus::FAILED,
                                 net::ERR_REQUEST_RANGE_NOT_SATISFIABLE));
     }
   }
 }
 
 void DriveURLRequestJob::Start() {
   DVLOG(1) << "Starting request";
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(!stream_reader_);
 
   // We only support GET request.
   if (request()->method() != "GET") {
     LOG(WARNING) << "Failed to start request: "
                  << request()->method() << " method is not supported";
     NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
                                            net::ERR_METHOD_NOT_SUPPORTED));
     return;
   }
 
-  base::FilePath drive_file_path(util::DriveURLToFilePath(request_->url()));
-  if (drive_file_path.empty()) {
-    // Not a valid url.
+  // Check if the scheme is correct.
+  if (!request()->url().SchemeIs(chrome::kDriveScheme)) {
     NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
                                            net::ERR_INVALID_URL));
     return;
   }
 
-  // Initialize the stream reader.
-  stream_reader_.reset(
-      new DriveFileStreamReader(file_system_getter_, file_task_runner_.get()));
-  stream_reader_->Initialize(
-      drive_file_path,
-      byte_range_,
-      base::Bind(&DriveURLRequestJob::OnDriveFileStreamReaderInitialized,
+  // Owned by itself.
+  new GetFileSystemContextDelegate(
+      profile_id_,
+      request()->url(),
+      base::Bind(&DriveURLRequestJob::OnDelegateResultObtained,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
+void DriveURLRequestJob::OnDelegateResultObtained(
+    net::Error error,
+    const scoped_refptr<storage::FileSystemContext>& file_system_context,
+    const storage::FileSystemURL& file_system_url,
+    const std::string& mime_type) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  if (error != net::OK) {
+    NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
+                                           error));
+    return;
+  }
+
+  DCHECK(file_system_context.get());
+  file_system_context_ = file_system_context;
+  file_system_url_ = file_system_url;
+  mime_type_ = mime_type;
+
+  // Check if the entry has a redirect URL.
+  file_system_context_->external_backend()->GetRedirectURLForContents(
+      file_system_url_,
+      base::Bind(&DriveURLRequestJob::OnRedirectURLObtained,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+void DriveURLRequestJob::OnRedirectURLObtained(const GURL& redirect_url) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  redirect_url_ = redirect_url;
+  if (!redirect_url_.is_empty()) {
+    NotifyHeadersComplete();
+    return;
+  }
+
+  // Obtain file system context.
+  file_system_context_->operation_runner()->GetMetadata(
+      file_system_url_,
+      base::Bind(&DriveURLRequestJob::OnFileInfoObtained,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+void DriveURLRequestJob::OnFileInfoObtained(base::File::Error result,
+                                            const base::File::Info& file_info) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (result == base::File::FILE_ERROR_NOT_FOUND) {
+    NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
+                                           net::ERR_FILE_NOT_FOUND));
+    return;
+  }
+
+  if (result != base::File::FILE_OK || file_info.is_directory) {
+    NotifyStartError(
+        net::URLRequestStatus(net::URLRequestStatus::FAILED, net::ERR_FAILED));
+    return;
+  }
+
+  // Compute content size.
+  int64 offset = 0;
+  int64 size = storage::kMaximumLength;
+  if (byte_range_.ComputeBounds(file_info.size)) {
+    offset = byte_range_.first_byte_position();
+    size = byte_range_.last_byte_position() + 1 -
+           byte_range_.first_byte_position();
+    set_expected_content_size(size);
+  }
+  remaining_bytes_ = size;
+
+  // Create file stream reader.
+  stream_reader_ = file_system_context_->CreateFileStreamReader(
+      file_system_url_, offset, size, base::Time());
+  if (!stream_reader_) {
+    NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
+                                           net::ERR_FILE_NOT_FOUND));
+    return;
+  }
+
+  NotifyHeadersComplete();
+}
+
 void DriveURLRequestJob::Kill() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   stream_reader_.reset();
+  file_system_context_ = NULL;
   net::URLRequestJob::Kill();
   weak_ptr_factory_.InvalidateWeakPtrs();
 }
 
 bool DriveURLRequestJob::GetMimeType(std::string* mime_type) const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-
-  if (!entry_) {
-    return false;
-  }
-
-  mime_type->assign(
-      FixupMimeType(entry_->file_specific_info().content_mime_type()));
+  mime_type->assign(mime_type_);
   return !mime_type->empty();
 }
 
 bool DriveURLRequestJob::IsRedirectResponse(
     GURL* location, int* http_status_code) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-
-  if (!entry_ || !entry_->file_specific_info().is_hosted_document()) {
+  if (redirect_url_.is_empty())
     return false;
-  }
 
   // Redirect a hosted document.
-  *location = GURL(entry_->file_specific_info().alternate_url());
+  *location = redirect_url_;
   const int kHttpFound = 302;
   *http_status_code = kHttpFound;
   return true;
 }
 
 bool DriveURLRequestJob::ReadRawData(
     net::IOBuffer* buf, int buf_size, int* bytes_read) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(stream_reader_ && stream_reader_->IsInitialized());
+  DCHECK(stream_reader_);
 
-  int result = stream_reader_->Read(
-      buf, buf_size,
+  if (remaining_bytes_ == 0) {
+    *bytes_read = 0;
+    return true;
+  }
+
+  const int result = stream_reader_->Read(
+      buf,
+      std::min(static_cast<int64>(buf_size), remaining_bytes_),
       base::Bind(&DriveURLRequestJob::OnReadCompleted,
                  weak_ptr_factory_.GetWeakPtr()));
 
   if (result == net::ERR_IO_PENDING) {
     // The data is not yet available.
     SetStatus(net::URLRequestStatus(net::URLRequestStatus::IO_PENDING, 0));
     return false;
   }
   if (result < 0) {
     // An error occurs.
     NotifyDone(net::URLRequestStatus(net::URLRequestStatus::FAILED, result));
     return false;
   }
 
   // Reading has been finished immediately.
   *bytes_read = result;
+  remaining_bytes_ -= result;
   return true;
 }
 
 DriveURLRequestJob::~DriveURLRequestJob() {
 }
 
-void DriveURLRequestJob::OnDriveFileStreamReaderInitialized(
-    int error, scoped_ptr<ResourceEntry> entry) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(stream_reader_);
-
-  if (error != FILE_ERROR_OK) {
-    NotifyStartError(
-        net::URLRequestStatus(net::URLRequestStatus::FAILED, error));
-    return;
-  }
-
-  DCHECK(entry && entry->has_file_specific_info());
-  entry_ = entry.Pass();
-
-  if (!entry_->file_specific_info().is_hosted_document()) {
-    // We don't need to set content size for hosted documents,
-    // because it will be redirected.
-    set_expected_content_size(entry_->file_info().size());
-  }
-
-  NotifyHeadersComplete();
-}
-
 void DriveURLRequestJob::OnReadCompleted(int read_result) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   if (read_result < 0) {
     DCHECK_NE(read_result, net::ERR_IO_PENDING);
     NotifyDone(net::URLRequestStatus(net::URLRequestStatus::FAILED,
                                      read_result));
   }
 
+  remaining_bytes_ -= read_result;
   SetStatus(net::URLRequestStatus());  // Clear the IO_PENDING status.
   NotifyReadComplete(read_result);
 }
 
 }  // namespace drive