Support contents upload on FakeDriveService

chrome/browser/drive/fake_drive_service.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 "chrome/browser/drive/fake_drive_service.h"
 
 #include <string>
 
+#include "base/file_util.h"
 #include "base/logging.h"
+#include "base/md5.h"
 #include "base/message_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_tokenizer.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/google_apis/drive_api_parser.h"
 #include "chrome/browser/google_apis/gdata_wapi_parser.h"
 #include "chrome/browser/google_apis/test_util.h"
@@ skipping 69 matching lines @@
     // TODO(peria): Deal with other attributes than title.
     if (!key.empty() && key != "title")
       return false;
     // Search query in the title.
     if (entry.title().find(value) == std::string::npos)
       return false;
   }
   return true;
 }
 
-// Gets the upload URL from the given entry. Returns an empty URL if not
-// found.
-GURL GetUploadUrl(const base::DictionaryValue& entry) {
-  std::string upload_url;
-  const base::ListValue* links = NULL;
-  if (entry.GetList("link", &links) && links) {
-    for (size_t link_index = 0;
-         link_index < links->GetSize();
-         ++link_index) {
-      const base::DictionaryValue* link = NULL;
-      std::string rel;
-      if (links->GetDictionary(link_index, &link) &&
-          link && link->GetString("rel", &rel) &&
-          rel == kUploadUrlRel &&
-          link->GetString("href", &upload_url)) {
-        break;
-      }
-    }
-  }
-  return GURL(upload_url);
-}
-
 // Returns |url| without query parameter.
 GURL RemoveQueryParameter(const GURL& url) {
   GURL::Replacements replacements;
   replacements.ClearQuery();
   return url.ReplaceComponents(replacements);
 }
 
+void ScheduleUploadRangeCallback(const UploadRangeCallback& callback,
+                                 int64 start_position,
+                                 int64 end_position,
+                                 GDataErrorCode error,
+                                 scoped_ptr<ResourceEntry> entry) {
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE,
+      base::Bind(callback,
+                 UploadRangeResponse(GDATA_NO_CONNECTION,

[hashimoto, 2013/06/21 08:05:32]

Shouldn't this be |error|?

[tzik, 2013/06/21 10:41:30]

Done.

+                                     start_position,
+                                     end_position),
+                 base::Passed(&entry)));
+}
+
 }  // namespace
 
+struct FakeDriveService::UploadSession {
+  std::string content_type;
+  int64 content_length;
+  std::string parent_resource_id;
+  std::string resource_id;
+  std::string etag;
+  std::string title;
+
+  int64 uploaded_size;
+
+  UploadSession()
+      : content_length(0),
+        uploaded_size(0) {}
+
+  UploadSession(
+      std::string content_type,
+      int64 content_length,
+      std::string parent_resource_id,
+      std::string resource_id,
+      std::string etag,
+      std::string title)
+    : content_type(content_type),
+      content_length(content_length),
+      parent_resource_id(parent_resource_id),
+      resource_id(resource_id),
+      etag(etag),
+      title(title),
+      uploaded_size(0) {
+  }
+};
+
 FakeDriveService::FakeDriveService()
     : largest_changestamp_(0),
       published_date_seq_(0),
+      next_upload_sequence_number_(0),
       default_max_results_(0),
       resource_id_count_(0),
       resource_list_load_count_(0),
       change_list_load_count_(0),
       directory_load_count_(0),
       about_resource_load_count_(0),
       offline_(false) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
@@ skipping 398 matching lines @@
   if (!entry) {
     base::MessageLoopProxy::current()->PostTask(
         FROM_HERE,
         base::Bind(download_action_callback, HTTP_NOT_FOUND, base::FilePath()));
     return CancelCallback();
   }
 
   // Write "x"s of the file size specified in the entry.
   std::string file_size_string;
   entry->GetString("docs$size.$t", &file_size_string);
-  // TODO(satorux): To be correct, we should update docs$md5Checksum.$t here.
   int64 file_size = 0;
   if (base::StringToInt64(file_size_string, &file_size)) {
     base::BinaryValue* content_binary_data;
     std::string content_data;
     if (entry->GetBinary("test$data", &content_binary_data)) {
       content_data = std::string(content_binary_data->GetBuffer(),
           content_binary_data->GetSize());
     }
     DCHECK_EQ(static_cast<size_t>(file_size), content_data.size());
 
@@ skipping 81 matching lines @@
           entry->Set("link", links);
         }
         links->Clear();
 
         base::DictionaryValue* link = new base::DictionaryValue;
         link->SetString(
             "rel", "http://schemas.google.com/docs/2007#parent");
         link->SetString("href", GetFakeLinkUrl(parent_resource_id).spec());
         links->Append(link);
 
-        AddNewChangestamp(copied_entry.get());
+        AddNewChangestampAndETag(copied_entry.get());
 
         // Parse the new entry.
         scoped_ptr<ResourceEntry> resource_entry =
             ResourceEntry::CreateFrom(*copied_entry);
         // Add it to the resource list.
         entries->Append(copied_entry.release());
 
         base::MessageLoop::current()->PostTask(
             FROM_HERE,
             base::Bind(callback,
@@ skipping 30 matching lines @@
 
   if (offline_) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(callback, GDATA_NO_CONNECTION));
     return CancelCallback();
   }
 
   base::DictionaryValue* entry = FindEntryByResourceId(resource_id);
   if (entry) {
     entry->SetString("title.$t", new_name);
-    AddNewChangestamp(entry);
+    AddNewChangestampAndETag(entry);
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(callback, HTTP_SUCCESS));
     return CancelCallback();
   }
 
   base::MessageLoop::current()->PostTask(
       FROM_HERE, base::Bind(callback, HTTP_NOT_FOUND));
   return CancelCallback();
 }
 
@@ skipping 21 matching lines @@
         FROM_HERE,
         base::Bind(callback, HTTP_NOT_FOUND,
                    base::Passed(scoped_ptr<ResourceEntry>())));
     return CancelCallback();
   }
 
   entry->SetString("updated.$t",
                    util::FormatTimeAsString(modified_date));
   entry->SetString("gd$lastViewed.$t",
                    util::FormatTimeAsString(last_viewed_by_me_date));
-  AddNewChangestamp(entry);
+  AddNewChangestampAndETag(entry);
 
   scoped_ptr<ResourceEntry> parsed_entry(ResourceEntry::CreateFrom(*entry));
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(callback, HTTP_SUCCESS, base::Passed(&parsed_entry)));
   return CancelCallback();
 }
 
 CancelCallback FakeDriveService::AddResourceToDirectory(
     const std::string& parent_resource_id,
@@ skipping 19 matching lines @@
     // On the real Drive server, resources do not necessary shape a tree
     // structure. That is, each resource can have multiple parent.
     // We mimic the behavior here; AddResourceToDirectoy just adds
     // one more parent link, not overwriting old links.
     base::DictionaryValue* link = new base::DictionaryValue;
     link->SetString("rel", "http://schemas.google.com/docs/2007#parent");
     link->SetString(
         "href", GetFakeLinkUrl(parent_resource_id).spec());
     links->Append(link);
 
-    AddNewChangestamp(entry);
+    AddNewChangestampAndETag(entry);
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(callback, HTTP_SUCCESS));
     return CancelCallback();
   }
 
   base::MessageLoop::current()->PostTask(
       FROM_HERE, base::Bind(callback, HTTP_NOT_FOUND));
   return CancelCallback();
 }
 
@@ skipping 18 matching lines @@
       for (size_t i = 0; i < links->GetSize(); ++i) {
         base::DictionaryValue* link = NULL;
         std::string rel;
         std::string href;
         if (links->GetDictionary(i, &link) &&
             link->GetString("rel", &rel) &&
             link->GetString("href", &href) &&
             rel == "http://schemas.google.com/docs/2007#parent" &&
             GURL(href) == parent_content_url) {
           links->Remove(i, NULL);
-          AddNewChangestamp(entry);
+          AddNewChangestampAndETag(entry);
           base::MessageLoop::current()->PostTask(
               FROM_HERE, base::Bind(callback, HTTP_SUCCESS));
           return CancelCallback();
         }
       }
     }
   }
 
   base::MessageLoop::current()->PostTask(
       FROM_HERE, base::Bind(callback, HTTP_NOT_FOUND));
@@ skipping 49 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
 
   if (offline_) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(callback, GDATA_NO_CONNECTION, GURL()));
     return CancelCallback();
   }
 
-  // Content length should be zero, as we'll create an empty file first. The
-  // content will be added in ResumeUpload().
-  const base::DictionaryValue* new_entry = AddNewEntry(content_type,
-                                                       "",  // content_data
-                                                       parent_resource_id,
-                                                       title,
-                                                       false,  // shared_with_me
-                                                       "file");
-  if (!new_entry) {
+  if (parent_resource_id != GetRootResourceId() &&
+      !FindEntryByResourceId(parent_resource_id)) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(callback, HTTP_NOT_FOUND, GURL()));
     return CancelCallback();
   }
-  const GURL upload_url = GetUploadUrl(*new_entry);
-  DCHECK(upload_url.is_valid());
+
+  GURL session_url = GetNewUploadSessionUrl();
+  upload_sessions_[session_url] =
+      UploadSession(content_type, content_length,
+                    parent_resource_id,
+                    "",  // resource_id
+                    "",  // etag
+                    title);
 
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
-      base::Bind(callback, HTTP_SUCCESS,
-                 net::AppendQueryParameter(upload_url, "mode", "newfile")));
+      base::Bind(callback, HTTP_SUCCESS, session_url));
   return CancelCallback();
 }
 
 CancelCallback FakeDriveService::InitiateUploadExistingFile(
     const base::FilePath& drive_file_path,
     const std::string& content_type,
     int64 content_length,
     const std::string& resource_id,
     const std::string& etag,
     const InitiateUploadCallback& callback) {
@@ skipping 16 matching lines @@
   }
 
   std::string entry_etag;
   entry->GetString("gd$etag", &entry_etag);
   if (!etag.empty() && etag != entry_etag) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(callback, HTTP_PRECONDITION, GURL()));
     return CancelCallback();
   }
-  entry->SetString("docs$size.$t", "0");
 
-  const GURL upload_url = GetUploadUrl(*entry);
-  DCHECK(upload_url.is_valid());
+  GURL session_url = GetNewUploadSessionUrl();
+  upload_sessions_[session_url] =
+      UploadSession(content_type, content_length,
+                    "",  // parent_resource_id
+                    resource_id,
+                    entry_etag,
+                    "" /* title */);
 
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
-      base::Bind(callback, HTTP_SUCCESS,
-                 net::AppendQueryParameter(upload_url, "mode", "existing")));
+      base::Bind(callback, HTTP_SUCCESS, session_url));
   return CancelCallback();
 }
 
 CancelCallback FakeDriveService::GetUploadStatus(
     const base::FilePath& drive_file_path,
     const GURL& upload_url,
     int64 content_length,
     const UploadRangeCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
   return CancelCallback();
 }
 
 CancelCallback FakeDriveService::ResumeUpload(
       const base::FilePath& drive_file_path,
       const GURL& upload_url,
       int64 start_position,
       int64 end_position,
       int64 content_length,
       const std::string& content_type,
       const base::FilePath& local_file_path,
       const UploadRangeCallback& callback,
       const ProgressCallback& progress_callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
 
-  scoped_ptr<ResourceEntry> result_entry;
+  GetResourceEntryCallback completion_callback
+      = base::Bind(&ScheduleUploadRangeCallback,
+                   callback, start_position, end_position);
 
+  scoped_ptr<ResourceEntry> uploaded_entry;

[hashimoto, 2013/06/21 08:05:32]

nit: It seems there is no need to have this variable?
scoped_ptr<ResourceEntry>() can be passed directly as an argument for NULL cases
and ResourceEntry::CreateFrom(*entry) can be passed for non-NULL cases.

[tzik, 2013/06/21 10:41:30]

Done.

   if (offline_) {
-    base::MessageLoop::current()->PostTask(
-        FROM_HERE,
-        base::Bind(callback,
-                   UploadRangeResponse(GDATA_NO_CONNECTION,
-                                       start_position,
-                                       end_position),
-                   base::Passed(&result_entry)));
+    completion_callback.Run(GDATA_NO_CONNECTION,
+                            uploaded_entry.Pass());
     return CancelCallback();
   }
 
-  DictionaryValue* entry = NULL;
-  entry = FindEntryByUploadUrl(RemoveQueryParameter(upload_url));
-  if (!entry) {
-    base::MessageLoop::current()->PostTask(
-        FROM_HERE,
-        base::Bind(callback,
-                   UploadRangeResponse(HTTP_NOT_FOUND,
-                                       start_position,
-                                       end_position),
-                   base::Passed(&result_entry)));
+  if (!upload_sessions_.count(upload_url)) {
+    completion_callback.Run(HTTP_NOT_FOUND,

[hashimoto, 2013/06/21 08:05:32]

nit: The next line can be merged into this line without violating 80 column
rule? The same goes for other places.

[tzik, 2013/06/21 10:41:30]

Done.

+                            uploaded_entry.Pass());
     return CancelCallback();
   }
 
+  UploadSession* session = &upload_sessions_[upload_url];
+
   // Chunks are required to be sent in such a ways that they fill from the start
   // of the not-yet-uploaded part with no gaps nor overlaps.
-  std::string current_size_string;
-  int64 current_size;
-  if (!entry->GetString("docs$size.$t", &current_size_string) ||
-      !base::StringToInt64(current_size_string, &current_size) ||
-      current_size != start_position) {
-    base::MessageLoop::current()->PostTask(
-        FROM_HERE,
-        base::Bind(callback,
-                   UploadRangeResponse(HTTP_BAD_REQUEST,
-                                       start_position,
-                                       end_position),
-                   base::Passed(&result_entry)));
+  if (session->uploaded_size != start_position) {
+    completion_callback.Run(HTTP_BAD_REQUEST,
+                            uploaded_entry.Pass());
     return CancelCallback();
   }
 
-  entry->SetString("docs$size.$t", base::Int64ToString(end_position));
-
   if (!progress_callback.is_null()) {
     // In the real GDataWapi/Drive DriveService, progress is reported in
     // nondeterministic timing. In this fake implementation, we choose to call
     // it twice per one ResumeUpload. This is for making sure that client code
     // works fine even if the callback is invoked more than once; it is the
     // crucial difference of the progress callback from others.
     // Note that progress is notified in the relative offset in each chunk.
     const int64 chunk_size = end_position - start_position;
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(progress_callback, chunk_size / 2, chunk_size));
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(progress_callback, chunk_size, chunk_size));
   }
 
   if (content_length != end_position) {
-    base::MessageLoop::current()->PostTask(
-        FROM_HERE,
-        base::Bind(callback,
-                   UploadRangeResponse(HTTP_RESUME_INCOMPLETE,
-                                       start_position,
-                                       end_position),
-                    base::Passed(&result_entry)));
+    session->uploaded_size = end_position;
+    completion_callback.Run(HTTP_RESUME_INCOMPLETE,
+                            uploaded_entry.Pass());
     return CancelCallback();
   }
 
-  AddNewChangestamp(entry);
-  result_entry = ResourceEntry::CreateFrom(*entry).Pass();
+  std::string content_data;
+  if (!file_util::ReadFileToString(local_file_path, &content_data)) {
+    session->uploaded_size = end_position;
+    completion_callback.Run(GDATA_FILE_ERROR,
+                            uploaded_entry.Pass());
+    return CancelCallback();
+  }
+  session->uploaded_size = end_position;
 
-  std::string upload_mode;
-  bool upload_mode_found =
-      net::GetValueForKeyInQuery(upload_url, "mode", &upload_mode);
-  DCHECK(upload_mode_found &&
-         (upload_mode == "newfile" || upload_mode == "existing"));
+  // |resource_id| is empty if the upload is for new file.
+  if (session->resource_id.empty()) {
+    DCHECK(!session->parent_resource_id.empty());
+    DCHECK(!session->title.empty());
+    const DictionaryValue* new_entry = AddNewEntry(
+        session->content_type,
+        content_data,
+        session->parent_resource_id,
+        session->title,
+        false,  // shared_with_me
+        "file");
+    if (!new_entry) {
+      completion_callback.Run(HTTP_NOT_FOUND,
+                              uploaded_entry.Pass());
+      return CancelCallback();
+    }
 
-  GDataErrorCode return_code =
-      upload_mode == "newfile" ? HTTP_CREATED : HTTP_SUCCESS;
+    uploaded_entry = ResourceEntry::CreateFrom(*new_entry);
+    completion_callback.Run(HTTP_CREATED,
+                            uploaded_entry.Pass());
+    return CancelCallback();
+  }
 
-  base::MessageLoop::current()->PostTask(
-      FROM_HERE,
-      base::Bind(callback,
-                 UploadRangeResponse(return_code,
-                                     start_position,
-                                     end_position),
-                 base::Passed(&result_entry)));
+  DictionaryValue* entry = FindEntryByResourceId(session->resource_id);
+  if (!entry) {
+    completion_callback.Run(HTTP_NOT_FOUND,
+                            uploaded_entry.Pass());
+    return CancelCallback();
+  }
+
+  std::string entry_etag;
+  entry->GetString("gd$etag", &entry_etag);
+  if (entry_etag.empty() || session->etag != entry_etag) {
+    completion_callback.Run(HTTP_PRECONDITION,
+                            uploaded_entry.Pass());
+    return CancelCallback();
+  }
+
+  entry->SetString("docs$md5Checksum.$t", base::MD5String(content_data));
+  entry->Set("test$data",
+             base::BinaryValue::CreateWithCopiedBuffer(
+                 content_data.data(), content_data.size()));
+  entry->SetString("docs$size.$t", base::Int64ToString(end_position));
+  AddNewChangestampAndETag(entry);
+
+  uploaded_entry = ResourceEntry::CreateFrom(*entry);
+  completion_callback.Run(HTTP_SUCCESS,
+                          uploaded_entry.Pass());
   return CancelCallback();
 }
 
 CancelCallback FakeDriveService::AuthorizeApp(
     const std::string& resource_id,
     const std::string& app_id,
     const AuthorizeAppCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
   return CancelCallback();
@@ skipping 121 matching lines @@
           entry->GetString("content.src", &current_content_url) &&
           content_url == GURL(current_content_url)) {
         return entry;
       }
     }
   }
 
   return NULL;
 }
 
-base::DictionaryValue* FakeDriveService::FindEntryByUploadUrl(
-    const GURL& upload_url) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  base::ListValue* entries = NULL;
-  // Go through entries and return the one that matches |upload_url|.
-  if (resource_list_value_->GetList("entry", &entries)) {
-    for (size_t i = 0; i < entries->GetSize(); ++i) {
-      base::DictionaryValue* entry = NULL;
-      base::ListValue* links = NULL;
-      if (entries->GetDictionary(i, &entry) &&
-          entry->GetList("link", &links) &&
-          links) {
-        for (size_t link_index = 0;
-            link_index < links->GetSize();
-            ++link_index) {
-          base::DictionaryValue* link = NULL;
-          std::string rel;
-          std::string found_upload_url;
-          if (links->GetDictionary(link_index, &link) &&
-              link && link->GetString("rel", &rel) &&
-              rel == kUploadUrlRel &&
-              link->GetString("href", &found_upload_url) &&
-              GURL(found_upload_url) == upload_url) {
-            return entry;
-          }
-        }
-      }
-    }
-  }
-
-  return NULL;
-}
-
 std::string FakeDriveService::GetNewResourceId() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   ++resource_id_count_;
   return base::StringPrintf("resource_id_%d", resource_id_count_);
 }
 
-void FakeDriveService::AddNewChangestamp(base::DictionaryValue* entry) {
+void FakeDriveService::AddNewChangestampAndETag(base::DictionaryValue* entry) {
   ++largest_changestamp_;
   entry->SetString("docs$changestamp.value",
                    base::Int64ToString(largest_changestamp_));
+  entry->SetString("gd$etag",
+                   "etag_" + base::Int64ToString(largest_changestamp_));
 }
 
 const base::DictionaryValue* FakeDriveService::AddNewEntry(
     const std::string& content_type,
     const std::string& content_data,
     const std::string& parent_resource_id,
     const std::string& title,
     bool shared_with_me,
     const std::string& entry_kind) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ skipping 11 matching lines @@
   new_entry->SetString("gd$resourceId.$t", resource_id);
   new_entry->SetString("title.$t", title);
   new_entry->SetString("docs$filename", title);
   // Set the contents, size and MD5 for a file.
   if (entry_kind == "file") {
     new_entry->Set("test$data",
         base::BinaryValue::CreateWithCopiedBuffer(
             content_data.c_str(), content_data.size()));
     new_entry->SetString("docs$size.$t",
                          base::Int64ToString(content_data.size()));
-    // TODO(satorux): Set the correct MD5 here.
     new_entry->SetString("docs$md5Checksum.$t",
-                         "3b4385ebefec6e743574c76bbd0575de");
+                         base::MD5String(content_data));
   }
 
   // Add "category" which sets the resource type to |entry_kind|.
   base::ListValue* categories = new base::ListValue;
   base::DictionaryValue* category = new base::DictionaryValue;
   category->SetString("scheme", "http://schemas.google.com/g/2005#kind");
   category->SetString("term", "http://schemas.google.com/docs/2007#" +
                       entry_kind);
   categories->Append(category);
   new_entry->Set("category", categories);
@@ skipping 28 matching lines @@
   edit_link->SetString("href", "https://xxx/edit/" + escaped_resource_id);
   edit_link->SetString("rel", "edit");
   links->Append(edit_link);
 
   base::DictionaryValue* upload_link = new base::DictionaryValue;
   upload_link->SetString("href", upload_url.spec());
   upload_link->SetString("rel", kUploadUrlRel);
   links->Append(upload_link);
   new_entry->Set("link", links);
 
-  AddNewChangestamp(new_entry.get());
+  AddNewChangestampAndETag(new_entry.get());
 
   base::Time published_date =
       base::Time() + base::TimeDelta::FromMilliseconds(++published_date_seq_);
   new_entry->SetString("published.$t",
                        util::FormatTimeAsString(published_date));
 
   // If there are no entries, prepare an empty entry to add.
   if (!resource_list_value_->HasKey("entry"))
     resource_list_value_->Set("entry", new ListValue);
 
@@ skipping 115 matching lines @@
 
   if (load_counter)
     *load_counter += 1;
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(callback,
                  HTTP_SUCCESS,
                  base::Passed(&resource_list)));
 }
 
+GURL FakeDriveService::GetNewUploadSessionUrl() {
+  return GURL("https://upload_session_url/" +
+              base::Int64ToString(next_upload_sequence_number_++));
+}
+
 }  // namespace drive