src/webkit/browser/fileapi/recursive_operation_delegate.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "webkit/browser/fileapi/recursive_operation_delegate.h"
   6
   7 #include "base/bind.h"
   8 #include "webkit/browser/fileapi/file_system_context.h"
   9 #include "webkit/browser/fileapi/file_system_operation_runner.h"
  10
  11 namespace fileapi {
  12
  13 namespace {
  14 // Don't start too many inflight operations.
  15 const int kMaxInflightOperations = 5;
  16 }
  17
  18 RecursiveOperationDelegate::RecursiveOperationDelegate(
  19     FileSystemContext* file_system_context)
  20     : file_system_context_(file_system_context),
  21       inflight_operations_(0),
  22       canceled_(false) {
  23 }
  24
  25 RecursiveOperationDelegate::~RecursiveOperationDelegate() {
  26 }
  27
  28 void RecursiveOperationDelegate::Cancel() {
  29   canceled_ = true;
  30   OnCancel();
  31 }
  32
  33 void RecursiveOperationDelegate::StartRecursiveOperation(
  34     const FileSystemURL& root,
  35     const StatusCallback& callback) {
  36   DCHECK(pending_directory_stack_.empty());
  37   DCHECK(pending_files_.empty());
  38   DCHECK_EQ(0, inflight_operations_);
  39
  40   callback_ = callback;
  41   ++inflight_operations_;
  42   ProcessFile(
  43       root,
  44       base::Bind(&RecursiveOperationDelegate::DidTryProcessFile,
  45                  AsWeakPtr(), root));
  46 }
  47
  48 FileSystemOperationRunner* RecursiveOperationDelegate::operation_runner() {
  49   return file_system_context_->operation_runner();
  50 }
  51
  52 void RecursiveOperationDelegate::OnCancel() {
  53 }
  54
  55 void RecursiveOperationDelegate::DidTryProcessFile(
  56     const FileSystemURL& root,
  57     base::File::Error error) {
  58   DCHECK(pending_directory_stack_.empty());
  59   DCHECK(pending_files_.empty());
  60   DCHECK_EQ(1, inflight_operations_);
  61
  62   --inflight_operations_;
  63   if (canceled_ || error != base::File::FILE_ERROR_NOT_A_FILE) {
  64     Done(error);
  65     return;
  66   }
  67
  68   pending_directory_stack_.push(std::queue<FileSystemURL>());
  69   pending_directory_stack_.top().push(root);
  70   ProcessNextDirectory();
  71 }
  72
  73 void RecursiveOperationDelegate::ProcessNextDirectory() {
  74   DCHECK(pending_files_.empty());
  75   DCHECK(!pending_directory_stack_.empty());
  76   DCHECK(!pending_directory_stack_.top().empty());
  77   DCHECK_EQ(0, inflight_operations_);
  78
  79   const FileSystemURL& url = pending_directory_stack_.top().front();
  80
  81   ++inflight_operations_;
  82   ProcessDirectory(
  83       url,
  84       base::Bind(
  85           &RecursiveOperationDelegate::DidProcessDirectory, AsWeakPtr()));
  86 }
  87
  88 void RecursiveOperationDelegate::DidProcessDirectory(
  89     base::File::Error error) {
  90   DCHECK(pending_files_.empty());
  91   DCHECK(!pending_directory_stack_.empty());
  92   DCHECK(!pending_directory_stack_.top().empty());
  93   DCHECK_EQ(1, inflight_operations_);
  94
  95   --inflight_operations_;
  96   if (canceled_ || error != base::File::FILE_OK) {
  97     Done(error);
  98     return;
  99   }
 100
 101   const FileSystemURL& parent = pending_directory_stack_.top().front();
 102   pending_directory_stack_.push(std::queue<FileSystemURL>());
 103   operation_runner()->ReadDirectory(
 104       parent,
 105       base::Bind(&RecursiveOperationDelegate::DidReadDirectory,
 106                  AsWeakPtr(), parent));
 107 }
 108
 109 void RecursiveOperationDelegate::DidReadDirectory(
 110     const FileSystemURL& parent,
 111     base::File::Error error,
 112     const FileEntryList& entries,
 113     bool has_more) {
 114   DCHECK(!pending_directory_stack_.empty());
 115   DCHECK_EQ(0, inflight_operations_);
 116
 117   if (canceled_ || error != base::File::FILE_OK) {
 118     Done(error);
 119     return;
 120   }
 121
 122   for (size_t i = 0; i < entries.size(); i++) {
 123     FileSystemURL url = file_system_context_->CreateCrackedFileSystemURL(
 124         parent.origin(),
 125         parent.mount_type(),
 126         parent.virtual_path().Append(entries[i].name));
 127     if (entries[i].is_directory)
 128       pending_directory_stack_.top().push(url);
 129     else
 130       pending_files_.push(url);
 131   }
 132
 133   // Wait for next entries.
 134   if (has_more)
 135     return;
 136
 137   ProcessPendingFiles();
 138 }
 139
 140 void RecursiveOperationDelegate::ProcessPendingFiles() {
 141   DCHECK(!pending_directory_stack_.empty());
 142
 143   if ((pending_files_.empty() || canceled_) && inflight_operations_ == 0) {
 144     ProcessSubDirectory();
 145     return;
 146   }
 147
 148   // Do not post any new tasks.
 149   if (canceled_)
 150     return;
 151
 152   // Run ProcessFile in parallel (upto kMaxInflightOperations).
 153   scoped_refptr<base::MessageLoopProxy> current_message_loop =
 154       base::MessageLoopProxy::current();
 155   while (!pending_files_.empty() &&
 156          inflight_operations_ < kMaxInflightOperations) {
 157     ++inflight_operations_;
 158     current_message_loop->PostTask(
 159         FROM_HERE,
 160         base::Bind(&RecursiveOperationDelegate::ProcessFile,
 161                    AsWeakPtr(), pending_files_.front(),
 162                    base::Bind(&RecursiveOperationDelegate::DidProcessFile,
 163                               AsWeakPtr())));
 164     pending_files_.pop();
 165   }
 166 }
 167
 168 void RecursiveOperationDelegate::DidProcessFile(
 169     base::File::Error error) {
 170   --inflight_operations_;
 171   if (error != base::File::FILE_OK) {
 172     // If an error occurs, invoke Done immediately (even if there remain
 173     // running operations). It is because in the callback, this instance is
 174     // deleted.
 175     Done(error);
 176     return;
 177   }
 178
 179   ProcessPendingFiles();
 180 }
 181
 182 void RecursiveOperationDelegate::ProcessSubDirectory() {
 183   DCHECK(pending_files_.empty());
 184   DCHECK(!pending_directory_stack_.empty());
 185   DCHECK_EQ(0, inflight_operations_);
 186
 187   if (canceled_) {
 188     Done(base::File::FILE_ERROR_ABORT);
 189     return;
 190   }
 191
 192   if (!pending_directory_stack_.top().empty()) {
 193     // There remain some sub directories. Process them first.
 194     ProcessNextDirectory();
 195     return;
 196   }
 197
 198   // All subdirectories are processed.
 199   pending_directory_stack_.pop();
 200   if (pending_directory_stack_.empty()) {
 201     // All files/directories are processed.
 202     Done(base::File::FILE_OK);
 203     return;
 204   }
 205
 206   DCHECK(!pending_directory_stack_.top().empty());
 207   ++inflight_operations_;
 208   PostProcessDirectory(
 209       pending_directory_stack_.top().front(),
 210       base::Bind(&RecursiveOperationDelegate::DidPostProcessDirectory,
 211                  AsWeakPtr()));
 212 }
 213
 214 void RecursiveOperationDelegate::DidPostProcessDirectory(
 215     base::File::Error error) {
 216   DCHECK(pending_files_.empty());
 217   DCHECK(!pending_directory_stack_.empty());
 218   DCHECK(!pending_directory_stack_.top().empty());
 219   DCHECK_EQ(1, inflight_operations_);
 220
 221   --inflight_operations_;
 222   pending_directory_stack_.top().pop();
 223   if (canceled_ || error != base::File::FILE_OK) {
 224     Done(error);
 225     return;
 226   }
 227
 228   ProcessSubDirectory();
 229 }
 230
 231 void RecursiveOperationDelegate::Done(base::File::Error error) {
 232   if (canceled_ && error == base::File::FILE_OK) {
 233     callback_.Run(base::File::FILE_ERROR_ABORT);
 234   } else {
 235     callback_.Run(error);
 236   }
 237 }
 238
 239 }  // namespace fileapi