Rename FileUtilProxy::Create to EnsureFileExists

base/file_util_proxy.cc

 // Copyright (c) 2010 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 "base/file_util_proxy.h"
 
 #include "base/message_loop_proxy.h"
 
 // TODO(jianli): Move the code from anonymous namespace to base namespace so
 // that all of the base:: prefixes would be unnecessary.
 namespace {
 
 namespace {
 
 // Performs common checks for move and copy.
 // This also removes the destination directory if it's non-empty and all other
-// checks are passed (so that the copy/move correctly overwrites the destination).
+// checks are passed (so that the copy/move correctly overwrites the
+// destination).
 static base::PlatformFileError PerformCommonCheckAndPreparationForMoveAndCopy(
     const FilePath& src_file_path,
     const FilePath& dest_file_path) {
   // Exits earlier if the source path does not exist.
   if (!file_util::PathExists(src_file_path))
     return base::PLATFORM_FILE_ERROR_NOT_FOUND;
 
   // The parent of the |dest_file_path| does not exist.
   if (!file_util::DirectoryExists(dest_file_path.DirName()))
     return base::PLATFORM_FILE_ERROR_NOT_FOUND;
@@ skipping 84 matching lines @@
   scoped_refptr<base::MessageLoopProxy> origin_message_loop_proxy_;
   base::PlatformFileError error_code_;
 };
 
 class RelayCreateOrOpen : public MessageLoopRelay {
  public:
   RelayCreateOrOpen(
       scoped_refptr<base::MessageLoopProxy> message_loop_proxy,
       const FilePath& file_path,
       int file_flags,
-      bool return_no_handle,
       base::FileUtilProxy::CreateOrOpenCallback* callback)
       : message_loop_proxy_(message_loop_proxy),
         file_path_(file_path),
         file_flags_(file_flags),
         callback_(callback),
         file_handle_(base::kInvalidPlatformFileValue),
-        return_no_handle_(return_no_handle),
         created_(false) {
     DCHECK(callback);
   }
 
  protected:
   virtual ~RelayCreateOrOpen() {
     if (file_handle_ != base::kInvalidPlatformFileValue)
       base::FileUtilProxy::Close(message_loop_proxy_, file_handle_, NULL);
   }
 
   virtual void RunWork() {
     if (!file_util::DirectoryExists(file_path_.DirName())) {
       // If its parent does not exist, should return NOT_FOUND error.
       set_error_code(base::PLATFORM_FILE_ERROR_NOT_FOUND);
       return;
     }
     base::PlatformFileError error_code = base::PLATFORM_FILE_OK;
     file_handle_ = base::CreatePlatformFile(file_path_, file_flags_,
                                             &created_, &error_code);
-    // If the return_no_handle is true the caller is not interested
-    // in the file_handle_.  Close it right now.
-    if (return_no_handle_ && file_handle_ != base::kInvalidPlatformFileValue) {
-      // We don't check the return value here.
-      base::ClosePlatformFile(file_handle_);
-      file_handle_ = base::kInvalidPlatformFileValue;
-    }
     set_error_code(error_code);
   }
 
   virtual void RunCallback() {
     callback_->Run(error_code(), base::PassPlatformFile(&file_handle_),
                    created_);
     delete callback_;
   }
 
  private:
   scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
   FilePath file_path_;
   int file_flags_;
   base::FileUtilProxy::CreateOrOpenCallback* callback_;
   base::PlatformFile file_handle_;
-  bool return_no_handle_;
   bool created_;
 };
 
 class RelayCreateTemporary : public MessageLoopRelay {
  public:
   RelayCreateTemporary(
       scoped_refptr<base::MessageLoopProxy> message_loop_proxy,
       base::FileUtilProxy::CreateTemporaryCallback* callback)
       : message_loop_proxy_(message_loop_proxy),
         callback_(callback),
@@ skipping 70 matching lines @@
  protected:
   virtual void RunWork() {
     if (!base::ClosePlatformFile(file_handle_))
       set_error_code(base::PLATFORM_FILE_ERROR_FAILED);
   }
 
  private:
   base::PlatformFile file_handle_;
 };
 
+class RelayEnsureFileExists : public MessageLoopRelay {
+ public:
+  RelayEnsureFileExists(
+      scoped_refptr<base::MessageLoopProxy> message_loop_proxy,
+      const FilePath& file_path,
+      base::FileUtilProxy::EnsureFileExistsCallback* callback)
+      : message_loop_proxy_(message_loop_proxy),
+        file_path_(file_path),
+        callback_(callback),
+        created_(false) {
+    DCHECK(callback);
+  }
+
+ protected:
+  virtual void RunWork() {
+    if (!file_util::DirectoryExists(file_path_.DirName())) {
+      // If its parent does not exist, should return NOT_FOUND error.
+      set_error_code(base::PLATFORM_FILE_ERROR_NOT_FOUND);
+      return;
+    }
+    base::PlatformFileError error_code = base::PLATFORM_FILE_OK;
+    // Tries to create the |file_path_| exclusively.  This should fail
+    // with PLATFORM_FILE_ERROR_EXISTS if the path already exists.
+    base::PlatformFile handle = base::CreatePlatformFile(
+        file_path_,
+        base::PLATFORM_FILE_CREATE | base::PLATFORM_FILE_READ,
+        &created_, &error_code);
+    if (error_code == base::PLATFORM_FILE_ERROR_EXISTS) {
+      // Make sure created_ is false.
+      created_ = false;
+      error_code = base::PLATFORM_FILE_OK;
+    }
+    if (handle != base::kInvalidPlatformFileValue)
+      base::ClosePlatformFile(handle);
+    set_error_code(error_code);
+  }
+
+  virtual void RunCallback() {
+    callback_->Run(error_code(), created_);
+    delete callback_;
+  }
+
+ private:
+  scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
+  FilePath file_path_;
+  base::FileUtilProxy::EnsureFileExistsCallback* callback_;
+  bool created_;
+};
+
 class RelayDelete : public RelayWithStatusCallback {
  public:
   RelayDelete(const FilePath& file_path,
               bool recursive,
               base::FileUtilProxy::StatusCallback* callback)
       : RelayWithStatusCallback(callback),
         file_path_(file_path),
         recursive_(recursive) {
   }
 
@@ skipping 416 matching lines @@
 }  // namespace
 
 namespace base {
 
 // static
 bool FileUtilProxy::CreateOrOpen(
     scoped_refptr<MessageLoopProxy> message_loop_proxy,
     const FilePath& file_path, int file_flags,
     CreateOrOpenCallback* callback) {
   return Start(FROM_HERE, message_loop_proxy, new RelayCreateOrOpen(
-      message_loop_proxy, file_path, file_flags, false /* return_no_handle */,
-      callback));
+      message_loop_proxy, file_path, file_flags, callback));
 }
 
 // static
-bool FileUtilProxy::Create(
-    scoped_refptr<MessageLoopProxy> message_loop_proxy,
-    const FilePath& file_path, int file_flags,
-    CreateOrOpenCallback* callback) {
-  return Start(FROM_HERE, message_loop_proxy, new RelayCreateOrOpen(
-      message_loop_proxy, file_path, file_flags, true /* return_no_handle */,
-      callback));
-}
-
-// static
 bool FileUtilProxy::CreateTemporary(
     scoped_refptr<MessageLoopProxy> message_loop_proxy,
     CreateTemporaryCallback* callback) {
   return Start(FROM_HERE, message_loop_proxy,
                new RelayCreateTemporary(message_loop_proxy, callback));
 }
 
 // static
 bool FileUtilProxy::CreateDirectory(
     scoped_refptr<MessageLoopProxy> message_loop_proxy,
     const FilePath& file_path,
     bool exclusive,
     bool recursive,
     StatusCallback* callback) {
   return Start(FROM_HERE, message_loop_proxy, new RelayCreateDirectory(
       file_path, exclusive, recursive, callback));
 }
 
 // static
 bool FileUtilProxy::Close(scoped_refptr<MessageLoopProxy> message_loop_proxy,
                           base::PlatformFile file_handle,
                           StatusCallback* callback) {
   return Start(FROM_HERE, message_loop_proxy,
                new RelayClose(file_handle, callback));
 }
 
 // static
+bool FileUtilProxy::EnsureFileExists(
+    scoped_refptr<MessageLoopProxy> message_loop_proxy,
+    const FilePath& file_path,
+    EnsureFileExistsCallback* callback) {
+  return Start(FROM_HERE, message_loop_proxy, new RelayEnsureFileExists(
+      message_loop_proxy, file_path, callback));
+}
+
+// static
 bool FileUtilProxy::Delete(scoped_refptr<MessageLoopProxy> message_loop_proxy,
                            const FilePath& file_path,
                            bool recursive,
                            StatusCallback* callback) {
   return Start(FROM_HERE, message_loop_proxy,
                new RelayDelete(file_path, recursive, callback));
 }
 
 // static
 bool FileUtilProxy::Copy(scoped_refptr<MessageLoopProxy> message_loop_proxy,
@@ skipping 120 matching lines @@
 
 // static
 bool FileUtilProxy::Flush(
     scoped_refptr<MessageLoopProxy> message_loop_proxy,
     PlatformFile file,
     StatusCallback* callback) {
   return Start(FROM_HERE, message_loop_proxy, new RelayFlush(file, callback));
 }
 
 }  // namespace base