Home | History | Annotate | Download | only in fileapi 
      1 /*
      2  * Copyright (C) 2010 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef SyncCallbackHelper_h
     32 #define SyncCallbackHelper_h
     33 
     34 #if ENABLE(FILE_SYSTEM)
     35 
     36 #include "DirectoryEntry.h"
     37 #include "EntriesCallback.h"
     38 #include "EntryArraySync.h"
     39 #include "EntryCallback.h"
     40 #include "ErrorCallback.h"
     41 #include "ExceptionCode.h"
     42 #include "FileEntry.h"
     43 #include "FileError.h"
     44 #include "FileException.h"
     45 #include "FileSystemCallback.h"
     46 #include "MetadataCallback.h"
     47 #include "VoidCallback.h"
     48 #include <wtf/PassRefPtr.h>
     49 #include <wtf/RefCounted.h>
     50 
     51 namespace WebCore {
     52 
     53 class AsyncFileSystem;
     54 class DirectoryEntrySync;
     55 class EntryArraySync;
     56 class EntrySync;
     57 class FileEntrySync;
     58 
     59 // A helper template for FileSystemSync implementation.
     60 template <typename SuccessCallback, typename ObserverType, typename CallbackArg, typename ResultType>
     61 class SyncCallbackHelper {
     62     WTF_MAKE_NONCOPYABLE(SyncCallbackHelper);
     63 public:
     64     typedef SyncCallbackHelper<SuccessCallback, ObserverType, CallbackArg, ResultType> HelperType;
     65     SyncCallbackHelper(ObserverType* observer = 0)
     66         : m_observer(observer)
     67         , m_successCallback(SuccessCallbackImpl::create(this))
     68         , m_errorCallback(ErrorCallbackImpl::create(this))
     69         , m_exceptionCode(0)
     70         , m_completed(false)
     71     {
     72     }
     73 
     74     PassRefPtr<ResultType> getResult(ExceptionCode& ec)
     75     {
     76         if (m_observer) {
     77             while (!m_completed) {
     78                 if (!m_observer->waitForOperationToComplete()) {
     79                     m_exceptionCode = FileException::ABORT_ERR;
     80                     break;
     81                 }
     82             }
     83         }
     84         ec = m_exceptionCode;
     85         return m_result.release();
     86     }
     87 
     88     PassRefPtr<SuccessCallback> successCallback() { return m_successCallback; }
     89     PassRefPtr<ErrorCallback> errorCallback() { return m_errorCallback; }
     90 
     91 private:
     92     class SuccessCallbackImpl : public SuccessCallback {
     93     public:
     94         static PassRefPtr<SuccessCallbackImpl> create(HelperType* helper)
     95         {
     96             return adoptRef(new SuccessCallbackImpl(helper));
     97         }
     98 
     99         virtual void handleEvent()
    100         {
    101             m_helper->setError(0);
    102         }
    103 
    104         virtual bool handleEvent(CallbackArg* arg)
    105         {
    106             m_helper->setResult(ResultType::create(arg));
    107             return true;
    108         }
    109 
    110     private:
    111         SuccessCallbackImpl(HelperType* helper)
    112             : m_helper(helper)
    113         {
    114         }
    115         HelperType* m_helper;
    116     };
    117 
    118     class ErrorCallbackImpl : public ErrorCallback {
    119     public:
    120         static PassRefPtr<ErrorCallbackImpl> create(HelperType* helper)
    121         {
    122             return adoptRef(new ErrorCallbackImpl(helper));
    123         }
    124 
    125         virtual bool handleEvent(FileError* error)
    126         {
    127             ASSERT(error);
    128             m_helper->setError(error->code());
    129             return true;
    130         }
    131 
    132     private:
    133         ErrorCallbackImpl(HelperType* helper)
    134             : m_helper(helper)
    135         {
    136         }
    137         HelperType* m_helper;
    138     };
    139 
    140     friend class SuccessCallbackImpl;
    141     friend class ErrorCallbackImpl;
    142 
    143     void setError(int code)
    144     {
    145         m_exceptionCode = FileException::ErrorCodeToExceptionCode(code);
    146         m_completed = true;
    147     }
    148 
    149     void setResult(PassRefPtr<ResultType> result)
    150     {
    151         m_result = result;
    152         m_completed = true;
    153     }
    154 
    155     ObserverType* m_observer;
    156     RefPtr<SuccessCallbackImpl> m_successCallback;
    157     RefPtr<ErrorCallbackImpl> m_errorCallback;
    158     RefPtr<ResultType> m_result;
    159     ExceptionCode m_exceptionCode;
    160     bool m_completed;
    161 };
    162 
    163 struct EmptyType : public RefCounted<EmptyType> {
    164     static PassRefPtr<EmptyType> create(EmptyType*)
    165     {
    166         return 0;
    167     }
    168 };
    169 
    170 struct EmptyObserverType {
    171     bool waitForOperationToComplete()
    172     {
    173         return false;
    174     }
    175 };
    176 
    177 typedef SyncCallbackHelper<EntryCallback, AsyncFileSystem, Entry, EntrySync> EntrySyncCallbackHelper;
    178 typedef SyncCallbackHelper<EntriesCallback, AsyncFileSystem, EntryArray, EntryArraySync> EntriesSyncCallbackHelper;
    179 typedef SyncCallbackHelper<MetadataCallback, AsyncFileSystem, Metadata, Metadata> MetadataSyncCallbackHelper;
    180 typedef SyncCallbackHelper<VoidCallback, AsyncFileSystem, EmptyType, EmptyType> VoidSyncCallbackHelper;
    181 typedef SyncCallbackHelper<FileSystemCallback, EmptyObserverType, DOMFileSystem, DOMFileSystemSync> FileSystemSyncCallbackHelper;
    182 
    183 } // namespace WebCore
    184 
    185 #endif // ENABLE(FILE_SYSTEM)
    186 
    187 #endif // SyncCallbackHelper_h
    188