third_party/WebKit/Source/modules/filesystem/DirectoryReader.cpp

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "modules/filesystem/DirectoryReader.h"

#include "core/fileapi/FileError.h"
#include "modules/filesystem/EntriesCallback.h"
#include "modules/filesystem/Entry.h"
#include "modules/filesystem/ErrorCallback.h"
#include "modules/filesystem/FileSystemCallbacks.h"

namespace blink {

class DirectoryReader::EntriesCallbackHelper final : public EntriesCallback {
 public:
  explicit EntriesCallbackHelper(DirectoryReader* reader) : m_reader(reader) {}

  void handleEvent(const EntryHeapVector& entries) override {
    m_reader->addEntries(entries);
  }

  DEFINE_INLINE_VIRTUAL_TRACE() {
    visitor->trace(m_reader);
    EntriesCallback::trace(visitor);
  }

 private:
  // FIXME: This Member keeps the reader alive until all of the readDirectory
  // results are received. crbug.com/350285
  Member<DirectoryReader> m_reader;
};

class DirectoryReader::ErrorCallbackHelper final : public ErrorCallbackBase {
 public:
  explicit ErrorCallbackHelper(DirectoryReader* reader) : m_reader(reader) {}

  void invoke(FileError::ErrorCode error) override { m_reader->onError(error); }

  DEFINE_INLINE_VIRTUAL_TRACE() {
    visitor->trace(m_reader);
    ErrorCallbackBase::trace(visitor);
  }

 private:
  Member<DirectoryReader> m_reader;
};

DirectoryReader::DirectoryReader(DOMFileSystemBase* fileSystem,
                                 const String& fullPath)
    : DirectoryReaderBase(fileSystem, fullPath), m_isReading(false) {}

DirectoryReader::~DirectoryReader() {}

void DirectoryReader::readEntries(EntriesCallback* entriesCallback,
                                  ErrorCallback* errorCallback) {
  if (!m_isReading) {
    m_isReading = true;
    filesystem()->readDirectory(this, m_fullPath,
                                new EntriesCallbackHelper(this),
                                new ErrorCallbackHelper(this));
  }

  if (m_error) {
    filesystem()->reportError(ScriptErrorCallback::wrap(errorCallback),
                              m_error);
    return;
  }

  if (m_entriesCallback) {
    // Non-null m_entriesCallback means multiple readEntries() calls are made
    // concurrently. We don't allow doing it.
    filesystem()->reportError(ScriptErrorCallback::wrap(errorCallback),
                              FileError::kInvalidStateErr);
    return;
  }

  if (!m_hasMoreEntries || !m_entries.isEmpty()) {
    if (entriesCallback)
      DOMFileSystem::scheduleCallback(
          filesystem()->getExecutionContext(),
          createSameThreadTask(&EntriesCallback::handleEvent,
                               wrapPersistent(entriesCallback),
                               PersistentHeapVector<Member<Entry>>(m_entries)));
    m_entries.clear();
    return;
  }

  m_entriesCallback = entriesCallback;
  m_errorCallback = errorCallback;
}

void DirectoryReader::addEntries(const EntryHeapVector& entries) {
  m_entries.appendVector(entries);
  m_errorCallback = nullptr;
  if (m_entriesCallback) {
    EntriesCallback* entriesCallback = m_entriesCallback.release();
    EntryHeapVector entries;
    entries.swap(m_entries);
    entriesCallback->handleEvent(entries);
  }
}

void DirectoryReader::onError(FileError::ErrorCode error) {
  m_error = error;
  m_entriesCallback = nullptr;
  if (m_errorCallback)
    m_errorCallback->handleEvent(FileError::createDOMException(error));
}

DEFINE_TRACE(DirectoryReader) {
  visitor->trace(m_entries);
  visitor->trace(m_entriesCallback);
  visitor->trace(m_errorCallback);
  DirectoryReaderBase::trace(visitor);
}

}  // namespace blink