root/Source/modules/filesystem/FileWriter.cpp

DEFINITIONS

1. create
2. m_lastProgressNotificationTimeMS
3. interfaceName
4. stop
5. write
6. seek
7. truncate
8. abort
9. didWrite
10. didTruncate
11. didFail
12. completeAbort
13. doOperation
14. signalCompletion
15. fireEvent
16. setError
17. trace

/*
 * 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,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "modules/filesystem/FileWriter.h"

#include "bindings/v8/ExceptionState.h"
#include "core/dom/ExceptionCode.h"
#include "core/events/ProgressEvent.h"
#include "core/fileapi/Blob.h"
#include "public/platform/WebFileWriter.h"
#include "public/platform/WebURL.h"
#include "wtf/CurrentTime.h"

namespace WebCore {

static const int kMaxRecursionDepth = 3;
static const double progressNotificationIntervalMS = 50;

PassRefPtrWillBeRawPtr<FileWriter> FileWriter::create(ExecutionContext* context)
{
    RefPtrWillBeRawPtr<FileWriter> fileWriter(adoptRefWillBeRefCountedGarbageCollected(new FileWriter(context)));
    fileWriter->suspendIfNeeded();
    return fileWriter.release();
}

FileWriter::FileWriter(ExecutionContext* context)
    : ActiveDOMObject(context)
    , m_readyState(INIT)
    , m_operationInProgress(OperationNone)
    , m_queuedOperation(OperationNone)
    , m_bytesWritten(0)
    , m_bytesToWrite(0)
    , m_truncateLength(-1)
    , m_numAborts(0)
    , m_recursionDepth(0)
    , m_lastProgressNotificationTimeMS(0)
{
    ScriptWrappable::init(this);
}

FileWriter::~FileWriter()
{
    ASSERT(!m_recursionDepth);
    if (m_readyState == WRITING)
        stop();
}

const AtomicString& FileWriter::interfaceName() const
{
    return EventTargetNames::FileWriter;
}

void FileWriter::stop()
{
    // Make sure we've actually got something to stop, and haven't already called abort().
    if (!writer() || m_readyState != WRITING)
        return;
    doOperation(OperationAbort);
    m_readyState = DONE;
}

void FileWriter::write(Blob* data, ExceptionState& exceptionState)
{
    ASSERT(writer());
    ASSERT(data);
    ASSERT(m_truncateLength == -1);
    if (m_readyState == WRITING) {
        setError(FileError::INVALID_STATE_ERR, exceptionState);
        return;
    }
    if (!data) {
        setError(FileError::TYPE_MISMATCH_ERR, exceptionState);
        return;
    }
    if (m_recursionDepth > kMaxRecursionDepth) {
        setError(FileError::SECURITY_ERR, exceptionState);
        return;
    }

    m_blobBeingWritten = data;
    m_readyState = WRITING;
    m_bytesWritten = 0;
    m_bytesToWrite = data->size();
    ASSERT(m_queuedOperation == OperationNone);
    if (m_operationInProgress != OperationNone) {
        // We must be waiting for an abort to complete, since m_readyState wasn't WRITING.
        ASSERT(m_operationInProgress == OperationAbort);
        m_queuedOperation = OperationWrite;
    } else
        doOperation(OperationWrite);

    fireEvent(EventTypeNames::writestart);
}

void FileWriter::seek(long long position, ExceptionState& exceptionState)
{
    ASSERT(writer());
    if (m_readyState == WRITING) {
        setError(FileError::INVALID_STATE_ERR, exceptionState);
        return;
    }

    ASSERT(m_truncateLength == -1);
    ASSERT(m_queuedOperation == OperationNone);
    seekInternal(position);
}

void FileWriter::truncate(long long position, ExceptionState& exceptionState)
{
    ASSERT(writer());
    ASSERT(m_truncateLength == -1);
    if (m_readyState == WRITING || position < 0) {
        setError(FileError::INVALID_STATE_ERR, exceptionState);
        return;
    }
    if (m_recursionDepth > kMaxRecursionDepth) {
        setError(FileError::SECURITY_ERR, exceptionState);
        return;
    }

    m_readyState = WRITING;
    m_bytesWritten = 0;
    m_bytesToWrite = 0;
    m_truncateLength = position;
    ASSERT(m_queuedOperation == OperationNone);
    if (m_operationInProgress != OperationNone) {
        // We must be waiting for an abort to complete, since m_readyState wasn't WRITING.
        ASSERT(m_operationInProgress == OperationAbort);
        m_queuedOperation = OperationTruncate;
    } else
        doOperation(OperationTruncate);
    fireEvent(EventTypeNames::writestart);
}

void FileWriter::abort(ExceptionState& exceptionState)
{
    ASSERT(writer());
    if (m_readyState != WRITING)
        return;
    ++m_numAborts;

    doOperation(OperationAbort);
    signalCompletion(FileError::ABORT_ERR);
}

void FileWriter::didWrite(long long bytes, bool complete)
{
    if (m_operationInProgress == OperationAbort) {
        completeAbort();
        return;
    }
    ASSERT(m_readyState == WRITING);
    ASSERT(m_truncateLength == -1);
    ASSERT(m_operationInProgress == OperationWrite);
    ASSERT(!m_bytesToWrite || bytes + m_bytesWritten > 0);
    ASSERT(bytes + m_bytesWritten <= m_bytesToWrite);
    m_bytesWritten += bytes;
    ASSERT((m_bytesWritten == m_bytesToWrite) || !complete);
    setPosition(position() + bytes);
    if (position() > length())
        setLength(position());
    if (complete) {
        m_blobBeingWritten.clear();
        m_operationInProgress = OperationNone;
    }

    int numAborts = m_numAborts;
    // We could get an abort in the handler for this event. If we do, it's
    // already handled the cleanup and signalCompletion call.
    double now = currentTimeMS();
    if (complete || !m_lastProgressNotificationTimeMS || (now - m_lastProgressNotificationTimeMS > progressNotificationIntervalMS)) {
        m_lastProgressNotificationTimeMS = now;
        fireEvent(EventTypeNames::progress);
    }

    if (complete) {
      if (numAborts == m_numAborts)
          signalCompletion(FileError::OK);
      unsetPendingActivity(this);
    }
}

void FileWriter::didTruncate()
{
    if (m_operationInProgress == OperationAbort) {
        completeAbort();
        return;
    }
    ASSERT(m_operationInProgress == OperationTruncate);
    ASSERT(m_truncateLength >= 0);
    setLength(m_truncateLength);
    if (position() > length())
        setPosition(length());
    m_operationInProgress = OperationNone;
    signalCompletion(FileError::OK);
    unsetPendingActivity(this);
}

void FileWriter::didFail(blink::WebFileError code)
{
    ASSERT(m_operationInProgress != OperationNone);
    ASSERT(static_cast<FileError::ErrorCode>(code) != FileError::OK);
    if (m_operationInProgress == OperationAbort) {
        completeAbort();
        return;
    }
    ASSERT(static_cast<FileError::ErrorCode>(code) != FileError::ABORT_ERR);
    ASSERT(m_queuedOperation == OperationNone);
    ASSERT(m_readyState == WRITING);
    m_blobBeingWritten.clear();
    m_operationInProgress = OperationNone;
    signalCompletion(static_cast<FileError::ErrorCode>(code));
    unsetPendingActivity(this);
}

void FileWriter::completeAbort()
{
    ASSERT(m_operationInProgress == OperationAbort);
    m_operationInProgress = OperationNone;
    Operation operation = m_queuedOperation;
    m_queuedOperation = OperationNone;
    doOperation(operation);
    unsetPendingActivity(this);
}

void FileWriter::doOperation(Operation operation)
{
    switch (operation) {
    case OperationWrite:
        ASSERT(m_operationInProgress == OperationNone);
        ASSERT(m_truncateLength == -1);
        ASSERT(m_blobBeingWritten.get());
        ASSERT(m_readyState == WRITING);
        setPendingActivity(this);
        writer()->write(position(), m_blobBeingWritten->uuid());
        break;
    case OperationTruncate:
        ASSERT(m_operationInProgress == OperationNone);
        ASSERT(m_truncateLength >= 0);
        ASSERT(m_readyState == WRITING);
        setPendingActivity(this);
        writer()->truncate(m_truncateLength);
        break;
    case OperationNone:
        ASSERT(m_operationInProgress == OperationNone);
        ASSERT(m_truncateLength == -1);
        ASSERT(!m_blobBeingWritten.get());
        ASSERT(m_readyState == DONE);
        break;
    case OperationAbort:
        if (m_operationInProgress == OperationWrite || m_operationInProgress == OperationTruncate)
            writer()->cancel();
        else if (m_operationInProgress != OperationAbort)
            operation = OperationNone;
        m_queuedOperation = OperationNone;
        m_blobBeingWritten.clear();
        m_truncateLength = -1;
        break;
    }
    ASSERT(m_queuedOperation == OperationNone);
    m_operationInProgress = operation;
}

void FileWriter::signalCompletion(FileError::ErrorCode code)
{
    m_readyState = DONE;
    m_truncateLength = -1;
    if (FileError::OK != code) {
        m_error = FileError::create(code);
        if (FileError::ABORT_ERR == code)
            fireEvent(EventTypeNames::abort);
        else
            fireEvent(EventTypeNames::error);
    } else
        fireEvent(EventTypeNames::write);
    fireEvent(EventTypeNames::writeend);
}

void FileWriter::fireEvent(const AtomicString& type)
{
    ++m_recursionDepth;
    dispatchEvent(ProgressEvent::create(type, true, m_bytesWritten, m_bytesToWrite));
    --m_recursionDepth;
    ASSERT(m_recursionDepth >= 0);
}

void FileWriter::setError(FileError::ErrorCode errorCode, ExceptionState& exceptionState)
{
    ASSERT(errorCode);
    FileError::throwDOMException(exceptionState, errorCode);
    m_error = FileError::create(errorCode);
}

void FileWriter::trace(Visitor* visitor)
{
    visitor->trace(m_error);
    visitor->trace(m_blobBeingWritten);
    FileWriterBase::trace(visitor);
}

} // namespace WebCore