diff -r 000000000000 -r 4f2f89ce4247 WebCore/html/FileStream.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/FileStream.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,185 @@
+/*
+ * 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"
+
+#if ENABLE(FILE_READER) || ENABLE(FILE_WRITER)
+
+#include "FileStream.h"
+
+#include "Blob.h"
+#include "PlatformString.h"
+
+namespace WebCore {
+
+FileStream::FileStream(FileStreamClient* client)
+    : m_client(client)
+    , m_handle(invalidPlatformFileHandle)
+    , m_bytesProcessed(0)
+    , m_totalBytesToRead(0)
+{
+}
+
+FileStream::~FileStream()
+{
+    ASSERT(!isHandleValid(m_handle));
+}
+
+void FileStream::start()
+{
+    ASSERT(!isMainThread());
+    m_client->didStart();
+}
+
+void FileStream::stop()
+{
+    ASSERT(!isMainThread());
+    close();
+    m_client->didStop();
+}
+
+void FileStream::openForRead(Blob* blob)
+{
+    ASSERT(!isMainThread());
+
+    if (isHandleValid(m_handle))
+        return;
+
+    // FIXME: Need to handle multiple items that may include non-file ones when BlobBuilder is introduced.
+    ASSERT(blob->items().size() >= 1);
+    const FileBlobItem* fileItem = blob->items().at(0)->toFileBlobItem();
+    if (!fileItem) {
+        ASSERT(false);
+        m_client->didFail(NOT_READABLE_ERR);
+        return;
+    }
+
+    // Check if the file exists by querying its modification time. We choose not to call fileExists() in order to save an
+    // extra file system call when the modification time is needed to check the validity of the sliced file blob.
+    // Per the spec, we need to return different error codes to differentiate between non-existent file and permission error.
+    // openFile() could not tell use the failure reason.
+    time_t currentModificationTime;
+    if (!getFileModificationTime(fileItem->path(), currentModificationTime)) {
+        m_client->didFail(NOT_FOUND_ERR);
+        return;
+    }
+
+    // Open the file blob.
+    m_handle = openFile(fileItem->path(), OpenForRead);
+    if (!isHandleValid(m_handle)) {
+        m_client->didFail(NOT_READABLE_ERR);
+        return;
+    }
+
+#if ENABLE(BLOB_SLICE)
+    const FileRangeBlobItem* fileRangeItem = fileItem->toFileRangeBlobItem();
+    if (fileRangeItem) {
+        // Check the modificationt time for the possible file change.
+        if (static_cast<time_t>(fileRangeItem->snapshotModificationTime()) != currentModificationTime) {
+            m_client->didFail(NOT_READABLE_ERR);
+            return;
+        }
+
+        // Jump to the beginning position if the file has been sliced.
+        if (fileRangeItem->start() > 0) {
+            if (seekFile(m_handle, fileRangeItem->start(), SeekFromBeginning) < 0) {
+                m_client->didFail(NOT_READABLE_ERR);
+                return;
+            }
+        }
+    }
+#endif
+
+    // Get the size.
+    m_totalBytesToRead = blob->size();
+    m_client->didGetSize(m_totalBytesToRead);
+}
+
+void FileStream::openForWrite(const String&)
+{
+    ASSERT(!isMainThread());
+    // FIXME: to be implemented.
+}
+
+void FileStream::close()
+{
+    ASSERT(!isMainThread());
+    if (isHandleValid(m_handle)) {
+        closeFile(m_handle);
+        m_handle = invalidPlatformFileHandle;
+    }
+}
+
+void FileStream::read(char* buffer, int length)
+{
+    ASSERT(!isMainThread());
+
+    if (!isHandleValid(m_handle)) {
+        m_client->didFail(NOT_READABLE_ERR);
+        return;
+    }
+
+    if (m_bytesProcessed >= m_totalBytesToRead) {
+        m_client->didFinish();
+        return;
+    }
+
+    long long remaining = m_totalBytesToRead - m_bytesProcessed;
+    int bytesToRead = (remaining < length) ? static_cast<int>(remaining) : length;
+    int bytesRead = readFromFile(m_handle, buffer, bytesToRead);
+    if (bytesRead < 0) {
+        m_client->didFail(NOT_READABLE_ERR);
+        return;
+    }
+
+    if (!bytesRead) {
+        m_client->didFinish();
+        return;
+    }
+
+    m_bytesProcessed += bytesRead;
+    m_client->didRead(buffer, bytesRead);
+}
+
+void FileStream::write(Blob*, long long, int)
+{
+    ASSERT(!isMainThread());
+    // FIXME: to be implemented.
+}
+
+void FileStream::truncate(long long)
+{
+    ASSERT(!isMainThread());
+    // FIXME: to be implemented.
+}
+
+} // namespace WebCore
+
+#endif // ENABLE(FILE_READER) || ENABLE(FILE_WRITER)