Implement Blob.close().

Source/core/fileapi/File.cpp

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 144 matching lines @@
 {
     ScriptWrappable::init(this);
 }
 
 double File::lastModifiedDate() const
 {
     if (hasValidSnapshotMetadata() && isValidFileTime(m_snapshotModificationTime))
         return m_snapshotModificationTime * msPerSecond;
 
     time_t modificationTime;
-    if (getFileModificationTime(m_path, modificationTime) && isValidFileTime(modificationTime))
+    if (hasBackingFile() && getFileModificationTime(m_path, modificationTime) && isValidFileTime(modificationTime))
         return modificationTime * msPerSecond;
 
     return currentTime() * msPerSecond;
 }
 
 unsigned long long File::size() const
 {
     if (hasValidSnapshotMetadata())
         return m_snapshotSize;
 
     // FIXME: JavaScript cannot represent sizes as large as unsigned long long, we need to
     // come up with an exception to throw if file size is not representable.
     long long size;
-    if (!getFileSize(m_path, size))
+    if (!hasBackingFile() || !getFileSize(m_path, size))
         return 0;
     return static_cast<unsigned long long>(size);
 }
 
 PassRefPtr<Blob> File::slice(long long start, long long end, const String& contentType) const
 {
     if (!m_hasBackingFile)
         return Blob::slice(start, end, contentType);
 
     // FIXME: This involves synchronous file operation. We need to figure out how to make it asynchronous.
@@ skipping 18 matching lines @@
 {
     if (hasValidSnapshotMetadata()) {
         snapshotSize = m_snapshotSize;
         snapshotModificationTime = m_snapshotModificationTime;
         return;
     }
 
     // Obtains a snapshot of the file by capturing its current size and modification time. This is used when we slice a file for the first time.
     // If we fail to retrieve the size or modification time, probably due to that the file has been deleted, 0 size is returned.
     FileMetadata metadata;
-    if (!getFileMetadata(m_path, metadata)) {
+    if (!hasBackingFile() || !getFileMetadata(m_path, metadata)) {
         snapshotSize = 0;
         snapshotModificationTime = invalidFileTime();
         return;
     }
 
     snapshotSize = metadata.length;
     snapshotModificationTime = metadata.modificationTime;
 }
 
+void File::close(ExecutionContext* executionContext)
+{
+    if (!hasBeenClosed()) {
+        // Reset the File to its closed representation, an empty
+        // Blob. The name isn't cleared, as it should still be
+        // available.
+        m_hasBackingFile = false;
+        m_path = String();
+        m_fileSystemURL = KURL();
+        invalidateSnapshotMetadata();
+        m_relativePath = String();
+        Blob::close(executionContext);
+    }
+}
+
 void File::appendTo(BlobData& blobData) const
 {
     if (!m_hasBackingFile) {
         Blob::appendTo(blobData);
         return;
     }
 
     // FIXME: This involves synchronous file operation. We need to figure out how to make it asynchronous.
     long long size;
     double modificationTime;
     captureSnapshot(size, modificationTime);
     if (!m_fileSystemURL.isEmpty()) {
         blobData.appendFileSystemURL(m_fileSystemURL, 0, size, modificationTime);
         return;
     }
     ASSERT(!m_path.isEmpty());
     blobData.appendFile(m_path, 0, size, modificationTime);
 }
 
 } // namespace WebCore