Implement Blob.close().

Source/core/fileapi/File.h

 /*
  * 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 14 matching lines @@
 
 #ifndef File_h
 #define File_h
 
 #include "core/fileapi/Blob.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
+class ExecutionContext;
 struct FileMetadata;
 class KURL;
 
 class File FINAL : public Blob {
 public:
     // AllContentTypes should only be used when the full path/name are trusted; otherwise, it could
     // allow arbitrary pages to determine what applications an user has installed.
     enum ContentTypeLookupPolicy {
         WellKnownContentTypes,
         AllContentTypes,
@@ skipping 23 matching lines @@
     static PassRefPtr<File> createForFileSystemFile(const String& name, const FileMetadata& metadata)
     {
         return adoptRef(new File(name, metadata));
     }
 
     static PassRefPtr<File> createForFileSystemFile(const KURL& url, const FileMetadata& metadata)
     {
         return adoptRef(new File(url, metadata));
     }
 
     KURL fileSystemURL() const { ASSERT(m_hasBackingFile); return m_fileSystemURL; }

[michaeln, 2014/02/18 18:59:54]

That assertion looks like a landmine in a world with blobs that get closed.

[sof, 2014/02/18 19:12:47]

Yes, I'll see what I can do. The landmine is already present with being able to
create File objects from blobBits using the File constructor:

  var noBackingFile = new File(["foo"], {..});

 
     // Create a file with a name exposed to the author (via File.name and associated DOM properties) that differs from the one provided in the path.
     static PassRefPtr<File> createWithName(const String& path, const String& name, ContentTypeLookupPolicy policy = WellKnownContentTypes)
     {
         if (name.isEmpty())
             return adoptRef(new File(path, policy));
         return adoptRef(new File(path, name, policy));
     }
 
     virtual unsigned long long size() const OVERRIDE;
     virtual PassRefPtr<Blob> slice(long long start = 0, long long end = std::numeric_limits<long long>::max(), const String& contentType = String()) const OVERRIDE;
+    virtual void close(ExecutionContext*) OVERRIDE;
 
     virtual bool isFile() const OVERRIDE { return true; }
     virtual bool hasBackingFile() const OVERRIDE { return m_hasBackingFile; }
 
     virtual void appendTo(BlobData&) const OVERRIDE;
 
     const String& path() const { ASSERT(m_hasBackingFile); return m_path; }

[michaeln, 2014/02/18 18:59:54]

Ditto landmind.

[sof, 2014/02/19 11:47:39]

I checked the call sites & they do check backing file status, so this looks like
a defensive measure should that slip.

I've kept the assert, but tweaked it slightly.

-    const String& name() const { return m_name; }
+    const String name() const { return m_name; }
 
-    // This returns the current date and time if the file's last modifiecation date is not known (per spec: http://www.w3.org/TR/FileAPI/#dfn-lastModifiedDate).
+    // This returns the current date and time if the file's last modification date is not known (per spec: http://www.w3.org/TR/FileAPI/#dfn-lastModifiedDate).
     double lastModifiedDate() const;
 
     // Returns the relative path of this file in the context of a directory selection.
     const String& webkitRelativePath() const { return m_relativePath; }
 
     // Note that this involves synchronous file operation. Think twice before calling this function.
     void captureSnapshot(long long& snapshotSize, double& snapshotModificationTime) const;
 
     // Returns true if this has a valid snapshot metadata (i.e. m_snapshotSize >= 0).
     bool hasValidSnapshotMetadata() const { return m_snapshotSize >= 0; }
 
 private:
     File(const String& path, ContentTypeLookupPolicy);
     File(const String& path, const String& name, ContentTypeLookupPolicy);
     File(const String& path, const String& name, const String& relativePath, bool hasSnaphotData, uint64_t size, double lastModified, PassRefPtr<BlobDataHandle>);
     File(const String& name, double modificationTime, PassRefPtr<BlobDataHandle>);
     File(const String& name, const FileMetadata&);
     File(const KURL& fileSystemURL, const FileMetadata&);
 
+    void invalidateSnapshotMetadata() { m_snapshotSize = -1; }
+
     bool m_hasBackingFile;
     String m_path;
     String m_name;
 
     KURL m_fileSystemURL;
 
     // If m_snapshotSize is negative (initialized to -1 by default), the snapshot metadata is invalid and we retrieve the latest metadata synchronously in size(), lastModifiedTime() and slice().
     // Otherwise, the snapshot metadata are used directly in those methods.
-    const long long m_snapshotSize;
+    long long m_snapshotSize;
     const double m_snapshotModificationTime;
 
     String m_relativePath;
 };
 
 DEFINE_TYPE_CASTS(File, Blob, blob, blob->isFile(), blob.isFile());
 
 } // namespace WebCore
 
 #endif // File_h