[BlobStorage] Enforcing renderer constraints to prevent broken blobs

third_party/WebKit/Source/platform/blob/BlobData.h

 /*
  * 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
@@ skipping 134 matching lines @@
 };
 
 typedef Vector<BlobDataItem> BlobDataItemList;
 
 class PLATFORM_EXPORT BlobData {
   USING_FAST_MALLOC(BlobData);
   WTF_MAKE_NONCOPYABLE(BlobData);
 
  public:
   static std::unique_ptr<BlobData> create();
-  // Calling append* on the returned object will check-fail. The caller can only
-  // have an unknown-length file if it is the only item in the blob.
+
+  // Calling append* on objects returned by createFor___WithUnknownSize will
+  // check-fail. The caller can only have an unknown-length file if it is the
+  // only item in the blob.
   static std::unique_ptr<BlobData> createForFileWithUnknownSize(
       const String& path);
+  static std::unique_ptr<BlobData> createForFileWithUnknownSize(
+      const String& path,
+      double expectedModificationTime);
+  static std::unique_ptr<BlobData> createForFileSystemURLWithUnknownSize(
+      const KURL& fileSystemURL,
+      double expectedModificationTime);
 
   // Detaches from current thread so that it can be passed to another thread.
   void detachFromCurrentThread();
 
   const String& contentType() const { return m_contentType; }
   void setContentType(const String&);
 
   const BlobDataItemList& items() const { return m_items; }
 
   void appendBytes(const void*, size_t length);
   void appendData(PassRefPtr<RawData>, long long offset, long long length);
   void appendFile(const String& path,
                   long long offset,
                   long long length,
                   double expectedModificationTime);
+
+  // The given blob must not be a file with unknown size. Please use the
+  // File::appendTo instead.
   void appendBlob(PassRefPtr<BlobDataHandle>,
                   long long offset,
                   long long length);
   void appendFileSystemURL(const KURL&,
                            long long offset,
                            long long length,
                            double expectedModificationTime);
   void appendText(const String&, bool normalizeLineEndingsToNative);
 
   // The value of the size property for a Blob who has this data.
   // BlobDataItem::toEndOfFile if the Blob has a file whose size was not yet
   // determined.
   long long length() const;
 
+  bool isSingleUnknownSizeFile() const {
+    return m_fileComposition == FileCompositionStatus::SINGLE_UNKNOWN_SIZE_FILE;
+  }
+
  private:
   FRIEND_TEST_ALL_PREFIXES(BlobDataTest, Consolidation);
 
   enum class FileCompositionStatus {
     SINGLE_UNKNOWN_SIZE_FILE,
     NO_UNKNOWN_SIZE_FILES
   };
 
   explicit BlobData(FileCompositionStatus composition)
       : m_fileComposition(composition) {}
@@ skipping 23 matching lines @@
   static PassRefPtr<BlobDataHandle> create(const String& uuid,
                                            const String& type,
                                            long long size) {
     return adoptRef(new BlobDataHandle(uuid, type, size));
   }
 
   String uuid() const { return m_uuid.isolatedCopy(); }
   String type() const { return m_type.isolatedCopy(); }
   unsigned long long size() const { return m_size; }
 
+  bool isSingleUnknownSizeFile() const { return m_isSingleUnknownSizeFile; }
+
   ~BlobDataHandle();
 
  private:
   BlobDataHandle();
   BlobDataHandle(std::unique_ptr<BlobData>, long long size);
   BlobDataHandle(const String& uuid, const String& type, long long size);
 
   const String m_uuid;
   const String m_type;
   const long long m_size;
+  const bool m_isSingleUnknownSizeFile;
 };
 
 }  // namespace blink
 
 #endif  // BlobData_h