text: // Copyright 2013 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef CONTENT_RENDERER_MEDIA_CACHE_UTIL_H_
  #define CONTENT_RENDERER_MEDIA_CACHE_UTIL_H_
  
  #include <vector>
  
  #include "base/basictypes.h"
  #include "content/common/content_export.h"
  
  namespace WebKit {
  class WebURLResponse;
  }
  
  namespace content {
  
  // Reasons that a cached WebURLResponse will *not* prevent a future request to
  // the server.  Reported via UMA, so don't change/reuse previously-existing
  // values.
  enum UncacheableReason {
    kNoData = 1 << 0,  // Not 200 or 206.
    kPre11PartialResponse = 1 << 1,  // 206 but HTTP version < 1.1.
    kNoStrongValidatorOnPartialResponse = 1 << 2,  // 206, no strong validator.
    kShortMaxAge = 1 << 3,  // Max age less than 1h (arbitrary value).
    kExpiresTooSoon = 1 << 4,  // Expires in less than 1h (arbitrary value).
    kHasMustRevalidate = 1 << 5,  // Response asks for revalidation.
    kNoCache = 1 << 6,  // Response included a no-cache header.
    kNoStore = 1 << 7,  // Response included a no-store header.
    kMaxReason  // Needs to be one more than max legitimate reason.
  };
  
  // Return the logical OR of the reasons "response" cannot be used for a future
  // request (using the disk cache), or 0 if it might be useful.
  uint32 CONTENT_EXPORT GetReasonsForUncacheability(
      const WebKit::WebURLResponse& response);
  
  }  // namespace content
  
  #endif  // CONTENT_RENDERER_MEDIA_CACHE_UTIL_H_
  