pagespeed/kernel/http/user_agent_normalizer.h

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */



#ifndef PAGESPEED_KERNEL_HTTP_USER_AGENT_NORMALIZER_H_
#define PAGESPEED_KERNEL_HTTP_USER_AGENT_NORMALIZER_H_

#include <vector>

#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/util/re2.h"

namespace net_instaweb {

// Base class for user agent string normalizer. The idea is that UA strings,
// sometimes include irrelevant information, so this provides a way of stripping
// it, to improve cache hit-rates when the normalized UAs are used in cache
// keys.
class UserAgentNormalizer {
 public:
  UserAgentNormalizer() {}
  virtual ~UserAgentNormalizer();

  virtual GoogleString Normalize(const GoogleString& in) const = 0;

  // Helper that applies all the normalizers in the ua_normalizers list
  // to ua_in.
  static GoogleString NormalizeWithAll(
      const std::vector<const UserAgentNormalizer*>& ua_normalizers,
      const GoogleString& ua_in);

 private:
  DISALLOW_COPY_AND_ASSIGN(UserAgentNormalizer);
};

// This normalizes some common UA strings for Android devices
// by dropping the device & build names from them.
class AndroidUserAgentNormalizer : public UserAgentNormalizer {
 public:
  AndroidUserAgentNormalizer();
  virtual ~AndroidUserAgentNormalizer();

  virtual GoogleString Normalize(const GoogleString& in) const;

 private:
  RE2 dalvik_ua_;
  RE2 chrome_android_ua_;
  RE2 android_browser_ua_;
};

// This normalizes UA strings for MSIE, by dropping the long list of
// installed extensions (like .NET) it likes to include, and just keeping the
// important info like browser, OS, and chromeframe version.
class IEUserAgentNormalizer : public UserAgentNormalizer {
 public:
  IEUserAgentNormalizer();
  virtual ~IEUserAgentNormalizer();

  virtual GoogleString Normalize(const GoogleString& in) const;

 private:
  RE2 ie_ua_;
};

}  // namespace net_instaweb

#endif  // PAGESPEED_KERNEL_HTTP_USER_AGENT_NORMALIZER_H_