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// 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
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#ifndef IMPALA_UTIL_URL_PARSER_H
#define IMPALA_UTIL_URL_PARSER_H

#include "runtime/string-value.h"
#include "runtime/string-search.h"

namespace impala {

/// TODO: For now, our parse_url may not behave exactly like Hive
/// when given malformed URLs.
/// If necessary, we can closely follow Java's URL implementation
/// to behave exactly like Hive.

/// Example for explaining URL parts:
/// http://user:pass@example.com:80/docs/books/tutorial/index.html?name=networking#DOWNLOADING
/// PROTOCOL = http
/// AUTHORITY = example.com:80
/// HOST = example.com
/// PATH = /docs/books/tutorial/index.html
/// QUERY = name=networking
/// FILENAME = /docs/books/tutorial/index.html?name=networking
/// REF = DOWNLOADING
/// USERINFO = user:pass
/// More details on what exactly the URL parts mean can be found here:
/// http://docs.oracle.com/javase/tutorial/networking/urls/urlInfo.html
class UrlParser {
 public:
  /// Parts of a URL that can be requested.
  enum UrlPart {
    INVALID,
    AUTHORITY,
    FILE,
    HOST,
    PATH,
    PROTOCOL,
    QUERY,
    REF,
    USERINFO
  };

  /// Tries to parse the part from url. Places the result in result.
  /// Returns false if the URL is malformed or if part is invalid. True otherwise.
  /// If false is returned the contents of results are undefined.
  static bool ParseUrl(const StringValue& url, UrlPart part, StringValue* result);

  /// Tries to parse key from url. Places the result in result.
  /// Returns false if the URL is malformed or if part is invalid. True otherwise.
  /// If false is returned the contents of results are undefined.
  static bool ParseUrlKey(const StringValue& url, UrlPart part, const StringValue& key,
      StringValue* result);

  /// Compares part against url_authority, url_file, url_host, etc.,
  /// and returns the corresponding enum.
  /// If part did not match any of the url part constants, returns INVALID.
  static UrlPart GetUrlPart(const StringValue& part);

 private:
  // Constants representing parts of a URL.
  static const StringValue url_authority;
  static const StringValue url_file;
  static const StringValue url_host;
  static const StringValue url_path;
  static const StringValue url_protocol;
  static const StringValue url_query;
  static const StringValue url_ref;
  static const StringValue url_userinfo;
  // Constants used in searching for URL parts.
  static const StringValue protocol;
  static const StringValue at;
  static const StringValue slash;
  static const StringValue colon;
  static const StringValue question;
  static const StringValue hash;
  static const StringSearch protocol_search;
  static const StringSearch at_search;
  static const StringSearch slash_search;
  static const StringSearch colon_search;
  static const StringSearch question_search;
  static const StringSearch hash_search;
};

}

#endif