content: /*
   * Copyright (C) 2009-2024 Lightbend Inc. <https://www.lightbend.com>
   */
  
  /*
   * Adapted from github.com/twitter/hpack with this license:
   *
   * Copyright 2014 Twitter, Inc.
   *
   * Licensed 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.
   */
  
  package akka.http.shaded.com.twitter.hpack;
  
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import static akka.http.shaded.com.twitter.hpack.HpackUtil.ISO_8859_1;
  
  final class StaticTable {
  
    private static final String EMPTY = "";
  
    // Appendix A: Static Table
    // http://tools.ietf.org/html/rfc7541#appendix-A
    private static final List<HeaderField> STATIC_TABLE = Arrays.asList(
      /*  1 */ new HeaderField(":authority", EMPTY),
      /*  2 */ new HeaderField(":method", "GET"),
      /*  3 */ new HeaderField(":method", "POST"),
      /*  4 */ new HeaderField(":path", "/"),
      /*  5 */ new HeaderField(":path", "/index.html"),
      /*  6 */ new HeaderField(":scheme", "http"),
      /*  7 */ new HeaderField(":scheme", "https"),
      /*  8 */ new HeaderField(":status", "200"),
      /*  9 */ new HeaderField(":status", "204"),
      /* 10 */ new HeaderField(":status", "206"),
      /* 11 */ new HeaderField(":status", "304"),
      /* 12 */ new HeaderField(":status", "400"),
      /* 13 */ new HeaderField(":status", "404"),
      /* 14 */ new HeaderField(":status", "500"),
      /* 15 */ new HeaderField("accept-charset", EMPTY),
      /* 16 */ new HeaderField("accept-encoding", "gzip, deflate"),
      /* 17 */ new HeaderField("accept-language", EMPTY),
      /* 18 */ new HeaderField("accept-ranges", EMPTY),
      /* 19 */ new HeaderField("accept", EMPTY),
      /* 20 */ new HeaderField("access-control-allow-origin", EMPTY),
      /* 21 */ new HeaderField("age", EMPTY),
      /* 22 */ new HeaderField("allow", EMPTY),
      /* 23 */ new HeaderField("authorization", EMPTY),
      /* 24 */ new HeaderField("cache-control", EMPTY),
      /* 25 */ new HeaderField("content-disposition", EMPTY),
      /* 26 */ new HeaderField("content-encoding", EMPTY),
      /* 27 */ new HeaderField("content-language", EMPTY),
      /* 28 */ new HeaderField("content-length", EMPTY),
      /* 29 */ new HeaderField("content-location", EMPTY),
      /* 30 */ new HeaderField("content-range", EMPTY),
      /* 31 */ new HeaderField("content-type", EMPTY),
      /* 32 */ new HeaderField("cookie", EMPTY),
      /* 33 */ new HeaderField("date", EMPTY),
      /* 34 */ new HeaderField("etag", EMPTY),
      /* 35 */ new HeaderField("expect", EMPTY),
      /* 36 */ new HeaderField("expires", EMPTY),
      /* 37 */ new HeaderField("from", EMPTY),
      /* 38 */ new HeaderField("host", EMPTY),
      /* 39 */ new HeaderField("if-match", EMPTY),
      /* 40 */ new HeaderField("if-modified-since", EMPTY),
      /* 41 */ new HeaderField("if-none-match", EMPTY),
      /* 42 */ new HeaderField("if-range", EMPTY),
      /* 43 */ new HeaderField("if-unmodified-since", EMPTY),
      /* 44 */ new HeaderField("last-modified", EMPTY),
      /* 45 */ new HeaderField("link", EMPTY),
      /* 46 */ new HeaderField("location", EMPTY),
      /* 47 */ new HeaderField("max-forwards", EMPTY),
      /* 48 */ new HeaderField("proxy-authenticate", EMPTY),
      /* 49 */ new HeaderField("proxy-authorization", EMPTY),
      /* 50 */ new HeaderField("range", EMPTY),
      /* 51 */ new HeaderField("referer", EMPTY),
      /* 52 */ new HeaderField("refresh", EMPTY),
      /* 53 */ new HeaderField("retry-after", EMPTY),
      /* 54 */ new HeaderField("server", EMPTY),
      /* 55 */ new HeaderField("set-cookie", EMPTY),
      /* 56 */ new HeaderField("strict-transport-security", EMPTY),
      /* 57 */ new HeaderField("transfer-encoding", EMPTY),
      /* 58 */ new HeaderField("user-agent", EMPTY),
      /* 59 */ new HeaderField("vary", EMPTY),
      /* 60 */ new HeaderField("via", EMPTY),
      /* 61 */ new HeaderField("www-authenticate", EMPTY)
    );
  
    private static final Map<String, Integer> STATIC_INDEX_BY_NAME = createMap();
  
    /**
     * The number of header fields in the static table.
     */
    static final int length = STATIC_TABLE.size();
  
    /**
     * Return the header field at the given index value.
     */
    static HeaderField getEntry(int index) {
      return STATIC_TABLE.get(index - 1);
    }
  
    /**
     * Returns the lowest index value for the given header field name in the static table.
     * Returns -1 if the header field name is not in the static table.
     */
    static int getIndex(String nameString) {
      Integer index = STATIC_INDEX_BY_NAME.get(nameString);
      if (index == null) {
        return -1;
      }
      return index;
    }
  
    /**
     * Returns the index value for the given header field in the static table.
     * Returns -1 if the header field is not in the static table.
     */
    static int getIndex(String name, String value) {
      int index = getIndex(name);
      if (index == -1) {
        return -1;
      }
  
      // Note this assumes all entries for a given header field are sequential.
      while (index <= length) {
        HeaderField entry = getEntry(index);
        if (name.equals(entry.name) && value.equals(entry.value)) {
          return index;
        }
        index++;
      }
  
      return -1;
    }
  
    // create a map of header name to index value to allow quick lookup
    private static Map<String, Integer> createMap() {
      int length = STATIC_TABLE.size();
      HashMap<String, Integer> ret = new HashMap<String, Integer>(length);
      // Iterate through the static table in reverse order to
      // save the smallest index for a given name in the map.
      for (int index = length; index > 0; index--) {
        HeaderField entry = getEntry(index);
        ret.put(entry.name, index);
      }
      return ret;
    }
  
    // singleton
    private StaticTable() {}
  }
  