text: /*
   * nghttp3
   *
   * Copyright (c) 2019 nghttp3 contributors
   * Copyright (c) 2017 ngtcp2 contributors
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  #include "nghttp3_idtr.h"
  
  #include <assert.h>
  
  int nghttp3_idtr_init(nghttp3_idtr *idtr, int server, const nghttp3_mem *mem) {
    int rv;
  
    rv = nghttp3_gaptr_init(&idtr->gap, mem);
    if (rv != 0) {
      return rv;
    }
  
    idtr->server = server;
    idtr->mem = mem;
  
    return 0;
  }
  
  void nghttp3_idtr_free(nghttp3_idtr *idtr) {
    if (idtr == NULL) {
      return;
    }
  
    nghttp3_gaptr_free(&idtr->gap);
  }
  
  /*
   * id_from_stream_id translates |stream_id| to id space used by
   * nghttp3_idtr.
   */
  static uint64_t id_from_stream_id(int64_t stream_id) {
    return (uint64_t)(stream_id >> 2);
  }
  
  int nghttp3_idtr_open(nghttp3_idtr *idtr, int64_t stream_id) {
    uint64_t q;
  
    assert((idtr->server && (stream_id % 2)) ||
           (!idtr->server && (stream_id % 2)) == 0);
  
    q = id_from_stream_id(stream_id);
  
    if (nghttp3_gaptr_is_pushed(&idtr->gap, q, 1)) {
      return NGHTTP3_ERR_STREAM_IN_USE;
    }
  
    return nghttp3_gaptr_push(&idtr->gap, q, 1);
  }
  
  int nghttp3_idtr_is_open(nghttp3_idtr *idtr, int64_t stream_id) {
    uint64_t q;
  
    assert((idtr->server && (stream_id % 2)) ||
           (!idtr->server && (stream_id % 2)) == 0);
  
    q = id_from_stream_id(stream_id);
  
    return nghttp3_gaptr_is_pushed(&idtr->gap, q, 1);
  }
  
  uint64_t nghttp3_idtr_first_gap(nghttp3_idtr *idtr) {
    return nghttp3_gaptr_first_gap_offset(&idtr->gap);
  }
  