text: /*
   * ngtcp2
   *
   * 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 "ngtcp2_gaptr.h"
  
  #include <string.h>
  #include <assert.h>
  
  #include "ngtcp2_macro.h"
  
  int ngtcp2_gaptr_init(ngtcp2_gaptr *gaptr, const ngtcp2_mem *mem) {
    int rv;
    ngtcp2_range range = {0, UINT64_MAX};
    ngtcp2_ksl_key key;
  
    rv = ngtcp2_ksl_init(&gaptr->gap, ngtcp2_ksl_range_compar,
                         sizeof(ngtcp2_range), mem);
    if (rv != 0) {
      return rv;
    }
  
    rv = ngtcp2_ksl_insert(&gaptr->gap, NULL, ngtcp2_ksl_key_ptr(&key, &range),
                           NULL);
    if (rv != 0) {
      ngtcp2_ksl_free(&gaptr->gap);
      return rv;
    }
  
    gaptr->mem = mem;
  
    return 0;
  }
  
  void ngtcp2_gaptr_free(ngtcp2_gaptr *gaptr) {
    if (gaptr == NULL) {
      return;
    }
  
    ngtcp2_ksl_free(&gaptr->gap);
  }
  
  int ngtcp2_gaptr_push(ngtcp2_gaptr *gaptr, uint64_t offset, size_t datalen) {
    int rv;
    ngtcp2_range k, m, l, r, q = {offset, offset + datalen};
    ngtcp2_ksl_it it;
    ngtcp2_ksl_key key, old_key;
  
    it = ngtcp2_ksl_lower_bound_compar(&gaptr->gap, ngtcp2_ksl_key_ptr(&key, &q),
                                       ngtcp2_ksl_range_exclusive_compar);
  
    for (; !ngtcp2_ksl_it_end(&it);) {
      k = *(ngtcp2_range *)ngtcp2_ksl_it_key(&it).ptr;
      m = ngtcp2_range_intersect(&q, &k);
      if (!ngtcp2_range_len(&m)) {
        break;
      }
  
      if (ngtcp2_range_eq(&k, &m)) {
        ngtcp2_ksl_remove(&gaptr->gap, &it, ngtcp2_ksl_key_ptr(&key, &k));
        continue;
      }
      ngtcp2_range_cut(&l, &r, &k, &m);
      if (ngtcp2_range_len(&l)) {
        ngtcp2_ksl_update_key(&gaptr->gap, ngtcp2_ksl_key_ptr(&old_key, &k),
                              ngtcp2_ksl_key_ptr(&key, &l));
  
        if (ngtcp2_range_len(&r)) {
          rv = ngtcp2_ksl_insert(&gaptr->gap, &it, ngtcp2_ksl_key_ptr(&key, &r),
                                 NULL);
          if (rv != 0) {
            return rv;
          }
        }
      } else if (ngtcp2_range_len(&r)) {
        ngtcp2_ksl_update_key(&gaptr->gap, ngtcp2_ksl_key_ptr(&old_key, &k),
                              ngtcp2_ksl_key_ptr(&key, &r));
      }
      ngtcp2_ksl_it_next(&it);
    }
    return 0;
  }
  
  uint64_t ngtcp2_gaptr_first_gap_offset(ngtcp2_gaptr *gaptr) {
    ngtcp2_ksl_it it = ngtcp2_ksl_begin(&gaptr->gap);
    ngtcp2_range r = *(ngtcp2_range *)ngtcp2_ksl_it_key(&it).ptr;
    return r.begin;
  }
  
  ngtcp2_ksl_it ngtcp2_gaptr_get_first_gap_after(ngtcp2_gaptr *gaptr,
                                                 uint64_t offset) {
    ngtcp2_range q = {offset, offset + 1};
    ngtcp2_ksl_key key;
    return ngtcp2_ksl_lower_bound_compar(&gaptr->gap,
                                         ngtcp2_ksl_key_ptr(&key, &q),
                                         ngtcp2_ksl_range_exclusive_compar);
  }
  
  int ngtcp2_gaptr_is_pushed(ngtcp2_gaptr *gaptr, uint64_t offset,
                             size_t datalen) {
    ngtcp2_ksl_key key;
    ngtcp2_range q = {offset, offset + datalen};
    ngtcp2_ksl_it it =
        ngtcp2_ksl_lower_bound_compar(&gaptr->gap, ngtcp2_ksl_key_ptr(&key, &q),
                                      ngtcp2_ksl_range_exclusive_compar);
    ngtcp2_range k = *(ngtcp2_range *)ngtcp2_ksl_it_key(&it).ptr;
    ngtcp2_range m = ngtcp2_range_intersect(&q, &k);
    return ngtcp2_range_len(&m) == 0;
  }
  