/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-â
âvi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :viâ
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â Copyright 2020 Justine Alexandra Roberts Tunney                              â
â                                                                              â
â Permission to use, copy, modify, and/or distribute this software for         â
â any purpose with or without fee is hereby granted, provided that the         â
â above copyright notice and this permission notice appear in all copies.      â
â                                                                              â
â THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                â
â WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                â
â WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             â
â AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         â
â DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        â
â PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               â
â TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             â
â PERFORMANCE OF THIS SOFTWARE.                                                â
ââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââ*/
#include "libc/macros.internal.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "tool/build/lib/iovs.h"

void InitIovs(struct Iovs *ib) {
  ib->p = ib->init;
  ib->i = 0;
  ib->n = ARRAYLEN(ib->init);
}

void FreeIovs(struct Iovs *ib) {
  if (ib->p != ib->init) {
    free(ib->p);
  }
}

/**
 * Appends memory region to i/o vector builder.
 */
int AppendIovs(struct Iovs *ib, void *base, size_t len) {
  unsigned i, n;
  struct iovec *p;
  if (len) {
    p = ib->p;
    i = ib->i;
    n = ib->n;
    if (i && (intptr_t)base == (intptr_t)p[i - 1].iov_base + p[i - 1].iov_len) {
      p[i - 1].iov_len += len;
    } else {
      if (__builtin_expect(i == n, 0)) {
        n += n >> 1;
        if (p == ib->init) {
          if (!(p = malloc(sizeof(struct iovec) * n))) return -1;
          memcpy(p, ib->init, sizeof(ib->init));
        } else {
          if (!(p = realloc(p, sizeof(struct iovec) * n))) return -1;
        }
        ib->p = p;
        ib->n = n;
      }
      p[i].iov_base = base;
      p[i].iov_len = len;
      ++ib->i;
    }
  }
  return 0;
}
