/*

 * ngtcp2

 *

 * Copyright (c) 2022 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_balloc.h"

#include <assert.h>

#include "ngtcp2_mem.h"

void ngtcp2_balloc_init(ngtcp2_balloc *balloc, size_t blklen,

                        const ngtcp2_mem *mem) {

  assert((blklen & 0xFU) == 0);

  balloc->mem = mem;

  balloc->blklen = blklen;

  balloc->head = NULL;

  ngtcp2_buf_init(&balloc->buf, (void *)"", 0);

}

void ngtcp2_balloc_free(ngtcp2_balloc *balloc) {

  if (balloc == NULL) {

    return;

  }

  ngtcp2_balloc_clear(balloc);

}

void ngtcp2_balloc_clear(ngtcp2_balloc *balloc) {

  ngtcp2_memblock_hd *p, *next;

  for (p = balloc->head; p; p = next) {

    next = p->next;

    ngtcp2_mem_free(balloc->mem, p);

  }

  balloc->head = NULL;

  ngtcp2_buf_init(&balloc->buf, (void *)"", 0);

}

int ngtcp2_balloc_get(ngtcp2_balloc *balloc, void **pbuf, size_t n) {

  uint8_t *p;

  ngtcp2_memblock_hd *hd;

  assert(n <= balloc->blklen);

  if (ngtcp2_buf_left(&balloc->buf) < n) {

    p = ngtcp2_mem_malloc(balloc->mem,

                          sizeof(ngtcp2_memblock_hd) + 0x8U + balloc->blklen);

    if (p == NULL) {

      return NGTCP2_ERR_NOMEM;

    }

    hd = (void *)p;

    hd->next = balloc->head;

    balloc->head = hd;

    ngtcp2_buf_init(

      &balloc->buf,

      (uint8_t *)(((uintptr_t)p + sizeof(ngtcp2_memblock_hd) + 0xFU) &

                  ~(uintptr_t)0xFU),

      balloc->blklen);

  }

  assert(((uintptr_t)balloc->buf.last & 0xFU) == 0);

  *pbuf = balloc->buf.last;

  balloc->buf.last += (n + 0xFU) & ~(uintptr_t)0xFU;

  return 0;

}