external/nghttp2/nghttp2_buf.c

/*
 * nghttp2 - HTTP/2 C Library
 *
 * Copyright (c) 2014 Tatsuhiro Tsujikawa
 *
 * 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 "nghttp2_buf.h"

#include <stdio.h>

#include "nghttp2_helper.h"
#include "nghttp2_debug.h"

void nghttp2_buf_init(nghttp2_buf *buf)
{
    buf->begin = NULL;
    buf->end = NULL;
    buf->pos = NULL;
    buf->last = NULL;
    buf->mark = NULL;
}

int nghttp2_buf_init2(nghttp2_buf *buf, size_t initial, nghttp2_mem *mem)
{
    nghttp2_buf_init(buf);
    return nghttp2_buf_reserve(buf, initial, mem);
}

void nghttp2_buf_free(nghttp2_buf *buf, nghttp2_mem *mem)
{
    if (buf == NULL) {
        return;
    }

    nghttp2_mem_free(mem, buf->begin);
    buf->begin = NULL;
}

int nghttp2_buf_reserve(nghttp2_buf *buf, size_t new_cap, nghttp2_mem *mem)
{
    uint8_t *ptr;
    size_t cap;

    cap = nghttp2_buf_cap(buf);

    if (cap >= new_cap) {
        return 0;
    }

    new_cap = nghttp2_max(new_cap, cap * 2);

    ptr = nghttp2_mem_realloc(mem, buf->begin, new_cap);
    if (ptr == NULL) {
        return NGHTTP2_ERR_NOMEM;
    }

    buf->pos = ptr + (buf->pos - buf->begin);
    buf->last = ptr + (buf->last - buf->begin);
    buf->mark = ptr + (buf->mark - buf->begin);
    buf->begin = ptr;
    buf->end = ptr + new_cap;

    return 0;
}

void nghttp2_buf_reset(nghttp2_buf *buf)
{
    buf->pos = buf->last = buf->mark = buf->begin;
}

void nghttp2_buf_wrap_init(nghttp2_buf *buf, uint8_t *begin, size_t len)
{
    buf->begin = buf->pos = buf->last = buf->mark = begin;
    buf->end = begin + len;
}

static int buf_chain_new(nghttp2_buf_chain **chain, size_t chunk_length,
                         nghttp2_mem *mem)
{
    int rv;

    *chain = nghttp2_mem_malloc(mem, sizeof(nghttp2_buf_chain));
    if (*chain == NULL) {
        return NGHTTP2_ERR_NOMEM;
    }

    (*chain)->next = NULL;

    rv = nghttp2_buf_init2(&(*chain)->buf, chunk_length, mem);
    if (rv != 0) {
        nghttp2_mem_free(mem, *chain);
        return NGHTTP2_ERR_NOMEM;
    }

    return 0;
}

static void buf_chain_del(nghttp2_buf_chain *chain, nghttp2_mem *mem)
{
    nghttp2_buf_free(&chain->buf, mem);
    nghttp2_mem_free(mem, chain);
}

int nghttp2_bufs_init(nghttp2_bufs *bufs, size_t chunk_length, size_t max_chunk,
                      nghttp2_mem *mem)
{
    return nghttp2_bufs_init2(bufs, chunk_length, max_chunk, 0, mem);
}

int nghttp2_bufs_init2(nghttp2_bufs *bufs, size_t chunk_length,
                       size_t max_chunk, size_t offset, nghttp2_mem *mem)
{
    return nghttp2_bufs_init3(bufs, chunk_length, max_chunk, max_chunk, offset,
                              mem);
}

int nghttp2_bufs_init3(nghttp2_bufs *bufs, size_t chunk_length,
                       size_t max_chunk, size_t chunk_keep, size_t offset,
                       nghttp2_mem *mem)
{
    int rv;
    nghttp2_buf_chain *chain;

    if (chunk_keep == 0 || max_chunk < chunk_keep || chunk_length < offset) {
        return NGHTTP2_ERR_INVALID_ARGUMENT;
    }

    rv = buf_chain_new(&chain, chunk_length, mem);
    if (rv != 0) {
        return rv;
    }

    bufs->mem = mem;
    bufs->offset = offset;

    bufs->head = chain;
    bufs->cur = bufs->head;

    nghttp2_buf_shift_right(&bufs->cur->buf, offset);

    bufs->chunk_length = chunk_length;
    bufs->chunk_used = 1;
    bufs->max_chunk = max_chunk;
    bufs->chunk_keep = chunk_keep;

    return 0;
}

int nghttp2_bufs_realloc(nghttp2_bufs *bufs, size_t chunk_length)
{
    int rv;
    nghttp2_buf_chain *chain;

    if (chunk_length < bufs->offset) {
        return NGHTTP2_ERR_INVALID_ARGUMENT;
    }

    rv = buf_chain_new(&chain, chunk_length, bufs->mem);
    if (rv != 0) {
        return rv;
    }

    nghttp2_bufs_free(bufs);

    bufs->head = chain;
    bufs->cur = bufs->head;

    nghttp2_buf_shift_right(&bufs->cur->buf, bufs->offset);

    bufs->chunk_length = chunk_length;
    bufs->chunk_used = 1;

    return 0;
}

void nghttp2_bufs_free(nghttp2_bufs *bufs)
{
    nghttp2_buf_chain *chain, *next_chain;

    if (bufs == NULL) {
        return;
    }

    for (chain = bufs->head; chain;) {
        next_chain = chain->next;

        buf_chain_del(chain, bufs->mem);

        chain = next_chain;
    }

    bufs->head = NULL;
}

int nghttp2_bufs_wrap_init(nghttp2_bufs *bufs, uint8_t *begin, size_t len,
                           nghttp2_mem *mem)
{
    nghttp2_buf_chain *chain;

    chain = nghttp2_mem_malloc(mem, sizeof(nghttp2_buf_chain));
    if (chain == NULL) {
        return NGHTTP2_ERR_NOMEM;
    }

    chain->next = NULL;

    nghttp2_buf_wrap_init(&chain->buf, begin, len);

    bufs->mem = mem;
    bufs->offset = 0;

    bufs->head = chain;
    bufs->cur = bufs->head;

    bufs->chunk_length = len;
    bufs->chunk_used = 1;
    bufs->max_chunk = 1;
    bufs->chunk_keep = 1;

    return 0;
}

int nghttp2_bufs_wrap_init2(nghttp2_bufs *bufs, const nghttp2_vec *vec,
                            size_t veclen, nghttp2_mem *mem)
{
    size_t i = 0;
    nghttp2_buf_chain *cur_chain;
    nghttp2_buf_chain *head_chain;
    nghttp2_buf_chain **dst_chain = &head_chain;

    if (veclen == 0) {
        return nghttp2_bufs_wrap_init(bufs, NULL, 0, mem);
    }

    head_chain = nghttp2_mem_malloc(mem, sizeof(nghttp2_buf_chain) * veclen);
    if (head_chain == NULL) {
        return NGHTTP2_ERR_NOMEM;
    }

    for (i = 0; i < veclen; ++i) {
        cur_chain = &head_chain[i];
        cur_chain->next = NULL;
        nghttp2_buf_wrap_init(&cur_chain->buf, vec[i].base, vec[i].len);

        *dst_chain = cur_chain;
        dst_chain = &cur_chain->next;
    }

    bufs->mem = mem;
    bufs->offset = 0;

    bufs->head = head_chain;
    bufs->cur = bufs->head;

    /* We don't use chunk_length since no allocation is expected. */
    bufs->chunk_length = 0;
    bufs->chunk_used = veclen;
    bufs->max_chunk = veclen;
    bufs->chunk_keep = veclen;

    return 0;
}

void nghttp2_bufs_wrap_free(nghttp2_bufs *bufs)
{
    if (bufs == NULL) {
        return;
    }

    if (bufs->head) {
        nghttp2_mem_free(bufs->mem, bufs->head);
    }
}

void nghttp2_bufs_seek_last_present(nghttp2_bufs *bufs)
{
    nghttp2_buf_chain *ci;

    for (ci = bufs->cur; ci; ci = ci->next) {
        if (nghttp2_buf_len(&ci->buf) == 0) {
            return;
        } else {
            bufs->cur = ci;
        }
    }
}

size_t nghttp2_bufs_len(nghttp2_bufs *bufs)
{
    nghttp2_buf_chain *ci;
    size_t len;

    len = 0;
    for (ci = bufs->head; ci; ci = ci->next) {
        len += nghttp2_buf_len(&ci->buf);
    }

    return len;
}

static int bufs_alloc_chain(nghttp2_bufs *bufs)
{
    int rv;
    nghttp2_buf_chain *chain;

    if (bufs->cur->next) {
        bufs->cur = bufs->cur->next;

        return 0;
    }

    if (bufs->max_chunk == bufs->chunk_used) {
        return NGHTTP2_ERR_BUFFER_ERROR;
    }

    rv = buf_chain_new(&chain, bufs->chunk_length, bufs->mem);
    if (rv != 0) {
        return rv;
    }

    DEBUGF("new buffer %zu bytes allocated for bufs %p, used %zu\n",
           bufs->chunk_length, bufs, bufs->chunk_used);

    ++bufs->chunk_used;

    bufs->cur->next = chain;
    bufs->cur = chain;

    nghttp2_buf_shift_right(&bufs->cur->buf, bufs->offset);

    return 0;
}

int nghttp2_bufs_add(nghttp2_bufs *bufs, const void *data, size_t len)
{
    int rv;
    size_t nwrite;
    nghttp2_buf *buf;
    const uint8_t *p;

    p = data;

    while (len) {
        buf = &bufs->cur->buf;

        nwrite = nghttp2_min(nghttp2_buf_avail(buf), len);
        if (nwrite == 0) {
            rv = bufs_alloc_chain(bufs);
            if (rv != 0) {
                return rv;
            }
            continue;
        }

        buf->last = nghttp2_cpymem(buf->last, p, nwrite);
        p += nwrite;
        len -= nwrite;
    }

    return 0;
}

static int bufs_ensure_addb(nghttp2_bufs *bufs)
{
    int rv;
    nghttp2_buf *buf;

    buf = &bufs->cur->buf;

    if (nghttp2_buf_avail(buf) > 0) {
        return 0;
    }

    rv = bufs_alloc_chain(bufs);
    if (rv != 0) {
        return rv;
    }

    return 0;
}

int nghttp2_bufs_addb(nghttp2_bufs *bufs, uint8_t b)
{
    int rv;

    rv = bufs_ensure_addb(bufs);
    if (rv != 0) {
        return rv;
    }

    *bufs->cur->buf.last++ = b;

    return 0;
}

int nghttp2_bufs_addb_hold(nghttp2_bufs *bufs, uint8_t b)
{
    int rv;

    rv = bufs_ensure_addb(bufs);
    if (rv != 0) {
        return rv;
    }

    *bufs->cur->buf.last = b;

    return 0;
}

int nghttp2_bufs_orb(nghttp2_bufs *bufs, uint8_t b)
{
    int rv;

    rv = bufs_ensure_addb(bufs);
    if (rv != 0) {
        return rv;
    }

    *bufs->cur->buf.last++ |= b;

    return 0;
}

int nghttp2_bufs_orb_hold(nghttp2_bufs *bufs, uint8_t b)
{
    int rv;

    rv = bufs_ensure_addb(bufs);
    if (rv != 0) {
        return rv;
    }

    *bufs->cur->buf.last |= b;

    return 0;
}

ssize_t nghttp2_bufs_remove(nghttp2_bufs *bufs, uint8_t **out)
{
    size_t len;
    nghttp2_buf_chain *chain;
    nghttp2_buf *buf;
    uint8_t *res;
    nghttp2_buf resbuf;

    len = 0;

    for (chain = bufs->head; chain; chain = chain->next) {
        len += nghttp2_buf_len(&chain->buf);
    }

    if (len == 0) {
        res = NULL;
        return 0;
    }

    res = nghttp2_mem_malloc(bufs->mem, len);
    if (res == NULL) {
        return NGHTTP2_ERR_NOMEM;
    }

    nghttp2_buf_wrap_init(&resbuf, res, len);

    for (chain = bufs->head; chain; chain = chain->next) {
        buf = &chain->buf;
        resbuf.last =
            nghttp2_cpymem(resbuf.last, buf->pos, nghttp2_buf_len(buf));
    }

    *out = res;

    return (ssize_t)len;
}

size_t nghttp2_bufs_remove_copy(nghttp2_bufs *bufs, uint8_t *out)
{
    size_t len;
    nghttp2_buf_chain *chain;
    nghttp2_buf *buf;
    nghttp2_buf resbuf;

    len = nghttp2_bufs_len(bufs);

    nghttp2_buf_wrap_init(&resbuf, out, len);

    for (chain = bufs->head; chain; chain = chain->next) {
        buf = &chain->buf;
        resbuf.last =
            nghttp2_cpymem(resbuf.last, buf->pos, nghttp2_buf_len(buf));
    }

    return len;
}

void nghttp2_bufs_reset(nghttp2_bufs *bufs)
{
    nghttp2_buf_chain *chain, *ci;
    size_t k;

    k = bufs->chunk_keep;

    for (ci = bufs->head; ci; ci = ci->next) {
        nghttp2_buf_reset(&ci->buf);
        nghttp2_buf_shift_right(&ci->buf, bufs->offset);

        if (--k == 0) {
            break;
        }
    }

    if (ci) {
        chain = ci->next;
        ci->next = NULL;

        for (ci = chain; ci;) {
            chain = ci->next;

            buf_chain_del(ci, bufs->mem);

            ci = chain;
        }

        bufs->chunk_used = bufs->chunk_keep;
    }

    bufs->cur = bufs->head;
}

int nghttp2_bufs_advance(nghttp2_bufs *bufs)
{
    return bufs_alloc_chain(bufs);
}

int nghttp2_bufs_next_present(nghttp2_bufs *bufs)
{
    nghttp2_buf_chain *chain;

    chain = bufs->cur->next;

    return chain && nghttp2_buf_len(&chain->buf);
}