buckets/apr_buckets_simple.c

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

#include "apr_buckets.h"

APU_DECLARE_NONSTD(apr_status_t) apr_bucket_simple_copy(apr_bucket *a,
                                                        apr_bucket **b)
{
    *b = apr_bucket_alloc(sizeof(**b), a->list); /* XXX: check for failure? */
    **b = *a;

    return APR_SUCCESS;
}

APU_DECLARE_NONSTD(apr_status_t) apr_bucket_simple_split(apr_bucket *a,
                                                         apr_size_t point)
{
    apr_bucket *b;

    if (point > a->length) {
        return APR_EINVAL;
    }

    apr_bucket_simple_copy(a, &b);

    a->length  = point;
    b->length -= point;
    b->start  += point;

    APR_BUCKET_INSERT_AFTER(a, b);

    return APR_SUCCESS;
}

static apr_status_t simple_bucket_read(apr_bucket *b, const char **str, 
                                       apr_size_t *len, apr_read_type_e block)
{
    *str = (char *)b->data + b->start;
    *len = b->length;
    return APR_SUCCESS;
}

APU_DECLARE(apr_bucket *) apr_bucket_immortal_make(apr_bucket *b,
                                                   const char *buf,
                                                   apr_size_t length)
{
    b->data   = (char *)buf;
    b->length = length;
    b->start  = 0;
    b->type   = &apr_bucket_type_immortal;

    return b;
}

APU_DECLARE(apr_bucket *) apr_bucket_immortal_create(const char *buf,
                                                     apr_size_t length,
                                                     apr_bucket_alloc_t *list)
{
    apr_bucket *b = apr_bucket_alloc(sizeof(*b), list);

    APR_BUCKET_INIT(b);
    b->free = apr_bucket_free;
    b->list = list;
    return apr_bucket_immortal_make(b, buf, length);
}

/*
 * XXX: This function could do with some tweaking to reduce memory
 * usage in various cases, e.g. share buffers in the heap between all
 * the buckets that are set aside, or even spool set-aside data to
 * disk if it gets too voluminous (but if it does then that's probably
 * a bug elsewhere). There should probably be a apr_brigade_setaside()
 * function that co-ordinates the action of all the bucket setaside
 * functions to improve memory efficiency.
 */
static apr_status_t transient_bucket_setaside(apr_bucket *b, apr_pool_t *pool)
{
    b = apr_bucket_heap_make(b, (char *)b->data + b->start, b->length, NULL);
    if (b == NULL) {
        return APR_ENOMEM;
    }
    return APR_SUCCESS;
}

APU_DECLARE(apr_bucket *) apr_bucket_transient_make(apr_bucket *b,
                                                    const char *buf,
                                                    apr_size_t length)
{
    b->data   = (char *)buf;
    b->length = length;
    b->start  = 0;
    b->type   = &apr_bucket_type_transient;
    return b;
}

APU_DECLARE(apr_bucket *) apr_bucket_transient_create(const char *buf,
                                                      apr_size_t length,
                                                      apr_bucket_alloc_t *list)
{
    apr_bucket *b = apr_bucket_alloc(sizeof(*b), list);

    APR_BUCKET_INIT(b);
    b->free = apr_bucket_free;
    b->list = list;
    return apr_bucket_transient_make(b, buf, length);
}

const apr_bucket_type_t apr_bucket_type_immortal = {
    "IMMORTAL", 5, APR_BUCKET_DATA,
    apr_bucket_destroy_noop,
    simple_bucket_read,
    apr_bucket_setaside_noop,
    apr_bucket_simple_split,
    apr_bucket_simple_copy
};

APU_DECLARE_DATA const apr_bucket_type_t apr_bucket_type_transient = {
    "TRANSIENT", 5, APR_BUCKET_DATA,
    apr_bucket_destroy_noop, 
    simple_bucket_read,
    transient_bucket_setaside,
    apr_bucket_simple_split,
    apr_bucket_simple_copy
};