buckets/apr_buckets_simple.c

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 */

#include "apr_buckets.h"
#include <stdlib.h>

APU_DECLARE_NONSTD(apr_status_t) apr_bucket_simple_copy(apr_bucket *a,
                                                        apr_bucket **b)
{
    if ((*b = malloc(sizeof(**b))) == NULL) {
	return APR_ENOMEM;
    }
    **b = *a;

    return APR_SUCCESS;
}

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

    if (point < 0 || point > a->length) {
	return APR_EINVAL;
    }

    rv = apr_bucket_simple_copy(a, &b);
    if (rv != APR_SUCCESS) {
        return rv;
    }

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

    APR_BUCKET_INSERT_AFTER(a, b);

    return APR_SUCCESS;
}

static apr_status_t simple_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_do_create(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_setaside(apr_bucket *b)
{
    b = apr_bucket_heap_make(b, (char *)b->data + b->start, b->length, 1, 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_do_create(apr_bucket_transient_make(b, buf, length));
}

const apr_bucket_type_t apr_bucket_type_immortal = {
    "IMMORTAL", 5,
    apr_bucket_destroy_notimpl,
    simple_read,
    apr_bucket_setaside_notimpl,
    apr_bucket_simple_split,
    apr_bucket_simple_copy
};

APU_DECLARE_DATA const apr_bucket_type_t apr_bucket_type_transient = {
    "TRANSIENT", 5,
    apr_bucket_destroy_notimpl, 
    simple_read,
    transient_setaside,
    apr_bucket_simple_split,
    apr_bucket_simple_copy
};