buckets/apr_buckets_heap.c

/* ====================================================================
 * The Apache Software License, Version 1.1
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 * Copyright (c) 2000 The Apache Software Foundation.  All rights
 * reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *       "This product includes software developed by the
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 */

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

/*
 * The size of heap bucket memory allocations.
 * XXX: This is currently a guess and should be adjusted to an
 * empirically good value.
 */
#ifndef DEFAULT_BUCKET_SIZE
#define DEFAULT_BUCKET_SIZE (4096)
#endif

static apr_status_t heap_read(ap_bucket *b, const char **str, 
			      apr_size_t *len, ap_read_type block)
{
    ap_bucket_shared *s = b->data;
    ap_bucket_heap *h = s->data;

    *str = h->base + s->start;
    *len = s->end - s->start;
    return APR_SUCCESS;
}

static void heap_destroy(void *data)
{
    ap_bucket_heap *h;

    h = ap_bucket_destroy_shared(data);
    if (h == NULL) {
	return;
    }
    free(h->base);
    free(h);
}

APR_DECLARE(ap_bucket *) ap_bucket_make_heap(ap_bucket *b,
		const char *buf, apr_size_t length, int copy, apr_size_t *w)
{
    ap_bucket_heap *h;

    h = malloc(sizeof(*h));
    if (h == NULL) {
	return NULL;
    }

    if (copy) {
	h->base = malloc(DEFAULT_BUCKET_SIZE);
	if (h->base == NULL) {
	    free(h);
	    return NULL;
	}
	h->alloc_len = DEFAULT_BUCKET_SIZE;
	if (length > DEFAULT_BUCKET_SIZE) {
	    length = DEFAULT_BUCKET_SIZE;
	}
	memcpy(h->base, buf, length);
    }
    else {
	/* XXX: we lose the const qualifier here which indicates
         * there's something screwy with the API...
	 */
	h->base = (char *) buf;
	h->alloc_len = length;
    }

    b = ap_bucket_make_shared(b, h, 0, length);
    if (b == NULL) {
	if (copy) {
	    free(h->base);
	}
	free(h);
	return NULL;
    }

    b->type = &ap_heap_type;

    if (w)
        *w = length;

    return b;
}

APR_DECLARE(ap_bucket *) ap_bucket_create_heap(
		const char *buf, apr_size_t length, int copy, apr_size_t *w)
{
    ap_bucket_do_create(ap_bucket_make_heap(b, buf, length, copy, w));
}

APR_DECLARE_DATA const ap_bucket_type ap_heap_type = {
    "HEAP", 5,
    heap_destroy,
    heap_read,
    ap_bucket_setaside_notimpl,
    ap_bucket_split_shared,
    ap_bucket_copy_shared
};