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 * The Apache Software License, Version 1.1
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 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
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 *    if and wherever such third-party acknowledgments normally appear.
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 *
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 */

#include "apr_buckets.h"

#if APR_HAS_MMAP

static apr_status_t mmap_bucket_read(apr_bucket *b, const char **str, 
                                     apr_size_t *length, apr_read_type_e block)
{
    apr_bucket_mmap *m = b->data;
    apr_status_t ok;
    void *addr;
    
    if (!m->mmap) {
        /* due to cleanup issues we have no choice but to check this */
        return APR_EINVAL;
    }

    ok = apr_mmap_offset(&addr, m->mmap, b->start);
    if (ok != APR_SUCCESS) {
        return ok;
    }
    *str = addr;
    *length = b->length;
    return APR_SUCCESS;
}

static apr_status_t mmap_bucket_cleanup(void *data)
{
    /* the mmap has disappeared out from under us.  we have no choice
     * but to invalidate this bucket.  from now on, all you can do to this
     * bucket is destroy it, not read from it.
     */
    apr_bucket_mmap *m = data;

    m->mmap = NULL;
    return APR_SUCCESS;
}

static void mmap_bucket_destroy(void *data)
{
    apr_bucket_mmap *m = data;

    if (apr_bucket_shared_destroy(m)) {
        if (m->mmap && m->mmap->is_owner) {
            apr_pool_cleanup_kill(m->mmap->cntxt, m, mmap_bucket_cleanup);
            apr_mmap_delete(m->mmap);
        }
        apr_bucket_free(m);
    }
}

/*
 * XXX: are the start and length arguments useful?
 */
APU_DECLARE(apr_bucket *) apr_bucket_mmap_make(apr_bucket *b, apr_mmap_t *mm, 
                                               apr_off_t start, 
                                               apr_size_t length)
{
    apr_bucket_mmap *m;

    m = apr_bucket_alloc(sizeof(*m), b->list);
    m->mmap = mm;

    if (mm->is_owner) {
        apr_pool_cleanup_register(mm->cntxt, m, mmap_bucket_cleanup,
                                  apr_pool_cleanup_null);
    }

    b = apr_bucket_shared_make(b, m, start, length);
    b->type = &apr_bucket_type_mmap;

    return b;
}


APU_DECLARE(apr_bucket *) apr_bucket_mmap_create(apr_mmap_t *mm, 
                                                 apr_off_t start, 
                                                 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_mmap_make(b, mm, start, length);
}

static apr_status_t mmap_bucket_setaside(apr_bucket *data, apr_pool_t *p)
{
    apr_bucket_mmap *m = data->data;
    apr_mmap_t *mm = m->mmap;
    apr_mmap_t *new_mm;
    apr_status_t ok;

    if (!mm) {
        /* due to cleanup issues we have no choice but to check this */
        return APR_EINVAL;
    }

    if (apr_pool_is_ancestor(mm->cntxt, p)) {
        return APR_SUCCESS;
    }

    ok = apr_mmap_dup(&new_mm, mm, p, 1);
    if (ok != APR_SUCCESS) {
        return ok;
    }
    
    m->mmap = new_mm;
    if (new_mm->is_owner) {
        apr_pool_cleanup_kill(mm->cntxt, m, mmap_bucket_cleanup);
        apr_pool_cleanup_register(new_mm->cntxt, m, mmap_bucket_cleanup,
                                  apr_pool_cleanup_null);
    }

    return APR_SUCCESS;
}

APU_DECLARE_DATA const apr_bucket_type_t apr_bucket_type_mmap = {
    "MMAP", 5, APR_BUCKET_DATA,
    mmap_bucket_destroy,
    mmap_bucket_read,
    mmap_bucket_setaside,
    apr_bucket_shared_split,
    apr_bucket_shared_copy
};

#endif
