summaryrefslogtreecommitdiff
path: root/buckets/apr_buckets_mmap.c
blob: 19de291b5332d2258b98636fe5017e17406f52f5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#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) {
        /* the apr_mmap_t was already cleaned up out from under us */
        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 apr_mmap_t is about to disappear out from under us, so we
     * have no choice but to pretend it doesn't exist anymore.  the
     * refcount is now useless because there's nothing to refer to
     * anymore.  so the only valid action on any remaining referrer
     * is to delete it.  no more reads, no more anything. */
    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) {
            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;

    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 *b, apr_pool_t *p)
{
    apr_bucket_mmap *m = b->data;
    apr_mmap_t *mm = m->mmap;
    apr_mmap_t *new_mm;
    apr_status_t ok;

    if (!mm) {
        /* the apr_mmap_t was already cleaned up out from under us */
        return APR_EINVAL;
    }

    /* shortcut if possible */
    if (apr_pool_is_ancestor(mm->cntxt, p)) {
        return APR_SUCCESS;
    }

    /* duplicate apr_mmap_t into new pool */
    ok = apr_mmap_dup(&new_mm, mm, p);
    if (ok != APR_SUCCESS) {
        return ok;
    }

    /* decrement refcount on old apr_bucket_mmap */
    mmap_bucket_destroy(m);

    /* create new apr_bucket_mmap pointing to new apr_mmap_t */
    apr_bucket_mmap_make(b, new_mm, b->start, b->length);

    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