1/* ====================================================================
2 *    Licensed to the Apache Software Foundation (ASF) under one
3 *    or more contributor license agreements.  See the NOTICE file
4 *    distributed with this work for additional information
5 *    regarding copyright ownership.  The ASF licenses this file
6 *    to you under the Apache License, Version 2.0 (the
7 *    "License"); you may not use this file except in compliance
8 *    with the License.  You may obtain a copy of the License at
9 *
10 *      http://www.apache.org/licenses/LICENSE-2.0
11 *
12 *    Unless required by applicable law or agreed to in writing,
13 *    software distributed under the License is distributed on an
14 *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 *    KIND, either express or implied.  See the License for the
16 *    specific language governing permissions and limitations
17 *    under the License.
18 * ====================================================================
19 */
20
21#include <apr_pools.h>
22
23#include "serf.h"
24#include "serf_bucket_util.h"
25#include "serf_private.h"
26
27typedef struct {
28    serf_bucket_t *stream;
29    apr_uint64_t remaining;
30} limit_context_t;
31
32
33serf_bucket_t *serf_bucket_limit_create(
34    serf_bucket_t *stream, apr_uint64_t len, serf_bucket_alloc_t *allocator)
35{
36    limit_context_t *ctx;
37
38    ctx = serf_bucket_mem_alloc(allocator, sizeof(*ctx));
39    ctx->stream = stream;
40    ctx->remaining = len;
41
42    return serf_bucket_create(&serf_bucket_type_limit, allocator, ctx);
43}
44
45static apr_status_t serf_limit_read(serf_bucket_t *bucket,
46                                    apr_size_t requested,
47                                    const char **data, apr_size_t *len)
48{
49    limit_context_t *ctx = bucket->data;
50    apr_status_t status;
51
52    if (!ctx->remaining) {
53        *len = 0;
54        return APR_EOF;
55    }
56
57    if (requested == SERF_READ_ALL_AVAIL || requested > ctx->remaining) {
58        if (ctx->remaining <= REQUESTED_MAX) {
59            requested = (apr_size_t) ctx->remaining;
60        } else {
61            requested = REQUESTED_MAX;
62        }
63    }
64
65    status = serf_bucket_read(ctx->stream, requested, data, len);
66
67    if (!SERF_BUCKET_READ_ERROR(status)) {
68        ctx->remaining -= *len;
69    }
70
71    /* If we have met our limit and don't have a status, return EOF. */
72    if (!ctx->remaining && !status) {
73        status = APR_EOF;
74    }
75
76    return status;
77}
78
79static apr_status_t serf_limit_readline(serf_bucket_t *bucket,
80                                         int acceptable, int *found,
81                                         const char **data, apr_size_t *len)
82{
83    limit_context_t *ctx = bucket->data;
84    apr_status_t status;
85
86    if (!ctx->remaining) {
87        *len = 0;
88        return APR_EOF;
89    }
90
91    status = serf_bucket_readline(ctx->stream, acceptable, found, data, len);
92
93    if (!SERF_BUCKET_READ_ERROR(status)) {
94        ctx->remaining -= *len;
95    }
96
97    /* If we have met our limit and don't have a status, return EOF. */
98    if (!ctx->remaining && !status) {
99        status = APR_EOF;
100    }
101
102    return status;
103}
104
105static apr_status_t serf_limit_peek(serf_bucket_t *bucket,
106                                     const char **data,
107                                     apr_size_t *len)
108{
109    limit_context_t *ctx = bucket->data;
110
111    return serf_bucket_peek(ctx->stream, data, len);
112}
113
114static void serf_limit_destroy(serf_bucket_t *bucket)
115{
116    limit_context_t *ctx = bucket->data;
117
118    serf_bucket_destroy(ctx->stream);
119
120    serf_default_destroy_and_data(bucket);
121}
122
123const serf_bucket_type_t serf_bucket_type_limit = {
124    "LIMIT",
125    serf_limit_read,
126    serf_limit_readline,
127    serf_default_read_iovec,
128    serf_default_read_for_sendfile,
129    serf_default_read_bucket,
130    serf_limit_peek,
131    serf_limit_destroy,
132};
133