contrib/subversion/subversion/libsvn_ra_serf/eagain_bucket.c

   1 /*
   2  * eagain_bucket.c :  a serf bucket that handles slowing down data
   3  *                   for specific readers that would have unwanted
   4  *                   behavior if they read everything too fast
   5  * ====================================================================
   6  *    Licensed to the Apache Software Foundation (ASF) under one
   7  *    or more contributor license agreements.  See the NOTICE file
   8  *    distributed with this work for additional information
   9  *    regarding copyright ownership.  The ASF licenses this file
  10  *    to you under the Apache License, Version 2.0 (the
  11  *    "License"); you may not use this file except in compliance
  12  *    with the License.  You may obtain a copy of the License at
  13  *
  14  *      http://www.apache.org/licenses/LICENSE-2.0
  15  *
  16  *    Unless required by applicable law or agreed to in writing,
  17  *    software distributed under the License is distributed on an
  18  *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  19  *    KIND, either express or implied.  See the License for the
  20  *    specific language governing permissions and limitations
  21  *    under the License.
  22  * ====================================================================
  23  */
  24
  25 #include <serf.h>
  26 #include <serf_bucket_util.h>
  27
  28 #include "svn_private_config.h"
  29
  30 #include "ra_serf.h"
  31
  32 typedef struct eagain_baton_t
  33 {
  34   const char *data;
  35   apr_size_t remaining;
  36 } eagain_baton_t;
  37
  38 static apr_status_t
  39 eagain_bucket_read(serf_bucket_t *bucket,
  40                    apr_size_t requested,
  41                    const char **data,
  42                    apr_size_t *len)
  43 {
  44   eagain_baton_t *eab = bucket->data;
  45
  46   if (eab->remaining > 0)
  47     {
  48       *data = eab->data;
  49       if (requested > eab->remaining || requested == SERF_READ_ALL_AVAIL)
  50         {
  51           *len = eab->remaining;
  52           eab->data = NULL;
  53           eab->remaining = 0;
  54         }
  55       else
  56         {
  57           *len = requested;
  58           eab->data += requested;
  59           eab->remaining -= requested;
  60         }
  61
  62       if (eab->remaining)
  63         return APR_SUCCESS;
  64     }
  65
  66   return APR_EAGAIN;
  67 }
  68
  69
  70 static apr_status_t
  71 eagain_bucket_readline(serf_bucket_t *bucket,
  72                        int acceptable,
  73                        int *found,
  74                        const char **data,
  75                        apr_size_t *len)
  76 {
  77   /* ### for now, we know callers won't use this function.  */
  78   svn_error_clear(svn_error__malfunction(TRUE, __FILE__, __LINE__,
  79                                          "Not implemented."));
  80   return APR_ENOTIMPL;
  81 }
  82
  83
  84 static apr_status_t
  85 eagain_bucket_peek(serf_bucket_t *bucket,
  86                    const char **data,
  87                    apr_size_t *len)
  88 {
  89   const eagain_baton_t *eab = bucket->data;
  90
  91   *data = eab->data ? eab->data : "";
  92   *len = eab->remaining;
  93
  94   return APR_SUCCESS;
  95 }
  96
  97
  98 static const serf_bucket_type_t delay_bucket_vtable = {
  99     "BUF-EAGAIN",
 100     eagain_bucket_read,
 101     eagain_bucket_readline,
 102     serf_default_read_iovec,
 103     serf_default_read_for_sendfile,
 104     serf_default_read_bucket,
 105     eagain_bucket_peek,
 106     serf_default_destroy_and_data,
 107 };
 108
 109
 110 serf_bucket_t *
 111 svn_ra_serf__create_bucket_with_eagain(const char *data,
 112                                        apr_size_t len,
 113                                        serf_bucket_alloc_t *allocator)
 114 {
 115   eagain_baton_t *eab;
 116
 117   eab = serf_bucket_mem_alloc(allocator, sizeof(*eab));
 118   eab->data = data;
 119   eab->remaining = len;
 120
 121   return serf_bucket_create(&delay_bucket_vtable, allocator, eab);
 122 }