e2sim/ASN1c/asn_internal.c

   1 /*****************************************************************************
   2 #                                                                            *
   3 # Copyright 2019 AT&T Intellectual Property                                  *
   4 #                                                                            *
   5 # Licensed under the Apache License, Version 2.0 (the "License");            *
   6 # you may not use this file except in compliance with the License.           *
   7 # You may obtain a copy of the License at                                    *
   8 #                                                                            *
   9 #      http://www.apache.org/licenses/LICENSE-2.0                            *
  10 #                                                                            *
  11 # Unless required by applicable law or agreed to in writing, software        *
  12 # distributed under the License is distributed on an "AS IS" BASIS,          *
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   *
  14 # See the License for the specific language governing permissions and        *
  15 # limitations under the License.                                             *
  16 #                                                                            *
  17 ******************************************************************************/
  18
  19 #include <asn_internal.h>
  20
  21 ssize_t
  22 asn__format_to_callback(int (*cb)(const void *, size_t, void *key), void *key,
  23                         const char *fmt, ...) {
  24     char scratch[64];
  25     char *buf = scratch;
  26     size_t buf_size = sizeof(scratch);
  27     int wrote;
  28     int cb_ret;
  29
  30     do {
  31         va_list args;
  32         va_start(args, fmt);
  33
  34         wrote = vsnprintf(buf, buf_size, fmt, args);
  35         if(wrote < (ssize_t)buf_size) {
  36             if(wrote < 0) {
  37                 if(buf != scratch) FREEMEM(buf);
  38                 va_end(args);
  39                 return -1;
  40             }
  41             break;
  42         }
  43
  44         buf_size <<= 1;
  45         if(buf == scratch) {
  46             buf = MALLOC(buf_size);
  47             if(!buf) return -1;
  48         } else {
  49             void *p = REALLOC(buf, buf_size);
  50             if(!p) {
  51                 FREEMEM(buf);
  52                 return -1;
  53             }
  54             buf = p;
  55         }
  56     } while(1);
  57
  58     cb_ret = cb(buf, wrote, key);
  59     if(buf != scratch) FREEMEM(buf);
  60     if(cb_ret < 0) {
  61         return -1;
  62     }
  63
  64     return wrote;
  65 }
  66