mdw@git.distorted.org.uk Git - disorder/blob - lib/sink.c

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2004, 2007, 2008 Richard Kettlewell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 /** @file lib/sink.c
  21  * @brief Abstract output sink type
  22  */
  23
  24 #include "common.h"
  25
  26 #include <stdarg.h>
  27 #include <errno.h>
  28
  29 #include "mem.h"
  30 #include "vector.h"
  31 #include "sink.h"
  32 #include "log.h"
  33 #include "printf.h"
  34
  35 /** @brief Formatted output to a sink
  36  * @param s Sink to write to
  37  * @param fmt Format string
  38  * @param ap Argument list
  39  * @return Number of bytes written on success, -1 on error
  40  */
  41 int sink_vprintf(struct sink *s, const char *fmt, va_list ap) {
  42   return byte_vsinkprintf(s, fmt, ap);
  43 }
  44
  45 /** @brief Formatted output to a sink
  46  * @param s Sink to write to
  47  * @param fmt Format string
  48  * @return Number of bytes written on success, -1 on error
  49  */
  50 int sink_printf(struct sink *s, const char *fmt, ...) {
  51   va_list ap;
  52   int n;
  53
  54   va_start(ap, fmt);
  55   n = byte_vsinkprintf(s, fmt, ap);
  56   va_end(ap);
  57   return n;
  58 }
  59
  60 /* stdio sink *****************************************************************/
  61
  62 /** @brief Sink that writes to a stdio @c FILE */
  63 struct stdio_sink {
  64   /** @brief Base member */
  65   struct sink s;
  66
  67   /** @brief Filename */
  68   const char *name;
  69
  70   /** @brief Stream to write to */
  71   FILE *fp;
  72 };
  73
  74 /** @brief Reinterpret a @ref sink as a @ref stdio_sink */
  75 #define S(s) ((struct stdio_sink *)s)
  76
  77 /** @brief Write callback for @ref stdio_sink */
  78 static int sink_stdio_write(struct sink *s, const void *buffer, int nbytes) {
  79   int n = fwrite(buffer, 1, nbytes, S(s)->fp);
  80   if(n < nbytes) {
  81     if(S(s)->name)
  82       fatal(errno, "error writing to %s", S(s)->name);
  83     else
  84       return -1;
  85   }
  86   return n;
  87 }
  88
  89 /** @brief Create a sink that writes to a stdio stream
  90  * @param name Filename for use in error messages
  91  * @param fp Stream to write to
  92  * @return Pointer to new sink
  93  */
  94 struct sink *sink_stdio(const char *name, FILE *fp) {
  95   struct stdio_sink *s = xmalloc(sizeof *s);
  96
  97   s->s.write = sink_stdio_write;
  98   s->name = name;
  99   s->fp = fp;
 100   return (struct sink *)s;
 101 }
 102
 103 /* dynstr sink ****************************************************************/
 104
 105 /** @brief Sink that writes to a dynamic string */
 106 struct dynstr_sink {
 107   /** @brief Base member */
 108   struct sink s;
 109   /** @brief Pointer to dynamic string to append to */
 110   struct dynstr *d;
 111 };
 112
 113 /** @brief Write callback for @ref dynstr_sink */
 114 static int sink_dynstr_write(struct sink *s, const void *buffer, int nbytes) {
 115   dynstr_append_bytes(((struct dynstr_sink *)s)->d, buffer, nbytes);
 116   return nbytes;
 117 }
 118
 119 /** @brief Create a sink that appends to a @ref dynstr
 120  * @param output Dynamic string to append to
 121  * @return Pointer to new sink
 122  */
 123 struct sink *sink_dynstr(struct dynstr *output) {
 124   struct dynstr_sink *s = xmalloc(sizeof *s);
 125
 126   s->s.write = sink_dynstr_write;
 127   s->d = output;
 128   return (struct sink *)s;
 129 }
 130
 131 /* discard sink **************************************************************/
 132
 133 static int sink_discard_write(struct sink attribute((unused)) *s,
 134                               const void attribute((unused)) *buffer,
 135                               int nbytes) {
 136   return nbytes;
 137 }
 138
 139 /** @brief Return a sink which discards all output */
 140 struct sink *sink_discard(void) {
 141   struct sink *s = xmalloc(sizeof *s);
 142
 143   s->write = sink_discard_write;
 144   return s;
 145 }
 146
 147 /* error sink **************************************************************/
 148
 149 static int sink_error_write(struct sink attribute((unused)) *s,
 150                             const void attribute((unused)) *buffer,
 151                             int attribute((unused)) nbytes) {
 152   return -1;
 153 }
 154
 155 /** @brief Return a sink which discards all output */
 156 struct sink *sink_error(void) {
 157   struct sink *s = xmalloc(sizeof *s);
 158
 159   s->write = sink_error_write;
 160   return s;
 161 }
 162
 163 /*
 164 Local Variables:
 165 c-basic-offset:2
 166 comment-column:40
 167 End:
 168 */