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 3 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,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU 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, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/sink.c
  19  * @brief Abstract output sink type
  20  */
  21
  22 #include "common.h"
  23
  24 #include <stdarg.h>
  25 #include <errno.h>
  26
  27 #include "mem.h"
  28 #include "vector.h"
  29 #include "sink.h"
  30 #include "log.h"
  31 #include "printf.h"
  32
  33 /** @brief Formatted output to a sink
  34  * @param s Sink to write to
  35  * @param fmt Format string
  36  * @param ap Argument list
  37  * @return Number of bytes written on success, -1 on error
  38  */
  39 int sink_vprintf(struct sink *s, const char *fmt, va_list ap) {
  40   return byte_vsinkprintf(s, fmt, ap);
  41 }
  42
  43 /** @brief Formatted output to a sink
  44  * @param s Sink to write to
  45  * @param fmt Format string
  46  * @return Number of bytes written on success, -1 on error
  47  */
  48 int sink_printf(struct sink *s, const char *fmt, ...) {
  49   va_list ap;
  50   int n;
  51
  52   va_start(ap, fmt);
  53   n = byte_vsinkprintf(s, fmt, ap);
  54   va_end(ap);
  55   return n;
  56 }
  57
  58 /* stdio sink *****************************************************************/
  59
  60 /** @brief Sink that writes to a stdio @c FILE */
  61 struct stdio_sink {
  62   /** @brief Base member */
  63   struct sink s;
  64
  65   /** @brief Filename */
  66   const char *name;
  67
  68   /** @brief Stream to write to */
  69   FILE *fp;
  70 };
  71
  72 /** @brief Reinterpret a @ref sink as a @ref stdio_sink */
  73 #define S(s) ((struct stdio_sink *)s)
  74
  75 /** @brief Write callback for @ref stdio_sink */
  76 static int sink_stdio_write(struct sink *s, const void *buffer, int nbytes) {
  77   int n = fwrite(buffer, 1, nbytes, S(s)->fp);
  78   if(n < nbytes) {
  79     if(S(s)->name)
  80       disorder_fatal(errno, "error writing to %s", S(s)->name);
  81     else
  82       return -1;
  83   }
  84   return n;
  85 }
  86
  87 /** @brief Create a sink that writes to a stdio stream
  88  * @param name Filename for use in error messages
  89  * @param fp Stream to write to
  90  * @return Pointer to new sink
  91  */
  92 struct sink *sink_stdio(const char *name, FILE *fp) {
  93   struct stdio_sink *s = xmalloc(sizeof *s);
  94
  95   s->s.write = sink_stdio_write;
  96   s->name = name;
  97   s->fp = fp;
  98   return (struct sink *)s;
  99 }
 100
 101 /* dynstr sink ****************************************************************/
 102
 103 /** @brief Sink that writes to a dynamic string */
 104 struct dynstr_sink {
 105   /** @brief Base member */
 106   struct sink s;
 107   /** @brief Pointer to dynamic string to append to */
 108   struct dynstr *d;
 109 };
 110
 111 /** @brief Write callback for @ref dynstr_sink */
 112 static int sink_dynstr_write(struct sink *s, const void *buffer, int nbytes) {
 113   dynstr_append_bytes(((struct dynstr_sink *)s)->d, buffer, nbytes);
 114   return nbytes;
 115 }
 116
 117 /** @brief Create a sink that appends to a @ref dynstr
 118  * @param output Dynamic string to append to
 119  * @return Pointer to new sink
 120  */
 121 struct sink *sink_dynstr(struct dynstr *output) {
 122   struct dynstr_sink *s = xmalloc(sizeof *s);
 123
 124   s->s.write = sink_dynstr_write;
 125   s->d = output;
 126   return (struct sink *)s;
 127 }
 128
 129 /* discard sink **************************************************************/
 130
 131 static int sink_discard_write(struct sink attribute((unused)) *s,
 132                               const void attribute((unused)) *buffer,
 133                               int nbytes) {
 134   return nbytes;
 135 }
 136
 137 /** @brief Return a sink which discards all output */
 138 struct sink *sink_discard(void) {
 139   struct sink *s = xmalloc(sizeof *s);
 140
 141   s->write = sink_discard_write;
 142   return s;
 143 }
 144
 145 /* error sink **************************************************************/
 146
 147 static int sink_error_write(struct sink attribute((unused)) *s,
 148                             const void attribute((unused)) *buffer,
 149                             int attribute((unused)) nbytes) {
 150   return -1;
 151 }
 152
 153 /** @brief Return a sink which discards all output */
 154 struct sink *sink_error(void) {
 155   struct sink *s = xmalloc(sizeof *s);
 156
 157   s->write = sink_error_write;
 158   return s;
 159 }
 160
 161 /*
 162 Local Variables:
 163 c-basic-offset:2
 164 comment-column:40
 165 End:
 166 */