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

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2004, 2007, 2008, 2013 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.h
  19  * @brief Abstract output sink type
  20  */
  21
  22 #ifndef SINK_H
  23 #define SINK_H
  24
  25 #include <stdarg.h>
  26
  27 struct dynstr;
  28 struct socketio;
  29
  30 /** @brief Sink type
  31  *
  32  * A sink is something you write bytes to; the opposite would be a
  33  * source.  We provide sink_stdio() and sink_dynstr() to create sinks
  34  * to write to stdio streams and dynamic strings.
  35  */
  36 struct sink {
  37   /** @brief Write callback
  38    * @param s Sink to write to
  39    * @param buffer First byte to write
  40    * @param nbytes Number of bytes to write
  41    * @return non-negative on success, -1 on error
  42    */
  43   int (*write)(struct sink *s, const void *buffer, int nbytes);
  44
  45   /** @brief Flush callback
  46    * @param s Sink to write to
  47    * @return non-negative on success, -1 on error
  48    */
  49   int (*flush)(struct sink *s);
  50
  51   /** @brief Error callback
  52    * @param s Sink
  53    * @return Last error code
  54    */
  55   int (*error)(struct sink *s);
  56
  57   enum error_class eclass;
  58 };
  59
  60 struct sink *sink_stdio(const char *name, FILE *fp);
  61 /* return a sink which writes to @fp@.  If @name@ is not a null
  62  * pointer, it will be used in (fatal) error messages; if it is a null
  63  * pointer then errors will be signalled by returning -1. */
  64
  65 struct sink *sink_dynstr(struct dynstr *output);
  66 /* return a sink which appends to @output@. */
  67
  68 struct sink *sink_discard(void);
  69 /* return a sink which junks everything */
  70
  71 struct sink *sink_error(void);
  72 /* return a sink which fails all writes */
  73
  74 struct sink *sink_socketio(struct socketio *sio);
  75 /* return a sink which writes to a socket */
  76
  77 int sink_vprintf(struct sink *s, const char *fmt, va_list ap);
  78 int sink_printf(struct sink *s, const char *fmt, ...)
  79   attribute((format (printf, 2, 3)));
  80 /* equivalent of vfprintf/fprintf for sink @s@ */
  81
  82 /** @brief Write bytes to a sink
  83  * @param s Sink to write to
  84  * @param buffer First byte to write
  85  * @param nbytes Number of bytes to write
  86  * @return non-negative on success, -1 on error
  87  */
  88 static inline int sink_write(struct sink *s, const void *buffer, int nbytes) {
  89   return s->write(s, buffer, nbytes);
  90 }
  91
  92 /** @brief Write string to a sink
  93  * @param s Sink to write to
  94  * @param str String to write
  95  * @return non-negative on success, -1 on error
  96  */
  97 static inline int sink_writes(struct sink *s, const char *str) {
  98   return s->write(s, str, strlen(str));
  99 }
 100
 101 static inline int sink_flush(struct sink *s) {
 102   return s->flush(s);
 103 }
 104
 105 /** @brief Write one byte to a sink
 106  * @param s Sink to write to
 107  * @param c Byte to write (as a @c char)
 108  * @return non-negative on success, -1 on error
 109  */
 110 static inline int sink_writec(struct sink *s, char c) {
 111   return s->write(s, &c, 1);
 112 }
 113
 114 static inline int sink_err(struct sink *s) {
 115   return s->error(s);
 116 }
 117
 118 struct source {
 119   int (*getch)(struct source *s);
 120   int (*error)(struct source *s);
 121   int (*eof)(struct source *s);
 122
 123   enum error_class eclass;
 124 };
 125
 126 struct source *source_stdio(FILE *fp);
 127 struct source *source_socketio(struct socketio *sio);
 128
 129 static inline int source_getc(struct source *s) {
 130   return s->getch(s);
 131 }
 132
 133 static inline int source_err(struct source *s) {
 134   return s->error(s);
 135 }
 136
 137 static inline int source_eof(struct source *s) {
 138   return s->eof(s);
 139 }
 140
 141 #endif /* SINK_H */
 142
 143 /*
 144 Local Variables:
 145 c-basic-offset:2
 146 comment-column:40
 147 End:
 148 */