X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/763d5e6ad88ef3ba1cd1d7742d060e4f1e54c6b8..4265e5d362914f3732b4035dcf67162e525e0142:/lib/sink.h

diff --git a/lib/sink.h b/lib/sink.h
index 291476e..5d09c18 100644
--- a/lib/sink.h
+++ b/lib/sink.h
@@ -1,33 +1,45 @@
 /*
  * This file is part of DisOrder
- * Copyright (C) 2004 Richard Kettlewell
+ * Copyright (C) 2004, 2007, 2008 Richard Kettlewell
  *
- * This program is free software; you can redistribute it and/or modify
+ * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
- * USA
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/** @file lib/sink.h
+ * @brief Abstract output sink type
  */
 
 #ifndef SINK_H
 #define SINK_H
 
-/* a sink is something you write to (the opposite would be a source) */
+#include <stdarg.h>
 
 struct dynstr;
 
+/** @brief Sink type
+ *
+ * A sink is something you write bytes to; the opposite would be a
+ * source.  We provide sink_stdio() and sink_dynstr() to create sinks
+ * to write to stdio streams and dynamic strings.
+ */
 struct sink {
+  /** @brief Write callback
+   * @param s Sink to write to
+   * @param buffer First byte to write
+   * @param nbytes Number of bytes to write
+   * @return non-negative on success, -1 on error
+   */
   int (*write)(struct sink *s, const void *buffer, int nbytes);
-  /* return >= 0 on success, -1 on error */
 };
 
 struct sink *sink_stdio(const char *name, FILE *fp);
@@ -38,19 +50,41 @@ struct sink *sink_stdio(const char *name, FILE *fp);
 struct sink *sink_dynstr(struct dynstr *output);
 /* return a sink which appends to @output@. */
 
+struct sink *sink_discard(void);
+/* return a sink which junks everything */
+
+struct sink *sink_error(void);
+/* return a sink which fails all writes */
+
 int sink_vprintf(struct sink *s, const char *fmt, va_list ap);
 int sink_printf(struct sink *s, const char *fmt, ...)
   attribute((format (printf, 2, 3)));
 /* equivalent of vfprintf/fprintf for sink @s@ */
 
+/** @brief Write bytes to a sink
+ * @param s Sink to write to
+ * @param buffer First byte to write
+ * @param nbytes Number of bytes to write
+ * @return non-negative on success, -1 on error
+ */
 static inline int sink_write(struct sink *s, const void *buffer, int nbytes) {
   return s->write(s, buffer, nbytes);
 }
 
+/** @brief Write string to a sink
+ * @param s Sink to write to
+ * @param str String to write
+ * @return non-negative on success, -1 on error
+ */
 static inline int sink_writes(struct sink *s, const char *str) {
   return s->write(s, str, strlen(str));
 }
 
+/** @brief Write one byte to a sink
+ * @param s Sink to write to
+ * @param c Byte to write (as a @c char)
+ * @return non-negative on success, -1 on error
+ */
 static inline int sink_writec(struct sink *s, char c) {
   return s->write(s, &c, 1);
 }