1/*	$NetBSD$	*/
2
3/*++
4/* NAME
5/*	rec_streamlf 3
6/* SUMMARY
7/*	record interface to stream-lf files
8/* SYNOPSIS
9/*	#include <rec_streamlf.h>
10/*
11/*	int	rec_streamlf_get(stream, buf, maxlen)
12/*	VSTREAM	*stream;
13/*	VSTRING	*buf;
14/*	int	maxlen;
15/*
16/*	int	rec_streamlf_put(stream, type, data, len)
17/*	VSTREAM	*stream;
18/*	int	type;
19/*	const char *data;
20/*	int	len;
21/* AUXILIARY FUNCTIONS
22/*	int	REC_STREAMLF_PUT_BUF(stream, type, buf)
23/*	VSTREAM	*stream;
24/*	int	type;
25/*	VSTRING	*buf;
26/* DESCRIPTION
27/*	This module implements record I/O on top of stream-lf files.
28/*
29/*	rec_streamlf_get() reads one record from the specified stream.
30/*	The result is null-terminated and may contain embedded null
31/*	characters.
32/*	The \fImaxlen\fR argument specifies an upper bound to the amount
33/*	of data read. The result is REC_TYPE_NORM when the record was
34/*	terminated by newline, REC_TYPE_CONT when no terminating newline
35/*	was found (the record was larger than \fImaxlen\fR characters or
36/*	EOF was reached), and REC_TYPE_EOF when no data could be read or
37/*	when an I/O error was detected.
38/*
39/*	rec_streamlf_put() writes one record to the named stream.
40/*	When the record type is REC_TYPE_NORM, a newline character is
41/*	appended to the output. The result is the record type, or
42/*	REC_TYPE_EOF in case of problems.
43/*
44/*	REC_STREAMLF_PUT_BUF() is a wrapper for rec_streamlf_put() that
45/*	makes it more convenient to output VSTRING buffers.
46/*	REC_STREAMLF_PUT_BUF() is an unsafe macro that evaluates some
47/*	arguments more than once.
48/* SEE ALSO
49/*	record(3) typed records
50/* LICENSE
51/* .ad
52/* .fi
53/*	The Secure Mailer license must be distributed with this software.
54/* AUTHOR(S)
55/*	Wietse Venema
56/*	IBM T.J. Watson Research
57/*	P.O. Box 704
58/*	Yorktown Heights, NY 10598, USA
59/*--*/
60
61/* System library. */
62
63#include <sys_defs.h>
64
65/* Utility library. */
66
67#include <vstring.h>
68#include <vstream.h>
69
70/* Global library. */
71
72#include <record.h>
73#include <rec_type.h>
74#include <rec_streamlf.h>
75
76/* rec_streamlf_get - read record from stream-lf file */
77
78int     rec_streamlf_get(VSTREAM *stream, VSTRING *buf, int maxlen)
79{
80    int     n = maxlen;
81    int     ch;
82
83    /*
84     * If this one character ar a time code proves to be a performance
85     * bottleneck, switch to block search (memchr()) and to block move
86     * (memcpy()) operations.
87     */
88    VSTRING_RESET(buf);
89    while (n-- > 0) {
90	if ((ch = VSTREAM_GETC(stream)) == VSTREAM_EOF)
91	    return (VSTRING_LEN(buf) > 0 ? REC_TYPE_CONT : REC_TYPE_EOF);
92	if (ch == '\n') {
93	    VSTRING_TERMINATE(buf);
94	    return (REC_TYPE_NORM);
95	}
96	VSTRING_ADDCH(buf, ch);
97    }
98    VSTRING_TERMINATE(buf);
99    return (REC_TYPE_CONT);
100}
101
102/* rec_streamlf_put - write record to stream-lf file */
103
104int     rec_streamlf_put(VSTREAM *stream, int type, const char *data, int len)
105{
106    if (len > 0)
107	(void) vstream_fwrite(stream, data, len);
108    if (type == REC_TYPE_NORM)
109	(void) VSTREAM_PUTC('\n', stream);
110    return (vstream_ferror(stream) ? REC_TYPE_EOF : type);
111}
112