src/common/portio.c

#ifndef lint
static const char       RCSid[] = "$Id: portio.c,v 2.15 2012/10/19 01:40:33 greg Exp $";
#endif
/*
 * Portable i/o for binary files
 *
 * External symbols declared in rtio.h
 */

#include "copyright.h"

#include "rtio.h"

#include <math.h>

#ifdef getc_unlocked            /* avoid horrendous overhead of flockfile */
#undef getc
#undef putc
#define getc    getc_unlocked
#define putc    putc_unlocked
#endif


void
putstr(                         /* write null-terminated string to fp */
        char  *s,
        FILE  *fp
)
{
        do
                putc(*s, fp);
        while (*s++);
}


void
putint(                         /* write a siz-byte integer to fp */
        long  i,
        int  siz,
        FILE  *fp
)
{
        while (siz--)
                putc((int)(i>>(siz<<3) & 0xff), fp);
}


void
putflt(                         /* put out floating point number */
        double  f,
        FILE  *fp
)
{
        long  m;
        int  e;

        m = frexp(f, &e) * 0x7fffffff;
        if (e > 127) {                  /* overflow */
                m = m > 0 ? (long)0x7fffffff : -(long)0x7fffffff;
                e = 127;
        } else if (e < -128) {          /* underflow */
                m = 0;
                e = 0;
        }
        putint(m, 4, fp);
        putint((long)e, 1, fp);
}


int
putbinary(                      /* fwrite() replacement for small objects */
        char *s,
        int elsiz,
        int nel,
        FILE *fp)
{
        int     nbytes = elsiz*nel;

        if (nbytes > 512)
                return(fwrite(s, elsiz, nel, fp));
        
        while (nbytes-- > 0)
                putc(*s++, fp);

        return(nel);
}


char *
getstr(                         /* get null-terminated string */
        char  *s,
        FILE  *fp
)
{
        char  *cp;
        int  c;

        cp = s;
        while ((c = getc(fp)) != EOF)
                if ((*cp++ = c) == '\0')
                        return(s);
                
        return(NULL);
}


long
getint(                         /* get a siz-byte integer */
        int  siz,
        FILE  *fp
)
{
        int  c;
        long  r;

        if ((c = getc(fp)) == EOF)
                return(EOF);
        r = 0x80&c ? -1<<8|c : c;               /* sign extend */
        while (--siz > 0) {
                if ((c = getc(fp)) == EOF)
                        return(EOF);
                r <<= 8;
                r |= c;
        }
        return(r);
}


double
getflt(                         /* get a floating point number */
        FILE  *fp
)
{
        long    l;
        double  d;

        l = getint(4, fp);
        if (l == EOF && feof(fp))       /* EOF? */
                return((double)EOF);
        if (l == 0) {
                getc(fp);               /* exactly zero -- ignore exponent */
                return(0.0);
        }
        d = (l + (l > 0 ? .5 : -.5)) * (1./0x7fffffff);
        return(ldexp(d, (int)getint(1, fp)));
}


int
getbinary(                      /* fread() replacement for small objects */
        char *s,
        int elsiz,
        int nel,
        FILE *fp)
{
        int     nbytes = elsiz*nel;
        int     c;

        if (nbytes > 512)
                return(fread(s, elsiz, nel, fp));
        
        while (nbytes-- > 0) {
                if ((c = getc(fp)) == EOF)
                        return((elsiz*nel - nbytes)/elsiz);
                *s++ = c;
        }
        return(nel);
}
Revision:	2.16
Committed:	Thu Mar 3 22:06:18 2016 UTC (8 years, 3 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.15:	+42 -1 lines
Log Message:	Added fread() and fwrite() replacements
#	User	Rev	Content
1	greg	2.1	#ifndef lint
2	greg	2.16	static const char RCSid[] = "$Id: portio.c,v 2.15 2012/10/19 01:40:33 greg Exp $";
3	greg	2.1	#endif
4			/*
5			* Portable i/o for binary files
6	greg	2.6	*
7	greg	2.14	* External symbols declared in rtio.h
8	greg	2.6	*/
9
10	greg	2.7	#include "copyright.h"
11	greg	2.1
12	schorsch	2.8	#include "rtio.h"
13	greg	2.1
14	greg	2.9	#include <math.h>
15	greg	2.10
16			#ifdef getc_unlocked /* avoid horrendous overhead of flockfile */
17	greg	2.11	#undef getc
18			#undef putc
19	greg	2.10	#define getc getc_unlocked
20			#define putc putc_unlocked
21			#endif
22	greg	2.1
23	greg	2.3
24	greg	2.6	void
25	greg	2.15	putstr( /* write null-terminated string to fp */
26			char *s,
27			FILE *fp
28			)
29	greg	2.1	{
30			do
31			putc(*s, fp);
32			while (*s++);
33			}
34
35
36	greg	2.6	void
37	greg	2.15	putint( /* write a siz-byte integer to fp */
38			long i,
39			int siz,
40			FILE *fp
41			)
42	greg	2.1	{
43			while (siz--)
44	greg	2.2	putc((int)(i>>(siz<<3) & 0xff), fp);
45	greg	2.1	}
46
47
48	greg	2.6	void
49	greg	2.15	putflt( /* put out floating point number */
50			double f,
51			FILE *fp
52			)
53	greg	2.1	{
54	greg	2.13	long m;
55	greg	2.1	int e;
56
57	greg	2.13	m = frexp(f, &e) * 0x7fffffff;
58			if (e > 127) { /* overflow */
59			m = m > 0 ? (long)0x7fffffff : -(long)0x7fffffff;
60			e = 127;
61			} else if (e < -128) { /* underflow */
62			m = 0;
63			e = 0;
64			}
65			putint(m, 4, fp);
66	greg	2.1	putint((long)e, 1, fp);
67			}
68
69
70	greg	2.16	int
71			putbinary( /* fwrite() replacement for small objects */
72			char *s,
73			int elsiz,
74			int nel,
75			FILE *fp)
76			{
77			int nbytes = elsiz*nel;
78
79			if (nbytes > 512)
80			return(fwrite(s, elsiz, nel, fp));
81
82			while (nbytes-- > 0)
83			putc(*s++, fp);
84
85			return(nel);
86			}
87
88
89	greg	2.1	char *
90	greg	2.15	getstr( /* get null-terminated string */
91			char *s,
92			FILE *fp
93			)
94	greg	2.1	{
95	greg	2.15	char *cp;
96			int c;
97	greg	2.1
98			cp = s;
99			while ((c = getc(fp)) != EOF)
100			if ((*cp++ = c) == '\0')
101			return(s);
102
103			return(NULL);
104			}
105
106
107			long
108	greg	2.15	getint( /* get a siz-byte integer */
109			int siz,
110			FILE *fp
111			)
112	greg	2.1	{
113	greg	2.15	int c;
114			long r;
115	greg	2.1
116			if ((c = getc(fp)) == EOF)
117			return(EOF);
118			r = 0x80&c ? -1<<8\|c : c; /* sign extend */
119			while (--siz > 0) {
120			if ((c = getc(fp)) == EOF)
121			return(EOF);
122			r <<= 8;
123			r \|= c;
124			}
125			return(r);
126			}
127
128
129			double
130	greg	2.15	getflt( /* get a floating point number */
131			FILE *fp
132			)
133	greg	2.1	{
134	greg	2.5	long l;
135	greg	2.2	double d;
136	greg	2.1
137	greg	2.5	l = getint(4, fp);
138	greg	2.15	if (l == EOF && feof(fp)) /* EOF? */
139			return((double)EOF);
140	greg	2.12	if (l == 0) {
141			getc(fp); /* exactly zero -- ignore exponent */
142			return(0.0);
143			}
144	greg	2.5	d = (l + (l > 0 ? .5 : -.5)) * (1./0x7fffffff);
145	greg	2.1	return(ldexp(d, (int)getint(1, fp)));
146			}
147	greg	2.16
148
149			int
150			getbinary( /* fread() replacement for small objects */
151			char *s,
152			int elsiz,
153			int nel,
154			FILE *fp)
155			{
156			int nbytes = elsiz*nel;
157			int c;
158
159			if (nbytes > 512)
160			return(fread(s, elsiz, nel, fp));
161
162			while (nbytes-- > 0) {
163			if ((c = getc(fp)) == EOF)
164			return((elsiz*nel - nbytes)/elsiz);
165			*s++ = c;
166			}
167			return(nel);
168			}