src/common/portio.c

#ifndef lint
static const char       RCSid[] = "$Id: portio.c,v 2.17 2016/03/03 22:09:59 greg Exp $";
#endif
/*
 * Portable i/o for binary files
 *
 * External symbols declared in rtio.h
 */

#include "copyright.h"

#include "rtio.h"

#include <math.h>


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
)
{
        siz <<= 3;
        while ((siz -= 8) >= 0)
                putc((int)(i>>siz & 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:	2.18
Committed:	Tue Mar 15 13:57:09 2016 UTC (8 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.17:	+4 -3 lines
Log Message:	Minor optimization should not affect behavior
#	User	Rev	Content
1	greg	2.1	#ifndef lint
2	greg	2.18	static const char RCSid[] = "$Id: portio.c,v 2.17 2016/03/03 22:09:59 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	greg	2.3
17	greg	2.6	void
18	greg	2.15	putstr( /* write null-terminated string to fp */
19			char *s,
20			FILE *fp
21			)
22	greg	2.1	{
23			do
24			putc(*s, fp);
25			while (*s++);
26			}
27
28
29	greg	2.6	void
30	greg	2.15	putint( /* write a siz-byte integer to fp */
31			long i,
32			int siz,
33			FILE *fp
34			)
35	greg	2.1	{
36	greg	2.18	siz <<= 3;
37			while ((siz -= 8) >= 0)
38			putc((int)(i>>siz & 0xff), fp);
39	greg	2.1	}
40
41
42	greg	2.6	void
43	greg	2.15	putflt( /* put out floating point number */
44			double f,
45			FILE *fp
46			)
47	greg	2.1	{
48	greg	2.13	long m;
49	greg	2.1	int e;
50
51	greg	2.13	m = frexp(f, &e) * 0x7fffffff;
52			if (e > 127) { /* overflow */
53			m = m > 0 ? (long)0x7fffffff : -(long)0x7fffffff;
54			e = 127;
55			} else if (e < -128) { /* underflow */
56			m = 0;
57			e = 0;
58			}
59			putint(m, 4, fp);
60	greg	2.1	putint((long)e, 1, fp);
61			}
62
63
64	greg	2.16	int
65			putbinary( /* fwrite() replacement for small objects */
66			char *s,
67			int elsiz,
68			int nel,
69			FILE *fp)
70			{
71			int nbytes = elsiz*nel;
72
73			if (nbytes > 512)
74			return(fwrite(s, elsiz, nel, fp));
75
76			while (nbytes-- > 0)
77			putc(*s++, fp);
78
79			return(nel);
80			}
81
82
83	greg	2.1	char *
84	greg	2.15	getstr( /* get null-terminated string */
85			char *s,
86			FILE *fp
87			)
88	greg	2.1	{
89	greg	2.15	char *cp;
90			int c;
91	greg	2.1
92			cp = s;
93			while ((c = getc(fp)) != EOF)
94			if ((*cp++ = c) == '\0')
95			return(s);
96
97			return(NULL);
98			}
99
100
101			long
102	greg	2.15	getint( /* get a siz-byte integer */
103			int siz,
104			FILE *fp
105			)
106	greg	2.1	{
107	greg	2.15	int c;
108			long r;
109	greg	2.1
110			if ((c = getc(fp)) == EOF)
111			return(EOF);
112			r = 0x80&c ? -1<<8\|c : c; /* sign extend */
113			while (--siz > 0) {
114			if ((c = getc(fp)) == EOF)
115			return(EOF);
116			r <<= 8;
117			r \|= c;
118			}
119			return(r);
120			}
121
122
123			double
124	greg	2.15	getflt( /* get a floating point number */
125			FILE *fp
126			)
127	greg	2.1	{
128	greg	2.5	long l;
129	greg	2.2	double d;
130	greg	2.1
131	greg	2.5	l = getint(4, fp);
132	greg	2.15	if (l == EOF && feof(fp)) /* EOF? */
133			return((double)EOF);
134	greg	2.12	if (l == 0) {
135			getc(fp); /* exactly zero -- ignore exponent */
136			return(0.0);
137			}
138	greg	2.5	d = (l + (l > 0 ? .5 : -.5)) * (1./0x7fffffff);
139	greg	2.1	return(ldexp(d, (int)getint(1, fp)));
140			}
141	greg	2.16
142
143			int
144			getbinary( /* fread() replacement for small objects */
145			char *s,
146			int elsiz,
147			int nel,
148			FILE *fp)
149			{
150			int nbytes = elsiz*nel;
151			int c;
152
153			if (nbytes > 512)
154			return(fread(s, elsiz, nel, fp));
155
156			while (nbytes-- > 0) {
157			if ((c = getc(fp)) == EOF)
158			return((elsiz*nel - nbytes)/elsiz);
159			*s++ = c;
160			}
161			return(nel);
162			}