svn commit: r294037 - head/lib/libmd
Jonathan T. Looney
jtl at FreeBSD.org
Thu Jan 14 21:08:24 UTC 2016
Author: jtl
Date: Thu Jan 14 21:08:23 2016
New Revision: 294037
URL: https://svnweb.freebsd.org/changeset/base/294037
Log:
Improvements to the MDXFileChunk() template function:
- Remove unneeded fstat()/lseek() calls.
- Return NULL and set errno to EINVAL on negative length.
- Fix small style problems and expand variable names.
After this change, it is possible to use this code for some irregular
files. For example, 'md5 /dev/md0' should now succeed.
Differential Revision: https://reviews.freebsd.org/D4748
Suggested by: bde
Reviewed by: bde, allanjude, delphij
Modified:
head/lib/libmd/mdXhl.c
Modified: head/lib/libmd/mdXhl.c
==============================================================================
--- head/lib/libmd/mdXhl.c Thu Jan 14 20:51:48 2016 (r294036)
+++ head/lib/libmd/mdXhl.c Thu Jan 14 21:08:23 2016 (r294037)
@@ -1,4 +1,5 @@
-/* mdXhl.c * ----------------------------------------------------------------------------
+/* mdXhl.c
+ * ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk at FreeBSD.org> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
@@ -52,43 +53,44 @@ MDXFileChunk(const char *filename, char
unsigned char buffer[16*1024];
MDX_CTX ctx;
struct stat stbuf;
- int f, i, e;
- off_t n;
+ int fd, readrv, e;
+ off_t remain;
- MDXInit(&ctx);
- f = open(filename, O_RDONLY);
- if (f < 0)
- return 0;
- if (fstat(f, &stbuf) < 0) {
- i = -1;
- goto error;
+ if (len < 0) {
+ errno = EINVAL;
+ return NULL;
}
- if (ofs > stbuf.st_size)
- ofs = stbuf.st_size;
- if ((len == 0) || (len > stbuf.st_size - ofs))
- len = stbuf.st_size - ofs;
- if (lseek(f, ofs, SEEK_SET) < 0) {
- i = -1;
- goto error;
+
+ MDXInit(&ctx);
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ return NULL;
+ if (ofs != 0) {
+ errno = 0;
+ if (lseek(fd, ofs, SEEK_SET) != ofs ||
+ (ofs == -1 && errno != 0)) {
+ readrv = -1;
+ goto error;
+ }
}
- n = len;
- i = 0;
- while (n > 0) {
- if (n > sizeof(buffer))
- i = read(f, buffer, sizeof(buffer));
+ remain = len;
+ readrv = 0;
+ while (len == 0 || remain > 0) {
+ if (len == 0 || remain > sizeof(buffer))
+ readrv = read(fd, buffer, sizeof(buffer));
else
- i = read(f, buffer, n);
- if (i <= 0)
+ readrv = read(fd, buffer, remain);
+ if (readrv <= 0)
break;
- MDXUpdate(&ctx, buffer, i);
- n -= i;
+ MDXUpdate(&ctx, buffer, readrv);
+ remain -= readrv;
}
error:
e = errno;
- close(f);
+ close(fd);
errno = e;
- if (i < 0)
- return 0;
+ if (readrv < 0)
+ return NULL;
return (MDXEnd(&ctx, buf));
}
More information about the svn-src-all
mailing list