Using stdio in getent() results in a minor wallclock speedup but
halves the system time on my test machine. As a bonus we can reuse
pfp in tcgetnext().
- todd
Index: lib/libc/gen/getcap.c
===================================================================
RCS file: /cvs/src/lib/libc/gen/getcap.c,v
retrieving revision 1.28
diff -u -r1.28 getcap.c
--- lib/libc/gen/getcap.c 6 Jul 2011 18:51:09 -0000 1.28
+++ lib/libc/gen/getcap.c 6 Jul 2011 21:28:46 -0000
@@ -58,7 +58,7 @@
static int gottoprec; /* Flag indicating retrieval of toprecord */
static int cdbget(DB *, char **, const char *);
-static int getent(char **, u_int *, char **, int, const char *, int, char
*);
+static int getent(char **, u_int *, char **, FILE *, const char *, int,
char *);
static int nfcmp(const char *, char *);
static int usedb = 1;
@@ -168,12 +168,12 @@
{
u_int dummy;
- return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
+ return (getent(buf, &dummy, db_array, NULL, name, 0, NULL));
}
/*
- * Getent implements the functions of cgetent. If fd is non-negative,
- * *db_array has already been opened and fd is the open file descriptor. We
+ * Getent implements the functions of cgetent. If fp is non-NULL,
+ * *db_array has already been opened and fp is the open file descriptor. We
* do this to save time and avoid using up file descriptors for tc=
* recursions.
*
@@ -190,7 +190,7 @@
* MAX_RECURSION.
*/
static int
-getent(char **cap, u_int *len, char **db_array, int fd,
+getent(char **cap, u_int *len, char **db_array, FILE *fp,
const char *name, int depth, char *nfield)
{
DB *capdbp;
@@ -240,8 +240,8 @@
/*
* Open database if not already open.
*/
- if (fd >= 0) {
- (void)lseek(fd, (off_t)0, SEEK_SET);
+ if (fp != NULL) {
+ (void)fseek(fp, 0L, SEEK_SET);
myfd = 0;
opened++;
} else {
@@ -272,8 +272,8 @@
*cap = cbuf;
return (retval);
} else {
- fd = open(*db_p, O_RDONLY, 0);
- if (fd < 0) {
+ fp = fopen(*db_p, "r");
+ if (fp == NULL) {
/* No error on unfound file. */
continue;
}
@@ -308,20 +308,19 @@
rp = record;
for (;;) {
if (bp >= b_end) {
- int n;
+ size_t n;
- n = read(fd, buf, sizeof(buf));
- if (n <= 0) {
+ n = fread(buf, 1, sizeof(buf), fp);
+ if (n == 0) {
+ eof = feof(fp);
if (myfd)
- (void)close(fd);
- if (n < 0) {
- free(record);
- return (-2);
- } else {
- fd = -1;
- eof = 1;
+ (void)fclose(fp);
+ if (eof) {
+ fp = NULL;
break;
}
+ free(record);
+ return (-2);
}
b_end = buf+n;
bp = buf;
@@ -343,7 +342,7 @@
* some more.
*/
if (rp >= r_end) {
- u_int pos;
+ size_t pos;
size_t newsize;
char *nrecord;
@@ -354,7 +353,7 @@
if (record)
free(record);
if (myfd)
- (void)close(fd);
+ (void)fclose(fp);
errno = ENOMEM;
return (-2);
}
@@ -440,13 +439,13 @@
tclen = s - tcstart;
tcend = s;
- iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
+ iret = getent(&icap, &ilen, db_p, fp, tc, depth+1,
NULL);
if (iret != 0) {
/* an error */
if (iret < -1) {
if (myfd)
- (void)close(fd);
+ (void)fclose(fp);
free(record);
return (iret);
}
@@ -498,7 +497,7 @@
if (record)
free(record);
if (myfd)
- (void)close(fd);
+ (void)fclose(fp);
free(ibuf);
errno = ENOMEM;
return (-2);
@@ -532,7 +531,7 @@
* return capability, length and success.
*/
if (myfd)
- (void)close(fd);
+ (void)fclose(fp);
*len = rp - record - 1; /* don't count NUL */
if (r_end > rp) {
char *nrecord;
@@ -660,13 +659,12 @@
cgetnext(char **cap, char **db_array)
{
size_t len;
- int serrno, status = -1;
- char nbuf[BSIZE];
- char *record = NULL, *r_end, *rp;
- char buf[BUFSIZ];
- char *b_end, *bp;
- int c;
+ int c, serrno, status = -1;
+ char buf[BUFSIZ], nbuf[BSIZE];
+ char *b_end, *bp, *r_end, *rp;
+ char *record = NULL;
u_int dummy;
+ off_t pos;
if (dbp == NULL)
dbp = db_array;
@@ -747,17 +745,17 @@
* some more.
*/
if (rp >= r_end) {
- size_t newsize, pos;
+ size_t newsize, off;
char *nrecord;
- pos = rp - record;
+ off = rp - record;
newsize = r_end - record + BFRAG;
nrecord = realloc(record, newsize);
if (nrecord == NULL)
goto done;
record = nrecord;
r_end = record + newsize;
- rp = record + pos;
+ rp = record + off;
}
}
/* loop invariant lets us do this */
@@ -783,7 +781,10 @@
nbuf[len] = '\0';
/* return value of getent() is one less than cgetnext() */
- status = getent(cap, &dummy, db_array, -1, nbuf, 0, NULL) + 1;
+ pos = ftello(pfp);
+ status = getent(cap, &dummy, db_array, pfp, nbuf, 0, NULL) + 1;
+ if (status > 0)
+ fseeko(pfp, pos, SEEK_SET);
done:
serrno = errno;
free(record);
