hgfs: various improvements

lazily close revlog files and keep up to 8
revlogs arround. also cache the latest extracted
file descriptor of a revision in the revlog.
this avoids the quite expensive reextracting/patching
when we reopen the same file revision.

dont use the racy mktemp()/create, instead create
a uniqueue name and create with OEXCL. this also
avoids a bunch of access() calls.

fix eof case and use pread() in fcopy() to avoid the
seeks.

dont modify changelog temp file but simulate trailing
newline instead.

1 files changed, 10 insertions, 5 deletions

diff --git a/sys/src/cmd/hgfs/info.c b/sys/src/cmd/hgfs/info.c
index 6a17a8fcc..45877f957 100644
--- a/sys/src/cmd/hgfs/info.c
+++ b/sys/src/cmd/hgfs/info.c
@@ -8,16 +8,13 @@ Revinfo*
 loadrevinfo(Revlog *changelog, int rev)
 {
 	char buf[BUFSZ], *p, *e;
-	int fd, line, inmsg, n;
+	int fd, line, eof, inmsg, n;
 	Revinfo *ri;
 	vlong off;
 
 	if((fd = revlogopentemp(changelog, rev)) < 0)
 		return nil;
 
-	seek(fd, 0, 2);
-	write(fd, "\n", 1);
-
 	off = fmetaheader(fd);
 	seek(fd, off, 0);
 
@@ -26,11 +23,19 @@ loadrevinfo(Revlog *changelog, int rev)
 
 	memmove(ri->chash, changelog->map[rev].hash, HASHSZ);
 
+	eof = 0;
 	line = 0;
 	inmsg = 0;
 	p = buf;
 	e = buf + BUFSZ;
-	while((n = read(fd, p, e - p)) > 0){
+	while(eof == 0){
+		if((n = read(fd, p, e - p)) < 0)
+			break;
+		if(n == 0){
+			eof = 1;
+			*p = '\n';
+			n++;
+		}
 		p += n;
 		while((p > buf) && (e = memchr(buf, '\n', p - buf))){
 			*e++ = 0;