20060303

1 files changed, 186 insertions, 0 deletions

diff --git a/os/port/log.c b/os/port/log.c
new file mode 100644
index 00000000..14708233
--- /dev/null
+++ b/os/port/log.c
@@ -0,0 +1,186 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+
+static char Ebadlogctl[] = "unknown log ctl message";
+
+void
+logopen(Log *alog)
+{
+	lock(alog);
+	if(waserror()){
+		unlock(alog);
+		nexterror();
+	}
+	if(alog->opens == 0){
+		if(alog->nlog == 0)
+			alog->nlog = 4*1024;
+		if(alog->minread == 0)
+			alog->minread = 1;
+		if(alog->buf == nil)
+			alog->buf = malloc(alog->nlog);
+		alog->rptr = alog->buf;
+		alog->end = alog->buf + alog->nlog;
+		alog->len = 0;
+	}
+	alog->opens++;
+	unlock(alog);
+	poperror();
+}
+
+void
+logclose(Log *alog)
+{
+	lock(alog);
+	alog->opens--;
+	if(alog->opens == 0){
+		free(alog->buf);
+		alog->buf = nil;
+	}
+	unlock(alog);
+}
+
+static int
+logready(void *a)
+{
+	Log *alog = a;
+
+	return alog->len >= alog->minread;
+}
+
+long
+logread(Log *alog, void *a, ulong, long n)
+{
+	int i, d;
+	char *p, *rptr;
+
+	qlock(&alog->readq);
+	if(waserror()){
+		qunlock(&alog->readq);
+		nexterror();
+	}
+
+	for(;;){
+		lock(alog);
+		if(alog->len >= alog->minread || alog->len >= n){
+			if(n > alog->len)
+				n = alog->len;
+			d = 0;
+			rptr = alog->rptr;
+			alog->rptr += n;
+			if(alog->rptr >= alog->end){
+				d = alog->rptr - alog->end;
+				alog->rptr = alog->buf + d;
+			}
+			alog->len -= n;
+			unlock(alog);
+
+			i = n-d;
+			p = a;
+			memmove(p, rptr, i);
+			memmove(p+i, alog->buf, d);
+			break;
+		}
+		else
+			unlock(alog);
+
+		sleep(&alog->readr, logready, alog);
+	}
+
+	qunlock(&alog->readq);
+	poperror();
+
+	return n;
+}
+
+char*
+logctl(Log *alog, int argc, char *argv[], Logflag *flags)
+{
+	int i, set;
+	Logflag *fp;
+
+	if(argc < 2)
+		return Ebadlogctl;
+
+	if(strcmp("set", argv[0]) == 0)
+		set = 1;
+	else if(strcmp("clear", argv[0]) == 0)
+		set = 0;
+	else
+		return Ebadlogctl;
+
+	for(i = 1; i < argc; i++){
+		for(fp = flags; fp->name; fp++)
+			if(strcmp(fp->name, argv[i]) == 0)
+				break;
+		if(fp->name == nil)
+			continue;
+		if(set)
+			alog->logmask |= fp->mask;
+		else
+			alog->logmask &= ~fp->mask;
+	}
+
+	return nil;
+}
+
+void
+logn(Log *alog, int mask, void *buf, int n)
+{
+	char *fp, *t;
+	int dowake, i;
+
+	if(!(alog->logmask & mask))
+		return;
+
+	if(alog->opens == 0)
+		return;
+
+	if(n > alog->nlog)
+		return;
+
+	lock(alog);
+	i = alog->len + n - alog->nlog;
+	if(i > 0){
+		alog->len -= i;
+		alog->rptr += i;
+		if(alog->rptr >= alog->end)
+			alog->rptr = alog->buf + (alog->rptr - alog->end);
+	}
+	t = alog->rptr + alog->len;
+	fp = buf;
+	alog->len += n;
+	while(n-- > 0){
+		if(t >= alog->end)
+			t = alog->buf + (t - alog->end);
+		*t++ = *fp++;
+	}
+	dowake = alog->len >= alog->minread;
+	unlock(alog);
+
+	if(dowake)
+		wakeup(&alog->readr);
+}
+
+void
+logb(Log *alog, int mask, char *fmt, ...)
+{
+	int n;
+	va_list arg;
+	char buf[128];
+
+	if(!(alog->logmask & mask))
+		return;
+
+	if(alog->opens == 0)
+		return;
+
+	va_start(arg, fmt);
+	n = vseprint(buf, buf+sizeof(buf), fmt, arg) - buf;
+	va_end(arg);
+
+	logn(alog, mask, buf, n);
+}