code: libextents

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rename qalloc to allot and qfree to release

--- a/extents.c

+++ b/extents.c

@@ -735,12 +735,11 @@

 	return oldstart;

 }

-/* allocate n blocks and return that block number */

-u64

-qalloc(Extents *es, u64 n)

+/* allocate n blocks and return a status. start has a block number if allocated */

+s8

+allot(Extents *es, u64 n, u64 *start)

 {

 	Extent *e, *euse;

-	u64 start;

 	char msg[64];

 	s64 dir;

@@ -748,8 +747,7 @@

 		es->panic("qalloc: es == nil");

 	if(es->n == 0)

 		es->panic("qalloc entering es->n == 0\n");

-	start = 0;

-	USED(start);

+

 	qlock(&es->lck);

 	if(es->n == 0)

 		rsleep(&es->isempty);

@@ -790,17 +788,22 @@

 			qunlock(&es->lck);

 			(*es->flush)();

 			qlock(&es->lck);

-		}else

-			rsleep(&es->isempty);

+		}else{

+			if(es->linger)

+				rsleep(&es->isempty);

+			else

+				return 0;

+		}

 		goto again;

 	}

 	else if(e->len == n)

-		start = pluck(es, e);

-	else /* found something bigger */

-		start = slice(es, e, n);

+		*start = pluck(es, e);

+	else{ /* found something bigger */

+		*start = slice(es, e, n);

+	}

 	if(es->log && es->loglevel == Everbose){

-		es->log(es->logfd, "qalloc()'ed start %llud len %llud blocks:\n", start, n);

+		es->log(es->logfd, "qalloc()'ed start %llud len %llud blocks:\n", *start, n);

 	}else if(es->log && es->loglevel == Edebug){

 		snprint(msg, 64, "qalloc() %llud blocks:\n", n);

 		showextentslists(es->logfd, msg, es);

@@ -810,8 +813,8 @@

 	qunlock(&es->lck);

 	/* use to generate test cases of unforeseen behaviour */

 	if(es->log && es->loglevel)

-		es->log(es->logfd, "%s-%llud %llud\n", es->name, start, n);

-	return start;

+		es->log(es->logfd, "%s-%llud %llud\n", es->name, *start, n);

+	return 1;

 }

 /*

@@ -823,7 +826,7 @@

  free n blocks allocated at block number

  */

 void

-qfree(Extents *es, u64 start, u64 len)

+release(Extents *es, u64 start, u64 len)

 {

 	char msg[64];

@@ -955,7 +958,7 @@

 		p = ep;

 		p++; /* to skip over the new line */

-		qfree(es, start, nblocks);

+		release(es, start, nblocks);

 	}

 	return es->n;

 }

@@ -1063,7 +1066,7 @@

 }

 void

-initextents(Extents *es, char *name, u8 loglevel, u32 logfd, void (*flush)(void), void (*log)(int fd, char *fmt, ...), void (*panic)(char *fmt, ...), void *(*malloc)(u32 sz))

+initextents(Extents *es, char *name, u8 linger, u8 loglevel, u32 logfd, void (*flush)(void), void (*log)(int fd, char *fmt, ...), void (*panic)(char *fmt, ...), void *(*malloc)(u32 sz))

 {

 	es->isempty.l = &es->lck;

 	if(name != nil)

@@ -1071,6 +1074,7 @@

 	es->loglevel = loglevel;

 	es->logfd = logfd;

 	es->flush = flush;

+	es->linger = linger;

 	es->log = log;

 	es->panic = panic;

 	es->malloc = malloc;

@@ -1104,7 +1108,7 @@

 		return nil;

 	for(e=lowest(es); e!=nil && e->high != nil; e=e->high){

 		start = e->start+e->len;

-		qfree(inv, start, e->high->start-start);

+		release(inv, start, e->high->start-start);

 	}

 	return inv;

 }

--- a/extents.h

+++ b/extents.h

@@ -50,13 +50,14 @@

 */

 struct Extents {

 	char name[32];

-	void (*flush)(void);	/* flush when nothing is available */

+	void (*flush)(void);/* flush when nothing is available */

+	u8 linger;			/* wait until something becomes available */

 	u8 loglevel;	/* Everbose or Edebug */

 	u32 logfd;

 	void (*log)(int fd, char *fmt, ...);

 	void (*panic)(char *fmt, ...);

-	void *(*malloc)(u32 sz);

+	void *(*malloc)(u32 sz);	/* as 9p servers use a different malloc */

 	/* private and derived */

 	Extent *lowest;	/* find the first block number in a jiffy */

@@ -78,12 +79,13 @@

 	struct Extent *prev, *next;

 };

-void	initextents(Extents *es, char *name, u8 loglevel, u32 logfd, void (*flush)(void), void (*log)(int fd, char *fmt, ...), void (*panic)(char *fmt, ...), void *(*malloc)(u32 sz));

+void	initextents(Extents *es, char *name, u8 linger, u8 loglevel, u32 logfd, void (*flush)(void), void (*log)(int fd, char *fmt, ...), void (*panic)(char *fmt, ...), void *(*malloc)(u32 sz));

 void	freeextents(Extents *es);

-u64	 qalloc(Extents *es, u64 len);			/* allocate len units */

-void qfree(Extents *es, u64 start, u64 len);/* free len units starting from start */

-u64	 nfrees(Extents *es);

+/* allocate n quanta */

+s8	 allot(Extents *es, u64 n, u64 *start);

+void release(Extents *es, u64 start, u64 len);/* free len units starting from start */

+u64	 navailable(Extents *es);

 Extents *holes(Extents *es, Extents *inv);

 void	showblocknos(int fd, Extents *es);

--- a/testextents.c

+++ b/testextents.c

@@ -67,17 +67,17 @@

 	bp = Bfdopen(0, OREAD);

 	Blethal(bp, nil);

-	initextents(&es, "testextents", 0, 1, nil, nil, panic, emalloc);

+	initextents(&es, "testextents", 0, 0, 1, nil, nil, panic, emalloc);

 	while((line = Brdstr(bp, '\n', 1)) != nil) {

 		act = line[0];

 		if(act == '-'){

 			len = strtoull(line+1, nil, 10);

-			qalloc(&es, len);

+			allot(&es, len);

 		}else{

 			bno = strtoull(line, &p, 10);

 			p++;	/* for the space */

 			len = strtoull(p, nil, 10);

-			qfree(&es, bno, len);

+			release(&es, bno, len);

 		}

 		free(line);

 	}