From: Martin Mares <mj@ucw.cz>
Date: Sun, 6 Oct 2002 15:50:02 +0000 (+0000)
Subject: Introduced obuck_slurp_pool() to make reading of the whole bucket
X-Git-Tag: holmes-import~1326
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=98bc6b8a48b5cc006dd650cfdc5cf46966d501a6;p=libucw.git

Introduced obuck_slurp_pool() to make reading of the whole bucket
pool faster, possibly using mmap.

Use it in `buckettool -c'.
---

diff --git a/lib/bucket.c b/lib/bucket.c
index db00678a..aff99310 100644
--- a/lib/bucket.c
+++ b/lib/bucket.c
@@ -30,12 +30,14 @@ static sh_off_t bucket_start, bucket_current;
 byte *obuck_name = "not/configured";
 static uns obuck_io_buflen = 65536;
 static int obuck_shake_buflen = 1048576;
+static uns obuck_slurp_buflen = 65536;
 
 static struct cfitem obuck_config[] = {
   { "Buckets",		CT_SECTION,	NULL },
   { "BucketFile",	CT_STRING,	&obuck_name },
   { "BufSize",		CT_INT,		&obuck_io_buflen },
   { "ShakeBufSize",	CT_INT,		&obuck_shake_buflen },
+  { "SlurpBufSize",	CT_INT,		&obuck_slurp_buflen },
   { NULL,		CT_STOP,	NULL }
 };
 
@@ -314,6 +316,73 @@ obuck_delete(oid_t oid)
   obuck_unlock();
 }
 
+/*** Fast reading of the whole pool ***/
+
+static struct fastbuf *obuck_rpf;
+
+static int
+obuck_slurp_refill(struct fastbuf *f)
+{
+  uns l;
+
+  if (!obuck_remains)
+    return 0;
+  l = bdirect_read_prepare(obuck_rpf, &f->buffer);
+  if (!l)
+    obuck_broken("Incomplete object");
+  l = MIN(l, obuck_remains);
+  bdirect_read_commit(obuck_rpf, f->buffer + l);
+  obuck_remains -= l;
+  f->bptr = f->buffer;
+  f->bufend = f->bstop = f->buffer + l;
+  return 1;
+}
+
+struct fastbuf *
+obuck_slurp_pool(struct obuck_header *hdrp)
+{
+  static struct fastbuf limiter;
+  uns l;
+
+  do
+    {
+      if (!obuck_rpf)
+	{
+	  obuck_lock_read();
+	  obuck_rpf = bopen(obuck_name, O_RDONLY, obuck_slurp_buflen);
+	}
+      else
+	{
+	  bsetpos(obuck_rpf, bucket_current - 4);
+	  if (bgetl(obuck_rpf) != OBUCK_TRAILER)
+	    obuck_broken("Missing trailer");
+	}
+      bucket_start = btell(obuck_rpf);
+      l = bread(obuck_rpf, hdrp, sizeof(struct obuck_header));
+      if (!l)
+	{
+	  bclose(obuck_rpf);
+	  obuck_unlock();
+	  return NULL;
+	}
+      if (l != sizeof(struct obuck_header))
+	obuck_broken("Short header read");
+      if (hdrp->magic != OBUCK_MAGIC)
+	obuck_broken("Missing magic number");
+      bucket_current = (bucket_start + sizeof(obuck_hdr) + hdrp->length +
+			4 + OBUCK_ALIGN - 1) & ~((sh_off_t)(OBUCK_ALIGN - 1));
+    }
+  while (hdrp->oid == OBUCK_OID_DELETED);
+  if (obuck_get_pos(hdrp->oid) != bucket_start)
+    obuck_broken("Invalid backlink");
+  obuck_remains = hdrp->length;
+  limiter.bptr = limiter.bstop = limiter.buffer = limiter.bufend = NULL;
+  limiter.name = "Bucket";
+  limiter.pos = 0;
+  limiter.refill = obuck_slurp_refill;
+  return &limiter;
+}
+
 /*** Shakedown ***/
 
 void
diff --git a/lib/bucket.h b/lib/bucket.h
index 24e7ae00..798e9a9a 100644
--- a/lib/bucket.h
+++ b/lib/bucket.h
@@ -62,6 +62,9 @@ void obuck_create_end(struct fastbuf *b, struct obuck_header *hdrp);
 /* Deleting buckets */
 void obuck_delete(oid_t oid);
 
+/* Fast reading of the whole pool */
+struct fastbuf *obuck_slurp_pool(struct obuck_header *hdrp);
+
 /* Convert bucket ID to file position (for size limitations etc.) */
 
 static inline sh_off_t obuck_get_pos(oid_t oid)
diff --git a/lib/buckettool.c b/lib/buckettool.c
index ae55b3ca..bc8ce32d 100644
--- a/lib/buckettool.c
+++ b/lib/buckettool.c
@@ -135,22 +135,18 @@ cat(void)
   int l, lf;
 
   obuck_init(0);
-  if (obuck_find_first(&h, 0))
-    do
-      {
-	printf("### %08x %6d %6d\n", h.oid, h.length, h.orig_length);
-	b = obuck_fetch();
-	lf = 1;
-	while ((l = bread(b, buf, sizeof(buf))))
-	  {
-	    fwrite(buf, 1, l, stdout);
-	    lf = (buf[l-1] == '\n');
-	  }
-	obuck_fetch_end(b);
-	if (!lf)
-	  printf("\n# <missing EOL>\n");
-      }
-    while (obuck_find_next(&h, 0));
+  while (b = obuck_slurp_pool(&h))
+    {
+      printf("### %08x %6d %6d\n", h.oid, h.length, h.orig_length);
+      lf = 1;
+      while ((l = bread(b, buf, sizeof(buf))))
+	{
+	  fwrite(buf, 1, l, stdout);
+	  lf = (buf[l-1] == '\n');
+	}
+      if (!lf)
+	printf("\n# <missing EOL>\n");
+    }
   obuck_cleanup();
 }