X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Fbucket.h;h=b493305d20a30c800268dcc04ee1883f0e4bcadd;hb=ed7c7b20afed72df0d4195548ec5346f1daac1d1;hp=bdf35e81d97c2df2c73747107347ac6a840fc937;hpb=995458e48d482bd5fa349882fba5cb4d6350076d;p=libucw.git

diff --git a/lib/bucket.h b/lib/bucket.h
index bdf35e81..b493305d 100644
--- a/lib/bucket.h
+++ b/lib/bucket.h
@@ -1,9 +1,15 @@
 /*
  *	Sherlock Library -- Object Buckets
  *
- *	(c) 2001 Martin Mares <mj@ucw.cz>
+ *	(c) 2001--2003 Martin Mares <mj@ucw.cz>
+ *
+ *	This software may be freely distributed and used according to the terms
+ *	of the GNU Lesser General Public License.
  */
 
+#ifndef _SHERLOCK_BUCKET_H
+#define _SHERLOCK_BUCKET_H
+
 /*
  * Format: The object pool is merely a sequence of object buckets.
  * Each bucket starts with struct obuck_header and it's padded
@@ -11,7 +17,9 @@
  *
  * Locking: Each operation on the pool is protected by a flock.
  *
- * The buckets emulate non-seekable fastbuf streams.
+ * The buckets emulate fastbuf streams. Read streams act as normal files,
+ * but there can be only one write stream which is non-seekable and you
+ * also shouldn't open new read streams when writing.
  *
  * fork()'ing if you don't have any bucket open is safe.
  */
@@ -29,16 +37,27 @@ extern byte *obuck_name;	/* Internal, for use by buckettool only! */
 struct obuck_header {
   u32 magic;			/* OBUCK_MAGIC should dwell here */
   oid_t oid;			/* ID of this object or OBUCK_OID_DELETED */
-  u32 length;			/* Length of compressed data in the bucket */
-  u32 orig_length;		/* Length of uncompressed data */
+  u32 length;			/* Length of data in the bucket */
+  u32 type;			/* Data type */
   /* Bucket data continue here */
 };
 
+enum bucket_type {
+  BUCKET_TYPE_COMPAT = 0x7fffffff,	/* and less -- buckets created by older versions of Sherlock */
+  BUCKET_TYPE_PLAIN = 0x80000000,	/* plain textual buckets */
+  BUCKET_TYPE_V30 = 0x80000001,		/* v3.0 uncompressed buckets */
+  BUCKET_TYPE_V30C = 0x80000002		/* v3.0 compressed buckets */
+};
+
 struct fastbuf;
 
 void obuck_init(int writeable);	/* Initialize the bucket module */
 void obuck_cleanup(void);	/* Clean up the bucket module */
 void obuck_sync(void);		/* Flush all buffers to disk */
+void obuck_lock_read(void);	/* Explicit locking to make sure other threads don't touch buckets now */
+void obuck_lock_write(void);
+void obuck_unlock(void);
+oid_t obuck_predict_last_oid(void); /* Get OID corresponding to the next to be created bucket (i.e., bucket file size estimate) */
 
 /* Searching for buckets */
 void obuck_find_by_oid(struct obuck_header *hdrp);
@@ -47,18 +66,25 @@ int obuck_find_next(struct obuck_header *hdrp, int full);
 
 /* Reading current bucket */
 struct fastbuf *obuck_fetch(void);
-void obuck_fetch_end(struct fastbuf *b);
 
 /* Creating buckets */
-struct fastbuf *obuck_create(void);
+struct fastbuf *obuck_create(u32 type);
 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)
 {
   return ((sh_off_t) oid) << OBUCK_SHIFT;
 }
+
+/* Shaking down bucket file */
+void obuck_shakedown(int (*kibitz)(struct obuck_header *old, oid_t new, byte *buck));
+
+#endif