X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fbucket.h;h=1af677cad8907556efe32502b40efa88ccf461eb;hb=271d2a02e7b798fd9781018c060d49e47f277cba;hp=a9b938bc4d9d6dea9d49906fcc0d0cf9e670327c;hpb=c6eff95276316f6c4fe39d22c81f2bf83e3d8528;p=libucw.git

diff --git a/lib/bucket.h b/lib/bucket.h
index a9b938bc..1af677ca 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--2004 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
@@ -11,33 +17,82 @@
  *
  * 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.
  */
 
+extern byte *obuck_name;	/* Internal, for use by buckettool only! */
+
 #define OBUCK_SHIFT 7
 #define OBUCK_ALIGN (1<<OBUCK_SHIFT)
 #define OBUCK_MAGIC 0xdeadf00d
+#define OBUCK_INCOMPLETE_MAGIC 0xdeadfeel
 #define OBUCK_TRAILER 0xfeedcafe
 #define OBUCK_OID_DELETED (~(oid_t)0)
+#define OBUCK_OID_FIRST_SPECIAL (~(oid_t)0xffff)
 
 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_V33 = 0x80000002,		/* v3.3 uncompressed buckets */
+  BUCKET_TYPE_V33_LIZARD = 0x80000003	/* v3.3 buckets compressed by lizard */
+};
+
 struct fastbuf;
 
-void obuck_init(int writeable);
-void obuck_cleanup(void);
-struct fastbuf * obuck_fetch(struct obuck_header *hdrp);
-void obuck_fetch_abort(struct fastbuf *b);
-void obuck_fetch_end(struct fastbuf *b);
-struct fastbuf * obuck_write(void);
-void obuck_write_end(struct fastbuf *b, struct obuck_header *hdrp);
+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);
+int obuck_find_first(struct obuck_header *hdrp, int full);
+int obuck_find_next(struct obuck_header *hdrp, int full);
+
+/* Reading current bucket */
+struct fastbuf *obuck_fetch(void);
+
+/* Creating buckets */
+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);
-struct fastbuf * obuck_walk_init(void);
-struct fastbuf * obuck_walk_next(struct fastbuf *b, struct obuck_header *hdrp);
-void obuck_walk_end(struct fastbuf *b);
+
+/* 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;
+}
+
+/* Calculate size of bucket which contains given amount of data */
+
+static inline uns obuck_bucket_size(uns len)
+{
+  return ALIGN(sizeof(struct obuck_header) + len + 4, OBUCK_ALIGN);
+}
+
+/* Shaking down bucket file */
+void obuck_shakedown(int (*kibitz)(struct obuck_header *old, oid_t new, byte *buck));
+
+#endif