X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftdb2.h;h=2b9f46217db77247c6617e4fa2fa75e413d1018e;hp=296410e74196573a955470b78c422daa870f8be5;hb=838db0d7ea37fc2a21d03d159b55b042f8144cb3;hpb=703cea0c78a896c658272af06306218fc0bb23cc

diff --git a/ccan/tdb2/tdb2.h b/ccan/tdb2/tdb2.h
index 296410e7..2b9f4621 100644
--- a/ccan/tdb2/tdb2.h
+++ b/ccan/tdb2/tdb2.h
@@ -80,6 +80,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 #define TDB_CONVERT 16 /* convert endian */
 #define TDB_NOSYNC   64 /* don't use synchronous transactions */
 #define TDB_SEQNUM   128 /* maintain a sequence number */
+#define TDB_ALLOW_NESTING   256 /* fake nested transactions */
 
 /**
  * tdb_close - close and free a tdb.
@@ -248,6 +249,15 @@ static inline struct tdb_data tdb_mkdata(const void *p, size_t len)
  * to read the tdb, but not alter it (they will block), nor will they see
  * any changes until tdb_transaction_commit() is called.
  *
+ * Note that if the TDB_ALLOW_NESTING flag is set, a tdb_transaction_start()
+ * within a transaction will succeed, but it's not a real transaction:
+ * (1) An inner transaction which is committed is not actually committed until
+ *     the outer transaction is; if the outer transaction is cancelled, the
+ *     inner ones are discarded.
+ * (2) tdb_transaction_cancel() marks the outer transaction as having an error,
+ *     so the final tdb_transaction_commit() will fail.
+ * (3) the outer transaction will see the results of the inner transaction.
+ *
  * See Also:
  *	tdb_transaction_cancel, tdb_transaction_commit.
  */
@@ -565,7 +575,7 @@ unsigned int tdb_get_flags(struct tdb_context *tdb);
 /**
  * tdb_add_flag - set a flag for a tdb
  * @tdb: the tdb context returned from tdb_open()
- * @flag: one of TDB_NOLOCK, TDB_NOMMAP or TDB_NOSYNC.
+ * @flag: one of TDB_NOLOCK, TDB_NOMMAP, TDB_NOSYNC or TDB_ALLOW_NESTING.
  *
  * You can use this to set a flag on the TDB.  You cannot set these flags
  * on a TDB_INTERNAL tdb.
@@ -575,7 +585,7 @@ void tdb_add_flag(struct tdb_context *tdb, unsigned flag);
 /**
  * tdb_remove_flag - unset a flag for a tdb
  * @tdb: the tdb context returned from tdb_open()
- * @flag: one of TDB_NOLOCK, TDB_NOMMAP or TDB_NOSYNC.
+ * @flag: one of TDB_NOLOCK, TDB_NOMMAP, TDB_NOSYNC or TDB_ALLOW_NESTING.
  *
  * You can use this to clear a flag on the TDB.  You cannot clear flags
  * on a TDB_INTERNAL tdb.
@@ -729,13 +739,13 @@ struct tdb_attribute_seed {
  * struct tdb_attribute_stats - tdb operational statistics
  *
  * This attribute records statistics of various low-level TDB operations.
- * This can be used to assist performance evaluation.
+ * This can be used to assist performance evaluation.  This is only
+ * useful for tdb_get_attribute().
  *
  * New fields will be added at the end, hence the "size" argument which
- * indicates how large your structure is.  If your size is larger than
- * that known about by this version of tdb, the size will be reduced to
- * the known structure size.  Thus you can detect older versions, and
- * thus know that newer stats will not be updated.
+ * indicates how large your structure is: it must be filled in before
+ * calling tdb_get_attribute(), which will overwrite it with the size
+ * tdb knows about.
  */
 struct tdb_attribute_stats {
 	struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_STATS */
@@ -747,21 +757,31 @@ struct tdb_attribute_stats {
 	uint64_t   alloc_bucket_max;
 	uint64_t   alloc_leftover;
 	uint64_t   alloc_coalesce_tried;
+	uint64_t     alloc_coalesce_iterate_clash;
 	uint64_t     alloc_coalesce_lockfail;
 	uint64_t     alloc_coalesce_race;
 	uint64_t     alloc_coalesce_succeeded;
-	uint64_t        alloc_coalesce_num_merged;
+	uint64_t       alloc_coalesce_num_merged;
 	uint64_t compares;
 	uint64_t   compare_wrong_bucket;
 	uint64_t   compare_wrong_offsetbits;
 	uint64_t   compare_wrong_keylen;
 	uint64_t   compare_wrong_rechash;
 	uint64_t   compare_wrong_keycmp;
+	uint64_t transactions;
+	uint64_t   transaction_cancel;
+	uint64_t   transaction_nest;
+	uint64_t   transaction_expand_file;
+	uint64_t   transaction_read_direct;
+	uint64_t      transaction_read_direct_fail;
+	uint64_t   transaction_write_direct;
+	uint64_t      transaction_write_direct_fail;
 	uint64_t expands;
 	uint64_t frees;
 	uint64_t locks;
-	uint64_t    lock_lowlevel;
-	uint64_t    lock_nonblock;
+	uint64_t   lock_lowlevel;
+	uint64_t   lock_nonblock;
+	uint64_t     lock_nonblock_fail;
 };
 
 /**