X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftdb2.h;h=525fbd71758c5c0632c101729dce761295b3cb66;hp=7a7aaca90fbfa7715749c5329fb447b63831b432;hb=614259f13c3e694fcd6b57fc05a329066e43c76d;hpb=937d0babe99dcd315040a9e48430140e63e4a7df

diff --git a/ccan/tdb2/tdb2.h b/ccan/tdb2/tdb2.h
index 7a7aaca9..525fbd71 100644
--- a/ccan/tdb2/tdb2.h
+++ b/ccan/tdb2/tdb2.h
@@ -86,6 +86,19 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 #define TDB_SEQNUM   128 /* maintain a sequence number */
 #define TDB_ALLOW_NESTING   256 /* fake nested transactions */
 #define TDB_RDONLY   512 /* implied by O_RDONLY */
+#define TDB_VERSION1  1024 /* create/open an old style TDB */
+
+/**
+ * tdb1_incompatible_hash - better (Jenkins) hash for tdb1
+ *
+ * This is better than the default hash for tdb1; but older versions of the
+ * tdb library (prior to version 1.2.6) won't be able to open them.
+ *
+ * It only makes sense to specify this (using tdb_attribute_hash) when
+ * creating (with O_CREAT) an old tdb version using TDB_VERSION1.  It's
+ * equivalent to the TDB_INCOMPATIBLE_HASH flag for tdb1.
+ */
+uint64_t tdb1_incompatible_hash(const void *, size_t, uint64_t, void *);
 
 /**
  * tdb_close - close and free a tdb.
@@ -504,6 +517,16 @@ void tdb_unlockall_read(struct tdb_context *tdb);
  */
 enum TDB_ERROR tdb_wipe_all(struct tdb_context *tdb);
 
+/**
+ * tdb_repack - repack the database
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * This repacks the database; if it is suffering from a great deal of
+ * fragmentation this might help.  However, it can take twice the
+ * memory of the existing TDB.
+ */
+enum TDB_ERROR tdb_repack(struct tdb_context *tdb);
+
 /**
  * tdb_check - check a TDB for consistency
  * @tdb: the tdb context returned from tdb_open()
@@ -606,7 +629,9 @@ enum tdb_attribute_type {
 	TDB_ATTRIBUTE_SEED = 2,
 	TDB_ATTRIBUTE_STATS = 3,
 	TDB_ATTRIBUTE_OPENHOOK = 4,
-	TDB_ATTRIBUTE_FLOCK = 5
+	TDB_ATTRIBUTE_FLOCK = 5,
+	TDB_ATTRIBUTE_TDB1_HASHSIZE = 128,
+	TDB_ATTRIBUTE_TDB1_MAX_DEAD = 129,
 };
 
 /**
@@ -630,8 +655,9 @@ enum TDB_ERROR tdb_get_attribute(struct tdb_context *tdb,
  * of the same type.  It returns TDB_ERR_EINVAL if the attribute is
  * unknown or invalid.
  *
- * Note that TDB_ATTRIBUTE_HASH, TDB_ATTRIBUTE_SEED and
- * TDB_ATTRIBUTE_OPENHOOK cannot currently be set after tdb_open.
+ * Note that TDB_ATTRIBUTE_HASH, TDB_ATTRIBUTE_SEED,
+ * TDB_ATTRIBUTE_OPENHOOK and TDB_ATTRIBUTE_TDB1_HASHSIZE cannot
+ * currently be set after tdb_open.
  */
 enum TDB_ERROR tdb_set_attribute(struct tdb_context *tdb,
 				 const union tdb_attribute *attr);
@@ -670,6 +696,20 @@ const char *tdb_name(const struct tdb_context *tdb);
  */
 int tdb_fd(const struct tdb_context *tdb);
 
+/**
+ * tdb_foreach - iterate through every open TDB.
+ * @fn: the function to call for every TDB
+ * @p: the pointer to hand to @fn
+ *
+ * TDB internally keeps track of all open TDBs; this function allows you to
+ * iterate through them.  If @fn returns non-zero, traversal stops.
+ */
+#define tdb_foreach(fn, p)						\
+	tdb_foreach_(typesafe_cb_preargs(int, void *, (fn), (p),	\
+					 struct tdb_context *), (p))
+
+void tdb_foreach_(int (*fn)(struct tdb_context *, void *), void *p);
+
 /**
  * struct tdb_attribute_base - common fields for all tdb attributes.
  */
@@ -823,6 +863,32 @@ struct tdb_attribute_flock {
 	void *data;
 };
 
+/**
+ * struct tdb_attribute_tdb1_hashsize - tdb1 hashsize
+ *
+ * This attribute allows setting the TDB1 hashsize; it only makes sense with
+ * O_CREAT and TDB_VERSION1.
+ *
+ * Hashsize should generally be a prime, such as 10007.
+ */
+struct tdb_attribute_tdb1_hashsize {
+	struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_TDB1_HASHSIZE */
+	unsigned int hsize;
+};
+
+/**
+ * struct tdb_attribute_tdb1_max_dead - tdb1 number of maximum dead records.
+ *
+ * TDB1 has a method to speed up its slow free list: it lets a certain
+ * number of "dead" records build up before freeing them.  This is
+ * particularly useful for volatile TDBs; setting it to 5 is
+ * equivalent to tdb1's TDB_VOLATILE flag.
+ */
+struct tdb_attribute_tdb1_max_dead {
+	struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_TDB1_MAX_DEAD */
+	unsigned int max_dead;
+};
+
 /**
  * union tdb_attribute - tdb attributes.
  *
@@ -841,6 +907,8 @@ union tdb_attribute {
 	struct tdb_attribute_stats stats;
 	struct tdb_attribute_openhook openhook;
 	struct tdb_attribute_flock flock;
+	struct tdb_attribute_tdb1_hashsize tdb1_hashsize;
+	struct tdb_attribute_tdb1_max_dead tdb1_max_dead;
 };
 
 #ifdef  __cplusplus