tdb2: tdb_repack

[ccan] / ccan / tdb2 / tdb2.h

diff --git a/ccan/tdb2/tdb2.h b/ccan/tdb2/tdb2.h
index 5643ef4f8a1e2aeae9736dc8a18fbe29380b7ca8..76ecbe5b9d7d59369063fe65b011ae0fc990ff99 100644 (file)
--- a/ccan/tdb2/tdb2.h
+++ b/ccan/tdb2/tdb2.h
@@ -85,6 +85,8 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 #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 */
+#define TDB_RDONLY   512 /* implied by O_RDONLY */
+#define TDB_VERSION1  1024 /* create/open an old style TDB */
 
 /**
  * tdb_close - close and free a tdb.
@@ -503,6 +505,16 @@ 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()
@@ -605,7 +617,8 @@ 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,
 };
 
 /**
@@ -616,8 +629,6 @@ enum tdb_attribute_type {
  * This gets an attribute from a TDB which has previously been set (or
  * may return the default values).  Set @attr.base.attr to the
  * attribute type you want get.
- *
- * Currently this does not work for TDB_ATTRIBUTE_OPENHOOK.
  */
 enum TDB_ERROR tdb_get_attribute(struct tdb_context *tdb,
                                 union tdb_attribute *attr);
@@ -631,8 +642,9 @@ 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);
@@ -671,6 +683,20 @@ 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.
  */
@@ -824,6 +850,19 @@ 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;
+};
+
 /**
  * union tdb_attribute - tdb attributes.
  *
@@ -842,6 +881,7 @@ 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;
 };
 
 #ifdef  __cplusplus