tdb2: add TDB_ATTRIBUTE_TDB1_HASHSIZE

[ccan] / ccan / tdb2 / tdb2.h

diff --git a/ccan/tdb2/tdb2.h b/ccan/tdb2/tdb2.h
index 7a7aaca90fbfa7715749c5329fb447b63831b432..c91ca7cad08613d53e1bfa3f317f6197eea3db30 100644 (file)
--- a/ccan/tdb2/tdb2.h
+++ b/ccan/tdb2/tdb2.h
@@ -86,6 +86,7 @@ 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 */
 
 /**
  * tdb_close - close and free a tdb.
@@ -606,7 +607,8 @@ 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,
 };
 
 /**
@@ -630,8 +632,9 @@ 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 +673,20 @@ 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 +840,19 @@ 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.
  *
@@ -841,6 +871,7 @@ 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