tdb2: feature support.

[ccan] / ccan / tdb2 / private.h

diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h
index 9abed97df08cdbe4b1fea9b9463adc8133ac72a2..8e7df501b716a139c77e8de2ff673fe1afa55266 100644 (file)
--- a/ccan/tdb2/private.h
+++ b/ccan/tdb2/private.h
@@ -18,8 +18,7 @@
    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
 
-#define _XOPEN_SOURCE 500
-#define _FILE_OFFSET_BITS 64
+#include "config.h"
 #include <stdint.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -33,7 +32,6 @@
 #include <stdio.h>
 #include <utime.h>
 #include <unistd.h>
-#include "config.h"
 #include <ccan/tdb2/tdb2.h>
 #include <ccan/likely/likely.h>
 #include <ccan/compiler/compiler.h>
@@ -73,7 +71,6 @@ typedef uint64_t tdb_off_t;
 #define TDB_RECOVERY_MAGIC (0xf53bc0e7ad124589ULL)
 #define TDB_RECOVERY_INVALID_MAGIC (0x0ULL)
 
-#define TDB_OFF_ERR ((tdb_off_t)-1)
 #define TDB_OFF_IS_ERR(off) unlikely(off >= (tdb_off_t)TDB_ERR_LAST)
 
 /* Packing errors into pointers and v.v. */
@@ -119,6 +116,9 @@ typedef int tdb_bool_err;
 #define TDB_OFF_HASH_EXTRA_BIT 57
 #define TDB_OFF_UPPER_STEAL_SUBHASH_BIT 56
 
+/* Additional features we understand.  Currently: none. */
+#define TDB_FEATURE_MASK ((uint64_t)0)
+
 /* The bit number where we store the extra hash bits. */
 /* Convenience mask to get actual offset. */
 #define TDB_OFF_MASK \
@@ -243,7 +243,10 @@ struct tdb_header {
        tdb_off_t free_table; /* (First) free table. */
        tdb_off_t recovery; /* Transaction recovery area. */
 
-       tdb_off_t reserved[26];
+       uint64_t features_used; /* Features all writers understand */
+       uint64_t features_offered; /* Features offered */
+
+       tdb_off_t reserved[24];
 
        /* Top level hash table. */
        tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS];
@@ -394,13 +397,13 @@ struct tdb_methods {
 /* hash.c: */
 void tdb_hash_init(struct tdb_context *tdb);
 
-int first_in_hash(struct tdb_context *tdb,
-                 struct traverse_info *tinfo,
-                 TDB_DATA *kbuf, size_t *dlen);
+tdb_bool_err first_in_hash(struct tdb_context *tdb,
+                          struct traverse_info *tinfo,
+                          TDB_DATA *kbuf, size_t *dlen);
 
-int next_in_hash(struct tdb_context *tdb,
-                struct traverse_info *tinfo,
-                TDB_DATA *kbuf, size_t *dlen);
+tdb_bool_err next_in_hash(struct tdb_context *tdb,
+                         struct traverse_info *tinfo,
+                         TDB_DATA *kbuf, size_t *dlen);
 
 /* Hash random memory. */
 uint64_t tdb_hash(struct tdb_context *tdb, const void *ptr, size_t len);
@@ -416,45 +419,45 @@ tdb_off_t find_and_lock(struct tdb_context *tdb,
                        struct tdb_used_record *rec,
                        struct traverse_info *tinfo);
 
-int replace_in_hash(struct tdb_context *tdb,
-                   struct hash_info *h,
-                   tdb_off_t new_off);
+enum TDB_ERROR replace_in_hash(struct tdb_context *tdb,
+                              struct hash_info *h,
+                              tdb_off_t new_off);
 
-int add_to_hash(struct tdb_context *tdb, struct hash_info *h,
-               tdb_off_t new_off);
+enum TDB_ERROR add_to_hash(struct tdb_context *tdb, struct hash_info *h,
+                          tdb_off_t new_off);
 
-int delete_from_hash(struct tdb_context *tdb, struct hash_info *h);
+enum TDB_ERROR delete_from_hash(struct tdb_context *tdb, struct hash_info *h);
 
 /* For tdb_check */
 bool is_subhash(tdb_off_t val);
 
 /* free.c: */
-int tdb_ftable_init(struct tdb_context *tdb);
+enum TDB_ERROR tdb_ftable_init(struct tdb_context *tdb);
 
 /* check.c needs these to iterate through free lists. */
 tdb_off_t first_ftable(struct tdb_context *tdb);
 tdb_off_t next_ftable(struct tdb_context *tdb, tdb_off_t ftable);
 
-/* This returns space or TDB_OFF_ERR. */
+/* This returns space or -ve error number. */
 tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen,
                uint64_t hash, unsigned magic, bool growing);
 
 /* Put this record in a free list. */
-int add_free_record(struct tdb_context *tdb,
-                   tdb_off_t off, tdb_len_t len_with_header);
+enum TDB_ERROR add_free_record(struct tdb_context *tdb,
+                              tdb_off_t off, tdb_len_t len_with_header);
 
 /* Set up header for a used/ftable/htable/chain record. */
-int set_header(struct tdb_context *tdb,
-              struct tdb_used_record *rec,
-              unsigned magic, uint64_t keylen, uint64_t datalen,
-              uint64_t actuallen, unsigned hashlow);
+enum TDB_ERROR set_header(struct tdb_context *tdb,
+                         struct tdb_used_record *rec,
+                         unsigned magic, uint64_t keylen, uint64_t datalen,
+                         uint64_t actuallen, unsigned hashlow);
 
 /* Used by tdb_check to verify. */
 unsigned int size_to_bucket(tdb_len_t data_len);
 tdb_off_t bucket_off(tdb_off_t ftable_off, unsigned bucket);
 
 /* Used by tdb_summary */
-size_t dead_space(struct tdb_context *tdb, tdb_off_t off);
+tdb_off_t dead_space(struct tdb_context *tdb, tdb_off_t off);
 
 /* io.c: */
 /* Initialize tdb->methods. */
@@ -561,8 +564,8 @@ bool tdb_has_expansion_lock(struct tdb_context *tdb);
 enum TDB_ERROR tdb_lock_and_recover(struct tdb_context *tdb);
 
 /* transaction.c: */
-int tdb_transaction_recover(struct tdb_context *tdb);
-bool tdb_needs_recovery(struct tdb_context *tdb);
+enum TDB_ERROR tdb_transaction_recover(struct tdb_context *tdb);
+tdb_bool_err tdb_needs_recovery(struct tdb_context *tdb);
 
 /* tdb.c: */
 enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,