tdb2: update documentation.

[ccan] / ccan / tdb2 / free.c

diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index 9af6f5d04ebf3afb6673fcaf11694e290e52d6df..efc29e884ea2078c54ed28616b9d0cdce1228ac1 100644 (file)
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -533,53 +533,6 @@ int set_header(struct tdb_context *tdb,
        return 0;
 }
 
-static tdb_len_t adjust_size(size_t keylen, size_t datalen, bool growing)
-{
-       tdb_len_t size = keylen + datalen;
-
-       if (size < MIN_DATA_LEN)
-               size = MIN_DATA_LEN;
-
-       /* Overallocate if this is coming from an enlarging store. */
-       if (growing)
-               size += datalen / 2;
-
-       /* Round to next uint64_t boundary. */
-       return (size + (sizeof(uint64_t) - 1ULL)) & ~(sizeof(uint64_t) - 1ULL);
-}
-
-/* If this fails, try tdb_expand. */
-tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen,
-               uint64_t hash, bool growing)
-{
-       tdb_off_t off;
-       tdb_len_t size, actual;
-       struct tdb_used_record rec;
-
-       /* We don't want header to change during this! */
-       assert(tdb->header_uptodate);
-
-       size = adjust_size(keylen, datalen, growing);
-
-       off = get_free(tdb, size, &actual);
-       if (unlikely(off == TDB_OFF_ERR || off == 0))
-               return off;
-
-       /* Some supergiant values can't be encoded. */
-       /* FIXME: Check before, and limit actual in get_free. */
-       if (set_header(tdb, &rec, keylen, datalen, actual, hash,
-                      tdb->zhdr.zone_bits) != 0) {
-               add_free_record(tdb, tdb->zhdr.zone_bits, off,
-                               sizeof(rec) + actual);
-               return TDB_OFF_ERR;
-       }
-
-       if (tdb_write_convert(tdb, off, &rec, sizeof(rec)) != 0)
-               return TDB_OFF_ERR;
-       
-       return off;
-}
-
 static bool zones_happy(struct tdb_context *tdb)
 {
        /* FIXME: look at distribution of zones. */
@@ -594,8 +547,7 @@ static tdb_len_t overhead(unsigned int zone_bits)
 }
 
 /* Expand the database (by adding a zone). */
-int tdb_expand(struct tdb_context *tdb, tdb_len_t klen, tdb_len_t dlen,
-              bool growing)
+static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 {
        uint64_t old_size;
        tdb_off_t off;
@@ -606,8 +558,7 @@ int tdb_expand(struct tdb_context *tdb, tdb_len_t klen, tdb_len_t dlen,
        bool enlarge_zone;
 
        /* We need room for the record header too. */
-       wanted = sizeof(struct tdb_used_record)
-               + (adjust_size(klen, dlen, growing)<<TDB_COMFORT_FACTOR_BITS);
+       wanted = sizeof(struct tdb_used_record) + size;
 
        /* Only one person can expand file at a time. */
        if (tdb_lock_expand(tdb, F_WRLCK) != 0)
@@ -667,6 +618,10 @@ int tdb_expand(struct tdb_context *tdb, tdb_len_t klen, tdb_len_t dlen,
        if (add_free_record(tdb, zone_bits, off, tdb->map_size-1-off) == -1)
                goto fail;
 
+       /* Try allocating from this zone now. */
+       tdb->zone_off = old_size - 1;
+       tdb->zhdr = zhdr;
+
 success:
        tdb_unlock_expand(tdb, F_WRLCK);
        return 0;
@@ -675,3 +630,57 @@ fail:
        tdb_unlock_expand(tdb, F_WRLCK);
        return -1;
 }
+
+static tdb_len_t adjust_size(size_t keylen, size_t datalen, bool growing)
+{
+       tdb_len_t size = keylen + datalen;
+
+       if (size < MIN_DATA_LEN)
+               size = MIN_DATA_LEN;
+
+       /* Overallocate if this is coming from an enlarging store. */
+       if (growing)
+               size += datalen / 2;
+
+       /* Round to next uint64_t boundary. */
+       return (size + (sizeof(uint64_t) - 1ULL)) & ~(sizeof(uint64_t) - 1ULL);
+}
+
+/* This won't fail: it will expand the database if it has to. */
+tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen,
+               uint64_t hash, bool growing)
+{
+       tdb_off_t off;
+       tdb_len_t size, actual;
+       struct tdb_used_record rec;
+
+       /* We don't want header to change during this! */
+       assert(tdb->header_uptodate);
+
+       size = adjust_size(keylen, datalen, growing);
+
+again:
+       off = get_free(tdb, size, &actual);
+       if (unlikely(off == TDB_OFF_ERR))
+               return off;
+
+       if (unlikely(off == 0)) {
+               if (tdb_expand(tdb, size) == -1)
+                       return TDB_OFF_ERR;
+               goto again;
+       }
+
+       /* Some supergiant values can't be encoded. */
+       /* FIXME: Check before, and limit actual in get_free. */
+       if (set_header(tdb, &rec, keylen, datalen, actual, hash,
+                      tdb->zhdr.zone_bits) != 0) {
+               add_free_record(tdb, tdb->zhdr.zone_bits, off,
+                               sizeof(rec) + actual);
+               return TDB_OFF_ERR;
+       }
+
+       if (tdb_write_convert(tdb, off, &rec, sizeof(rec)) != 0)
+               return TDB_OFF_ERR;
+       
+       return off;
+}