tdb2: direct access during transactions.

[ccan] / ccan / tdb2 / private.h

diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h
index b77d70c3ce6b0afa47eec11e2838a4cbbf4284ca..01172732980689ba3dd62a699ded3b38580ad9a9 100644 (file)
--- a/ccan/tdb2/private.h
+++ b/ccan/tdb2/private.h
@@ -91,6 +91,8 @@ typedef uint64_t tdb_off_t;
 #define TDB_SUBLEVEL_HASH_BITS 6
 /* And 8 entries in each group, ie 8 groups per sublevel. */
 #define TDB_HASH_GROUP_BITS 3
+/* This is currently 10: beyond this we chain. */
+#define TDB_MAX_LEVELS (1+(64-TDB_TOPLEVEL_HASH_BITS) / TDB_SUBLEVEL_HASH_BITS)
 
 /* Extend file by least 100 times larger than needed. */
 #define TDB_EXTENSION_FACTOR 100
@@ -212,6 +214,12 @@ struct tdb_recovery_record {
        uint64_t eof;
 };
 
+/* If we bottom out of the subhashes, we chain. */
+struct tdb_chain {
+       tdb_off_t rec[1 << TDB_HASH_GROUP_BITS];
+       tdb_off_t next;
+};
+
 /* this is stored at the front of every database */
 struct tdb_header {
        char magic_food[64]; /* for /etc/magic */
@@ -259,7 +267,7 @@ struct traverse_info {
                /* We ignore groups here, and treat it as a big array. */
                unsigned entry;
                unsigned int total_buckets;
-       } levels[64 / TDB_SUBLEVEL_HASH_BITS];
+       } levels[TDB_MAX_LEVELS + 1];
        unsigned int num_levels;
        unsigned int toplevel_group;
        /* This makes delete-everything-inside-traverse work as expected. */
@@ -282,6 +290,15 @@ struct tdb_lock_type {
        uint32_t ltype;
 };
 
+/* This is only needed for tdb_access_commit, but used everywhere to
+ * simplify. */
+struct tdb_access_hdr {
+       struct tdb_access_hdr *next;
+       tdb_off_t off;
+       tdb_len_t len;
+       bool convert;
+};
+
 struct tdb_context {
        /* Filename of the database. */
        const char *name;
@@ -336,6 +353,9 @@ struct tdb_context {
 
        struct tdb_attribute_stats *stats;
 
+       /* Direct access information */
+       struct tdb_access_hdr *access;
+
        /* Single list of all TDBs, to avoid multiple opens. */
        struct tdb_context *next;
        dev_t device;   
@@ -347,7 +367,7 @@ struct tdb_methods {
        int (*write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t);
        int (*oob)(struct tdb_context *, tdb_off_t, bool);
        int (*expand_file)(struct tdb_context *, tdb_len_t);
-       void *(*direct)(struct tdb_context *, tdb_off_t, size_t);
+       void *(*direct)(struct tdb_context *, tdb_off_t, size_t, bool);
 };
 
 /*
@@ -427,9 +447,6 @@ const void *tdb_access_read(struct tdb_context *tdb,
 void *tdb_access_write(struct tdb_context *tdb,
                       tdb_off_t off, tdb_len_t len, bool convert);
 
-/* Is this pointer direct?  (Otherwise it's malloced) */
-bool is_direct(const struct tdb_context *tdb, const void *p);
-
 /* Release result of tdb_access_read/write. */
 void tdb_access_release(struct tdb_context *tdb, const void *p);
 /* Commit result of tdb_acces_write. */