tdb2: TDB_SEQNUM and tdb_get_seqnum support.

As per TDB1, except that the sequence number is 63 bit.

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index 7e5dcb73160f4a441e6e978349e04c2bca5cbaa4..0e27e1d0faea07a2d8640e46db187a0298afcfb8 100644 (file)
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -563,6 +563,35 @@ static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len,
        return (char *)tdb->file->map_ptr + off;
 }
 
        return (char *)tdb->file->map_ptr + off;
 }
 

+void tdb_inc_seqnum(struct tdb_context *tdb)
+{
+       tdb_off_t seq;
+
+       if (likely(!(tdb->flags & TDB_CONVERT))) {
+               int64_t *direct;
+
+               direct = tdb->methods->direct(tdb,
+                                             offsetof(struct tdb_header,
+                                                      seqnum),
+                                             sizeof(*direct), true);
+               if (likely(direct)) {
+                       /* Don't let it go negative, even briefly */
+                       if (unlikely((*direct) + 1) < 0)
+                               *direct = 0;
+                       (*direct)++;
+                       return;
+               }
+       }
+
+       seq = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
+       if (!TDB_OFF_IS_ERR(seq)) {
+               seq++;
+               if (unlikely((int64_t)seq < 0))
+                       seq = 0;
+               tdb_write_off(tdb, offsetof(struct tdb_header, seqnum), seq);
+       }
+}
+

 void add_stat_(struct tdb_context *tdb, uint64_t *s, size_t val)
 {
        if ((uintptr_t)s < (uintptr_t)tdb->stats + tdb->stats->size)
 void add_stat_(struct tdb_context *tdb, uint64_t *s, size_t val)
 {
        if ((uintptr_t)s < (uintptr_t)tdb->stats + tdb->stats->size)

diff --git a/ccan/tdb2/open.c b/ccan/tdb2/open.c
index 473dc98b7e4c68d78da0be268c5434ab70042b3a..f2d23aed9cc2abe07cf1d1624f266c63ebd1797e 100644 (file)
--- a/ccan/tdb2/open.c
+++ b/ccan/tdb2/open.c
@@ -107,6 +107,7 @@ static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
                                         tdb->hash_priv);
        newdb.hdr.recovery = 0;
        newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
                                         tdb->hash_priv);
        newdb.hdr.recovery = 0;
        newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;

+       newdb.hdr.seqnum = 0;

        memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
        /* Initial hashes are empty. */
        memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
        memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
        /* Initial hashes are empty. */
        memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));


@@ -243,7 +244,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        }
 
        if (tdb_flags & ~(TDB_INTERNAL | TDB_NOLOCK | TDB_NOMMAP | TDB_CONVERT
        }
 
        if (tdb_flags & ~(TDB_INTERNAL | TDB_NOLOCK | TDB_NOMMAP | TDB_CONVERT

-                         | TDB_NOSYNC)) {
+                         | TDB_NOSYNC | TDB_SEQNUM)) {

                ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                                   "tdb_open: unknown flags %u", tdb_flags);
                goto fail;
                ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                                   "tdb_open: unknown flags %u", tdb_flags);
                goto fail;

diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h
index 4e7fc8ffeccaba5e2ab13348cf02a23bcbbb15bf..030b46ca38a2fbe1e4b751ebe7717133d98a37d3 100644 (file)
--- a/ccan/tdb2/private.h
+++ b/ccan/tdb2/private.h
@@ -246,7 +246,9 @@ struct tdb_header {
        uint64_t features_used; /* Features all writers understand */
        uint64_t features_offered; /* Features offered */
 
        uint64_t features_used; /* Features all writers understand */
        uint64_t features_offered; /* Features offered */
 

-       tdb_off_t reserved[24];
+       uint64_t seqnum; /* Sequence number for TDB_SEQNUM */
+
+       tdb_off_t reserved[23];

 
        /* Top level hash table. */
        tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS];
 
        /* Top level hash table. */
        tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS];


@@ -523,6 +525,9 @@ enum TDB_ERROR tdb_write_convert(struct tdb_context *tdb, tdb_off_t off,
 enum TDB_ERROR tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
                                void *rec, size_t len);
 
 enum TDB_ERROR tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
                                void *rec, size_t len);
 

+/* Bump the seqnum (caller checks for tdb->flags & TDB_SEQNUM) */
+void tdb_inc_seqnum(struct tdb_context *tdb);
+

 /* Adds a stat, if it's in range. */
 void add_stat_(struct tdb_context *tdb, uint64_t *stat, size_t val);
 #define add_stat(tdb, statname, val)                                   \
 /* Adds a stat, if it's in range. */
 void add_stat_(struct tdb_context *tdb, uint64_t *stat, size_t val);
 #define add_stat(tdb, statname, val)                                   \

diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c
index 79ccd0f1c260cb476b35c146f15a9438f843a673..569c3d04de90241217754a9602da34f747eaa22b 100644 (file)
--- a/ccan/tdb2/tdb.c
+++ b/ccan/tdb2/tdb.c
@@ -63,7 +63,9 @@ static enum TDB_ERROR replace_data(struct tdb_context *tdb,
                return ecode;
        }
 
                return ecode;
        }
 

-       /* FIXME: tdb_increment_seqnum(tdb); */
+       if (tdb->flags & TDB_SEQNUM)
+               tdb_inc_seqnum(tdb);
+

        return TDB_SUCCESS;
 }
 
        return TDB_SUCCESS;
 }
 


@@ -79,6 +81,9 @@ static enum TDB_ERROR update_data(struct tdb_context *tdb,
                /* Put a zero in; future versions may append other data. */
                ecode = tdb->methods->twrite(tdb, off + dbuf.dsize, "", 1);
        }
                /* Put a zero in; future versions may append other data. */
                ecode = tdb->methods->twrite(tdb, off + dbuf.dsize, "", 1);
        }

+       if (tdb->flags & TDB_SEQNUM)
+               tdb_inc_seqnum(tdb);
+

        return ecode;
 }
 
        return ecode;
 }
 


@@ -285,6 +290,9 @@ enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
                                + rec_data_length(&rec)
                                + rec_extra_padding(&rec));
 
                                + rec_data_length(&rec)
                                + rec_extra_padding(&rec));
 

+       if (tdb->flags & TDB_SEQNUM)
+               tdb_inc_seqnum(tdb);
+

 unlock:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
        return ecode;
 unlock:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
        return ecode;


@@ -313,6 +321,9 @@ void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
        case TDB_NOSYNC:
                tdb->flags |= TDB_NOSYNC;
                break;
        case TDB_NOSYNC:
                tdb->flags |= TDB_NOSYNC;
                break;

+       case TDB_SEQNUM:
+               tdb->flags |= TDB_SEQNUM;
+               break;

        default:
                tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                           "tdb_add_flag: Unknown flag %u", flag);
        default:
                tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                           "tdb_add_flag: Unknown flag %u", flag);


@@ -337,6 +348,9 @@ void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
        case TDB_NOSYNC:
                tdb->flags &= ~TDB_NOSYNC;
                break;
        case TDB_NOSYNC:
                tdb->flags &= ~TDB_NOSYNC;
                break;

+       case TDB_SEQNUM:
+               tdb->flags &= ~TDB_SEQNUM;
+               break;

        default:
                tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                           "tdb_remove_flag: Unknown flag %u", flag);
        default:
                tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                           "tdb_remove_flag: Unknown flag %u", flag);


@@ -433,6 +447,12 @@ const char *tdb_name(const struct tdb_context *tdb)
        return tdb->name;
 }
 
        return tdb->name;
 }
 

+int64_t tdb_get_seqnum(struct tdb_context *tdb)
+{
+       return tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
+}
+       
+

 int tdb_fd(const struct tdb_context *tdb)
 {
        return tdb->file->fd;
 int tdb_fd(const struct tdb_context *tdb)
 {
        return tdb->file->fd;

diff --git a/ccan/tdb2/tdb2.h b/ccan/tdb2/tdb2.h
index f934a7bf3baa70cb9fe27aa1731fe7dae771ba73..0940be1ceac40797435eaaa6241cbdd0e787484f 100644 (file)
--- a/ccan/tdb2/tdb2.h
+++ b/ccan/tdb2/tdb2.h
@@ -78,6 +78,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 #define TDB_NOMMAP   8 /* don't use mmap */
 #define TDB_CONVERT 16 /* convert endian */
 #define TDB_NOSYNC   64 /* don't use synchronous transactions */
 #define TDB_NOMMAP   8 /* don't use mmap */
 #define TDB_CONVERT 16 /* convert endian */
 #define TDB_NOSYNC   64 /* don't use synchronous transactions */

+#define TDB_SEQNUM   128 /* maintain a sequence number */

 
 /**
  * tdb_close - close and free a tdb.
 
 /**
  * tdb_close - close and free a tdb.


@@ -323,6 +324,25 @@ enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
                                                         TDB_DATA data,
                                                         void *p),
                                 void *p);
                                                         TDB_DATA data,
                                                         void *p),
                                 void *p);

+
+/**
+ * tdb_get_seqnum - get a database sequence number
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * This returns a sequence number: any change to the database from a
+ * tdb context opened with the TDB_SEQNUM flag will cause that number
+ * to increment.  Note that the incrementing is unreliable (it is done
+ * without locking), so this is only useful as an optimization.
+ *
+ * For example, you may have a regular database backup routine which
+ * does not operate if the sequence number is unchanged.  In the
+ * unlikely event of a failed increment, it will be backed up next
+ * time any way.
+ *
+ * Returns an enum TDB_ERROR (ie. negative) on error.
+ */
+int64_t tdb_get_seqnum(struct tdb_context *tdb);
+

 /**
  * tdb_firstkey - get the "first" key in a TDB
  * @tdb: the tdb context returned from tdb_open()
 /**
  * tdb_firstkey - get the "first" key in a TDB
  * @tdb: the tdb context returned from tdb_open()

diff --git a/ccan/tdb2/test/failtest_helper.h b/ccan/tdb2/test/failtest_helper.h
index c26774f32333dc0c5ed0b0c2d2a5066468a55e8a..6a02cdb0ec626fce20c9741ec1590b8c0120036d 100644 (file)
--- a/ccan/tdb2/test/failtest_helper.h
+++ b/ccan/tdb2/test/failtest_helper.h
@@ -4,7 +4,7 @@
 #include <stdbool.h>
 
 /* FIXME: Check these! */
 #include <stdbool.h>
 
 /* FIXME: Check these! */

-#define INITIAL_TDB_MALLOC     "open.c", 198, FAILTEST_MALLOC
+#define INITIAL_TDB_MALLOC     "open.c", 199, FAILTEST_MALLOC

 #define URANDOM_OPEN           "open.c", 44, FAILTEST_OPEN
 #define URANDOM_READ           "open.c", 24, FAILTEST_READ
 
 #define URANDOM_OPEN           "open.c", 44, FAILTEST_OPEN
 #define URANDOM_READ           "open.c", 24, FAILTEST_READ
 

diff --git a/ccan/tdb2/test/run-81-seqnum.c b/ccan/tdb2/test/run-81-seqnum.c
new file mode 100644 (file)
index 0000000..db42b97
--- /dev/null
+++ b/ccan/tdb2/test/run-81-seqnum.c
@@ -0,0 +1,71 @@
+#include <ccan/tdb2/tdb.c>
+#include <ccan/tdb2/open.c>
+#include <ccan/tdb2/free.c>
+#include <ccan/tdb2/lock.c>
+#include <ccan/tdb2/io.c>
+#include <ccan/tdb2/hash.c>
+#include <ccan/tdb2/transaction.c>
+#include <ccan/tdb2/traverse.c>
+#include <ccan/tdb2/check.c>
+#include <ccan/tap/tap.h>
+#include "logging.h"
+
+int main(int argc, char *argv[])
+{
+       unsigned int i;
+       struct tdb_context *tdb;
+       struct tdb_data d = { NULL, 0 }; /* Bogus GCC warning */
+       struct tdb_data key = { (unsigned char *)"key", 3 };
+       struct tdb_data data = { (unsigned char *)"data", 4 };
+       int flags[] = { TDB_INTERNAL, TDB_DEFAULT, TDB_NOMMAP,
+                       TDB_INTERNAL|TDB_CONVERT, TDB_CONVERT,
+                       TDB_NOMMAP|TDB_CONVERT };
+
+       plan_tests(sizeof(flags) / sizeof(flags[0]) * 15 + 4 * 13);
+       for (i = 0; i < sizeof(flags) / sizeof(flags[0]); i++) {
+               tdb = tdb_open("run-new_database.tdb", flags[i]|TDB_SEQNUM,
+                              O_RDWR|O_CREAT|O_TRUNC, 0600, &tap_log_attr);
+               if (!ok1(tdb))
+                       continue;
+               
+               ok1(tdb_get_seqnum(tdb) == 0);
+               ok1(tdb_store(tdb, key, data, TDB_INSERT) == 0);
+               ok1(tdb_get_seqnum(tdb) == 1);
+               /* Fetch doesn't change seqnum */
+               if (ok1(tdb_fetch(tdb, key, &d) == TDB_SUCCESS))
+                       free(d.dptr);
+               ok1(tdb_get_seqnum(tdb) == 1);
+               ok1(tdb_append(tdb, key, data) == TDB_SUCCESS);
+               ok1(tdb_get_seqnum(tdb) == 2);
+
+               ok1(tdb_delete(tdb, key) == TDB_SUCCESS);
+               ok1(tdb_get_seqnum(tdb) == 3);
+               /* Empty append works */
+               ok1(tdb_append(tdb, key, data) == TDB_SUCCESS);
+               ok1(tdb_get_seqnum(tdb) == 4);
+
+               ok1(tdb_wipe_all(tdb) == TDB_SUCCESS);
+               ok1(tdb_get_seqnum(tdb) == 5);
+
+               if (!(flags[i] & TDB_INTERNAL)) {
+                       ok1(tdb_transaction_start(tdb) == TDB_SUCCESS);
+                       ok1(tdb_store(tdb, key, data, TDB_INSERT) == 0);
+                       ok1(tdb_get_seqnum(tdb) == 6);
+                       ok1(tdb_append(tdb, key, data) == TDB_SUCCESS);
+                       ok1(tdb_get_seqnum(tdb) == 7);
+                       ok1(tdb_delete(tdb, key) == TDB_SUCCESS);
+                       ok1(tdb_get_seqnum(tdb) == 8);
+                       ok1(tdb_transaction_commit(tdb) == TDB_SUCCESS);
+                       ok1(tdb_get_seqnum(tdb) == 8);
+
+                       ok1(tdb_transaction_start(tdb) == TDB_SUCCESS);
+                       ok1(tdb_store(tdb, key, data, TDB_INSERT) == 0);
+                       ok1(tdb_get_seqnum(tdb) == 9);
+                       tdb_transaction_cancel(tdb);
+                       ok1(tdb_get_seqnum(tdb) == 8);
+               }
+               tdb_close(tdb);
+               ok1(tap_log_messages == 0);
+       }
+       return exit_status();
+}