Versioned sc structs

Signed-off-by: Mark Hannum <[email protected]>

bdb/llmeta.c

@@ -118,7 +118,7 @@ typedef enum {
                                   data = no data
                                   does db use authentication? */
     ,
-    LLMETA_ACCESSCONTROL_TABLExNODE = 19  /* XXX Deprecated */
+    LLMETA_ACCESSCONTROL_TABLExNODE = 19 /* XXX Deprecated */
 
     ,
     LLMETA_SQLITE_STAT1_PREV_DONT_USE = 20 /* store previous sqlite-stat1 records- dont use this. */
@@ -176,7 +176,8 @@ typedef enum {
     LLMETA_LUA_SFUNC_FLAG = 54,
     LLMETA_NEWSC_REDO_GENID = 55, /* 55 + TABLENAME + GENID -> MAX-LSN */
     LLMETA_SCHEMACHANGE_STATUS_V2 = 56,
-    LLMETA_SCHEMACHANGE_LIST = 57, /* list of all sc-s in a uuid txh */
+    LLMETA_SCHEMACHANGE_STATUS_VERSIONED = 57,
+    LLMETA_SCHEMACHANGE_LIST = 58, /* list of all sc-s in a uuid txh */
 } llmetakey_t;
 
 struct llmeta_file_type_key {
@@ -11336,14 +11337,18 @@ int bdb_del_view(tran_type *t, const char *view_name)
   coincide with the first 4 bytes of the rqid (fastseed) stored as the first
   member in old (7.0's) LLMETA_SCHEMACHANGE_STATUS payload.
 */
-static int buf_get_schemachange_key_type(void *p_buf, void *p_buf_end)
+static int buf_get_schemachange_key_type(void *p_buf, void *p_buf_end, int *version)
 {
     int first = 0;
 
     if (p_buf >= p_buf_end) return -1;
 
-    buf_get(&first, sizeof(first), p_buf, p_buf_end);
+    p_buf = (void *)buf_get(&first, sizeof(first), p_buf, p_buf_end);
 
+    if (first == SC_VERSIONED) {
+        buf_get(version, sizeof(int), p_buf, p_buf_end);
+        return LLMETA_SCHEMACHANGE_STATUS_VERSIONED;
+    }
     if (first > SC_INVALID && first < SC_LAST) {
         return LLMETA_SCHEMACHANGE_STATUS_V2;
     }
@@ -11353,9 +11358,18 @@ static int buf_get_schemachange_key_type(void *p_buf, void *p_buf_end)
 void *buf_get_schemachange(struct schema_change_type *s, void *p_buf,
                            void *p_buf_end)
 {
-    int sc_key_type = buf_get_schemachange_key_type(p_buf, p_buf_end);
+    int version;
+    int sc_key_type = buf_get_schemachange_key_type(p_buf, p_buf_end, &version);
 
     switch (sc_key_type) {
+    case LLMETA_SCHEMACHANGE_STATUS_VERSIONED:
+        if (version == 2) {
+            p_buf = p_buf + sizeof(int) + sizeof(int);
+            return buf_get_schemachange_v2(s, (void *)p_buf, (void *)p_buf_end);
+        } else {
+            logmsg(LOGMSG_FATAL, "%s: unknown version %d\n", __func__, version);
+            abort();
+        }
     case LLMETA_SCHEMACHANGE_STATUS:
         return buf_get_schemachange_v1(s, (void *)p_buf, (void *)p_buf_end);
     case LLMETA_SCHEMACHANGE_STATUS_V2:

db/config.c

@@ -447,6 +447,8 @@ static char *legacy_options[] = {
     "setattr max_sql_idle_time 864000",
     "retrieve_gen_from_ckp 0",
     "recovery_ckp 0",
+    "sc_versioned 0",
+    "sc_current_version 2",
 };
 // clang-format on
 

db/db_tunables.c

@@ -304,6 +304,8 @@ extern int gbl_memp_dump_cache_threshold;
 extern int gbl_disable_ckp;
 extern int gbl_abort_on_illegal_log_put;
 extern int gbl_sc_close_txn;
+extern int gbl_sc_versioned;
+extern int gbl_sc_current_version;
 extern int gbl_master_sends_query_effects;
 extern int gbl_create_dba_user;
 extern int gbl_lock_dba_user;

db/db_tunables.h

@@ -2385,6 +2385,10 @@ REGISTER_TUNABLE("wal_osync", "Open WAL files using the O_SYNC flag (Default: of
                  NULL, NULL, NULL, NULL);
 REGISTER_TUNABLE("sc_headroom", "Percentage threshold for low headroom calculation. (Default: 10)", TUNABLE_DOUBLE,
                  &gbl_sc_headroom, INTERNAL | SIGNED, NULL, NULL, NULL, NULL);
+REGISTER_TUNABLE("sc_versioned", "Enable versioned schema changes (Default: on)", TUNABLE_BOOLEAN, &gbl_sc_versioned, 0,
+                 NULL, NULL, NULL, NULL);
+REGISTER_TUNABLE("sc_current_version", "Current schema-change version (Default: 2)", TUNABLE_INTEGER,
+                 &gbl_sc_current_version, 0, NULL, NULL, NULL, NULL);
 REGISTER_TUNABLE("fdb_incoherence_percentage", "Generate random incoherent errors in remsql", TUNABLE_INTEGER,
                  &gbl_fdb_incoherence_percentage, INTERNAL, NULL, percent_verify, NULL, NULL);
 REGISTER_TUNABLE("fdb_socket_timeout_ms", "Timeout ms for fdb communications.  (Default: 10000)", TUNABLE_INTEGER,

schemachange/sc_struct.c

@@ -132,6 +132,10 @@ static size_t _partition_packed_size(struct comdb2_partition *p)
     }
 }
 
+/* When changing, increment & set legacy-defaults to old */
+int gbl_sc_current_version = 2;
+int gbl_sc_versioned = 1;
+
 size_t schemachange_packed_size(struct schema_change_type *s)
 {
     s->tablename_len = strlen(s->tablename) + 1;
@@ -161,6 +165,15 @@ size_t schemachange_packed_size(struct schema_change_type *s)
         sizeof(s->usedbtablevers) + sizeof(s->qdb_file_ver) +
         _partition_packed_size(&s->partition);
 
+    if (gbl_sc_versioned) {
+        /*
+        if (sc_current_version == 3) {
+            s->packed_len += XXXX;
+        }
+        */
+        s->packed_len += 8;
+    }
+
     return s->packed_len;
 }
 
@@ -189,6 +202,13 @@ void *buf_put_schemachange(struct schema_change_type *s, void *p_buf, void *p_bu
 
     if (p_buf >= p_buf_end) return NULL;
 
+    /* To change, increment SC_VERSION, and create new buf_get_schemachange_v[X] */
+    if (gbl_sc_versioned) {
+        int neg1 = -1, vers = gbl_sc_current_version;
+        p_buf = buf_put(&neg1, sizeof(neg1), p_buf, p_buf_end);
+        p_buf = buf_put(&vers, sizeof(vers), p_buf, p_buf_end);
+    }
+
     p_buf = buf_put(&s->kind, sizeof(s->kind), p_buf, p_buf_end);
 
     p_buf = buf_put(&s->rqid, sizeof(s->rqid), p_buf, p_buf_end);

schemachange/schemachange.h

@@ -90,6 +90,7 @@ struct timepart_view;
 
 /* in sync with do_schema_change_if */
 enum schema_change_kind {
+    SC_VERSIONED = -1,
     SC_INVALID = 0,
     SC_LEGACY_QUEUE = 1,
     SC_LEGACY_MORESTRIPE = 2,