More space for cnonce in hndl (match bb), save strlen

Signed-off-by: Salil Chandra <schandra107@bloomberg.net>

Author: chands10

cdb2api/cdb2api.c

@@ -4738,10 +4738,10 @@ static int cdb2_send_query(cdb2_hndl_tp *hndl, cdb2_hndl_tp *event_hndl, COMDB2B
         features[n_features++] = CDB2_CLIENT_FEATURES__ALLOW_MASTER_EXEC;
     }
 
-    if (hndl && hndl->cnonce[0]) { /* Have a query id associated with each transaction/query */
+    if (hndl && hndl->cnonce_len > 0) { /* Have a query id associated with each transaction/query */
         sqlquery.has_cnonce = 1;
         sqlquery.cnonce.data = (uint8_t *)hndl->cnonce;
-        sqlquery.cnonce.len = strlen(hndl->cnonce);
+        sqlquery.cnonce.len = hndl->cnonce_len;
     }
 
     CDB2SQLQUERY__Snapshotinfo snapshotinfo;
@@ -5286,12 +5286,20 @@ int cdb2_close(cdb2_hndl_tp *hndl)
     return rc;
 }
 
-void next_cnonce(cdb2_hndl_tp *hndl)
+static void make_random_str(char *str, size_t str_sz, int *len)
 {
     do_init_once(1);
     struct timeval tv;
     gettimeofday(&tv, NULL);
-    sprintf(hndl->cnonce, "%d-%d-%lld-%d", _MACHINE_ID, _PID, (long long)tv.tv_usec, cdb2_random_int());
+    int rc = snprintf(str, str_sz, "%d-%d-%lld-%d", _MACHINE_ID, _PID, (long long)tv.tv_usec, cdb2_random_int());
+    if (rc < 0 || (size_t)rc >= str_sz) {
+        // should not be possible to go here. 100 bytes is more than enough to fit the string for all numbers.
+        LOG_CALL("%s: snprintf failed or truncated (rc=%d str_sz=%zu)\n", __func__, rc, str_sz);
+        str[0] = '\0';
+        *len = 0;
+    } else {
+        *len = rc;
+    }
     return;
 }
 
@@ -6132,7 +6140,7 @@ static int cdb2_run_statement_typed_int(cdb2_hndl_tp *hndl, const char *sql, int
 
     if (!hndl->in_trans) { /* only one cnonce for a transaction. */
         clear_snapshot_info(hndl, __LINE__);
-        next_cnonce(hndl);
+        make_random_str(hndl->cnonce, sizeof(hndl->cnonce), &hndl->cnonce_len);
     }
     hndl->retry_all = 1;
     int run_last = 1;

cdb2api/cdb2api_hndl.h

@@ -49,20 +49,6 @@ struct cdb2_event {
     cdb2_event_arg argv[1];
 };
 
-/* A cnonce is composed of
-   - 32 bits of machine ID
-   - 32 bits of process PID
-   - 32 or 64 bits of handle address
-   - 52 bits for the epoch time in microseconds
-   - 12 bits for the sequence number
-
-   The allocation allows a handle to run at a maximum transaction rate of
-   4096 txn/us (~4 billion transactions per second) till September 17, 2112.
-
-   See next_cnonce() for details. */
-#define CNONCE_STR_FMT "%lx-%x-%llx-"
-#define CNONCE_STR_SZ 60 /* 16 + 1 + 8 + 1 + 16 + 1 + 16 + 1 (NUL) */
-
 struct cdb2_stmt_types;
 
 struct cdb2_query {
@@ -117,7 +103,8 @@ struct cdb2_hndl {
     int connected_host;
     int flags;
     char errstr[1024];
-    char cnonce[CNONCE_STR_SZ];
+    char cnonce[100];
+    int cnonce_len;
     char *sql;
     char partial_sql[64];
     int ntypes;