Function stmt_cache_add_new_entry

db/sql_stmt_cache.c:190–233

This will call stmt_cache_requeue_old_entry() after it has allocated memory for * the new entry. On error will return non zero and caller will need to * finalize_stmt(). */

 * the new entry. On error will return non zero and caller will need to
 * finalize_stmt(). */
int stmt_cache_add_new_entry(stmt_cache_t *stmt_cache, const char *sql,
                             const char *actual_sql, sqlite3_stmt *stmt,
                             struct sqlclntstate *clnt)
{
    if (!stmt_cache) {
        return 0;
    }

    if (strlen(sql) >= MAX_HASH_SQL_LENGTH) {
        return -1;
    }

    assert(stmt_cache->hash);

    /* stored procedure can call same stmt from a lua thread more than once so
     * we should not add stmt that exists already */
    if (hash_find(stmt_cache->hash, sql) != NULL) {
        return -1;
    }

    void *list = GET_STMT_LIST(stmt_cache, stmt);

    /* remove older entries to make room for new ones */
    if (gbl_max_sqlcache <= listc_size(list)) {
        stmt_cache_delete_last_entry(stmt_cache, list);
    }

    stmt_cache_entry_t *entry = sqlite3_malloc(sizeof(stmt_cache_entry_t));
    strncpy(entry->sql, sql, MAX_HASH_SQL_LENGTH - 1);
    entry->stmt = stmt;

    query_data_func(clnt, &entry->stmt_data, &entry->stmt_data_sz,
                    QUERY_STMT_DATA, QUERY_DATA_GET);
    /* Take ownership of stmt data */
    query_data_func(clnt, NULL, NULL, QUERY_STMT_DATA, QUERY_DATA_SET);
    entry->qd_func = clnt->plugin.query_data_func;

    if (actual_sql && gbl_debug_temptables)
        entry->query = strdup(actual_sql);
    else
        entry->query = NULL;

    return stmt_cache_requeue_old_entry(stmt_cache, entry);
}

int stmt_cache_find_and_remove_entry(stmt_cache_t *stmt_cache, const char *sql, stmt_cache_entry_t **entry)
{