Method get_available_columns

xtop/core/query_engine.py:246–274

Get available columns for dynamic query. Executes the query with LIMIT 0 and DESCRIBE to get column info.

(self, params: QueryParams = None)

        return self.execute(query, params, debug, debug_profile)
    
    def get_available_columns(self, params: QueryParams = None) -> List[str]:
        """
        Get available columns for dynamic query.
        Executes the query with LIMIT 0 and DESCRIBE to get column info.
        """
        if params is None:
            params = QueryParams()
        
        # Prepare query with LIMIT 0
        original_limit = params.limit
        params.limit = 0
        query = self.prepare_query(params)
        params.limit = original_limit
        
        # Remove any existing LIMIT clause and add LIMIT 0
        import re
        query = re.sub(r'\s+LIMIT\s+\d+\s*$', '', query, flags=re.IGNORECASE)
        query = query.rstrip().rstrip(';')
        
        # Use DESCRIBE to get column info
        describe_query = f"DESCRIBE ({query} LIMIT 0)"
        
        conn = self.data_source.connect()
        try:
            result = conn.execute(describe_query).fetchall()
            return [row[0] for row in result]
        except Exception as e:
            print(f"Error getting columns: {e}", file=sys.stderr)
            return []
    
    def lookup_stack_trace(self, stack_hash: str, is_kernel: bool = True) -> Optional[str]:
        """Look up a stack trace by its hash from kstacks/ustacks CSV"""