Function QueryGraph_ExtractPatterns

src/graph/query_graph.c:341–368

clones patterns from 'qg' into 'graph'

// clones patterns from 'qg' into 'graph'
QueryGraph *QueryGraph_ExtractPatterns
(
	const QueryGraph *qg,
	const cypher_astnode_t **patterns,
	uint n
) {

	// validate inputs
	ASSERT(qg != NULL && patterns != NULL);

	// create an empty query graph
	uint node_count = QueryGraph_NodeCount(qg);
	uint edge_count = QueryGraph_EdgeCount(qg);
	QueryGraph *graph = QueryGraph_New(node_count, edge_count);
	ASSERT(graph != NULL);

	// extract paths described by each pattern
	for(uint i = 0; i < n; i++) {
		const cypher_astnode_t *pattern = patterns[i];
		uint npaths = cypher_ast_pattern_npaths(pattern);
		for(uint j = 0; j < npaths; j ++) {
			const cypher_astnode_t *path = cypher_ast_pattern_get_path(pattern, j);
			_QueryGraph_ExtractPath(qg, graph, path);
		}
	}

	return graph;
}

// build a query graph from AST
QueryGraph *BuildQueryGraph