pydevDAG._compare module

pydevDAG._compare

Compare graphs to determine if they represent the same storage configuration.

class pydevDAG._compare.Compare

Bases: object

Compare two storage graphs.

classmethod is_equivalent(graph1, graph2, node_match, edge_match)

Whether these graphs represent equivalent storage configurations.

Parameters:

• graph1 – a graph
• graph2 – a graph
• node_match (node * node -> bool) – a function that checks whether nodes are equal
• edge_match (node * node -> bool) – a function that checks whether edges are equal

Returns:

True if the graphs are equivalent, otherwise False

Return type:

bool

class pydevDAG._compare.Differences

Bases: object

Find the differences between two graphs, if they exist.

static edge_differences(graph1, graph2, edges_equal)

Find the edge differences between graph1 and graph2 as a pair of graphs.

Parameters:

• graph1 (DiGraph) – a graph
• graph2 (DiGraph) – a graph
• edge_equal (DiGraph * DiGraph -> edge * edge -> bool) – a function that checks if two edges are equal

Returns:

a pair of graphs, representing graph1 - graph2 and vice-versa

Return type:

tuple of DiGraph

classmethod full_diff(graph1, graph2, node_equal=<function <lambda> at 0x7fa3c18c17d0>, edge_equal=<function <lambda> at 0x7fa3c18c1848>)

Return a graph that shows the full difference between graph1 and graph2.

Parameters:

• graph1 (DiGraph) – a graph
• graph2 (DiGraph) – a graph
• node_equal (DiGraph * DiGraph -> node * node -> bool) – a function that determines if two nodes are equal
• edge_equal (DiGraph * DiGraph -> edge * edge -> bool) – a function that determines if two edges are equal

Returns:

an annotated graph composed of graph1 and graph2

Return type:

DiGraph

classmethod left_diff(graph1, graph2, node_equal=<function <lambda> at 0x7fa3c18c1938>, edge_equal=<function <lambda> at 0x7fa3c18c19b0>)

Return a graph of the left difference between graph1 and graph2.

Parameters:

• graph1 (DiGraph) – a graph
• graph2 (DiGraph) – a graph
• node_equal (DiGraph * DiGraph -> node * node -> bool) – a function that determines if two nodes are equal
• edge_equal (DiGraph * DiGraph -> edge * edge -> bool) – a function that determines if two edges are equal

Returns:

graph1 with removed nodes marked

Return type:

DiGraph

static node_differences(graph1, graph2, node_equal)

Find the differences between graph1 and graph2 as a pair of graphs.

Parameters:

• graph1 (DiGraph) – a graph
• graph2 (DiGraph) – a graph
• node_equal (DiGraph * DiGraph -> node * node -> bool) – a function that checks if two nodes are equal

Returns:

a pair of graphs, representing graph1 - graph2 and vice-versa

Return type:

tuple of DiGraph

classmethod right_diff(graph1, graph2, node_equal=<function <lambda> at 0x7fa3c18c1aa0>, edge_equal=<function <lambda> at 0x7fa3c18c1b18>)

Return a graph of the right difference between graph1 and graph2.

Parameters:

• graph1 (DiGraph) – a graph
• graph2 (DiGraph) – a graph
• node_equal (DiGraph * DiGraph -> node * node -> bool) – a function that determines if two nodes are equal
• edge_equal (DiGraph * DiGraph -> edge * edge -> bool) – a function that determines if two edges are equal

Returns:

graph2 with added nodes marked

Return type:

DiGraph

class pydevDAG._compare.Matcher(keys, ele_type=u'node')

Bases: object

Class with functions to match graph elements based on selected keys.

Note that the keys must be at the top-level.

get_iso_match()

Get match function suitable for use with is_isomorphism method.

Returns:a function that checks the equality of two graph elements Return type:ele * ele -> bool

get_match(graph1, graph2)

Returns a function that checks equality of two graph elements.

Parameters:

• keys – a list of keys whose values must be equal
• graph1 (DiGraph) – a graph
• graph2 (DiGraph) – a graph

Types keys:

list of str

Returns:

a function that compares two graph elements

Return type:

ele * ele -> bool