DAG Shortest Path - Combinations

NEWS

@@ -6,6 +6,7 @@ pgRouting 3.2.0 Release Notes
 
 * pgr_bellmanFord(Combinations)
 * pgr_binaryBreadthFirstSearch(Combinations)
+* pgr_dagShortestPath(Combinations)
 * pgr_depthFirstSearch
 * pgr_dijkstraNear(One to Many)
 * pgr_dijkstraNear(Many to One)

doc/dagShortestPath/pgr_dagShortestPath.rst

@@ -24,14 +24,21 @@ In particular, the DAG shortest paths algorithm implemented by Boost.Graph.
 
 .. rubric:: Availability
 
+* Version 3.2.0
+
+  * New **experimental** function:
+
+    * pgr_dagShortestPath(Combinations)
+
 * Version 3.0.0
 
   * New **experimental** function
 
 .. rubric:: Support
 
 * **Supported versions:**
-  current(`3.1 <https://docs.pgrouting.org/3.1/en/pgr_dagShortestPath.html>`__)
+  current(`3.2 <https://docs.pgrouting.org/3.2/en/pgr_dagShortestPath.html>`__)
+  `3.1 <https://docs.pgrouting.org/3.1/en/pgr_dagShortestPath.html>`__
   `3.0 <https://docs.pgrouting.org/3.0/en/pgr_dagShortestPath.html>`__
 
 Description
@@ -74,10 +81,11 @@ Signatures
 
 .. code-block:: none
 
-    pgr_dagShortestPath(edges_sql, from_vid,  to_vid)
-    pgr_dagShortestPath(edges_sql, from_vid,  to_vids)
-    pgr_dagShortestPath(edges_sql, from_vids, to_vid)
-    pgr_dagShortestPath(edges_sql, from_vids, to_vids)
+    pgr_dagShortestPath(Edges SQL, from_vid,  to_vid)
+    pgr_dagShortestPath(Edges SQL, from_vid,  to_vids)
+    pgr_dagShortestPath(Edges SQL, from_vids, to_vid)
+    pgr_dagShortestPath(Edges SQL, from_vids, to_vids)
+    pgr_dagShortestPath(Edges SQL, Combinations) -- Experimental on v3.2
 
     RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
     OR EMPTY SET
@@ -91,7 +99,7 @@ One to One
 
 .. code-block:: none
 
-    pgr_dagShortestPath(edges_sql, from_vid,  to_vid)
+    pgr_dagShortestPath(Edges SQL, from_vid,  to_vid)
     RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
     OR EMPTY SET
 
@@ -109,7 +117,7 @@ One to Many
 
 .. code-block:: none
 
-    pgr_dagShortestPath(edges_sql, from_vid,  to_vids)
+    pgr_dagShortestPath(Edges SQL, from_vid,  to_vids)
     RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
     OR EMPTY SET
 
@@ -127,7 +135,7 @@ Many to One
 
 .. code-block:: none
 
-    pgr_dagShortestPath(edges_sql, from_vids, to_vid)
+    pgr_dagShortestPath(Edges SQL, from_vids, to_vid)
     RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
     OR EMPTY SET
 
@@ -145,7 +153,7 @@ Many to Many
 
 .. code-block:: none
 
-    pgr_dagShortestPath(edges_sql, from_vids, to_vids)
+    pgr_dagShortestPath(Edges SQL, from_vids, to_vids)
     RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
     OR EMPTY SET
 
@@ -156,32 +164,62 @@ Many to Many
    :start-after: -- q4
    :end-before: -- q5
 
+.. index::
+    single: dagShortestPath(Combinations) -- Experimental on v3.2
+
+Combinations
+...............................................................................
+
+.. code-block:: none
+
+    pgr_dagShortestPath(Edges SQL, Combinations)
+    RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
+    OR EMPTY SET
+
+:Example: Using a combinations table on a Directed Acyclic Graph.
+
+
+.. literalinclude:: doc-pgr_dagShortestPath.queries
+   :start-after: -- q5
+   :end-before: -- q6
+
 Parameters
 -------------------------------------------------------------------------------
 
 .. pgr_dagShortestPath_parameters_start
 
 .. rubric:: Description of the parameters of the signatures
 
-============== ================== ======== =================================================
-Parameter      Type               Default     Description
-============== ================== ======== =================================================
-**edges_sql**        ``TEXT``                    SQL query as described above.
-**start_vid**  ``BIGINT``                  Identifier of the starting vertex of the path.
-**start_vids** ``ARRAY[BIGINT]``           Array of identifiers of starting vertices.
-**end_vid**    ``BIGINT``                  Identifier of the ending vertex of the path.
-**end_vids**   ``ARRAY[BIGINT]``           Array of identifiers of ending vertices.
-============== ================== ======== =================================================
+===================== ================== ======== =================================================
+Parameter             Type               Default     Description
+===================== ================== ======== =================================================
+**Edges SQL**         ``TEXT``                    Edges query as described below.
+**Combinations SQL**  ``TEXT``                    Combinations query as described above.
+**start_vid**         ``BIGINT``                  Identifier of the starting vertex of the path.
+**start_vids**        ``ARRAY[BIGINT]``           Array of identifiers of starting vertices.
+**end_vid**           ``BIGINT``                  Identifier of the ending vertex of the path.
+**end_vids**          ``ARRAY[BIGINT]``           Array of identifiers of ending vertices.
+===================== ================== ======== =================================================
 
 .. pgr_dagShortestPath_parameters_end
 
-Inner Query
+Inner Queries
 -------------------------------------------------------------------------------
 
+Edges query
+...............................................................................
+
 .. include:: pgRouting-concepts.rst
     :start-after: basic_edges_sql_start
     :end-before: basic_edges_sql_end
 
+Combinations query
+...............................................................................
+
+.. include:: pgRouting-concepts.rst
+    :start-after: basic_combinations_sql_start
+    :end-before: basic_combinations_sql_end
+
 Results Columns
 -------------------------------------------------------------------------------
 

doc/src/release_notes.rst

@@ -65,6 +65,7 @@ pgRouting 3.2.0 Release Notes
 
 * pgr_bellmanFord(Combinations)
 * pgr_binaryBreadthFirstSearch(Combinations)
+* pgr_dagShortestPath(Combinations)
 * pgr_depthFirstSearch
 * pgr_dijkstraNear(One to Many)
 * pgr_dijkstraNear(Many to One)

docqueries/dagShortestPath/doc-pgr_dagShortestPath.result

@@ -69,5 +69,21 @@ SELECT * FROM pgr_dagShortestPath(
 (13 rows)
 
 -- q5
+SELECT * FROM pgr_dagShortestPath(
+    'SELECT id, source, target, cost FROM edge_table',
+    'SELECT * FROM ( VALUES (1, 6), (4, 12) ) AS t(source, target)'
+);
+ seq | path_seq | node | edge | cost | agg_cost
+-----+----------+------+------+------+----------
+   1 |        1 |    1 |    1 |    1 |        0
+   2 |        2 |    2 |    4 |    1 |        1
+   3 |        3 |    5 |    8 |    1 |        2
+   4 |        4 |    6 |   -1 |    0 |        3
+   5 |        1 |    4 |   16 |    1 |        0
+   6 |        2 |    9 |   15 |    1 |        1
+   7 |        3 |   12 |   -1 |    0 |        2
+(7 rows)
+
+-- q6
 ROLLBACK;
 ROLLBACK

docqueries/dagShortestPath/doc-pgr_dagShortestPath.test.sql

@@ -22,4 +22,8 @@ SELECT * FROM pgr_dagShortestPath(
     ARRAY[1, 4],ARRAY[12,6]
 );
 \echo -- q5
-
+SELECT * FROM pgr_dagShortestPath(
+    'SELECT id, source, target, cost FROM edge_table',
+    'SELECT * FROM ( VALUES (1, 6), (4, 12) ) AS t(source, target)'
+);
+\echo -- q6

include/dagShortestPath/pgr_dagShortestPath.hpp

@@ -183,6 +183,40 @@ class Pgr_dag {
          return paths;
      }
 
+     // preparation for parallel arrays
+     std::deque<Path> dag(
+             G &graph,
+             const std::vector<pgr_combination_t> &combinations,
+             bool only_cost) {
+         std::deque<Path> paths;
+
+         // group targets per distinct source
+         std::map< int64_t, std::vector<int64_t> > vertex_map;
+         for (const pgr_combination_t &comb : combinations) {
+             std::map< int64_t, std::vector<int64_t> >::iterator it = vertex_map.find(comb.source);
+             if (it != vertex_map.end()) {
+                 it->second.push_back(comb.target);
+             } else {
+                 std::vector<int64_t > targets{comb.target};
+                 vertex_map[comb.source] = targets;
+             }
+         }
+
+         for (const auto &start_ends : vertex_map) {
+             auto result_paths = dag(
+                     graph,
+                     start_ends.first,
+                     start_ends.second,
+                     only_cost);
+             paths.insert(
+                     paths.end(),
+                     std::make_move_iterator(result_paths.begin()),
+                     std::make_move_iterator(result_paths.end()));
+         }
+
+         return paths;
+     }
+
      //@}
 
  private:

include/drivers/dagShortestPath/dagShortestPath_driver.h

@@ -39,25 +39,20 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #endif
 
 #include "c_types/pgr_edge_t.h"
+#include "c_types/pgr_combination_t.h"
 #include "c_types/general_path_element_t.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-    /*********************************************************
-      TEXT,
-    BIGINT,
-    BIGINT,
-    directed BOOLEAN DEFAULT true,
-    only_cost BOOLEAN DEFAULT false,
-     ********************************************************/
-
 
     void
         do_pgr_dagShortestPath(
                 pgr_edge_t  *data_edges,
                 size_t total_tuples,
+                pgr_combination_t  *combinations,
+                size_t total_combinations,
                 int64_t  *start_vidsArr,
                 size_t size_start_vidsArr,
                 int64_t  *end_vidsArr,

pgtap/dagShortestPath/dagShortestPath-typesCheck.sql

@@ -1,22 +1,40 @@
 
 UPDATE edge_table SET cost = sign(cost), reverse_cost = sign(reverse_cost);
-SELECT plan(10);
+SELECT plan(14);
 
 SELECT has_function('pgr_dagshortestpath');
 
 SELECT has_function('pgr_dagshortestpath', ARRAY[ 'text', 'bigint', 'bigint' ]);
 SELECT has_function('pgr_dagshortestpath', ARRAY[ 'text', 'anyarray', 'bigint' ]);
 SELECT has_function('pgr_dagshortestpath', ARRAY[ 'text', 'bigint', 'anyarray' ]);
 SELECT has_function('pgr_dagshortestpath', ARRAY[ 'text', 'anyarray', 'anyarray' ]);
+SELECT has_function('pgr_dagshortestpath', ARRAY[ 'text', 'text' ]);
 
 SELECT function_returns('pgr_dagshortestpath', ARRAY[ 'text', 'bigint', 'bigint' ], 'setof record');
 SELECT function_returns('pgr_dagshortestpath', ARRAY[ 'text', 'anyarray', 'bigint' ], 'setof record');
 SELECT function_returns('pgr_dagshortestpath', ARRAY[ 'text', 'bigint', 'anyarray' ], 'setof record');
 SELECT function_returns('pgr_dagshortestpath', ARRAY[ 'text', 'anyarray', 'anyarray' ], 'setof record');
+SELECT function_returns('pgr_dagshortestpath', ARRAY[ 'text', 'text' ], 'setof record');
 
 -- testing column names
 SELECT bag_has(
     $$SELECT  proargnames from pg_proc where proname = 'pgr_dagshortestpath'$$,
     $$SELECT  '{"","","","seq","path_seq","node","edge","cost","agg_cost"}'::TEXT[] $$
 );
 
+SELECT bag_has(
+    $$SELECT  proargnames from pg_proc where proname = 'pgr_dagshortestpath'$$,
+    $$SELECT  '{"","",seq,path_seq,node,edge,cost,agg_cost}'::TEXT[] $$
+);
+
+-- parameter types
+SELECT set_eq(
+    $$SELECT  proallargtypes from pg_proc where proname = 'pgr_dagshortestpath'$$,
+    $$VALUES
+        ('{25,20,20,23,23,20,20,701,701}'::OID[]),
+        ('{25,20,2277,23,23,20,20,701,701}'::OID[]),
+        ('{25,2277,20,23,23,20,20,701,701}'::OID[]),
+        ('{25,2277,2277,23,23,20,20,701,701}'::OID[]),
+        ('{25,25,23,23,20,20,701,701}'::OID[])
+    $$
+);

pgtap/dagShortestPath/empty_combinations_empty_result.test.sql

@@ -0,0 +1,24 @@
+\i setup.sql
+
+SELECT plan(1);
+
+CREATE OR REPLACE FUNCTION foo()
+RETURNS SETOF TEXT AS
+$BODY$
+BEGIN
+
+    RETURN query SELECT is_empty(
+      'SELECT seq, path_seq, node, edge, cost, agg_cost FROM pgr_dagShortestPath(
+        ''SELECT id, source, target, cost FROM edge_table'',
+        ''SELECT * FROM combinations_table WHERE source IN (-1)'' ) '
+    );
+    RETURN;
+END
+$BODY$
+language plpgsql;
+
+SELECT * FROM foo();
+
+-- Finish the tests and clean up.
+SELECT * FROM finish();
+ROLLBACK;

pgtap/dagShortestPath/many_to_many_eq_combinations.test.sql

@@ -0,0 +1,51 @@
+\i setup.sql
+
+SELECT plan(1);
+
+UPDATE edge_table SET cost = sign(cost) + 0.001 * id * id, reverse_cost = sign(reverse_cost) + 0.001 * id * id;
+
+CREATE OR REPLACE FUNCTION foo( sql_TestFunction TEXT, cant INTEGER default 18 )
+RETURNS SETOF TEXT AS
+$BODY$
+DECLARE
+sql_Combinations TEXT;
+sql_Many TEXT;
+BEGIN
+
+    sql_Combinations := '';
+    sql_Many := '';
+    FOR i IN 1.. cant LOOP
+        IF (i > 1) THEN
+            sql_Many := sql_Many ||', ';
+        END IF;
+        sql_Many := sql_Many || i ;
+    END LOOP;
+
+    FOR i IN 1.. cant LOOP
+        FOR j IN 1..cant LOOP
+            IF NOT (i =  j) THEN
+                sql_Combinations := sql_Combinations || '(' || i || ',' || j || '),' ;
+            END IF;
+        END LOOP;
+    END LOOP;
+    sql_Combinations := trim(trailing ',' from sql_Combinations);
+
+    sql_Many := ( sql_TestFunction || '(
+        ''SELECT id, source, target, cost FROM edge_table'',
+        ARRAY[' || sql_Many  ||'], ARRAY[' || sql_Many || '] ) ');
+
+    sql_Combinations := ( sql_TestFunction || '(
+        ''SELECT id, source, target, cost FROM edge_table'',
+        ''SELECT * FROM (VALUES' || sql_Combinations  ||') AS combinations (source, target)'' ) ');
+
+    RETURN query SELECT set_eq( sql_Many, sql_Combinations );
+    RETURN;
+END
+$BODY$
+language plpgsql;
+
+SELECT * FROM foo('SELECT path_seq, node, edge, cost, agg_cost FROM pgr_dagShortestPath');
+
+-- Finish the tests and clean up.
+SELECT * FROM finish();
+ROLLBACK;