Line data    Source code

       1             : //------------------------------------------------------------------------------
       2             : // LAGraph_New:  create a new graph
       3             : //------------------------------------------------------------------------------
       4             : 
       5             : // LAGraph, (c) 2019-2022 by The LAGraph Contributors, All Rights Reserved.
       6             : // SPDX-License-Identifier: BSD-2-Clause
       7             : //
       8             : // For additional details (including references to third party source code and
       9             : // other files) see the LICENSE file or contact permission@sei.cmu.edu. See
      10             : // Contributors.txt for a full list of contributors. Created, in part, with
      11             : // funding and support from the U.S. Government (see Acknowledgments.txt file).
      12             : // DM22-0790
      13             : 
      14             : // Contributed by Timothy A. Davis, Texas A&M University
      15             : 
      16             : //------------------------------------------------------------------------------
      17             : 
      18             : // If succesful, the matrix A is moved into G->A, and the caller's A is set
      19             : // to NULL.
      20             : 
      21             : #include "LG_internal.h"
      22             : 
      23        1146 : int LAGraph_New
      24             : (
      25             :     // output:
      26             :     LAGraph_Graph *G,   // the graph to create, NULL if failure
      27             :     // input/output:
      28             :     GrB_Matrix    *A,   // the adjacency matrix of the graph, may be NULL.
      29             :                         // A is moved into G as G->A, and A itself is set
      30             :                         // to NULL to denote that is now a part of G.
      31             :                         // That is, { G->A = A ; A = NULL ; } is performed.
      32             :                         // When G is deleted, G->A is freed.  If A is NULL,
      33             :                         // the graph is invalid until G->A is set.
      34             :     // input:
      35             :     LAGraph_Kind kind,  // the kind of graph. This may be LAGRAPH_UNKNOWN,
      36             :                         // which must then be revised later before the
      37             :                         // graph can be used.
      38             :     char *msg
      39             : )
      40             : {
      41             : 
      42             :     //--------------------------------------------------------------------------
      43             :     // check inputs
      44             :     //--------------------------------------------------------------------------
      45             : 
      46        1146 :     LG_CLEAR_MSG ;
      47        1146 :     LG_ASSERT (G != NULL, GrB_NULL_POINTER) ;
      48             : 
      49             :     //--------------------------------------------------------------------------
      50             :     // allocate the graph
      51             :     //--------------------------------------------------------------------------
      52             : 
      53        1144 :     LG_TRY (LAGraph_Malloc ((void **) G, 1,
      54             :         sizeof (struct LAGraph_Graph_struct), msg)) ;
      55             : 
      56             :     //--------------------------------------------------------------------------
      57             :     // initialize its members
      58             :     //--------------------------------------------------------------------------
      59             : 
      60        1136 :     (*G)->A = NULL ;
      61        1136 :     (*G)->kind = LAGraph_KIND_UNKNOWN ;
      62        1136 :     (*G)->AT = NULL ;
      63        1136 :     (*G)->out_degree = NULL ;
      64        1136 :     (*G)->in_degree = NULL ;
      65        1136 :     (*G)->is_symmetric_structure = LAGRAPH_UNKNOWN ;
      66        1136 :     (*G)->nself_edges = LAGRAPH_UNKNOWN ;
      67        1136 :     (*G)->emin = NULL ;
      68        1136 :     (*G)->emin_state = LAGRAPH_UNKNOWN ;
      69        1136 :     (*G)->emax = NULL ;
      70        1136 :     (*G)->emax_state = LAGRAPH_UNKNOWN ;
      71             : 
      72             :     //--------------------------------------------------------------------------
      73             :     // assign its primary components
      74             :     //--------------------------------------------------------------------------
      75             : 
      76        1136 :     if ((A != NULL) && (*A != NULL))
      77             :     {
      78             :         // move &A into the graph and set &A to NULL to denote to the caller
      79             :         // that it is now a component of G.  The graph G is not opaque, so the
      80             :         // caller can get A back with A = G->A, but this helps with memory
      81             :         // management, since LAGraph_Delete (&G,msg) frees G->A, and if the
      82             :         // caller also does GrB_free (&A), a double-free would occur if this
      83             :         // move does not set A to NULL.
      84        1134 :         (*G)->A = (*A) ;
      85        1134 :         (*A) = NULL ;
      86             : 
      87        1134 :         (*G)->kind = kind ;
      88        1134 :         (*G)->is_symmetric_structure =
      89             :             (kind == LAGraph_ADJACENCY_UNDIRECTED)
      90             :             ? LAGraph_TRUE
      91        1134 :             : LAGRAPH_UNKNOWN ;
      92             :     }
      93             : 
      94        1136 :     return (GrB_SUCCESS) ;
      95             : }