matrix_input.c

Go to the documentation of this file.

/*PGR-GNU*****************************************************************
File: matrix_input.c
 
Copyright (c) 2021 pgRouting developers
Mail: [email protected]
 
Function's developer:
Copyright (c) 2021 Ashish Kumar
Mail: [email protected]
 
------
 
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 ********************************************************************PGR-GNU*/
 
#include "c_common/vroom/matrix_input.h"
 
/*
.. vrp_vroom start
 
A ``SELECT`` statement that returns the following columns:
 
::
 
    start_id, end_id, duration [, cost]
 
=============== ================= ============== ==================================================
Column          Type              Default        Description
=============== ================= ============== ==================================================
**start_id**    ``ANY-INTEGER``                  Identifier of the start node.
 
**end_id**      ``ANY-INTEGER``                  Identifier of the end node.
 
**duration**    |interval|                       Time to travel from ``start_id`` to ``end_id``
 
**cost**        ``INTEGER``       *duration*     Cost to travel from ``start_id`` to ``end_id``
=============== ================= ============== ==================================================
 
.. vrp_vroom end
*/
 
static
void fetch_matrix(
    HeapTuple *tuple,
    TupleDesc *tupdesc,
    Column_info_t *info,
    Vroom_matrix_t *matrix,
    bool is_plain) {
  matrix->start_id = get_MatrixIndex(tuple, tupdesc, info[0], -1);
  matrix->end_id = get_MatrixIndex(tuple, tupdesc, info[1], -1);
 
  if (is_plain) {
    matrix->duration = get_Duration(tuple, tupdesc, info[2], 0);
  } else {
    matrix->duration = (Duration)get_PositiveTInterval(tuple, tupdesc, info[2], 0);
  }
 
  // If unspecified, cost is same as the duration
  matrix->cost = get_Cost(tuple, tupdesc, info[3], matrix->duration);
}
 
 
static
void db_get_matrix(
    char *matrix_sql,
    Vroom_matrix_t **matrix,
    size_t *total_matrix_rows,
 
    Column_info_t *info,
    const int column_count,
    bool is_plain) {
#ifdef PROFILE
  clock_t start_t = clock();
  PGR_DBG("%s", matrix_sql);
#endif
 
  const int tuple_limit = 1000000;
 
  size_t total_tuples;
 
  void *SPIplan;
  SPIplan = pgr_SPI_prepare(matrix_sql);
  Portal SPIportal;
  SPIportal = pgr_SPI_cursor_open(SPIplan);
 
  bool moredata = true;
  (*total_matrix_rows) = total_tuples = 0;
 
  /* on the first tuple get the column numbers */
 
  while (moredata == true) {
    SPI_cursor_fetch(SPIportal, true, tuple_limit);
    if (total_tuples == 0) {
      pgr_fetch_column_info(info, column_count);
    }
    size_t ntuples = SPI_processed;
    total_tuples += ntuples;
    if (ntuples > 0) {
      if ((*matrix) == NULL)
        (*matrix) = (Vroom_matrix_t *)palloc0(
            total_tuples * sizeof(Vroom_matrix_t));
      else
        (*matrix) = (Vroom_matrix_t *)repalloc(
            (*matrix),
            total_tuples * sizeof(Vroom_matrix_t));
 
      if ((*matrix) == NULL) {
        elog(ERROR, "Out of memory");
      }
 
      size_t t;
      SPITupleTable *tuptable = SPI_tuptable;
      TupleDesc tupdesc = SPI_tuptable->tupdesc;
      for (t = 0; t < ntuples; t++) {
        HeapTuple tuple = tuptable->vals[t];
        fetch_matrix(&tuple, &tupdesc, info,
            &(*matrix)[total_tuples - ntuples + t], is_plain);
      }
      SPI_freetuptable(tuptable);
    } else {
      moredata = false;
    }
  }
 
  SPI_cursor_close(SPIportal);
 
  if (total_tuples == 0) {
    (*total_matrix_rows) = 0;
    return;
  }
 
  (*total_matrix_rows) = total_tuples;
#ifdef PROFILE
  time_msg("reading matrix", start_t, clock());
#endif
}
 
 
void
get_vroom_matrix(
    char *sql,
    Vroom_matrix_t **rows,
    size_t *total_rows,
    bool is_plain) {
  int kColumnCount = 4;
  Column_info_t info[kColumnCount];
 
  for (int i = 0; i < kColumnCount; ++i) {
    info[i].colNumber = -1;
    info[i].type = 0;
    info[i].strict = true;
    info[i].eType = ANY_INTEGER;
  }
  info[0].name = "start_id";
  info[1].name = "end_id";
  info[2].name = "duration";
  info[3].name = "cost";
 
  info[2].eType = INTEGER;     // duration
  info[3].eType = INTEGER;     // cost
 
  if (!is_plain) {
    info[2].eType = INTERVAL;  // duration
  }
 
  info[3].strict = false;
 
  db_get_matrix(sql, rows, total_rows, info, kColumnCount, is_plain);
}