trsp.c File Reference

#include "c_common/postgres_connection.h"
#include "catalog/pg_type.h"
#include "c_common/debug_macro.h"
#include "c_types/trsp/trsp.h"

Include dependency graph for trsp.c:

Go to the source code of this file.

Classes
struct	edge_columns
struct	restrict_columns

Typedefs
typedef struct edge_columns	edge_columns_t
typedef struct restrict_columns	restrict_columns_t

Functions
PGDLLEXPORT Datum	_pgr_trsp (PG_FUNCTION_ARGS)
static int	compute_trsp (char *sql, int dovertex, int64_t start_id, double start_pos, int64_t end_id, double end_pos, bool directed, bool has_reverse_cost, char *restrict_sql, path_element_tt **path, size_t *path_count)
static void	fetch_edge (HeapTuple *tuple, TupleDesc *tupdesc, edge_columns_t *edge_columns, edge_t *target_edge)
static int	fetch_edge_columns (SPITupleTable *tuptable, edge_columns_t *edge_columns, bool has_reverse_cost)
static void	fetch_restrict (HeapTuple *tuple, TupleDesc *tupdesc, restrict_columns_t *restrict_columns, restrict_t *rest)
static int	fetch_restrict_columns (SPITupleTable *tuptable, restrict_columns_t *restrict_columns)
static int	finish (int code, int ret)
	PG_FUNCTION_INFO_V1 (_pgr_trsp)

Typedef Documentation

edge_columns_t

typedef struct edge_columns edge_columns_t

restrict_columns_t

typedef struct restrict_columns restrict_columns_t

Function Documentation

_pgr_trsp()

PGDLLEXPORT Datum _pgr_trsp

(

PG_FUNCTION_ARGS

)

Definition at line 506 of file trsp.c.

                            {
  FuncCallContext     *funcctx;
  TupleDesc            tuple_desc;
  path_element_tt      *path;
 
  // stuff done only on the first call of the function
  if (SRF_IS_FIRSTCALL()) {
      MemoryContext   oldcontext;
      size_t path_count = 0;
      int i;
      double s_pos;
      double e_pos;
      char *               sql;
 
      // create a function context for cross-call persistence
      funcctx = SRF_FIRSTCALL_INIT();
 
      // switch to memory context appropriate for multiple function calls
      oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
      // verify that the first 5 args are not NULL
      for (i = 0; i < 7; i++) {
        if (i == 2 || i == 4) continue;
        if (PG_ARGISNULL(i)) {
            elog(ERROR, "turn_restrict_shortest_path(): "
            "Argument %i may not be NULL", i+1);
        }
      }
 
      if (PG_ARGISNULL(2)) {
        s_pos = 0.5;
      } else {
        s_pos = PG_GETARG_FLOAT8(2);
        if (s_pos < 0.0) s_pos = 0.5;
        if (s_pos > 1.0) s_pos = 0.5;
      }
 
      if (PG_ARGISNULL(4)) {
        e_pos = 0.5;
      } else {
        e_pos = PG_GETARG_FLOAT8(4);
        if (e_pos < 0.0) e_pos = 0.5;
        if (e_pos > 1.0) e_pos = 0.5;
      }
 
      if (PG_ARGISNULL(7)) {
        sql = NULL;
      } else {
        sql = text_to_cstring(PG_GETARG_TEXT_P(7));
        if (strlen(sql) == 0)
            sql = NULL;
      }
 
      PGR_DBG("Calling compute_trsp");
 
         compute_trsp(text_to_cstring(PG_GETARG_TEXT_P(0)),
                                   0,  // sdo edge
                                   PG_GETARG_INT32(1),
                                   s_pos,
                                   PG_GETARG_INT32(3),
                                   e_pos,
                                   PG_GETARG_BOOL(5),
                                   PG_GETARG_BOOL(6),
                                   sql,
                                   &path, &path_count);
 
      // total number of tuples to be returned
#if PGSQL_VERSION > 95
        funcctx->max_calls = path_count;
#else
        funcctx->max_calls = (uint32_t)path_count;
#endif
 
        funcctx->user_fctx = path;
        if (get_call_result_type(fcinfo, NULL, &tuple_desc)
                != TYPEFUNC_COMPOSITE) {
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("function returning record called in context "
                         "that cannot accept type record")));
        }
 
      funcctx->tuple_desc = tuple_desc;
 
      MemoryContextSwitchTo(oldcontext);
    }
 
  // stuff done on every call of the function
  funcctx = SRF_PERCALL_SETUP();
 
  tuple_desc = funcctx->tuple_desc;
  path = (path_element_tt*) funcctx->user_fctx;
 
  if (funcctx->call_cntr < funcctx->max_calls) {
      // do when there is more left to send
      HeapTuple    tuple;
      Datum        result;
      Datum *values;
      bool* nulls;
 
      values = palloc(4 * sizeof(Datum));
      nulls = palloc(4 * sizeof(char));
 
      values[0] = Int32GetDatum(funcctx->call_cntr);
      nulls[0] = false;
      values[1] = Int32GetDatum(path[funcctx->call_cntr].vertex_id);
      nulls[1] = false;
      values[2] = Int32GetDatum(path[funcctx->call_cntr].edge_id);
      nulls[2] = false;
      values[3] = Float8GetDatum(path[funcctx->call_cntr].cost);
      nulls[3] = false;
 
      tuple = heap_form_tuple(tuple_desc, values, nulls);
 
      // make the tuple into a datum
      result = HeapTupleGetDatum(tuple);
 
      // clean up (this is not really necessary)
      pfree(values);
      pfree(nulls);
 
      SRF_RETURN_NEXT(funcctx, result);
    } else {  // do when there is no more left
      PGR_DBG("Going to free path");
      if (path) free(path);
      SRF_RETURN_DONE(funcctx);
    }
}

References compute_trsp(), path_element::cost, path_element::edge_id, if(), PGR_DBG, and path_element::vertex_id.

compute_trsp()

static int compute_trsp ( char *  sql, int  dovertex, int64_t  start_id, double  start_pos, int64_t  end_id, double  end_pos, bool  directed, bool  has_reverse_cost, char *  restrict_sql, path_element_tt **  path, size_t *  path_count  )

static

Definition at line 236 of file trsp.c.

                        {
 
  int SPIcode;
  SPIPlanPtr SPIplan;
  Portal SPIportal;
  bool moredata = true;
  uint32_t TUPLIMIT = 1000;
  uint32_t ntuples;
 
  edge_t *edges = NULL;
  uint32_t total_tuples = 0;
#ifndef _MSC_VER
  edge_columns_t edge_columns = {.id = -1, .source = -1, .target = -1,
                                 .cost = -1, .reverse_cost = -1};
#else  // _MSC_VER
  edge_columns_t edge_columns = {-1, -1, -1, -1, -1};
#endif  // _MSC_VER
  restrict_t *restricts = NULL;
  uint32_t total_restrict_tuples = 0;
  restrict_columns_t restrict_columns = {.target_id = -1, .via_path = -1,
                                 .to_cost = -1};
  int64_t v_max_id = 0;
  int64_t v_min_id = INT_MAX;
 
  /* track if start and end are both in edge tuples */
  int s_count = 0;
  int t_count = 0;
 
  char *err_msg;
  int ret = -1;
  uint32_t z;
 
  PGR_DBG("start turn_restrict_shortest_path\n");
 
  SPIcode = SPI_connect();
  if (SPIcode  != SPI_OK_CONNECT) {
      elog(ERROR, "turn_restrict_shortest_path: "
      "couldn't open a connection to SPI");
      return -1;
  }
 
  SPIplan = SPI_prepare(sql, 0, NULL);
  if (SPIplan  == NULL) {
      elog(ERROR, "turn_restrict_shortest_path: "
      "couldn't create query plan via SPI");
      return -1;
  }
 
  if ((SPIportal = SPI_cursor_open(NULL, SPIplan, NULL, NULL, true)) == NULL) {
      elog(ERROR, "turn_restrict_shortest_path: "
      "SPI_cursor_open('%s') returns NULL", sql);
      return -1;
  }
 
  while (moredata == true) {
      // PGR_DBG("calling SPI_cursor_fetch");
      SPI_cursor_fetch(SPIportal, true, TUPLIMIT);
 
      if (SPI_tuptable == NULL) {
          elog(ERROR, "SPI_tuptable is NULL");
          return finish(SPIcode, -1);
      }
 
      if (edge_columns.id == -1) {
          if (fetch_edge_columns(SPI_tuptable, &edge_columns,
                                 has_reverse_cost) == -1)
                return finish(SPIcode, ret);
      }
 
      ntuples = SPI_processed;
 
      total_tuples += ntuples;
 
      if (ntuples > 0) {
          if (!edges)
            edges = palloc(total_tuples * sizeof(edge_t));
          else
            edges = repalloc(edges, total_tuples * sizeof(edge_t));
 
          if (edges == NULL) {
              elog(ERROR, "Out of memory");
              return finish(SPIcode, ret);
          }
 
          uint32_t t;
          SPITupleTable *tuptable = SPI_tuptable;
          TupleDesc tupdesc = SPI_tuptable->tupdesc;
 
          for (t = 0; t < ntuples; t++) {
              HeapTuple tuple = tuptable->vals[t];
              fetch_edge(&tuple, &tupdesc, &edge_columns,
                         &edges[total_tuples - ntuples + t]);
          }
          SPI_freetuptable(tuptable);
      } else {
          moredata = false;
      }
  }
  SPI_cursor_close(SPIportal);
 
  // defining min and max vertex id
 
  for (z = 0; z < total_tuples; z++) {
    if (edges[z].source < v_min_id)
      v_min_id = edges[z].source;
 
    if (edges[z].source > v_max_id)
      v_max_id = edges[z].source;
 
    if (edges[z].target < v_min_id)
      v_min_id = edges[z].target;
 
    if (edges[z].target > v_max_id)
      v_max_id = edges[z].target;
  }
 
  // ::::::::::::::::::::::::::::::::::::
  // :: reducing vertex id (renumbering)
  // ::::::::::::::::::::::::::::::::::::
  for (z = 0; z < total_tuples; z++) {
    // check if edges[] contains source and target
    if (dovertex) {
        if (edges[z].source == start_id || edges[z].target == start_id)
          ++s_count;
        if (edges[z].source == end_id || edges[z].target == end_id)
          ++t_count;
    } else {
        if (edges[z].id == start_id)
          ++s_count;
        if (edges[z].id == end_id)
          ++t_count;
    }
 
    edges[z].source -= v_min_id;
    edges[z].target -= v_min_id;
  }
 
  PGR_DBG("Min vertex id: %ld , Max vid: %ld", v_min_id, v_max_id);
  PGR_DBG("Total %i edge tuples", total_tuples);
 
  if (s_count == 0) {
    elog(ERROR, "Start id was not found.");
    return -1;
  }
 
  if (t_count == 0) {
    elog(ERROR, "Target id was not found.");
    return -1;
  }
 
  if (dovertex) {
      start_id -= v_min_id;
      end_id   -= v_min_id;
  }
 
  PGR_DBG("Fetching restriction tuples\n");
 
  if (restrict_sql == NULL) {
      PGR_DBG("Sql for restrictions is null.");
  } else {
      SPIplan = SPI_prepare(restrict_sql, 0, NULL);
      if (SPIplan  == NULL) {
          elog(ERROR, "turn_restrict_shortest_path: "
          "couldn't create query plan via SPI");
          return -1;
      }
 
      if ((SPIportal = SPI_cursor_open(NULL, SPIplan, NULL, NULL, true)) \
       == NULL) {
          elog(ERROR, "turn_restrict_shortest_path:"
          " SPI_cursor_open('%s') returns NULL", restrict_sql);
          return -1;
      }
 
      moredata = true;
      while (moredata == true) {
          SPI_cursor_fetch(SPIportal, true, TUPLIMIT);
 
          if (restrict_columns.target_id == -1) {
              if (fetch_restrict_columns(SPI_tuptable, &restrict_columns) \
              == -1) {
                PGR_DBG("fetch_restrict_columns failed!");
                return finish(SPIcode, ret);
              }
          }
 
          /* Suppress the -Wconversion warning temporarily */
          #pragma GCC diagnostic push
          #pragma GCC diagnostic ignored "-Wconversion"
          ntuples = SPI_processed;
          #pragma GCC diagnostic pop
 
          total_restrict_tuples += ntuples;
 
          if (ntuples > 0) {
              if (!restricts)
                restricts = palloc(total_restrict_tuples * sizeof(restrict_t));
              else
                restricts = repalloc(restricts,
                    total_restrict_tuples * sizeof(restrict_t));
 
              if (restricts == NULL) {
                  elog(ERROR, "Out of memory");
                  return finish(SPIcode, ret);
              }
 
              uint32_t t;
              SPITupleTable *tuptable = SPI_tuptable;
              TupleDesc tupdesc = SPI_tuptable->tupdesc;
 
              for (t = 0; t < ntuples; t++) {
                  HeapTuple tuple = tuptable->vals[t];
                  fetch_restrict(&tuple, &tupdesc, &restrict_columns,
                             &restricts[total_restrict_tuples - ntuples + t]);
              }
              SPI_freetuptable(tuptable);
          } else {
              moredata = false;
          }
      }
      SPI_cursor_close(SPIportal);
  }
 
  PGR_DBG("Total %i restriction tuples", total_restrict_tuples);
 
      PGR_DBG("Calling trsp_edge_wrapper\n");
      ret = trsp_edge_wrapper(edges, total_tuples,
                        restricts, total_restrict_tuples,
                        start_id, start_pos, end_id, end_pos,
                        directed, has_reverse_cost,
                        path, path_count, &err_msg);
 
  PGR_DBG("Message received from inside:");
  PGR_DBG("%s", err_msg);
 
 
  // ::::::::::::::::::::::::::::::::
  // :: restoring original vertex id
  // ::::::::::::::::::::::::::::::::
  for (z = 0; z < *path_count; z++) {
    if (z || (*path)[z].vertex_id != -1)
        (*path)[z].vertex_id += v_min_id;
  }
 
  PGR_DBG("ret = %i\n", ret);
 
  PGR_DBG("*path_count = %ld\n", *path_count);
 
  if (ret < 0) {
      ereport(ERROR, (errcode(ERRCODE_E_R_E_CONTAINING_SQL_NOT_PERMITTED),
        errmsg("Error computing path: %s", err_msg)));
    }
 
  return finish(SPIcode, ret);
}

References fetch_edge(), fetch_edge_columns(), fetch_restrict(), fetch_restrict_columns(), finish(), edge_columns::id, PGR_DBG, edge_t::source, edge_t::target, restrict_columns::target_id, and trsp_edge_wrapper().

Referenced by _pgr_trsp().

fetch_edge()

static void fetch_edge ( HeapTuple *  tuple, TupleDesc *  tupdesc, edge_columns_t *  edge_columns, edge_t *  target_edge  )

static

Definition at line 156 of file trsp.c.

                                                              {
  Datum binval;
  bool isnull;
 
  binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->id, &isnull);
  if (isnull)
    elog(ERROR, "id contains a null value");
  target_edge->id = DatumGetInt32(binval);
 
  binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->source, &isnull);
  if (isnull)
    elog(ERROR, "source contains a null value");
  target_edge->source = DatumGetInt32(binval);
 
  binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->target, &isnull);
  if (isnull)
    elog(ERROR, "target contains a null value");
  target_edge->target = DatumGetInt32(binval);
 
  binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->cost, &isnull);
  if (isnull)
    elog(ERROR, "cost contains a null value");
  target_edge->cost = DatumGetFloat8(binval);
 
  if (edge_columns->reverse_cost != -1) {
      binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->reverse_cost,
                             &isnull);
      if (isnull)
        elog(ERROR, "reverse_cost contains a null value");
      target_edge->reverse_cost =  DatumGetFloat8(binval);
    }
}

References edge_t::cost, edge_columns::cost, edge_t::id, edge_columns::id, edge_t::reverse_cost, edge_columns::reverse_cost, edge_t::source, edge_columns::source, edge_t::target, and edge_columns::target.

Referenced by compute_trsp().

fetch_edge_columns()

static int fetch_edge_columns ( SPITupleTable *  tuptable, edge_columns_t *  edge_columns, bool  has_reverse_cost  )

static

Definition at line 101 of file trsp.c.

                                          {
  edge_columns->id = SPI_fnumber(tuptable->tupdesc, "id");
  edge_columns->source = SPI_fnumber(tuptable->tupdesc, "source");
  edge_columns->target = SPI_fnumber(tuptable->tupdesc, "target");
  edge_columns->cost = SPI_fnumber(tuptable->tupdesc, "cost");
  if (edge_columns->id == SPI_ERROR_NOATTRIBUTE ||
      edge_columns->source == SPI_ERROR_NOATTRIBUTE ||
      edge_columns->target == SPI_ERROR_NOATTRIBUTE ||
      edge_columns->cost == SPI_ERROR_NOATTRIBUTE) {
      elog(ERROR, "Error, query must return columns "
           "'id', 'source', 'target' and 'cost'");
      return -1;
    }
 
  if (SPI_gettypeid(tuptable->tupdesc, edge_columns->source) != INT4OID ||
      SPI_gettypeid(tuptable->tupdesc, edge_columns->target) != INT4OID ||
      SPI_gettypeid(tuptable->tupdesc, edge_columns->cost) != FLOAT8OID) {
      elog(ERROR, "Error, columns 'source', 'target' must be of type int4, "
      "'cost' must be of type float8");
      return -1;
    }
 
  PGR_DBG("columns: id %i source %i target %i cost %i",
      edge_columns->id, edge_columns->source,
      edge_columns->target, edge_columns->cost);
 
  if (has_reverse_cost) {
      edge_columns->reverse_cost = SPI_fnumber(tuptable->tupdesc,
                                               "reverse_cost");
 
      if (edge_columns->reverse_cost == SPI_ERROR_NOATTRIBUTE) {
          elog(ERROR, "Error, reverse_cost is used, but query did't return "
               "'reverse_cost' column");
          return -1;
        }
 
      if (SPI_gettypeid(tuptable->tupdesc, edge_columns->reverse_cost)
          != FLOAT8OID) {
          elog(ERROR, "Error, columns 'reverse_cost' must be of type float8");
          return -1;
        }
 
      PGR_DBG("columns: reverse_cost cost %i", edge_columns->reverse_cost);
    }
 
  return 0;
}

References edge_columns::cost, edge_columns::id, PGR_DBG, edge_columns::reverse_cost, edge_columns::source, and edge_columns::target.

Referenced by compute_trsp().

fetch_restrict()

static void fetch_restrict ( HeapTuple *  tuple, TupleDesc *  tupdesc, restrict_columns_t *  restrict_columns, restrict_t *  rest  )

static

Definition at line 197 of file trsp.c.

                                                                   {
  Datum binval;
  bool isnull;
  int t;
 
  for (t = 0; t < MAX_RULE_LENGTH; ++t)
    rest->via[t] = -1;
 
  binval = SPI_getbinval(*tuple, *tupdesc, restrict_columns->target_id,
       &isnull);
  if (isnull)
    elog(ERROR, "target_id contains a null value");
  rest->target_id = DatumGetInt32(binval);
 
  binval = SPI_getbinval(*tuple, *tupdesc, restrict_columns->to_cost, &isnull);
  if (isnull)
    elog(ERROR, "to_cost contains a null value");
  rest->to_cost = DatumGetFloat8(binval);
  char *str = DatumGetCString(SPI_getvalue(*tuple, *tupdesc,
       restrict_columns->via_path));
 
  // PGR_DBG("restriction: %f, %i, %s", rest->to_cost, rest->target_id, str);
 
  if (str != NULL) {
    int ci = 0;
    char* pch = (char *)strtok(str, " ,");
 
    while (pch != NULL && ci < MAX_RULE_LENGTH) {
      rest->via[ci] = atoi(pch);
      // PGR_DBG("    rest->via[%i]=%i", ci, rest->via[ci]);
      ci++;
      pch = (char *)strtok(NULL, " ,");
    }
  }
}

References MAX_RULE_LENGTH, restrict_columns::target_id, restrict_struct::target_id, restrict_columns::to_cost, restrict_struct::to_cost, restrict_struct::via, and restrict_columns::via_path.

Referenced by compute_trsp().

fetch_restrict_columns()

static int fetch_restrict_columns ( SPITupleTable *  tuptable, restrict_columns_t *  restrict_columns  )

static

Definition at line 71 of file trsp.c.

                                                             {
  restrict_columns->target_id = SPI_fnumber(tuptable->tupdesc, "target_id");
  restrict_columns->via_path = SPI_fnumber(tuptable->tupdesc, "via_path");
  restrict_columns->to_cost =  SPI_fnumber(tuptable->tupdesc, "to_cost");
  if (restrict_columns->target_id == SPI_ERROR_NOATTRIBUTE ||
      restrict_columns->via_path == SPI_ERROR_NOATTRIBUTE ||
      restrict_columns->to_cost == SPI_ERROR_NOATTRIBUTE) {
    elog(ERROR, "Error, restriction query must return columns "
        "'target_id', 'via_path' and 'to_cost'");
    return -1;
  }
 
  if (SPI_gettypeid(tuptable->tupdesc,
       restrict_columns->target_id) != INT4OID ||
     SPI_gettypeid(tuptable->tupdesc, restrict_columns->via_path) != TEXTOID ||
     SPI_gettypeid(tuptable->tupdesc, restrict_columns->to_cost) != FLOAT8OID) {
    elog(ERROR, "Error, restriction columns 'target_id' must be of type int4,"
     "'via_path' must be of type text, 'to_cost' must be of type float8");
    return -1;
  }
 
  return 0;
}

References restrict_columns::target_id, restrict_columns::to_cost, and restrict_columns::via_path.

Referenced by compute_trsp().

finish()

static int finish ( int  code, int  ret  )

static

Definition at line 56 of file trsp.c.

                          {
  PGR_DBG("In finish, trying to disconnect from spi %d", ret);
  code = SPI_finish();
  if (code != SPI_OK_FINISH) {
    elog(ERROR, "couldn't disconnect from SPI");
    return -1;
  }
  return ret;
}

References PGR_DBG.

Referenced by compute_trsp().

PG_FUNCTION_INFO_V1()

PG_FUNCTION_INFO_V1

(

_pgr_trsp

)