stoerWagner.c File Reference

#include <stdbool.h>
#include "c_common/postgres_connection.h"
#include "c_common/debug_macro.h"
#include "c_common/e_report.h"
#include "c_common/time_msg.h"
#include "c_common/edges_input.h"
#include "drivers/mincut/stoerWagner_driver.h"

Include dependency graph for stoerWagner.c:

Go to the source code of this file.

Functions
PGDLLEXPORT Datum	_pgr_stoerwagner (PG_FUNCTION_ARGS)
	PG_FUNCTION_INFO_V1 (_pgr_stoerwagner)
static void	process (char *edges_sql, pgr_stoerWagner_t **result_tuples, size_t *result_count)

Function Documentation

_pgr_stoerwagner()

PGDLLEXPORT Datum _pgr_stoerwagner

(

PG_FUNCTION_ARGS

)

Definition at line 105 of file stoerWagner.c.

                                                     {
    FuncCallContext     *funcctx;
    TupleDesc           tuple_desc;
 
    /**************************************************************************/
    /*                          MODIFY AS NEEDED                              */
    /*                                                                        */
    pgr_stoerWagner_t *result_tuples = NULL;
    size_t result_count = 0;
    /*                                                                        */
    /**************************************************************************/
 
    if (SRF_IS_FIRSTCALL()) {
        MemoryContext   oldcontext;
        funcctx = SRF_FIRSTCALL_INIT();
        oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
 
        PGR_DBG("Calling process");
        process(
                text_to_cstring(PG_GETARG_TEXT_P(0)),
                &result_tuples,
                &result_count);
 
 
        /*                                                                    */
        /**********************************************************************/
 
#if PGSQL_VERSION > 94
        funcctx->max_calls = (uint32_t)result_count;
#else
        funcctx->max_calls = (uint32_t)result_count;
#endif
        funcctx->user_fctx = result_tuples;
        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);
    }
 
    funcctx = SRF_PERCALL_SETUP();
    tuple_desc = funcctx->tuple_desc;
    result_tuples = (pgr_stoerWagner_t*) funcctx->user_fctx;
 
    if (funcctx->call_cntr < funcctx->max_calls) {
        HeapTuple    tuple;
        Datum        result;
        Datum        *values;
        bool*        nulls;
 
        values = palloc(4 * sizeof(Datum));
        nulls = palloc(4 * sizeof(bool));
 
 
        size_t i;
        for (i = 0; i < 4; ++i) {
            nulls[i] = false;
        }
 
        // postgres starts counting from 1
        values[0] = Int32GetDatum(funcctx->call_cntr + 1);
        values[1] = Int64GetDatum(result_tuples[funcctx->call_cntr].edge);
        values[2] = Float8GetDatum(result_tuples[funcctx->call_cntr].cost);
        values[3] = Float8GetDatum(result_tuples[funcctx->call_cntr].mincut);
        /**********************************************************************/
 
        tuple = heap_form_tuple(tuple_desc, values, nulls);
        result = HeapTupleGetDatum(tuple);
        SRF_RETURN_NEXT(funcctx, result);
    } else {
        /**********************************************************************/
        /*                          MODIFY AS NEEDED                          */
 
        PGR_DBG("Clean up code");
 
        /**********************************************************************/
 
        SRF_RETURN_DONE(funcctx);
    }
}

References pgr_stoerWagner_t::cost, pgr_stoerWagner_t::edge, if(), pgr_stoerWagner_t::mincut, PGR_DBG, and process().

PG_FUNCTION_INFO_V1()

PG_FUNCTION_INFO_V1

(

_pgr_stoerwagner

)

process()

static void process ( char *  edges_sql, pgr_stoerWagner_t **  result_tuples, size_t *  result_count  )

static

Definition at line 48 of file stoerWagner.c.

                              {
    /*
     *  https://www.postgresql.org/docs/current/static/spi-spi-connect.html
     */
    pgr_SPI_connect();
 
    (*result_tuples) = NULL;
    (*result_count) = 0;
 
    PGR_DBG("Load data");
    pgr_edge_t *edges = NULL;
    size_t total_edges = 0;
 
    pgr_get_edges(edges_sql, &edges, &total_edges);
    PGR_DBG("Total %ld edges in query:", total_edges);
 
    if (total_edges == 0) {
        PGR_DBG("No edges found");
        pgr_SPI_finish();
        return;
    }
 
    PGR_DBG("Starting processing");
    clock_t start_t = clock();
    char *log_msg = NULL;
    char *notice_msg = NULL;
    char *err_msg = NULL;
    do_pgr_stoerWagner(
            edges,
            total_edges,
            result_tuples,
            result_count,
            &log_msg,
            &notice_msg,
            &err_msg);
 
    time_msg(" processing pgr_stoerWagner", start_t, clock());
    PGR_DBG("Returning %ld tuples", *result_count);
 
    if (err_msg) {
        if (*result_tuples) pfree(*result_tuples);
    }
    pgr_global_report(log_msg, notice_msg, err_msg);
 
    if (edges) pfree(edges);
    if (log_msg) pfree(log_msg);
    if (notice_msg) pfree(notice_msg);
    if (err_msg) pfree(err_msg);
 
    pgr_SPI_finish();
}

References do_pgr_stoerWagner(), PGR_DBG, pgr_get_edges(), pgr_global_report(), pgr_SPI_connect(), pgr_SPI_finish(), and time_msg().

Referenced by _pgr_stoerwagner().