pg_feedback.c

/*-------------------------------------------------------------------------
 *
 * pg_feedback.c
 *
 * Copyright (c) 2017-2021, Sergey Bronnikov
 *
 *-------------------------------------------------------------------------
 */

#include <inttypes.h>
#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#include <postgres.h>

#include <miscadmin.h>
#include <funcapi.h>
#include <utils/builtins.h>
#include <catalog/pg_control.h>
#include <common/controldata_utils.h>

#include "helpers.h"

static char *system_db_id()
{
    ControlFileData *ControlFile = NULL;
    char *sysident_str = NULL;
    sysident_str = (char *)malloc(32);
    if (!sysident_str) {
        perror("malloc");
        return NULL;
    }

    ControlFile = get_controlfile(DataDir, NULL);
    if (!ControlFile)
        ereport(ERROR,
          (errmsg("calculated CRC checksum does not match value stored in file")));
    snprintf(sysident_str, sizeof (sysident_str), UINT64_FORMAT, ControlFile->system_identifier);

    return sysident_str;
}

#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

PG_FUNCTION_INFO_V1(postmaster_uptime);

Datum
postmaster_uptime(PG_FUNCTION_ARGS)
{
    char pid[256];
    sprintf(pid, "%d", getppid());
    PG_RETURN_TEXT_P(cstring_to_text(pid));
}

PG_FUNCTION_INFO_V1(db_sys_id);

Datum
db_sys_id(PG_FUNCTION_ARGS)
{
    char *id;
    id = system_db_id();
    PG_RETURN_TEXT_P(cstring_to_text(id));
}

PG_FUNCTION_INFO_V1(datadir_fs);

Datum
datadir_fs(PG_FUNCTION_ARGS)
{
    char *fs;
    fs = dirfs(DataDir);
    PG_RETURN_TEXT_P(cstring_to_text(fs));
}

PG_FUNCTION_INFO_V1(sysinfo);

Datum
sysinfo(PG_FUNCTION_ARGS)
{
    char **values;
    HeapTuple tuple;
    Datum result;
    TupleDesc tupdesc;
    AttInMetadata *attinmeta;
    hwinfo *hw;
    osinfo *os;

    if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) {
        ereport(ERROR,
            (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
            errmsg("function returning record called in context "
            "that cannot accept type record")));
    }

    values = (char **)palloc(7 * sizeof (char *));
    values[0] = (char *)palloc(256 * sizeof (char));
    values[1] = (char *)palloc(256 * sizeof (char));
    values[2] = (char *)palloc(256 * sizeof (char));
    values[3] = (char *)palloc(256 * sizeof (char));
    values[4] = (char *)palloc(256 * sizeof (char));
    values[5] = (char *)palloc(256 * sizeof (char));
    values[6] = (char *)palloc(256 * sizeof (char));

    hw = get_hw_info();
    snprintf(values[0], 256, "%d", hw->ncpu);
    snprintf(values[1], 256, "%" PRId64, hw->memsize);
    snprintf(values[2], 256, "%llu", hw->uptime);
    free(hw);

    os = get_os_info();
    snprintf(values[3], 256, "%s", os->os_version);
    snprintf(values[4], 256, "%s", os->os_name);
    snprintf(values[5], 256, "%s", os->os_family);
    snprintf(values[6], 256, "%s", os->os_arch);
    free(os->os_version);
    free(os->os_name);
    free(os->os_family);
    free(os->os_arch);
    free(os);

    /* build a tuple */
    attinmeta = TupleDescGetAttInMetadata(tupdesc);
    tuple = BuildTupleFromCStrings(attinmeta, values);

    /* make the tuple into a datum */
    result = HeapTupleGetDatum(tuple);

    /* clean up (this is not really necessary) */
    pfree(values[0]);
    pfree(values[1]);
    pfree(values[2]);
    pfree(values[3]);
    pfree(values[4]);
    pfree(values[5]);
    pfree(values[6]);
    pfree(values);
    PG_RETURN_DATUM(result);
}