ancient-weatherstation/cronjob/chart/image_file/image_data.c

95 lines
2.6 KiB
C

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <postgresql/libpq-fe.h>
#include "image_data.h"
#include "image_common.h"
#include "../common.h"
#include "../definitions.h"
#define BUFFSIZE 512
#define BUFFSIZE_EXTRA 2048
static char *get_conn_string();
static PGconn *pg_check_connect(char *);
static PGresult *pg_check_exec(PGconn *, char *);
static char *get_type_table_by_id(PGconn *, int );
pix_list_ptr get_pix_list(int c_width){
double seconds_per_pix = (img_cfg.show_interval * 0.1)/(c_width * 0.1);
char *conn_string = get_conn_string();
PGconn *conn = pg_check_connect(conn_string);
PQfinish(conn);
free(conn_string);
return NULL;
}
/* baut den String fuer die Postgres-Verbindung zusammen */
static char *get_conn_string(){
char *conn_string = malloc(sizeof(char)*BUFFSIZE);
snprintf(conn_string, BUFFSIZE, "host=%s dbname=%s user=%s password=%s connect_timeout=%s", global_opts.pg_host, global_opts.pg_database, global_opts.pg_user, global_opts.pg_pass, global_opts.pg_timeout);
return conn_string;
}
/* Baut eine Vebindung zur postgres auf, bricht mit fehler ab wenn nicht moeglich */
static PGconn *pg_check_connect(char *conn_string){
PGconn *conn = PQconnectdb(conn_string); /* Connection aufbauen */
if(PQstatus(conn) != CONNECTION_OK){
DEBUGOUT2("\nFehler beim Aufbau der Datenbankverbindung\n%s\n", PQerrorMessage(conn));
exit_error(ERROR_MAKECONN);
}
DEBUGOUT1("Verbindung hergestellt \n");
return conn;
}
/* Fuehrt ein SQL-Statement aus. Bricht mit fehler ab wenn nicht moeglich */
static PGresult *pg_check_exec(PGconn *conn, char *query){
PGresult *res;
res = PQexec(conn, query);
if(!res || PQresultStatus(res) != PGRES_TUPLES_OK){
DEBUGOUT2("Fehler beim exec: %s\n", query);
exit_error(ERROR_QUERY);
} else {
DEBUGOUT2("Query: '%s' ausgeführt\n", query);
}
return res;
}
/* Tabellenname des typs aus der Datenbank holen */
static char *get_type_table_by_id(PGconn *connection, int sens_id){
char *table;
int table_field;
PGresult *table_res;
char *query_buff = malloc(sizeof(char)*BUFFSIZE);
snprintf(query_buff, BUFFSIZE, "select typen.tabelle as tbl FROM typen, sensoren WHERE sensoren.id=%d AND typen.typ=sensoren.typ", sens_id);
table_res = pg_check_exec(connection, query_buff);
if(PQntuples(table_res) < 1)
return NULL;
table_field = PQfnumber(table_res, "tbl");
table = strdup(PQgetvalue(table_res, 0, table_field));
DEBUGOUT2("\tTabelle: %s \n", table);
PQclear(table_res);
free(query_buff);
return table;
}