Viewing file:  SequenceExample.cpp (2.62 KB) -rw-r--r--
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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2004
* Sleepycat Software. All rights reserved.
*
* $Id: SequenceExample.cpp,v 1.1 2004/09/22 22:20:32 mjc Exp $
*/
#include <sys/types.h>
#include <iostream>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
extern "C" {
extern int getopt(int, char * const *, const char *);
extern int optind;
}
#else
#include <unistd.h>
#endif
#include <db_cxx.h>
#define DATABASE "sequence.db"
#define SEQUENCE "my_sequence"
using std::cout;
using std::cerr;
class SequenceExample
{
public:
SequenceExample();
void run(bool removeExistingDatabase, const char *fileName);
private:
// no need for copy and assignment
SequenceExample(const SequenceExample &);
void operator = (const SequenceExample &);
};
int
usage()
{
(void)fprintf(stderr, "usage: SequenceExample [-r] [database]\n");
return (EXIT_FAILURE);
}
int
main(int argc, char *argv[])
{
int ch, rflag;
const char *database;
rflag = 0;
while ((ch = getopt(argc, argv, "r")) != EOF)
switch (ch) {
case 'r':
rflag = 1;
break;
case '?':
default:
return (usage());
}
argc -= optind;
argv += optind;
/* Accept optional database name. */
database = *argv == NULL ? DATABASE : argv[0];
// Use a try block just to report any errors.
// An alternate approach to using exceptions is to
// use error models (see DbEnv::set_error_model()) so
// that error codes are returned for all Berkeley DB methods.
//
try {
SequenceExample app;
app.run((bool)(rflag == 1 ? true : false), database);
return (EXIT_SUCCESS);
}
catch (DbException &dbe) {
cerr << "SequenceExample: " << dbe.what() << "\n";
return (EXIT_FAILURE);
}
}
SequenceExample::SequenceExample()
{
}
void SequenceExample::run(bool removeExistingDatabase, const char *fileName)
{
// Remove the previous database.
if (removeExistingDatabase)
(void)remove(fileName);
// Create the database object.
// There is no environment for this simple example.
Db db(0, 0);
db.set_error_stream(&cerr);
db.set_errpfx("SequenceExample");
db.open(NULL, fileName, NULL, DB_BTREE, DB_CREATE, 0664);
// We put a try block around this section of code
// to ensure that our database is properly closed
// in the event of an error.
//
try {
Dbt key((void *)SEQUENCE, (u_int32_t)strlen(SEQUENCE));
DbSequence seq(&db, 0);
seq.open(0, &key, DB_CREATE);
for (int i = 0; i < 10; i++) {
db_seq_t seqnum;
seq.get(0, 1, &seqnum, 0);
cout << "Got sequence number: " << seqnum << "\n";
}
seq.close(0);
} catch (DbException &dbe) {
cerr << "SequenceExample: " << dbe.what() << "\n";
}
db.close(0);
}
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