Viewing file:  AccessExample.cpp (3.42 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: AccessExample.cpp,v 11.24 2004/09/17 22:00:28 mjc Exp $
*/
#include <sys/types.h>
#include <iostream>
#include <iomanip>
#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 "access.db"
using std::cin;
using std::cout;
using std::cerr;
class AccessExample
{
public:
AccessExample();
void run(bool removeExistingDatabase, const char *fileName);
private:
// no need for copy and assignment
AccessExample(const AccessExample &);
void operator = (const AccessExample &);
};
int
usage()
{
(void)fprintf(stderr, "usage: AccessExample [-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 {
AccessExample app;
app.run((bool)(rflag == 1 ? true : false), database);
return (EXIT_SUCCESS);
}
catch (DbException &dbe) {
cerr << "AccessExample: " << dbe.what() << "\n";
return (EXIT_FAILURE);
}
}
AccessExample::AccessExample()
{
}
void AccessExample::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("AccessExample");
db.set_pagesize(1024); /* Page size: 1K. */
db.set_cachesize(0, 32 * 1024, 0);
db.open(NULL, fileName, NULL, DB_BTREE, DB_CREATE, 0664);
//
// Insert records into the database, where the key is the user
// input and the data is the user input in reverse order.
//
char buf[1024], rbuf[1024];
char *p, *t;
int ret;
u_int32_t len;
for (;;) {
cout << "input> ";
cout.flush();
cin.getline(buf, sizeof(buf));
if (cin.eof())
break;
if ((len = (u_int32_t)strlen(buf)) <= 0)
continue;
for (t = rbuf, p = buf + (len - 1); p >= buf;)
*t++ = *p--;
*t++ = '\0';
Dbt key(buf, len + 1);
Dbt data(rbuf, len + 1);
ret = db.put(0, &key, &data, DB_NOOVERWRITE);
if (ret == DB_KEYEXIST) {
cout << "Key " << buf << " already exists.\n";
}
}
cout << "\n";
// 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 {
// Acquire a cursor for the table.
Dbc *dbcp;
db.cursor(NULL, &dbcp, 0);
// Walk through the table, printing the key/data pairs.
Dbt key;
Dbt data;
while (dbcp->get(&key, &data, DB_NEXT) == 0) {
char *key_string = (char *)key.get_data();
char *data_string = (char *)data.get_data();
cout << key_string << " : " << data_string << "\n";
}
dbcp->close();
}
catch (DbException &dbe) {
cerr << "AccessExample: " << dbe.what() << "\n";
}
db.close(0);
}
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