lix/src/db.hh
Eelco Dolstra 06d3d7355d * Enclose most operations that update the database in transactions.
* Open all database tables (Db objects) at initialisation time, not
  every time they are used.  This is necessary because tables have to
  outlive all transactions that refer to them.
2003-07-31 16:05:35 +00:00

84 lines
1.4 KiB
C++

#ifndef __DB_H
#define __DB_H
#include <string>
#include <list>
#include <map>
#include <db_cxx.h>
#include "util.hh"
using namespace std;
class Database;
class Transaction
{
friend class Database;
private:
DbTxn * txn;
public:
Transaction();
Transaction(Database & _db);
~Transaction();
void abort();
void commit();
};
#define noTxn Transaction()
typedef unsigned int TableId; /* table handles */
class Database
{
friend class Transaction;
private:
DbEnv * env;
TableId nextId;
map<TableId, Db *> tables;
void requireEnv();
Db * getDb(TableId table);
public:
Database();
~Database();
void open(const string & path);
TableId openTable(const string & table);
bool queryString(const Transaction & txn, TableId table,
const string & key, string & data);
bool queryStrings(const Transaction & txn, TableId table,
const string & key, Strings & data);
void setString(const Transaction & txn, TableId table,
const string & key, const string & data);
void setStrings(const Transaction & txn, TableId table,
const string & key, const Strings & data);
void delPair(const Transaction & txn, TableId table,
const string & key);
void enumTable(const Transaction & txn, TableId table,
Strings & keys);
};
#endif /* !__DB_H */