mongodb/db/database.h

// database.h

/**
*    Copyright (C) 2008 10gen Inc.
*  
*    This program is free software: you can redistribute it and/or  modify
*    it under the terms of the GNU Affero General Public License, version 3,
*    as published by the Free Software Foundation.
*  
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU Affero General Public License for more details.
*  
*    You should have received a copy of the GNU Affero General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#pragma once

/* Database represents a database database 
   Each database database has its own set of files -- dbname.ns, dbname.0, dbname.1, ...
*/

class Database { 
public:
	Database(const char *nm, bool& justCreated, const char *_path = dbpath) :
	name(nm),
	path(_path) { 
		assert( !string( nm ).empty() );
		justCreated = namespaceIndex.init(_path, nm);
		profile = 0;
		profileName = name + ".system.profile";
	} 
	~Database() { 
		int n = files.size();
		for( int i = 0; i < n; i++ )
			delete files[i];
	}

	PhysicalDataFile* getFile(int n) { 
		assert(this);

		if( n < 0 || n >= DiskLoc::MaxFiles ) {
			cout << "getFile(): n=" << n << endl;
			assert( n >= 0 && n < DiskLoc::MaxFiles );
		}
		DEV { 
			if( n > 100 )
				cout << "getFile(): n=" << n << "?" << endl;
		}
		while( n >= (int) files.size() )
			files.push_back(0);
		PhysicalDataFile* p = files[n];
		if( p == 0 ) {
			stringstream ss;
			ss << name << '.' << n;
			boost::filesystem::path fullName;
			fullName = boost::filesystem::path(path) / ss.str();
			string fullNameString = fullName.string();
			p = new PhysicalDataFile(n);
            try { 
                p->open(n, fullNameString.c_str() );
            } 
            catch( AssertionException& u ) { 
                delete p;
                throw u;
            }
			files[n] = p;
		}
		return p;
	}

	PhysicalDataFile* addAFile() {
		int n = (int) files.size();
		return getFile(n);
	}

    PhysicalDataFile* suitableFile(int sizeNeeded) { 
        PhysicalDataFile* f = newestFile();
        for( int i = 0; i < 8; i++ ) {
            if( f->getHeader()->unusedLength >= sizeNeeded ) 
                break;
            f = addAFile();
            if( f->getHeader()->fileLength > 1500000000 ) // this is as big as they get so might as well stop
                break;
        }
        return f;
    }

	PhysicalDataFile* newestFile() { 
		int n = (int) files.size();
		if( n > 0 ) n--;
		return getFile(n);
	}

    void finishInit(); // ugly...

	vector<PhysicalDataFile*> files;
	string name; // "alleyinsider"
	string path;
	NamespaceIndex namespaceIndex;
	int profile; // 0=off.
	string profileName; // "alleyinsider.system.profile"
    QueryOptimizer optimizer;

    bool haveLogged() { return _haveLogged; }
    void setHaveLogged();

private:
    // see dbinfo.h description.  if true, we have logged to the replication log.
    bool _haveLogged; 
};