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/**
* 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/>.
*/
/* storage.h
Storage subsystem management.
Lays out our datafiles on disk, manages disk space.
*/
#pragma once
namespace mongo {
#pragma pack(1)
class Record;
class DeletedRecord;
class Extent;
class BtreeBucket;
class BSONObj;
class MongoDataFile;
class DiskLoc {
int fileNo; /* this will be volume, file #, etc. */
int ofs;
public:
// Note: MaxFiles imposes a limit of about 32TB of data per process
enum SentinelValues { MaxFiles=16000, NullOfs = -1 };
int a() const {
return fileNo;
}
DiskLoc(int a, int b) : fileNo(a), ofs(b) {
//assert(ofs!=0);
}
DiskLoc() { Null(); }
DiskLoc(const DiskLoc& l) {
fileNo=l.fileNo;
ofs=l.ofs;
}
bool questionable() {
return ofs < -1 ||
fileNo < -1 ||
fileNo > 524288;
}
bool isNull() const {
return fileNo == -1;
// return ofs == NullOfs;
}
void Null() {
fileNo = -1;
ofs = 0;
}
void assertOk() {
assert(!isNull());
}
void setInvalid() {
fileNo = -2;
ofs = 0;
}
bool isValid() const {
return fileNo != -2;
}
string toString() const {
if ( isNull() )
return "null";
stringstream ss;
ss << hex << fileNo << ':' << ofs;
return ss.str();
}
operator string() const { return toString(); }
int& GETOFS() {
return ofs;
}
int getOfs() const {
return ofs;
}
void set(int a, int b) {
fileNo=a;
ofs=b;
}
void setOfs(int _fileNo, int _ofs) {
fileNo = _fileNo;
ofs = _ofs;
}
void inc(int amt) {
assert( !isNull() );
ofs += amt;
}
bool sameFile(DiskLoc b) {
return fileNo == b.fileNo;
}
bool operator==(const DiskLoc& b) const {
return fileNo==b.fileNo && ofs == b.ofs;
}
bool operator!=(const DiskLoc& b) const {
return !(*this==b);
}
const DiskLoc& operator=(const DiskLoc& b) {
fileNo=b.fileNo;
ofs = b.ofs;
//assert(ofs!=0);
return *this;
}
int compare(const DiskLoc& b) const {
int x = fileNo - b.fileNo;
if ( x )
return x;
return ofs - b.ofs;
}
bool operator<(const DiskLoc& b) const {
return compare(b) < 0;
}
/* get the "thing" associated with this disk location.
it is assumed the object is what it is -- you must asure that:
think of this as an unchecked type cast.
*/
BSONObj obj() const;
Record* rec() const;
DeletedRecord* drec() const;
Extent* ext() const;
BtreeBucket* btree() const;
BtreeBucket* btreemod() const; // marks modified / dirty
MongoDataFile& pdf() const;
};
#pragma pack()
const DiskLoc minDiskLoc(0, 1);
const DiskLoc maxDiskLoc(0x7fffffff, 0x7fffffff);
} // namespace mongo
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