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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
#pragma pack(push)
#pragma pack(1)
class Record;
class DeletedRecord;
class Extent;
class BtreeBucket;
class JSObj;
class PhysicalDataFile;
class DiskLoc {
int fileNo; /* this will be volume, file #, etc. */
int ofs;
public:
enum { NullOfs = -1, MaxFiles=4000 };
int a() const { return fileNo; }
DiskLoc(int a, int b) : fileNo(a), ofs(b) {
assert(ofs!=0);
}
DiskLoc() { fileNo = -1; ofs = NullOfs; }
DiskLoc(const DiskLoc& l) { fileNo=l.fileNo; ofs=l.ofs; }
bool questionable() {
return ofs < -1 ||
fileNo < -1 ||
fileNo > 20;
}
bool isNull() const { return ofs == NullOfs; }
void Null() { fileNo = -1; ofs = NullOfs; }
void setInvalid() { fileNo = -2; }
void assertOk() { assert(!isNull()); }
string toString() const {
if( isNull() )
return "null";
stringstream ss;
ss << hex << fileNo << ':' << ofs;
return ss.str();
}
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;
if( ofs == b.ofs ) return 0;
return ofs < b.ofs ? -1 : 1;
}
bool operator<(const DiskLoc& b) const {
if( fileNo == b.fileNo )
return ofs < b.ofs;
return fileNo < b.fileNo;
}
/* 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.
*/
JSObj obj() const;
Record* rec() const;
DeletedRecord* drec() const;
Extent* ext() const;
BtreeBucket* btree() const;
PhysicalDataFile& pdf() const;
};
#pragma pack(pop)
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