ceph/branches/ebofs/client/FileCache.h
sageweil dc48f25847 branch for ebofs changes
git-svn-id: https://ceph.svn.sf.net/svnroot/ceph@2100 29311d96-e01e-0410-9327-a35deaab8ce9
2007-11-21 00:32:00 +00:00

86 lines
1.9 KiB
C++

// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#ifndef __FILECACHE_H
#define __FILECACHE_H
#include <iostream>
using std::iostream;
#include "common/Cond.h"
#include "mds/Capability.h"
class ObjectCacher;
class FileCache {
ObjectCacher *oc;
inode_t inode;
// caps
int latest_caps;
map<int, list<Context*> > caps_callbacks;
int num_reading;
int num_writing;
//int num_unsafe;
// waiters
set<Cond*> waitfor_read;
set<Cond*> waitfor_write;
bool waitfor_release;
public:
FileCache(ObjectCacher *_oc, inode_t _inode) :
oc(_oc),
inode(_inode),
latest_caps(0),
num_reading(0), num_writing(0),// num_unsafe(0),
waitfor_release(false) {}
~FileCache() {
tear_down();
}
// waiters/waiting
bool can_read() { return latest_caps & CAP_FILE_RD; }
bool can_write() { return latest_caps & CAP_FILE_WR; }
bool all_safe();// { return num_unsafe == 0; }
void add_safe_waiter(Context *c);
void truncate(off_t olds, off_t news);
// ...
void flush_dirty(Context *onflush=0);
off_t release_clean();
void empty(Context *onempty=0);
bool is_empty() { return !(is_cached() || is_dirty()); }
bool is_cached();
bool is_dirty();
void tear_down();
int get_caps() { return latest_caps; }
int get_used_caps();
void set_caps(int caps, Context *onimplement=0);
void check_caps();
int read(off_t offset, size_t size, bufferlist& blist, Mutex& client_lock); // may block.
void write(off_t offset, size_t size, bufferlist& blist, Mutex& client_lock); // may block.
};
#endif