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irix-657m-src/eoe/cmd/fam/FileSystem.h
2022-09-29 17:59:04 +03:00

114 lines
3.4 KiB
C++

#ifndef FileSystem_included
#define FileSystem_included
#include "ClientInterest.h"
#include "Request.h"
#include "Set.h"
struct mntent;
struct stat;
// FileSystem is the abstract base class for a per-filesystem object.
// A FileSystem has two monitoring interfaces: high level and low
// level. It also maintains a set of all ClientInterests on the
// file system
//
// It also has miscellaneous access functions:
//
// dir() returns the mount point.
//
// fsname() returns the device name.
//
// matches() tests whether a given struct mntent describes the
// current filesystem.
//
// interests() returns a set of all ClientInterests on the
// filesystem.
//
// A FileSystem also can relocate its interests (after it's been
// dismounted or another FileSystem has been mounted on it), by calling
// relocate_interests(). This checks all Interests to see what FileSystem
// they're on, and moves them appropriately.
//
// The high level interface supports monitoring a file whether it
// exists or not, and can monitor all entries in a directory.
// The high level interface corresponds to what fam can rely
// on from a remote fam on an NFS server.
//
// The high level interface is:
//
// monitor()
// cancel()
// hl_suspend()
// hl_resume()
// hl_map_path()
//
// See the strong resemblance to FAM's client interface? (-:
// hl_map_path() maps a local pathname to a remote pathname.
// For a local FileSystem, this is trivial. For a remote
// file system, it's less trivial.
//
// The low level interface monitors a single filesystem entity
// and must be informed if the entity is a special file or does
// not exist. The low level interface corresponds to what fam
// needs for local files.
//
// The low level interface is:
//
// ll_monitor() start monitoring an interest.
// ll_notify_created() notify the FS that the interest was deleted.
// ll_notify_deleted() notify the FS that the interest was created.
//
// The two subclasses of FileSystem are LocalFileSystem and
// NFSFileSystem. LocalFileSystem implements the low level
// interface. NFSFileSystem implements the high level interface.
class FileSystem {
public:
typedef Set<ClientInterest *> Interests;
FileSystem(const mntent&);
virtual ~FileSystem();
// Miscellaneous routines
Boolean matches(const mntent& m) const;
const char *dir() const { return mydir; }
const char *fsname() const { return myfsname; }
const Interests& interests() { return myinterests; }
virtual Boolean dir_entries_scanned() const = 0;
void relocate_interests();
virtual int attr_cache_timeout() const = 0;
// High level monitoring interface
Request monitor(ClientInterest *, ClientInterest::Type);
void cancel(ClientInterest *, Request);
virtual void hl_suspend(Request) = 0;
virtual void hl_resume(Request) = 0;
virtual void hl_map_path(char *remote_path, const char *local_path,
const Cred& cr) = 0;
// Low level monitoring interface
virtual void ll_monitor(Interest *, Boolean imonitored) = 0;
virtual void ll_notify_created(Interest *) = 0;
virtual void ll_notify_deleted(Interest *) = 0;
private:
// Instance Variables
char *mydir;
char *myfsname;
Interests myinterests;
virtual Request hl_monitor(ClientInterest *, ClientInterest::Type) = 0;
virtual void hl_cancel(Request) = 0;
};
#endif /* !FileSystem_included */