FdTable< HandleT > Class Template Reference

#include <fd_table.h>

Inheritance diagram for FdTable< HandleT >:

Collaboration diagram for FdTable< HandleT >:

Classes
struct	FdWrapper

Public Member Functions
	FdTable (unsigned max_open_fds, const HandleT &invalid_handle)
void	AssignFrom (const FdTable< HandleT > &other)
FdTable< HandleT > *	Clone ()
int	OpenFd (const HandleT &handle)
HandleT	GetHandle (int fd)
int	CloseFd (int fd)
unsigned	GetMaxFds () const

Private Member Functions
bool	IsValid (int fd)
Private Member Functions inherited from SingleCopy
	SingleCopy ()

Private Attributes
HandleT	invalid_handle_
unsigned	fd_pivot_
std::vector< unsigned >	fd_index_
std::vector< FdWrapper >	open_fds_

Detailed Description

template<class HandleT>
class FdTable< HandleT >

This file is part of the CernVM File System. Maintains integers mapped to custom open file descriptors. File descriptors can be added, removed, and accessed. All operations take constant time. The maximum file descriptor number needs to be known upfront.

Note that new file descriptors do not necessarily have the smallest available number but any number between 0..max_open_fds.

This class is used by a couple of cache managers.

Definition at line 28 of file fd_table.h.

Constructor & Destructor Documentation

template<class HandleT>

FdTable< HandleT >::FdTable ( unsigned  max_open_fds, const HandleT &  invalid_handle  )

inline

Definition at line 30 of file fd_table.h.

Member Function Documentation

template<class HandleT>

void FdTable< HandleT >::AssignFrom ( const FdTable< HandleT > &  other )

inline

Used to restore the state.

Definition at line 48 of file fd_table.h.

Referenced by ExternalCacheManager::DoRestoreState().

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template<class HandleT>

FdTable<HandleT>* FdTable< HandleT >::Clone ( )

inline

Used to save the state.

Definition at line 62 of file fd_table.h.

template<class HandleT>

int FdTable< HandleT >::CloseFd ( int  fd )

inline

Releases fd back to the set of available numbers. Gracefully handles invalid handles (-EBADFD)

Definition at line 104 of file fd_table.h.

template<class HandleT>

HandleT FdTable< HandleT >::GetHandle ( int  fd )

inline

For invalid and unused numbers, the invalid handle is returned.

Definition at line 95 of file fd_table.h.

template<class HandleT>

unsigned FdTable< HandleT >::GetMaxFds ( ) const

inline

Definition at line 125 of file fd_table.h.

template<class HandleT>

bool FdTable< HandleT >::IsValid ( int  fd )

inlineprivate

Definition at line 139 of file fd_table.h.

Referenced by FdTable< ExternalCacheManager::ReadOnlyHandle >::CloseFd(), and FdTable< ExternalCacheManager::ReadOnlyHandle >::GetHandle().

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template<class HandleT>

int FdTable< HandleT >::OpenFd ( const HandleT &  handle )

inline

Registers fd with a currently unused number. If the table is full, returns -ENFILE;

Definition at line 78 of file fd_table.h.

Member Data Documentation

template<class HandleT>

std::vector<unsigned> FdTable< HandleT >::fd_index_

private

Maps into open_fds_. Until fd_pivot_, file descriptors are used. As of fd_pivot_, points to free file descriptors. Used to acquire new file descriptors in constant time.

Definition at line 158 of file fd_table.h.

Referenced by FdTable< ExternalCacheManager::ReadOnlyHandle >::AssignFrom(), FdTable< ExternalCacheManager::ReadOnlyHandle >::Clone(), FdTable< ExternalCacheManager::ReadOnlyHandle >::CloseFd(), FdTable< ExternalCacheManager::ReadOnlyHandle >::FdTable(), FdTable< ExternalCacheManager::ReadOnlyHandle >::GetMaxFds(), and FdTable< ExternalCacheManager::ReadOnlyHandle >::OpenFd().

template<class HandleT>

unsigned FdTable< HandleT >::fd_pivot_

private

The index of the first available file descriptor in fd_index_.

Definition at line 152 of file fd_table.h.

Referenced by FdTable< ExternalCacheManager::ReadOnlyHandle >::AssignFrom(), FdTable< ExternalCacheManager::ReadOnlyHandle >::Clone(), FdTable< ExternalCacheManager::ReadOnlyHandle >::CloseFd(), and FdTable< ExternalCacheManager::ReadOnlyHandle >::OpenFd().

template<class HandleT>

HandleT FdTable< HandleT >::invalid_handle_

private

An unused (available) file descriptor.

Definition at line 148 of file fd_table.h.

Referenced by FdTable< ExternalCacheManager::ReadOnlyHandle >::AssignFrom(), FdTable< ExternalCacheManager::ReadOnlyHandle >::Clone(), FdTable< ExternalCacheManager::ReadOnlyHandle >::CloseFd(), FdTable< ExternalCacheManager::ReadOnlyHandle >::GetHandle(), FdTable< ExternalCacheManager::ReadOnlyHandle >::IsValid(), and FdTable< ExternalCacheManager::ReadOnlyHandle >::OpenFd().

template<class HandleT>

std::vector<FdWrapper> FdTable< HandleT >::open_fds_

private

The file descriptor number mapped to a user-defined file descriptor (struct). The fd integer passed to users of the file descriptor table points into this array.

Definition at line 164 of file fd_table.h.

Referenced by FdTable< ExternalCacheManager::ReadOnlyHandle >::AssignFrom(), FdTable< ExternalCacheManager::ReadOnlyHandle >::Clone(), FdTable< ExternalCacheManager::ReadOnlyHandle >::CloseFd(), FdTable< ExternalCacheManager::ReadOnlyHandle >::FdTable(), FdTable< ExternalCacheManager::ReadOnlyHandle >::GetHandle(), FdTable< ExternalCacheManager::ReadOnlyHandle >::IsValid(), and FdTable< ExternalCacheManager::ReadOnlyHandle >::OpenFd().

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The documentation for this class was generated from the following file:

• /home/sftnight/jenkins/workspace/CvmfsDoxygen/label/docker-x86_64/cvmfs/cvmfs/fd_table.h