CAdvFileAttr Class Reference

#include <AdvFileAttr.h>

Inheritance diagram for CAdvFileAttr:

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Detailed Description

This class manages some special file attributes like Sparse and Compress.

Note:

All the threading code has been rewritten to use my little CWorkQueue and CWorkQueueItem threads. This may have fixed the exit crash issue mentionned below.

Some changes were also done to reduce the clash likelyhood between sparse scanning and downloads. This may have fixed the corruption issue when running sparse scans and downloading concurrently on the same file.

Bug:

Simultaneously sparse-scanning and downloading may cause corruptiion, not yet re-tested with the new implementations.

Warning:

Trying to [de]compress a file while downloading will cause eMule to lock-up - [de]compression makes any further file accesses stall until the operation is completed.

Note:

Complete sources with comments:

• AdvFileAttr.h : http://pages.infinit.net/moonligh/eMule/Sources/AdvFileAttr.h
• AdvFileAttr.cpp : http://pages.infinit.net/moonligh/eMule/Sources/AdvFileAttr.cpp

[2003-11-05] Finished the single-worker-thread rewriting. Appears to be working very smoothly.

Public Member Functions
	CAdvFileAttr (CFile *file=NULL)
	~CAdvFileAttr (void)
	Check if there is a worker thread, signal it to terminate and wait.
bool	MakeSparse (bool forceScan=false)
bool	MakeCompressed (bool makeCompressed=true)
void	SetFilePtr (CFile *file=NULL)
bool	LoadAttributes (void)
void	Cancel (void)
	Tell the thread to terminate by nullifying its structure pointer and pulsing its Cancel Event.
uint32	GetTempFSCappabilities (void)
	Returns the partfile's file system capabilities.
uint32	GetFileAttributes (void)
	Returns the partfile's attributes.
bool	isSparse (void)
	Returns true if the file is Sparse.
bool	isCompressed (void)
	Returns true if the file is Compressed.
bool	isFSSparse (void)
	Returns true if the file system supports Sparse files.
bool	isFSCompressed (void)
	Returns true if the file system supports Compressed files.
bool	isBusy (void)
	Returns true if the worker thread is running.
bool	isCancel (void)
	Returns true if the worker thread is running.
void	ThreadWork (void)
	Dispatches the queued workloads.
Private Types
enum	{ TOps_Nothing, TOps_Compress, TOps_Sparse, TOps_Cancel }
	Tells ThreadWork what to do.
Private Member Functions
bool	WorkSparse (void)
void	WorkCompress (void)
void	QueueDelCB (void)
	Workload removal from queue callback.
Private Attributes
enum CAdvFileAttr:: { ... }	m_LastOp
	Tells ThreadWork what to do.
uint32	m_FileAttributes
	Holds the file attributes from the last time attributes have been loaded.
uint32	m_TempFSCapabilities
	Holds the file system capabilities from the last time capabilities have been loaded.
CFile *	m_pCFile
	Pointer to the file that goes with this instance.
Static Private Attributes
CWorkQueue	m_WorkQueue
	Counts the number of threads that have been started.

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Constructor & Destructor Documentation

CAdvFileAttr::CAdvFileAttr (  CFile *  file = NULL  )

On creation, load the file's attributes if a CFile was provided. Parameters: file  Pointer to a file object to associate with this instance.

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Member Function Documentation

bool CAdvFileAttr::LoadAttributes (  void   )

Reloads file attributes Returns: True on success.

bool CAdvFileAttr::MakeCompressed (  bool  makeCompressed = true  )

Scans the file for sparseness. Returns: True if the thread started.

bool CAdvFileAttr::MakeSparse (  bool  forceScan = false  )

Makes a the associated file sparse if possible. Parameters: forceScan  If true, force re-scanning of the file to extract sparseness. Returns: True if the file was successfully made sparse and the scanning thread started.

void CAdvFileAttr::SetFilePtr (  CFile *  file = NULL  )

Sets the CFile associated to this instance and loads the file system capabilities for that file. Parameters: file  Pointer to the parent class' m_hpartfile.

void CAdvFileAttr::WorkCompress (  void   )  [private]

Set the compression attribute from a thread to avoid stalling the main GUI. Warning: While changing attributes, all writes (and maybe reads) on the file become blocking calls.

bool CAdvFileAttr::WorkSparse (  void   )  [private]

Scans the file for sparseness. Bug: Quitting while a sparse is under way will cause some exceptions and memory leaks even though the thread should quit pretty quickly. Returns: True on success.

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

• AdvFileAttr.h
• AdvFileAttr.cpp

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