// MCADefrag.h
// Interfaces to the cMCADefrag class encapsulating the entire app
#pragma once
#include "OSSupport/IsThread.h"
#include "StringCompression.h"
class cMCADefrag
{
public:
enum
{
MAX_COMPRESSED_CHUNK_DATA_SIZE = (1 MiB),
MAX_RAW_CHUNK_DATA_SIZE = (100 MiB),
} ;
cMCADefrag(void);
/** Reads the cmdline params and initializes the app.
Returns true if the app should continue, false if not. */
bool Init(int argc, char ** argv);
/** Runs the entire app. */
void Run(void);
protected:
/** A single thread processing MCA files from the queue */
class cThread :
public cIsThread
{
typedef cIsThread super;
public:
cThread(cMCADefrag & a_Parent);
protected:
/** The compression methods, as specified by the MCA compression method byte. */
enum
{
COMPRESSION_GZIP = 1,
COMPRESSION_ZLIB = 2,
} ;
cMCADefrag & m_Parent;
/** The current compressed chunk data. Valid after a successful ReadChunk().
This contains only the compression method byte and the compressed data,
but not the exact-length preceding the data in the MCA file. */
unsigned char m_CompressedChunkData[MAX_COMPRESSED_CHUNK_DATA_SIZE];
/** Size of the actual current compressed chunk data, excluding the 4 exact-length bytes.
This is the amount of bytes in m_CompressedChunkData[] that are valid. */
int m_CompressedChunkDataSize;
/** The current raw chunk data. Valid after a successful ReadChunk(), if recompression is active. */
unsigned char m_RawChunkData[MAX_RAW_CHUNK_DATA_SIZE];
/** Size of the actual current raw chunk data. */
int m_RawChunkDataSize;
/** Number of the sector where the next chunk will be written by WriteChunk(). */
int m_CurrentSectorOut;
/** Set to true when the chunk has been successfully uncompressed. Only used if recompression is active.
WriteChunk() tests this flag to decide whether to call Compress(). */
bool m_IsChunkUncompressed;
/** An instance of the compressor. */
Compression::Compressor m_Compressor;
/** An instance of the extractor. */
Compression::Extractor m_Extractor;
/** Processes the specified file. */
void ProcessFile(const AString & a_FileName);
/** Reads the chunk data into m_CompressedChunkData.
Calls DecompressChunkData() if recompression is active.
a_LocationRaw is the pointer to the first byte of the Location data in the MCA header.
Returns true if successful. */
bool ReadChunk(cFile & a_File, const Byte * a_LocationRaw);
/** Writes the chunk data from m_CompressedData or m_RawChunkData (performing recompression) into file.
Calls CompressChunkData() for the actual compression, if recompression is active.
a_LocationRaw is the pointer to the first byte of the Location data to be put into the MCA header,
the chunk's location is stored in that memory area. Updates m_CurrentSectorOut.
Returns true if successful. */
bool WriteChunk(cFile & a_File, Byte * a_LocationRaw);
/** Uncompresses the chunk data from m_CompressedChunkData into m_RawChunkData.
Returns true if successful, false on failure. */
bool UncompressChunk(void);
/** Uncompresses the chunk data from m_CompressedChunkData into m_RawChunkData, using Gzip.
Returns true if successful, false on failure. */
bool UncompressChunkGzip(void);
/** Uncompresses the chunk data from m_CompressedChunkData into m_RawChunkData, using Zlib.
Returns true if successful, false on failure. */
bool UncompressChunkZlib(void);
/** Compresses the chunk data from m_RawChunkData into m_CompressedChunkData.
Returns true if successful, false on failure. */
bool CompressChunk(void);
// cIsThread overrides:
virtual void Execute(void) override;
} ;
typedef std::list<cThread *> cThreads;
/** The mutex protecting m_Files agains multithreaded access. */
cCriticalSection m_CS;
/** The queue of MCA files to be processed by the threads. Protected by m_CS. */
AStringVector m_Queue;
/** List of threads that the server has running. */
cThreads m_Threads;
/** The number of threads that should be started. Configurable on the command line. */
int m_NumThreads;
/** If set to true, the chunk data is recompressed while saving each MCA file. */
bool m_ShouldRecompress;
/** Starts a new processing thread and adds it to cThreads. */
void StartThread(void);
/** Retrieves one file from the queue (and removes it from the queue).
Returns an empty string when queue empty. */
AString GetNextFileName(void);
} ;
