source-engine/utils/vmpi/vmpi_filesystem_internal.h

//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: 
//
//=============================================================================//

#ifndef VMPI_FILESYSTEM_INTERNAL_H
#define VMPI_FILESYSTEM_INTERNAL_H
#ifdef _WIN32
#pragma once
#endif


#include "vmpi_filesystem.h"
#include "filesystem.h"
#include "messbuf.h"
#include "iphelpers.h"
#include "vmpi.h"
#include "utlvector.h"
#include "utllinkedlist.h"
#include "filesystem_passthru.h"


// Sub packet IDs specific to the VMPI file system.
#define VMPI_FSPACKETID_FILE_REQUEST	1	// Sent by the worker to request a file.
#define VMPI_FSPACKETID_FILE_RESPONSE	2	// Master's response to a file request.
#define VMPI_FSPACKETID_CHUNK_RECEIVED	3	// Sent by workers to tell the master they received a chunk.
#define VMPI_FSPACKETID_FILE_RECEIVED	4	// Sent by workers to tell the master they received the whole file.
#define VMPI_FSPACKETID_MULTICAST_ADDR	5
#define VMPI_FSPACKETID_FILE_CHUNK		6	// Used to send file data when using TCP.


// In TCP mode, we send larger chunks in a sliding window.
#define TCP_CHUNK_QUEUE_LEN				16

#define TCP_CHUNK_PAYLOAD_SIZE			(16*1024)
#define MULTICAST_CHUNK_PAYLOAD_SIZE	(1024*1)
#define MAX_CHUNK_PAYLOAD_SIZE			MAX( TCP_CHUNK_PAYLOAD_SIZE, MULTICAST_CHUNK_PAYLOAD_SIZE )


class CMulticastFileInfo
{
public:
	unsigned long m_CompressedSize;
	unsigned long m_UncompressedSize;
	unsigned short m_FileID;
	unsigned short m_nChunks;
};


class CBaseVMPIFileSystem : public CFileSystemPassThru
{
public:
	virtual ~CBaseVMPIFileSystem();
	virtual void Release();

	virtual void CreateVirtualFile( const char *pFilename, const void *pData, int fileLength ) = 0;
	virtual bool HandleFileSystemPacket( MessageBuffer *pBuf, int iSource, int iPacketID ) = 0;

	virtual void			Close( FileHandle_t file );
	virtual int				Read( void* pOutput, int size, FileHandle_t file );
	virtual int				Write( void const* pInput, int size, FileHandle_t file );
	virtual void			Seek( FileHandle_t file, int pos, FileSystemSeek_t seekType );
	virtual unsigned int	Tell( FileHandle_t file );
	virtual unsigned int	Size( FileHandle_t file );
	virtual unsigned int	Size( const char *pFilename, const char *pathID );
	virtual bool			FileExists( const char *pFileName, const char *pPathID );
	virtual void			Flush( FileHandle_t file );
	virtual bool			Precache( const char* pFileName, const char *pPathID );
	virtual bool			ReadFile( const char *pFileName, const char *pPath, CUtlBuffer &buf, int nMaxBytes = 0, int nStartingByte = 0, FSAllocFunc_t pfnAlloc = 0 );
	virtual bool			WriteFile( const char *pFileName, const char *pPath, CUtlBuffer &buf );

// All the IFileSystem-specific ones pass the calls through.
// The worker opens its own filesystem_stdio fthrough.

protected:
	CIPAddr m_MulticastIP;
};


class IVMPIFile
{
public:
	virtual void Close() = 0;
	virtual void Seek( int pos, FileSystemSeek_t seekType ) = 0;
	virtual unsigned int Tell() = 0;
	virtual unsigned int Size() = 0;
	virtual void Flush() = 0;
	virtual int Read( void* pOutput, int size ) = 0;
	virtual int Write( void const* pInput, int size ) = 0;
};


// Both the workers and masters use this to hand out the file data.
class CVMPIFile_Memory : public IVMPIFile
{
public:
	void Init( const char *pData, long len, char chMode = 'b' );
	virtual void Close();
	virtual void Seek( int pos, FileSystemSeek_t seekType );
	virtual unsigned int Tell();
	virtual unsigned int Size();
	virtual void Flush();
	virtual int Read( void* pOutput, int size ) ;
	virtual int Write( void const* pInput, int size );

private:
	const char *m_pData;
	long m_DataLen;
	int m_iCurPos;
	char m_chMode; // 'b' or 't'
};


// We use different payload sizes if we're using TCP mode vs. multicast/broadcast mode.
inline int VMPI_GetChunkPayloadSize()
{
	if ( VMPI_GetFileSystemMode() == VMPI_FILESYSTEM_TCP )
		return TCP_CHUNK_PAYLOAD_SIZE;
	else
		return MULTICAST_CHUNK_PAYLOAD_SIZE;
}


extern bool g_bDisableFileAccess;
extern CBaseVMPIFileSystem *g_pBaseVMPIFileSystem;


#endif // VMPI_FILESYSTEM_INTERNAL_H