FileStream.h

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/*****************************************************************************/
/* FileStream.h Copyright (c) Ladislav Zezula 2012 */
/*---------------------------------------------------------------------------*/
/* Description: Definitions for FileStream object */
/*---------------------------------------------------------------------------*/
/* Date Ver Who Comment */
/* -------- ---- --- ------- */
/* 14.04.12 1.00 Lad The first version of FileStream.h */
/*****************************************************************************/

#ifndef __FILESTREAM_H__
#define __FILESTREAM_H__

//-----------------------------------------------------------------------------
// Function prototypes

typedef void (*STREAM_INIT)(
 struct TFileStream * pStream // Pointer to an unopened stream
);

typedef bool (*STREAM_CREATE)(
 struct TFileStream * pStream // Pointer to an unopened stream
 );

typedef bool (*STREAM_OPEN)(
 struct TFileStream * pStream, // Pointer to an unopened stream
 const TCHAR * szFileName, // Pointer to file name to be open
 DWORD dwStreamFlags // Stream flags
 );

typedef bool (*STREAM_READ)(
 struct TFileStream * pStream, // Pointer to an open stream
 ULONGLONG * pByteOffset, // Pointer to file byte offset. If NULL, it reads from the current position
 void * pvBuffer, // Pointer to data to be read
 DWORD dwBytesToRead // Number of bytes to read from the file
 );

typedef bool (*STREAM_WRITE)(
 struct TFileStream * pStream, // Pointer to an open stream
 ULONGLONG * pByteOffset, // Pointer to file byte offset. If NULL, it writes to the current position
 const void * pvBuffer, // Pointer to data to be written
 DWORD dwBytesToWrite // Number of bytes to read from the file
 );

typedef bool (*STREAM_RESIZE)(
 struct TFileStream * pStream, // Pointer to an open stream
 ULONGLONG FileSize // New size for the file, in bytes
 );

typedef bool (*STREAM_GETSIZE)(
 struct TFileStream * pStream, // Pointer to an open stream
 ULONGLONG * pFileSize // Receives the file size, in bytes
 );

typedef bool (*STREAM_GETPOS)(
 struct TFileStream * pStream, // Pointer to an open stream
 ULONGLONG * pByteOffset // Pointer to store current file position
 );

typedef void (*STREAM_CLOSE)(
 struct TFileStream * pStream // Pointer to an open stream
 );

typedef bool (*BLOCK_READ)(
 struct TFileStream * pStream, // Pointer to a block-oriented stream
 ULONGLONG StartOffset, // Byte offset of start of the block array
 ULONGLONG EndOffset, // End offset (either end of the block or end of the file)
 LPBYTE BlockBuffer, // Pointer to block-aligned buffer
 DWORD BytesNeeded, // Number of bytes that are really needed
 bool bAvailable // true if the block is available
 );

typedef bool (*BLOCK_CHECK)(
 struct TFileStream * pStream, // Pointer to a block-oriented stream
 ULONGLONG BlockOffset // Offset of the file to check
 );

typedef void (*BLOCK_SAVEMAP)(
 struct TFileStream * pStream // Pointer to a block-oriented stream
 );

//-----------------------------------------------------------------------------
// Local structures - partial file structure and bitmap footer

#define ID_FILE_BITMAP_FOOTER 0x33767470 // Signature of the file bitmap footer ('ptv3')
#define DEFAULT_BLOCK_SIZE 0x00004000 // Default size of the stream block
#define DEFAULT_BUILD_NUMBER 10958 // Build number for newly created partial MPQs

typedef struct _PART_FILE_HEADER
{
 DWORD PartialVersion; // Always set to 2
 char GameBuildNumber[0x20]; // Minimum build number of the game that can use this MPQ
 DWORD Flags; // Flags (details unknown)
 DWORD FileSizeLo; // Low 32 bits of the contained file size
 DWORD FileSizeHi; // High 32 bits of the contained file size
 DWORD BlockSize; // Size of one file block, in bytes

} PART_FILE_HEADER, *PPART_FILE_HEADER;

// Structure describing the block-to-file map entry
typedef struct _PART_FILE_MAP_ENTRY
{
 DWORD Flags; // 3 = the block is present in the file
 DWORD BlockOffsLo; // Low 32 bits of the block position in the file
 DWORD BlockOffsHi; // High 32 bits of the block position in the file
 DWORD LargeValueLo; // 64-bit value, meaning is unknown
 DWORD LargeValueHi;

} PART_FILE_MAP_ENTRY, *PPART_FILE_MAP_ENTRY;

typedef struct _FILE_BITMAP_FOOTER
{
 DWORD Signature; // 'ptv3' (ID_FILE_BITMAP_FOOTER)
 DWORD Version; // Unknown, seems to always have value of 3 (version?)
 DWORD BuildNumber; // Game build number for that MPQ
 DWORD MapOffsetLo; // Low 32-bits of the offset of the bit map
 DWORD MapOffsetHi; // High 32-bits of the offset of the bit map
 DWORD BlockSize; // Size of one block (usually 0x4000 bytes)

} FILE_BITMAP_FOOTER, *PFILE_BITMAP_FOOTER;

//-----------------------------------------------------------------------------
// Structure for file stream

union TBaseProviderData
{
 struct
 {
 ULONGLONG FileSize; // Size of the file
 ULONGLONG FilePos; // Current file position
 ULONGLONG FileTime; // Last write time
 HANDLE hFile; // File handle
 } File;

 struct
 {
 ULONGLONG FileSize; // Size of the file
 ULONGLONG FilePos; // Current file position
 ULONGLONG FileTime; // Last write time
 LPBYTE pbFile; // Pointer to mapped view
 } Map;

 struct
 {
 ULONGLONG FileSize; // Size of the file
 ULONGLONG FilePos; // Current file position
 ULONGLONG FileTime; // Last write time
 HANDLE hInternet; // Internet handle
 HANDLE hConnect; // Connection to the internet server
 } Http;
};

struct TFileStream
{
 // Stream provider functions
 STREAM_READ StreamRead; // Pointer to stream read function for this archive. Do not use directly.
 STREAM_WRITE StreamWrite; // Pointer to stream write function for this archive. Do not use directly.
 STREAM_RESIZE StreamResize; // Pointer to function changing file size
 STREAM_GETSIZE StreamGetSize; // Pointer to function returning file size
 STREAM_GETPOS StreamGetPos; // Pointer to function that returns current file position
 STREAM_CLOSE StreamClose; // Pointer to function closing the stream

 // Block-oriented functions
 BLOCK_READ BlockRead; // Pointer to function reading one or more blocks
 BLOCK_CHECK BlockCheck; // Pointer to function checking whether the block is present

 // Base provider functions
 STREAM_CREATE BaseCreate; // Pointer to base create function
 STREAM_OPEN BaseOpen; // Pointer to base open function
 STREAM_READ BaseRead; // Read from the stream
 STREAM_WRITE BaseWrite; // Write to the stream
 STREAM_RESIZE BaseResize; // Pointer to function changing file size
 STREAM_GETSIZE BaseGetSize; // Pointer to function returning file size
 STREAM_GETPOS BaseGetPos; // Pointer to function that returns current file position
 STREAM_CLOSE BaseClose; // Pointer to function closing the stream

 // Base provider data (file size, file position)
 TBaseProviderData Base;

 // Stream provider data
 TFileStream * pMaster; // Master stream (e.g. MPQ on a web server)
 TCHAR * szFileName; // File name (self-relative pointer)

 ULONGLONG StreamSize; // Stream size (can be less than file size)
 ULONGLONG StreamPos; // Stream position
 DWORD BuildNumber; // Game build number
 DWORD dwFlags; // Stream flags

 // Followed by stream provider data, with variable length
};

//-----------------------------------------------------------------------------
// Structures for block-oriented stream

struct TBlockStream : public TFileStream
{
 STREAM_DOWNLOAD_CALLBACK pfnCallback; // Callback for downloading
 void * FileBitmap; // Array of bits for file blocks
 void * UserData; // User data to be passed to the download callback
 DWORD BitmapSize; // Size of the file bitmap (in bytes)
 DWORD BlockSize; // Size of one block, in bytes
 DWORD BlockCount; // Number of data blocks in the file
 DWORD IsComplete; // If nonzero, no blocks are missing
 DWORD IsModified; // nonzero if the bitmap has been modified
}; 

//-----------------------------------------------------------------------------
// Structure for encrypted stream

#define ENCRYPTED_CHUNK_SIZE 0x40 // Size of one chunk to be decrypted

struct TEncryptedStream : public TBlockStream
{
 BYTE Key[ENCRYPTED_CHUNK_SIZE]; // File key
};

//-----------------------------------------------------------------------------
// Public functions for file stream

TFileStream * FileStream_CreateFile(const TCHAR * szFileName, DWORD dwStreamFlags);
TFileStream * FileStream_OpenFile(const TCHAR * szFileName, DWORD dwStreamFlags);
const TCHAR * FileStream_GetFileName(TFileStream * pStream);
size_t FileStream_Prefix(const TCHAR * szFileName, DWORD * pdwProvider);

bool FileStream_SetCallback(TFileStream * pStream, STREAM_DOWNLOAD_CALLBACK pfnCallback, void * pvUserData);

bool FileStream_Read(TFileStream * pStream, ULONGLONG * pByteOffset, void * pvBuffer, DWORD dwBytesToRead);
bool FileStream_Write(TFileStream * pStream, ULONGLONG * pByteOffset, const void * pvBuffer, DWORD dwBytesToWrite);
bool FileStream_SetSize(TFileStream * pStream, ULONGLONG NewFileSize);
bool FileStream_GetSize(TFileStream * pStream, ULONGLONG * pFileSize);
bool FileStream_GetPos(TFileStream * pStream, ULONGLONG * pByteOffset);
bool FileStream_GetTime(TFileStream * pStream, ULONGLONG * pFT);
bool FileStream_GetFlags(TFileStream * pStream, PDWORD pdwStreamFlags);
bool FileStream_Replace(TFileStream * pStream, TFileStream * pNewStream);
void FileStream_Close(TFileStream * pStream);


#endif // __FILESTREAM_H__