source: box/trunk/lib/backupstore/BackupStoreFileWire.h @ 2945

// --------------------------------------------------------------------------
//
// File
//              Name:    BackupStoreFileWire.h
//              Purpose: On the wire / disc formats for backup store files
//              Created: 12/1/04
//
// --------------------------------------------------------------------------

#ifndef BACKUPSTOREFILEWIRE__H
#define BACKUPSTOREFILEWIRE__H

#include "MD5Digest.h"

// set packing to one byte
#ifdef STRUCTURE_PACKING_FOR_WIRE_USE_HEADERS
#include "BeginStructPackForWire.h"
#else
BEGIN_STRUCTURE_PACKING_FOR_WIRE
#endif

typedef struct
{
        int32_t mMagicValue;    // also the version number
        int64_t mNumBlocks;             // number of blocks contained in the file
        int64_t mContainerID;
        int64_t mModificationTime;
        int32_t mMaxBlockClearSize;             // Maximum clear size that can be expected for a block
        int32_t mOptions;               // bitmask of options used
        // Then a BackupStoreFilename
        // Then a BackupClientFileAttributes
} file_StreamFormat;

typedef struct
{
        int32_t mMagicValue;    // different magic value
        int64_t mOtherFileID;   // the file ID of the 'other' file which may be referenced by the index
        uint64_t mEntryIVBase;  // base value for block IV
        int64_t mNumBlocks;             // repeat of value in file header
} file_BlockIndexHeader;

typedef struct
{
        int32_t mSize;                  // size in clear
        uint32_t mWeakChecksum; // weak, rolling checksum
        uint8_t mStrongChecksum[MD5Digest::DigestLength];       // strong digest based checksum
} file_BlockIndexEntryEnc;

typedef struct
{
        union
        {
                int64_t mEncodedSize;           // size encoded, if > 0
                int64_t mOtherBlockIndex;       // 0 - block number in other file, if <= 0
        };
        uint8_t mEnEnc[sizeof(file_BlockIndexEntryEnc)];        // Encoded section
} file_BlockIndexEntry;

// Use default packing
#ifdef STRUCTURE_PACKING_FOR_WIRE_USE_HEADERS
#include "EndStructPackForWire.h"
#else
END_STRUCTURE_PACKING_FOR_WIRE
#endif

// header for blocks of compressed data in files
#define HEADER_CHUNK_IS_COMPRESSED              1       // bit
#define HEADER_ENCODING_SHIFT                   1       // shift value
#define HEADER_BLOWFISH_ENCODING                1       // value stored in bits 1 -- 7
#define HEADER_AES_ENCODING                             2       // value stored in bits 1 -- 7


#endif // BACKUPSTOREFILEWIRE__H