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// --------------------------------------------------------------------------
//
// File
// Name: BackupStoreFileEncodeStream.h
// Purpose: Implement stream-based file encoding for the backup store
// Created: 12/1/04
//
// --------------------------------------------------------------------------
#ifndef BACKUPSTOREFILEENCODESTREAM__H
#define BACKUPSTOREFILEENCODESTREAM__H
#include <vector>
#include "IOStream.h"
#include "BackupStoreFilename.h"
#include "CollectInBufferStream.h"
#include "MD5Digest.h"
#include "BackupStoreFile.h"
namespace BackupStoreFileCreation
{
// Diffing and creation of files share some implementation details.
typedef struct _BlocksAvailableEntry
{
struct _BlocksAvailableEntry *mpNextInHashList;
int32_t mSize; // size in clear
uint32_t mWeakChecksum; // weak, rolling checksum
uint8_t mStrongChecksum[MD5Digest::DigestLength]; // strong digest based checksum
} BlocksAvailableEntry;
}
// --------------------------------------------------------------------------
//
// Class
// Name: BackupStoreFileEncodeStream
// Purpose: Encode a file into a stream
// Created: 8/12/03
//
// --------------------------------------------------------------------------
class BackupStoreFileEncodeStream : public IOStream
{
public:
BackupStoreFileEncodeStream();
~BackupStoreFileEncodeStream();
typedef struct
{
int64_t mSpaceBefore; // amount of bytes which aren't taken out of blocks which go
int32_t mBlocks; // number of block to reuse, starting at this one
BackupStoreFileCreation::BlocksAvailableEntry *mpStartBlock; // may be null
} RecipeInstruction;
class Recipe : public std::vector<RecipeInstruction>
{
// NOTE: This class is rather tied in with the implementation of diffing.
public:
Recipe(BackupStoreFileCreation::BlocksAvailableEntry *pBlockIndex, int64_t NumBlocksInIndex,
int64_t OtherFileID = 0);
~Recipe();
int64_t GetOtherFileID() {return mOtherFileID;}
int64_t BlockPtrToIndex(BackupStoreFileCreation::BlocksAvailableEntry *pBlock)
{
return pBlock - mpBlockIndex;
}
private:
BackupStoreFileCreation::BlocksAvailableEntry *mpBlockIndex;
int64_t mNumBlocksInIndex;
int64_t mOtherFileID;
};
void Setup(const char *Filename, Recipe *pRecipe, int64_t ContainerID, const BackupStoreFilename &rStoreFilename, int64_t *pModificationTime);
virtual int Read(void *pBuffer, int NBytes, int Timeout);
virtual void Write(const void *pBuffer, int NBytes);
virtual bool StreamDataLeft();
virtual bool StreamClosed();
private:
enum
{
Status_Header = 0,
Status_Blocks = 1,
Status_BlockListing = 2,
Status_Finished = 3
};
private:
void EncodeCurrentBlock();
void CalculateBlockSizes(int64_t DataSize, int64_t &rNumBlocksOut, int32_t &rBlockSizeOut, int32_t &rLastBlockSizeOut);
void SkipPreviousBlocksInInstruction();
void SetForInstruction();
void StoreBlockIndexEntry(int64_t WncSizeOrBlkIndex, int32_t ClearSize, uint32_t WeakChecksum, uint8_t *pStrongChecksum);
private:
Recipe *mpRecipe;
IOStream *mpFile; // source file
CollectInBufferStream mData; // buffer for header and index entries
int mStatus;
bool mSendData; // true if there's file data to send (ie not a symlink)
int64_t mTotalBlocks; // Total number of blocks in the file
int64_t mAbsoluteBlockNumber; // The absolute block number currently being output
// Instruction number
int64_t mInstructionNumber;
// All the below are within the current instruction
int64_t mNumBlocks; // number of blocks. Last one will be a different size to the rest in most cases
int64_t mCurrentBlock;
int32_t mCurrentBlockEncodedSize;
int32_t mPositionInCurrentBlock; // for reading out
int32_t mBlockSize; // Basic block size of most of the blocks in the file
int32_t mLastBlockSize; // the size (unencoded) of the last block in the file
// Buffers
uint8_t *mpRawBuffer; // buffer for raw data
BackupStoreFile::EncodingBuffer mEncodedBuffer;
// buffer for encoded data
int32_t mAllocatedBufferSize; // size of above two allocated blocks
uint64_t mEntryIVBase; // base for block entry IV
};
#endif // BACKUPSTOREFILEENCODESTREAM__H
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