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tdepim/akregator/src/mk4storage/metakit/src/persist.h

128 lines
3.0 KiB

// persist.h --
// $Id$
// This is part of Metakit, see http://www.equi4.com/metakit/
/** @file
* Definition of the core file management classes
*/
#ifndef __PERSIST_H__
#define __PERSIST_H__
/////////////////////////////////////////////////////////////////////////////
// Declarations in this file
class c4_SaveContext; // wraps file commits
class c4_Persist; // persistent table storage
class c4_Allocator; // not defined here
class c4_Column; // not defined here
class c4_Differ; // not defined here
class c4_FileMark; // not defined here
class c4_Strategy; // not defined here
class c4_HandlerSeq; // not defined here
/////////////////////////////////////////////////////////////////////////////
class c4_SaveContext
{
c4_Strategy& _strategy;
c4_Column* _walk;
c4_Differ* _differ;
c4_Allocator* _space;
c4_Allocator* _cleanup;
c4_Allocator* _nextSpace;
bool _preflight;
bool _fullScan;
int _mode;
c4_DWordArray _newPositions;
int _nextPosIndex;
t4_byte* _bufPtr;
t4_byte* _curr;
t4_byte* _limit;
t4_byte _buffer [512];
public:
c4_SaveContext (c4_Strategy& strategy_, bool fullScan_, int mode_,
c4_Differ* differ_, c4_Allocator* space_);
~c4_SaveContext ();
void SaveIt(c4_HandlerSeq& root_, c4_Allocator** spacePtr_,
c4_Bytes& rootWalk_);
void StoreValue(t4_i32 v_);
bool CommitColumn(c4_Column& col_);
void CommitSequence(c4_HandlerSeq& seq_, bool selfDesc_);
c4_Column* SetWalkBuffer(c4_Column* walk_);
bool IsFlipped() const;
bool Serializing() const;
void AllocDump(const char*, bool =false);
private:
void FlushBuffer();
void Write(const void* buf_, int len_);
};
/////////////////////////////////////////////////////////////////////////////
class c4_Persist
{
c4_Allocator* _space;
c4_Strategy& _strategy;
c4_HandlerSeq* _root;
c4_Differ* _differ;
c4_Bytes _rootWalk;
bool (c4_Persist::*_fCommit) (bool);
int _mode;
bool _owned;
// used for on-the-fly conversion of old-format datafiles
t4_byte* _oldBuf;
const t4_byte* _oldCurr;
const t4_byte* _oldLimit;
t4_i32 _oldSeek;
int OldRead(t4_byte* buf_, int len_);
public:
c4_Persist (c4_Strategy&, bool owned_, int mode_);
~c4_Persist ();
c4_HandlerSeq& Root() const;
void SetRoot(c4_HandlerSeq* root_);
c4_Strategy& Strategy() const;
bool AutoCommit(bool =true);
void DoAutoCommit();
bool SetAside(c4_Storage& aside_);
c4_Storage* GetAside() const;
bool Commit(bool full_);
bool Rollback(bool full_);
bool LoadIt(c4_Column& walk_);
void LoadAll();
t4_i32 LookupAside(int id_);
void ApplyAside(int id_, c4_Column& col_);
void OccupySpace(t4_i32 pos_, t4_i32 len_);
t4_i32 FetchOldValue();
void FetchOldLocation(c4_Column& col_);
static c4_HandlerSeq* Load(c4_Stream*);
static void Save(c4_Stream*, c4_HandlerSeq& root_);
};
/////////////////////////////////////////////////////////////////////////////
#endif