// mk4.h --
// $Id: mk4.h,v 1.39 2004/01/26 09:54:45 jcw Exp $
// This is part of Metakit, see
http://www.equi4.com/metakit/
/** @file
* Main Metakit library include file
*/
#ifndef __MK4_H__
#define __MK4_H__
//---------------------------------------------------------------------------
//
// TITLE
//
// The Metakit Library, by Jean-Claude Wippler, Equi4 Software, NL.
//
// DESCRIPTION
//
// Structured data storage with commit / rollback and on-demand loading.
//
// ACKNOWLEDGEMENTS
//
// To Liesbeth and Myra, for making this possible.
//
//---------------------------------------------------------------------------
//
// NAMING CONVENTIONS PREFIX REMARKS
//
// Compile time options q4_ Always defined as 1 or 0, capitalized
// Preprocessor defines d4_ Use with "#ifdef" or "#if defined()"
// Classes c4_ Classes, listed at start of headers
// Typedefs t4_ Type definitions, if outside classes
// Global functions f4_ Internal, these are rarely defined
//
// Member functions Start in uppercase
// Instance variables _ And start in lowercase
// Static members _ And start in uppercase
//
// Local variable names Start in lowercase
// Formal parameter names Start lowercase, end with underscore
//
//---------------------------------------------------------------------------
/// Current release = 100 * major + 10 * minor + maintenance
#define d4_MetakitLibraryVersion 249 // 2.4.9.3 release, Jan 26, 2004
#define d4_MetaKitLibraryVersion d4_MetakitLibraryVersion // compat, yuck
//---------------------------------------------------------------------------
// Declarations in this file
class c4_View; // a view on underlying data
class c4_Cursor; // an index into a view
class c4_RowRef; // a reference to a row
class c4_Row; // one row in a view
class c4_Bytes; // used to pass around generic data
class c4_Storage; // manages view persistence
class c4_CustomViewer; // used for customizable views
class c4_Stream; // abstract stream class
class c4_Strategy; // system and file interface
class c4_Property; // for access inside rows
class c4_IntProp;
class c4_LongProp;
class c4_FloatProp;
class c4_DoubleProp;
class c4_StringProp;
class c4_BytesProp;
class c4_ViewProp;
// Everything below is part of the implementation, not for public use
class c4_Sequence; // a collection of rows
class c4_Reference; // refers to the actual data values
class c4_IntRef;
class c4_LongRef;
class c4_FloatRef;
class c4_DoubleRef;
class c4_BytesRef;
class c4_StringRef;
class c4_ViewRef;
class c4_Dependencies; // not defined here
class c4_Handler; // not defined here
class c4_Notifier; // not defined here
class c4_Persist; // not defined here
//---------------------------------------------------------------------------
// determine whether we need to include "mk4dll.h" to link as DLL
#if defined (MKDLL_EXPORTS) && !defined (q4_KITDLL)
#define q4_KITDLL 1
#endif
// omit floats and doubles in small model 16-bit Intel builds
#if defined (_DOS) && defined (_M_I86SM) && !defined (q4_TINY)
#define q4_TINY 1
#endif
// and here's the other end of the scale...
#if !defined (_WIN32) && !defined (q4_LONG64)
#if defined (_PA_RISC2_0) || defined (__powerpc64__) || defined(__sparcv9) || \
defined (__x86_64__) || defined (__s390x__) || defined (__alpha) || \
(defined (__ia64) && (!defined (__HP_aCC) || defined(__LP64__)))
#define q4_LONG64 1
#endif
#endif
// default to inlining for maximum performance
#if !defined (q4_INLINE)
#define q4_INLINE 1
#endif
//---------------------------------------------------------------------------
// Borland C++ and C++ Builder
#if defined (__BORLANDC__)
// by default, if runtime is linked as a DLL, then so is Metakit
#if defined (_RTLDLL) && !defined (q4_KITDLL)
#define q4_KITDLL 1
#endif
// Borland 5.0 supports the bool datatype
#if __BORLANDC__ >= 0x500
#define q4_BOOL 1
#endif
#endif // __BORLANDC__
// IRIX supports the bool datatype
// define before gcc to cover both the gcc and MipsPRO compiler
#if defined (sgi)
#define q4_BOOL 1
#undef bool
#undef true
#undef false
#endif
// GNU gcc/egcs
#if defined (__GNUC__)
#ifndef q4_BOOL
#define q4_BOOL 1
#endif
#ifndef HAVE_LONG_LONG
#define HAVE_LONG_LONG 1
#endif
#endif
// HP aCC
#if defined (__HP_aCC)
#ifndef HAVE_LONG_LONG
#define HAVE_LONG_LONG 1
#endif
#endif
// Metrowerks CodeWarrior
#if defined (__MWERKS__)
#if __option(bool)
#define q4_BOOL 1 // bool datatype is optionally supported
// undef, these conflict with c4_Storage::c4_Storage overloading
#undef bool
#undef true
#undef false
#endif
#endif
// Microsoft Visual C++
#if defined (_MSC_VER)
// MSVC 5.0 supports the bool datatype, MSVC 4.x has no namespaces
#if _MSC_VER >= 1100
#define q4_BOOL 1
#define LONG_LONG __int64
#else
#define q4_NO_NS 1
#endif
// a kludge to avoid having to use ugly DLL exprt defs in this header
#pragma warning(disable: 4273) // inconsistent dll linkage
#endif // _MSC_VER
//---------------------------------------------------------------------------
// Other definitions needed by the public Metakit library header files
#if !q4_BOOL && !q4_STD // define a bool datatype
#define false 0
#define true 1
#define bool int
#endif
#if q4_KITDLL // add declaration specifiers
#include "mk4dll.h"
#endif
#if q4_INLINE // enable inline expansion
#define d4_inline inline
#else
#define d4_inline
#endif
typedef unsigned char t4_byte; // create typedefs for t4_byte, etc.
#if q4_LONG64
typedef int t4_i32; // if longs are 64b, then int must be 32b
#else
typedef long t4_i32; // if longs aren't 64b, then they are 32b
#endif
#if q4_LONG64 // choose a way to represent 64b integers
typedef long t4_i64;
#elif defined (LONG_LONG)
typedef LONG_LONG t4_i64;
#elif HAVE_LONG_LONG
typedef long long t4_i64;
#else
struct t4_i64 { long l1; long l2; };
bool operator== (const t4_i64 a_, const t4_i64 b_);
bool operator< (const t4_i64 a_, const t4_i64 b_);
#endif
//---------------------------------------------------------------------------
class c4_View
{
protected:
c4_Sequence* _seq;
public:
/* Construction / destruction / assignment */
c4_View (c4_Sequence* =0);
c4_View (c4_CustomViewer*);
c4_View (c4_Stream*);
c4_View (const c4_Property& property_);
c4_View (const c4_View&);
~c4_View ();
c4_View& operator= (const c4_View&);
c4_Persist* Persist() const; // added 16-11-2000 to simplify c4_Storage
/* Getting / setting the number of rows */
int GetSize() const;
void SetSize(int, int =-1);
void RemoveAll();
/*: Getting / setting individual elements */
c4_RowRef GetAt(int) const;
c4_RowRef operator[] (int) const;
void SetAt(int, const c4_RowRef&);
c4_RowRef ElementAt(int);
bool GetItem(int, int, c4_Bytes&) const;
void SetItem(int, int, const c4_Bytes&) const;
/* These can increase the number of rows */
void SetAtGrow(int, const c4_RowRef&);
int Add(const c4_RowRef&);
/* Insertion / deletion of rows */
void InsertAt(int, const c4_RowRef&, int =1);
void RemoveAt(int, int =1);
void InsertAt(int, const c4_View&);
bool IsCompatibleWith(const c4_View&) const;
void RelocateRows(int, int, c4_View&, int);
/* Dealing with the properties of this view */
int NumProperties() const;
const c4_Property& NthProperty(int) const;
int FindProperty(int);
int FindPropIndexByName(const char*) const;
c4_View Duplicate() const;
c4_View Clone() const;
int AddProperty(const c4_Property&);
c4_View operator, (const c4_Property&) const;
const char* Description() const;
/* Derived views */
c4_View Sort() const;
c4_View SortOn(const c4_View&) const;
c4_View SortOnReverse(const c4_View&, const c4_View&) const;
c4_View Select(const c4_RowRef&) const;
c4_View SelectRange(const c4_RowRef&, const c4_RowRef&) const;
c4_View Project(const c4_View&) const;
c4_View ProjectWithout(const c4_View&) const;
int GetIndexOf(const c4_RowRef&) const;
int RestrictSearch(const c4_RowRef&, int&, int&);
/* Custom views */
c4_View Slice(int, int =-1, int =1) const;
c4_View Product(const c4_View&) const;
c4_View RemapWith(const c4_View&) const;
c4_View Pair(const c4_View&) const;
c4_View Concat(const c4_View&) const;
c4_View Rename(const c4_Property&, const c4_Property&) const;
c4_View GroupBy(const c4_View&, const c4_ViewProp&) const;
c4_View Counts(const c4_View&, const c4_IntProp&) const;
c4_View Unique() const;
c4_View Union(const c4_View&) const;
c4_View Intersect(const c4_View&) const;
c4_View Different(const c4_View&) const;
c4_View Minus(const c4_View&) const;
c4_View JoinProp(const c4_ViewProp&, bool =false) const;
c4_View Join(const c4_View&, const c4_View&, bool =false) const;
c4_View ReadOnly() const;
c4_View Hash(const c4_View&, int =1) const;
c4_View Blocked() const;
c4_View Ordered(int =1) const;
c4_View Indexed(const c4_View&, const c4_View&, bool =false) const;
/* Searching */
int Find(const c4_RowRef&, int =0) const;
int Search(const c4_RowRef&) const;
int Locate(const c4_RowRef&, int* =0) const;
/* Comparing view contents */
int Compare(const c4_View&) const;
friend bool operator== (const c4_View&, const c4_View&);
friend bool operator!= (const c4_View&, const c4_View&);
friend bool operator< (const c4_View&, const c4_View&);
friend bool operator> (const c4_View&, const c4_View&);
friend bool operator<= (const c4_View&, const c4_View&);
friend bool operator>= (const c4_View&, const c4_View&);
protected:
void _IncSeqRef();
void _DecSeqRef();
/// View references are allowed to peek inside view objects
friend class c4_ViewRef;
// DROPPED: Structure() const;
// DROPPED: Description(const c4_View& view_);
};
//---------------------------------------------------------------------------
#if defined(os_aix) && defined(compiler_ibmcxx) && (compiler_ibmcxx > 500)
bool operator== (const c4_RowRef& a_, const c4_RowRef& b_);
bool operator!= (const c4_RowRef& a_, const c4_RowRef& b_);
bool operator<= (const c4_RowRef& a_, const c4_RowRef& b_);
bool operator>= (const c4_RowRef& a_, const c4_RowRef& b_);
bool operator> (const c4_RowRef& a_, const c4_RowRef& b_);
bool operator< (const c4_RowRef& a_, const c4_RowRef& b_);
#endif
class c4_Cursor
{
public:
/// Pointer to the sequence
c4_Sequence* _seq;
/// Current index into the sequence
int _index;
/* Construction / destruction / dereferencing */
/// Construct a new cursor
c4_Cursor (c4_Sequence&, int);
/// Dereference this cursor to "almost" a row
c4_RowRef operator* () const;
/// This is the same as *(cursor + offset)
c4_RowRef operator[] (int) const;
/* Stepping the iterator forwards / backwards */
/// Pre-increment the cursor
c4_Cursor& operator++ ();
/// Post-increment the cursor
c4_Cursor operator++ (int);
/// Pre-decrement the cursor
c4_Cursor& operator-- ();
/// Post-decrement the cursor
c4_Cursor operator-- (int);
/// Advance by a given offset
c4_Cursor& operator+= (int);
/// Back up by a given offset
c4_Cursor& operator-= (int);
/// Subtract a specified offset
c4_Cursor operator- (int) const;
/// Return the distance between two cursors
int operator- (c4_Cursor) const;
/// Add specified offset
friend c4_Cursor operator+ (c4_Cursor, int);
/// Add specified offset to cursor
friend c4_Cursor operator+ (int, c4_Cursor);
/* Comparing row positions */
/// Return true if both cursors are equal
friend bool operator== (c4_Cursor, c4_Cursor);
/// Return true if both cursors are not equal
friend bool operator!= (c4_Cursor, c4_Cursor);
/// True if first cursor is less than second cursor
friend bool operator< (c4_Cursor, c4_Cursor);
/// True if first cursor is greater than second cursor
friend bool operator> (c4_Cursor, c4_Cursor);
/// True if first cursor is less or equal to second cursor
friend bool operator<= (c4_Cursor, c4_Cursor);
/// True if first cursor is greater or equal to second cursor
friend bool operator>= (c4_Cursor, c4_Cursor);
/* Comparing row contents */
/// Return true if the contents of both rows are equal
friend bool operator== (const c4_RowRef&, const c4_RowRef&);
/// Return true if the contents of both rows are not equal
friend bool operator!= (const c4_RowRef&, const c4_RowRef&);
/// True if first row is less than second row
friend bool operator< (const c4_RowRef&, const c4_RowRef&);
/// True if first row is greater than second row
friend bool operator> (const c4_RowRef&, const c4_RowRef&);
/// True if first row is less or equal to second row
friend bool operator<= (const c4_RowRef&, const c4_RowRef&);
/// True if first row is greater or equal to second row
friend bool operator>= (const c4_RowRef&, const c4_RowRef&);
};
//---------------------------------------------------------------------------
class c4_RowRef
{
/// A row reference is a cursor in disguise
c4_Cursor _cursor;
public:
/* General operations */
/// Assign the value of another row to this one
c4_RowRef operator= (const c4_RowRef&);
/// Return the cursor associated to this row
c4_Cursor operator& () const;
/// Return the underlying container view
c4_View Container() const;
protected:
/// Constructor, not for general use
c4_RowRef (c4_Cursor);
friend class c4_Cursor;
friend class c4_Row;
};
//---------------------------------------------------------------------------
/// An entry in a collection with copy semantics.
//
// Rows can exist by themselves and as contents of views. Row assignment
// implies that a copy of the contents of the originating row is made.
//
// A row is implemented as an unattached view with exactly one element.
class c4_Row : public c4_RowRef
{
public:
/// Construct a row with no properties
c4_Row ();
/// Construct a row from another one
c4_Row (const c4_Row&);
/// Construct a row copy from a row reference
c4_Row (const c4_RowRef&);
/// Destructor
~c4_Row ();
/// Assign a copy of another row to this one
c4_Row& operator= (const c4_Row&);
/// Copy another row to this one
c4_Row& operator= (const c4_RowRef&);
/// Add all properties and values into this row
void ConcatRow(const c4_RowRef&);
/// Return a new row which is the concatenation of two others
friend c4_Row operator+ (const c4_RowRef&, const c4_RowRef&);
private:
static c4_Cursor Allocate();
static void Release(c4_Cursor);
};
//---------------------------------------------------------------------------
class c4_Bytes
{
union {
t4_byte _buffer [16];
double _aligner; // on a Sparc, the int below wasn't enough...
};
t4_byte* _contents;
int _size;
bool _copy;
public:
c4_Bytes ();
c4_Bytes (const void*, int);
c4_Bytes (const void*, int, bool);
c4_Bytes (const c4_Bytes&);
~c4_Bytes ();
c4_Bytes& operator= (const c4_Bytes&);
void Swap(c4_Bytes&);
int Size() const;
const t4_byte* Contents() const;
t4_byte* SetBuffer(int);
t4_byte* SetBufferClear(int);
friend bool operator== (const c4_Bytes&, const c4_Bytes&);
friend bool operator!= (const c4_Bytes&, const c4_Bytes&);
private:
void _MakeCopy();
void _LoseCopy();
};
//---------------------------------------------------------------------------
class c4_Storage : public c4_View
{
public:
/// Construct streaming-only storage object
c4_Storage ();
/// Construct a storage using the specified strategy handler
c4_Storage (c4_Strategy&, bool =false, int =1);
/// Construct a storage object, keeping the current structure
c4_Storage (const char*, int);
/// Reconstruct a storage object from a suitable view
c4_Storage (const c4_View&);
/// Destructor, usually closes file, but does not commit by default
~c4_Storage ();
void SetStructure(const char*);
bool AutoCommit(bool =true);
c4_Strategy& Strategy() const;
const char* Description(const char* =0);
bool SetAside(c4_Storage&);
c4_Storage* GetAside() const;
bool Commit(bool =false);
bool Rollback(bool =false);
c4_ViewRef View(const char*);
c4_View GetAs(const char*);
bool LoadFrom(c4_Stream&);
void SaveTo(c4_Stream&);
//DROPPED: c4_Storage (const char* filename_, const char* description_);
//DROPPED: c4_View Store(const char* name_, const c4_View& view_);
//DROPPED: c4_HandlerSeq& RootTable() const;
//DROPPED: c4_RowRef xContents() const;
private:
void Initialize(c4_Strategy&, bool, int);
};
//---------------------------------------------------------------------------
class c4_Property
{
short _id;
char _type;
public:
/// Construct a new property with the give type and id
c4_Property (char, int);
/// Construct a new property with the give type and name
c4_Property (char, const char*);
~c4_Property ();
c4_Property (const c4_Property&);
void operator= (const c4_Property&);
const char* Name() const;
char Type() const;
int GetId() const;
c4_Reference operator() (const c4_RowRef&) const;
void Refs(int) const;
c4_View operator, (const c4_Property&) const;
static void CleanupInternalData();
};
/// Integer properties.
class c4_IntProp : public c4_Property
{
public:
/// Construct a new property
c4_IntProp (const char*);
/// Destructor
~c4_IntProp ();
/// Get or set an integer property in a row
c4_IntRef operator() (const c4_RowRef&) const;
/// Get an integer property in a row
t4_i32 Get(const c4_RowRef&) const;
/// Set an integer property in a row
void Set(const c4_RowRef&, t4_i32) const;
/// Creates a row with one integer, shorthand for AsRow.
c4_Row operator[] (t4_i32) const;
/// Creates a row with one integer.
c4_Row AsRow(t4_i32) const;
};
#if !q4_TINY
/// Long int properties.
class c4_LongProp : public c4_Property
{
public:
/// Construct a new property
c4_LongProp (const char*);
/// Destructor
~c4_LongProp ();
/// Get or set a long int property in a row
c4_LongRef operator() (const c4_RowRef&) const;
/// Get a long int property in a row
t4_i64 Get(const c4_RowRef&) const;
/// Set a long int property in a row
void Set(const c4_RowRef&, t4_i64) const;
/// Creates a row with one long int, shorthand for AsRow.
c4_Row operator[] (t4_i64) const;
/// Creates a row with one long int.
c4_Row AsRow(t4_i64) const;
};
/// Floating point properties.
class c4_FloatProp : public c4_Property
{
public:
/// Construct a new property
c4_FloatProp (const char*);
/// Destructor
~c4_FloatProp ();
/// Get or set a floating point property in a row
c4_FloatRef operator() (const c4_RowRef&) const;
/// Get a floating point property in a row
double Get(const c4_RowRef&) const;
/// Set a floating point property in a row
void Set(const c4_RowRef&, double) const;
/// Create a row with one floating point value, shorthand for AsRow
c4_Row operator[] (double) const;
/// Create a row with one floating point value
c4_Row AsRow(double) const;
};
/// Double precision properties.
class c4_DoubleProp : public c4_Property
{
public:
/// Construct a new property.
c4_DoubleProp (const char*);
/// Destructor
~c4_DoubleProp ();
/// Get or set a double precision property in a row
c4_DoubleRef operator() (const c4_RowRef&) const;
/// Get a double precision property in a row
double Get(const c4_RowRef&) const;
/// Set a double precision property in a row
void Set(const c4_RowRef&, double) const;
/// Create a row with one double precision value, shorthand for AsRow
c4_Row operator[] (double) const;
/// Create a row with one double precision value
c4_Row AsRow(double) const;
};
#endif // !q4_TINY
/// String properties.
class c4_StringProp : public c4_Property
{
public:
/// Construct a new property
c4_StringProp (const char*);
/// Destructor
~c4_StringProp ();
/// Get or set a string property in a row
c4_StringRef operator() (const c4_RowRef&) const;
/// Get a string property in a row
const char* Get(const c4_RowRef&) const;
/// Set a string property in a row
void Set(const c4_RowRef&, const char*) const;
/// Create a row with one string, shorthand for AsRow
c4_Row operator[] (const char*) const;
/// Create a row with one string
c4_Row AsRow(const char*) const;
};
/// Binary properties.
class c4_BytesProp : public c4_Property
{
public:
/// Construct a new property
c4_BytesProp (const char*);
/// Destructor
~c4_BytesProp ();
/// Get or set a bytes property in a row
c4_BytesRef operator() (const c4_RowRef&) const;
/// Get a bytes property in a row
c4_Bytes Get(const c4_RowRef&) const;
/// Set a bytes property in a row
void Set(const c4_RowRef&, const c4_Bytes&) const;
/// Create a row with one bytes object, shorthand for AsRow
c4_Row operator[] (const c4_Bytes&) const;
/// Create a row with one bytes object
c4_Row AsRow(const c4_Bytes&) const;
};
/// View properties.
class c4_ViewProp : public c4_Property
{
public:
/// Construct a new property
c4_ViewProp (const char*);
/// Destructor
~c4_ViewProp ();
/// Get or set a view property in a row
c4_ViewRef operator() (const c4_RowRef&) const;
/// Get a view property in a row
c4_View Get(const c4_RowRef&) const;
/// Set a view property in a row
void Set(const c4_RowRef&, const c4_View&) const;
/// Create a row with one view, shorthand for AsRow
c4_Row operator[] (const c4_View&) const;
/// Create a row with one view
c4_Row AsRow(const c4_View&) const;
};
//---------------------------------------------------------------------------
class c4_CustomViewer
{
protected:
/// Constructor, must be overriden in derived class
c4_CustomViewer ();
public:
/// Destructor
virtual ~c4_CustomViewer ();
/// Return the structure of this view (initialization, called once)
virtual c4_View GetTemplate() = 0;
/// Return the number of rows in this view
virtual int GetSize() = 0;
int Lookup(const c4_RowRef&, int&);
virtual int Lookup(c4_Cursor, int&);
/// Fetch one data item, return it as a generic data value
virtual bool GetItem(int, int, c4_Bytes&) = 0;
virtual bool SetItem(int, int, const c4_Bytes&);
bool InsertRows(int, const c4_RowRef&, int =1);
virtual bool InsertRows(int, c4_Cursor, int =1);
virtual bool RemoveRows(int, int =1);
};
//---------------------------------------------------------------------------
/// A stream is a virtual helper class to serialize in binary form.
class c4_Stream
{
public:
virtual ~c4_Stream ();
/// Fetch some bytes sequentially
virtual int Read(void*, int) = 0;
/// Store some bytes sequentially
virtual bool Write(const void*, int) = 0;
};
//---------------------------------------------------------------------------
/// A strategy encapsulates code dealing with the I/O system interface.
class c4_Strategy
{
public:
c4_Strategy ();
virtual ~c4_Strategy ();
virtual bool IsValid() const;
virtual int DataRead(t4_i32, void*, int);
virtual void DataWrite(t4_i32, const void*, int);
virtual void DataCommit(t4_i32);
virtual void ResetFileMapping();
virtual t4_i32 FileSize();
virtual t4_i32 FreshGeneration();
void SetBase(t4_i32);
t4_i32 EndOfData(t4_i32 =-1);
/// True if the storage format is not native (default is false)
bool _bytesFlipped;
/// Error code of last failed I/O operation, zero if I/O was ok
int _failure;
/// First byte in file mapping, zero if not active
const t4_byte* _mapStart;
/// Number of bytes filled with active data
t4_i32 _dataSize;
/// All file positions are relative to this offset
t4_i32 _baseOffset;
/// The root position of the shallow tree walks
t4_i32 _rootPos;
/// The size of the root column
t4_i32 _rootLen;
};
//---------------------------------------------------------------------------
/// A sequence is an abstract base class for views on ranges of records.
//
// Sequences represent arrays of rows (or indexed collections / tables).
// Insertion and removal of entries is allowed, but could take linear time.
// A reference count is maintained to decide when the object should go away.
class c4_Sequence
{
/// Reference count
int _refCount;
/// Pointer to dependency list, or null if nothing depends on this
c4_Dependencies* _dependencies;
protected:
/// Optimization: cached property index
int _propertyLimit;
/// Optimization: property map for faster access
short* _propertyMap; // see c4_HandlerSeq::Reset()
/// allocated on first use by c4_Sequence::Buffer()
c4_Bytes* _tempBuf;
public:
/* General */
/// Abstract constructor
c4_Sequence ();
virtual int Compare(int, c4_Cursor) const;
virtual bool RestrictSearch(c4_Cursor, int&, int&);
void SetAt(int, c4_Cursor);
virtual int RemapIndex(int, const c4_Sequence*) const;
/* Reference counting */
void IncRef();
void DecRef();
int NumRefs() const;
/* Adding / removing rows */
/// Return the current number of rows
virtual int NumRows() const = 0;
void Resize(int, int =-1);
virtual void InsertAt(int, c4_Cursor, int =1);
virtual void RemoveAt(int, int =1);
virtual void Move(int, int);
/* Properties */
int NthPropId(int) const;
int PropIndex(int);
int PropIndex(const c4_Property&);
/// Return the number of data handlers in this sequence
virtual int NumHandlers() const = 0;
/// Return a reference to the N-th handler in this sequence
virtual c4_Handler& NthHandler(int) const = 0;
/// Return the context of the N-th handler in this sequence
virtual const c4_Sequence* HandlerContext(int) const = 0;
/// Add the specified data handler to this sequence
virtual int AddHandler(c4_Handler*) = 0;
/// Create a handler of the appropriate type
virtual c4_Handler* CreateHandler(const c4_Property&) = 0;
virtual const char* Description();
/* Element access */
/// Return width of specified data item
virtual int ItemSize(int, int);
/// Retrieve one data item from this sequence
virtual bool Get(int, int, c4_Bytes&);
/// Store a data item into this sequence
virtual void Set(int, const c4_Property&, const c4_Bytes&);
/* Dependency notification */
void Attach(c4_Sequence*);
void Detach(c4_Sequence*);
/// Return a pointer to the dependencies, or null
c4_Dependencies* GetDependencies() const;
virtual c4_Notifier* PreChange(c4_Notifier&);
virtual void PostChange(c4_Notifier&);
const char* UseTempBuffer(const char*);
protected:
virtual ~c4_Sequence ();
void ClearCache();
public: //! for c4_Table::Sequence setup
virtual void SetNumRows(int) = 0;
virtual c4_Persist* Persist() const;
c4_Bytes& Buffer();
private:
c4_Sequence (const c4_Sequence&); // not implemented
void operator= (const c4_Sequence&); // not implemented
};
//---------------------------------------------------------------------------
/// A reference is used to get or set typed data, using derived classes.
//
// Objects of this class are only intended to be used as a temporary handle
// while getting and setting properties in a row. They are normally only
// constructed as result of function overload operators: "property (row)".
class c4_Reference
{
protected:
/// The cursor which points to the data
c4_Cursor _cursor;
/// The property associated to this reference
const c4_Property& _property;
public:
/// Constructor
c4_Reference (const c4_RowRef&, const c4_Property&);
/// Assignment of one data item
c4_Reference& operator= (const c4_Reference&);
/// Return width of the referenced data item
int GetSize() const;
/// Retrieve the value of the referenced data item
bool GetData(c4_Bytes&) const;
/// Store a value into the referenced data item
void SetData(const c4_Bytes&) const;
/// Return true if the contents of both references is equal
friend bool operator== (const c4_Reference&, const c4_Reference&);
/// Return true if the contents of both references is not equal
friend bool operator!= (const c4_Reference&, const c4_Reference&);
private:
void operator& () const; // not implemented
};
//---------------------------------------------------------------------------
/// Used to get or set integer values.
class c4_IntRef : public c4_Reference
{
public:
/// Constructor
c4_IntRef (const c4_Reference&);
/// Get the value as integer
operator t4_i32 () const;
/// Set the value to the specified integer
c4_IntRef& operator= (t4_i32);
};
#if !q4_TINY
/// Used to get or set long int values.
class c4_LongRef : public c4_Reference
{
public:
/// Constructor
c4_LongRef (const c4_Reference&);
/// Get the value as long int
operator t4_i64 () const;
/// Set the value to the specified long int
c4_LongRef& operator= (t4_i64);
};
/// Used to get or set floating point values.
class c4_FloatRef : public c4_Reference
{
public:
/// Constructor
c4_FloatRef (const c4_Reference&);
/// Get the value as floating point
operator double () const;
/// Set the value to the specified floating point
c4_FloatRef& operator= (double);
};
/// Used to get or set double precision values.
class c4_DoubleRef : public c4_Reference
{
public:
/// Constructor
c4_DoubleRef (const c4_Reference&);
/// Get the value as floating point
operator double () const;
/// Set the value to the specified floating point
c4_DoubleRef& operator= (double);
};
#endif // !q4_TINY
/// Used to get or set binary object values.
class c4_BytesRef : public c4_Reference
{
public:
/// Constructor
c4_BytesRef (const c4_Reference&);
/// Get the value as binary object
operator c4_Bytes () const;
/// Set the value to the specified binary object
c4_BytesRef& operator= (const c4_Bytes&);
/// Fetch data from the memo field, up to end if length is zero
c4_Bytes Access(t4_i32, int =0) const;
/// Store data, resize by diff_ bytes, return true if successful
bool Modify(const c4_Bytes&, t4_i32, int =0) const;
};
/// Used to get or set string values.
class c4_StringRef : public c4_Reference
{
public:
/// Constructor
c4_StringRef (const c4_Reference&);
/// Get the value as string
operator const char* () const;
/// Set the value to the specified string
c4_StringRef& operator= (const char*);
};
/// Used to get or set view values.
class c4_ViewRef : public c4_Reference
{
public:
/// Constructor
c4_ViewRef (const c4_Reference&);
/// Get the value as view
operator c4_View () const;
/// Set the value to the specified view
c4_ViewRef& operator= (const c4_View&);
};
//---------------------------------------------------------------------------
// Debug logging option, can generate log of changes for one/all properties
#if q4_LOGPROPMODS
FILE* f4_LogPropMods(FILE* fp_, int propId_);
#else
#define f4_LogPropMods(a,b) 0
#endif
//---------------------------------------------------------------------------
#if q4_INLINE
#include "mk4.inl"
#endif
//---------------------------------------------------------------------------
#endif // __MK4_H__
