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58 lines
2.7 KiB
C++
58 lines
2.7 KiB
C++
/**************** Block H Declares Source Code File (.H) ***************/
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/* Name: BLOCK.H Version 2.0 */
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/* */
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/* (C) Copyright to the author Olivier BERTRAND 1998 */
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/* */
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/* This file contains the BLOCK pure virtual class definition. */
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/*---------------------------------------------------------------------*/
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/* Note: one of the main purpose of this base class is to take care */
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/* of the very specific way Plug handles memory allocation. */
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/* Instead of allocating small chunks of storage via new or malloc */
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/* Plug works in its private memory pool in which it does the sub- */
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/* allocation using the function PlugSubAlloc. These are never freed */
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/* separately but when a transaction is terminated, the entire pool */
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/* is set to empty, resulting in a very fast and efficient allocate */
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/* process, no garbage collection problem, and an automatic recovery */
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/* procedure (via LongJump) when the memory is exhausted. */
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/* For this to work new must be given two parameters, first the */
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/* global pointer of the Plug application, and an optional pointer to */
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/* the memory pool to use, defaulting to NULL meaning using the Plug */
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/* standard default memory pool, example: */
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/* tabp = new(g) XTAB("EMPLOYEE"); */
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/* allocates a XTAB class object in the standard Plug memory pool. */
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/***********************************************************************/
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#if !defined(BLOCK_DEFINED)
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#define BLOCK_DEFINED
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#if defined(WIN32) && !defined(NOEX)
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#define DllExport __declspec( dllexport )
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#else // !WIN32
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#define DllExport
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#endif // !WIN32
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/***********************************************************************/
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/* Definition of class BLOCK with its method function new. */
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/***********************************************************************/
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typedef class BLOCK *PBLOCK;
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class DllExport BLOCK {
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public:
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void * operator new(size_t size, PGLOBAL g, void *p = NULL) {
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#ifdef DEBTRACE
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if (debug != NULL)
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htrc("New BLOCK: size=%d g=%p p=%p\n", size, g, p);
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#endif
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return (PlugSubAlloc(g, p, size));
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} // end of new
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virtual void Print(PGLOBAL, FILE *, uint) {} // Produce file desc
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virtual void Print(PGLOBAL, char *, uint) {} // Produce string desc
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#if !defined(__BORLANDC__)
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// Avoid warning C4291 by defining a matching dummy delete operator
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void operator delete(void *, PGLOBAL, void *) {}
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#endif
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}; // end of class BLOCK
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#endif // !BLOCK_DEFINED
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