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Diffstat (limited to 'storage/connect/block.h')
| -rw-r--r-- | storage/connect/block.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/storage/connect/block.h b/storage/connect/block.h new file mode 100644 index 00000000..e8871277 --- /dev/null +++ b/storage/connect/block.h @@ -0,0 +1,61 @@ +/**************** Block H Declares Source Code File (.H) ***************/ +/* Name: BLOCK.H Version 2.1 */ +/* */ +/* (C) Copyright to the author Olivier BERTRAND 1998 - 2020 */ +/* */ +/* This file contains the BLOCK pure virtual class definition. */ +/*---------------------------------------------------------------------*/ +/* Note: one of the main purpose of this base class is to take care */ +/* of the very specific way Connect handles memory allocation. */ +/* Instead of allocating small chunks of storage via new or malloc */ +/* Connect works in its private memory pool in which it does the sub- */ +/* allocation using the function PlugSubAlloc. These are never freed */ +/* separately but when a transaction is terminated, the entire pool */ +/* is set to empty, resulting in a very fast and efficient allocate */ +/* process, no garbage collection problem, and an automatic recovery */ +/* procedure (via throw) when the memory is exhausted. */ +/* For this to work new must be given two parameters, first the */ +/* global pointer of the Plug application, and an optional pointer to */ +/* the memory pool to use, defaulting to NULL meaning using the Plug */ +/* standard default memory pool, example: */ +/* tabp = new(g) XTAB("EMPLOYEE"); */ +/* allocates a XTAB class object in the standard Plug memory pool. */ +/***********************************************************************/ +#if !defined(BLOCK_DEFINED) +#define BLOCK_DEFINED + +#if defined(_WIN32) && !defined(NOEX) +#define DllExport __declspec( dllexport ) +#else // !_WIN32 +#define DllExport +#endif // !_WIN32 + +/***********************************************************************/ +/* Definition of class BLOCK with its method function new. */ +/***********************************************************************/ +typedef class BLOCK *PBLOCK; + +class DllExport BLOCK { + public: + void *operator new(size_t size, PGLOBAL g, void *mp = NULL) { + xtrc(256, "New BLOCK: size=%d g=%p p=%p\n", size, g, mp); + return PlugSubAlloc(g, mp, size); + } // end of new + + void* operator new(size_t size, long long mp) { + xtrc(256, "Realloc at: mp=%lld\n", mp); + return (void*)mp; + } // end of new + + virtual void Printf(PGLOBAL, FILE *, uint) {} // Produce file desc + virtual void Prints(PGLOBAL, char *, uint) {} // Produce string desc + + // Avoid gcc errors by defining matching dummy delete operators + void operator delete(void*, PGLOBAL, void *) {} + void operator delete(void*, long long) {} + void operator delete(void*) {} + + virtual ~BLOCK() {} +}; // end of class BLOCK + +#endif // !BLOCK_DEFINED |