/*------------------------------------------------------------------------- * * memutils.h * this file contains general memory alignment, allocation * and manipulation stuff that used to be spread out * between the following files: * * align.h alignment macros * aset.h memory allocation set stuff * oset.h (used by aset.h) * (bit.h bit array type / extern) * clib.h mem routines * limit.h max bits/byte, etc. * * * Copyright (c) 1994, Regents of the University of California * * $Id: memutils.h,v 1.24 1999/05/22 23:19:36 tgl Exp $ * * NOTES * some of the information in this file will be moved to * other files, (like MaxHeapTupleSize and MaxAttributeSize). * *------------------------------------------------------------------------- */ #ifndef MEMUTILS_H #define MEMUTILS_H /* ---------------- * Alignment macros: align a length or address appropriately for a given type. * * There used to be some incredibly crufty platform-dependent hackery here, * but now we rely on the configure script to get the info for us. Much nicer. * * NOTE: _ALIGN will not work if ALIGNVAL is not a power of 2. * That case seems extremely unlikely to occur in practice, however. * ---------------- */ #define _ALIGN(ALIGNVAL,LEN) (((long)(LEN) + (ALIGNVAL-1)) & ~(ALIGNVAL-1)) #define SHORTALIGN(LEN) _ALIGN(ALIGNOF_SHORT, (LEN)) #define INTALIGN(LEN) _ALIGN(ALIGNOF_INT, (LEN)) #define LONGALIGN(LEN) _ALIGN(ALIGNOF_LONG, (LEN)) #define DOUBLEALIGN(LEN) _ALIGN(ALIGNOF_DOUBLE, (LEN)) #define MAXALIGN(LEN) _ALIGN(MAXIMUM_ALIGNOF, (LEN)) /***************************************************************************** * oset.h -- Fixed format ordered set definitions. * *****************************************************************************/ /* Note: * Fixed format ordered sets are . * XXX This is a preliminary version. Work is needed to explain * XXX semantics of the external definitions. Otherwise, the * XXX functional interface should not change. * */ typedef struct OrderedElemData OrderedElemData; typedef OrderedElemData *OrderedElem; typedef struct OrderedSetData OrderedSetData; typedef OrderedSetData *OrderedSet; struct OrderedElemData { OrderedElem next; /* Next elem or &this->set->dummy */ OrderedElem prev; /* Previous elem or &this->set->head */ OrderedSet set; /* Parent set */ }; struct OrderedSetData { OrderedElem head; /* First elem or &this->dummy */ OrderedElem dummy; /* (hack) Terminator == NULL */ OrderedElem tail; /* Last elem or &this->head */ Offset offset; /* Offset from struct base to elem */ /* this could be signed short int! */ }; extern void OrderedSetInit(OrderedSet set, Offset offset); extern bool OrderedSetContains(OrderedSet set, OrderedElem elem); extern Pointer OrderedSetGetHead(OrderedSet set); extern Pointer OrderedElemGetPredecessor(OrderedElem elem); extern Pointer OrderedElemGetSuccessor(OrderedElem elem); extern void OrderedElemPop(OrderedElem elem); extern void OrderedElemPushInto(OrderedElem elem, OrderedSet Set); /***************************************************************************** * aset.h -- Allocation set definitions. * *****************************************************************************/ /* * Description: * An allocation set is a set containing allocated elements. When * an allocation is requested for a set, memory is allocated and a * pointer is returned. Subsequently, this memory may be freed or * reallocated. In addition, an allocation set may be reset which * will cause all memory allocated within it to be freed. * * Allocations may occur in four different modes. The mode of * allocation does not affect the behavior of allocations except in * terms of performance. The allocation mode is set at the time of * set initialization. Once the mode is chosen, it cannot be changed * unless the set is reinitialized. * * "Dynamic" mode forces all allocations to occur in a heap. This * is a good mode to use when small memory segments are allocated * and freed very frequently. This is a good choice when allocation * characteristics are unknown. This is the default mode. * * "Static" mode attempts to allocate space as efficiently as possible * without regard to freeing memory. This mode should be chosen only * when it is known that many allocations will occur but that very * little of the allocated memory will be explicitly freed. * * "Tunable" mode is a hybrid of dynamic and static modes. The * tunable mode will use static mode allocation except when the * allocation request exceeds a size limit supplied at the time of set * initialization. "Big" objects are allocated using dynamic mode. * * "Bounded" mode attempts to allocate space efficiently given a limit * on space consumed by the allocation set. This restriction can be * considered a "soft" restriction, because memory segments will * continue to be returned after the limit is exceeded. The limit is * specified at the time of set initialization like for tunable mode. * * Note: * Allocation sets are not automatically reset on a system reset. * Higher level code is responsible for cleaning up. * * There may be other modes in the future. */ /* * AllocPointer * Aligned pointer which may be a member of an allocation set. */ typedef Pointer AllocPointer; /* * AllocMode * Mode of allocation for an allocation set. * * Note: * See above for a description of the various nodes. */ typedef enum AllocMode { DynamicAllocMode, /* always dynamically allocate */ StaticAllocMode, /* always "statically" allocate */ TunableAllocMode, /* allocations are "tuned" */ BoundedAllocMode /* allocations bounded to fixed usage */ } AllocMode; #define DefaultAllocMode DynamicAllocMode /* * AllocBlock * Small pieces of memory are taken from bigger blocks of * memory with a size aligned to a power of two. These * pieces are not free's separately, instead they are reused * for the next allocation of a fitting size. */ typedef struct AllocBlockData { struct AllocSetData *aset; struct AllocBlockData *next; char *freeptr; char *endptr; } AllocBlockData; typedef AllocBlockData *AllocBlock; /* * AllocChunk * The prefix of each piece of memory in an AllocBlock */ typedef struct AllocChunkData { /* aset is the owning aset if allocated, or the freelist link if free */ void *aset; /* size is always the chunk size */ Size size; } AllocChunkData; typedef AllocChunkData *AllocChunk; /* * AllocSet * Allocation set. */ typedef struct AllocSetData { struct AllocBlockData *blocks; #define ALLOCSET_NUM_FREELISTS 8 struct AllocChunkData *freelist[ALLOCSET_NUM_FREELISTS]; /* Note: this will change in the future to support other modes */ } AllocSetData; typedef AllocSetData *AllocSet; /* * AllocPointerIsValid * True iff pointer is valid allocation pointer. */ #define AllocPointerIsValid(pointer) PointerIsValid(pointer) /* * AllocSetIsValid * True iff set is valid allocation set. */ #define AllocSetIsValid(set) PointerIsValid(set) extern void AllocSetInit(AllocSet set, AllocMode mode, Size limit); extern void AllocSetReset(AllocSet set); extern bool AllocSetContains(AllocSet set, AllocPointer pointer); extern AllocPointer AllocSetAlloc(AllocSet set, Size size); extern void AllocSetFree(AllocSet set, AllocPointer pointer); extern AllocPointer AllocSetRealloc(AllocSet set, AllocPointer pointer, Size size); extern void AllocSetDump(AllocSet set); /***************************************************************************** * clib.h -- Standard C library definitions * *****************************************************************************/ /* * Note: * This file is OPERATING SYSTEM dependent!!! * */ /* * LibCCopyLength is only used within this file. -cim 6/12/90 * */ typedef int LibCCopyLength; /* * MemoryCopy * Copies fixed length block of memory to another. */ #define MemoryCopy(toBuffer, fromBuffer, length)\ memcpy(toBuffer, fromBuffer, length) /***************************************************************************** * limit.h -- POSTGRES limit definitions. * *****************************************************************************/ #define MaxBitsPerByte 8 typedef uint32 AttributeSize; /* XXX should be defined elsewhere */ #define MaxHeapTupleSize 0x7fffffff #define MaxAttributeSize 0x7fffffff #define MaxIndexAttributeNumber 7 #endif /* MEMUTILS_H */