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#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <stddef.h>
#include "test.h"
#define MAXIMUM_ALIGNOF 8
#define BLCKSZ 8192
typedef unsigned char uint8; /* == 8 bits */
typedef unsigned short uint16; /* == 16 bits */
typedef unsigned int uint32; /* == 32 bits */
typedef uint8 bits8; /* >= 8 bits */
typedef uint16 bits16; /* >= 16 bits */
typedef uint32 bits32; /* >= 32 bits */
#define FLEXIBLE_ARRAY_MEMBER /* empty */
typedef struct ItemIdData
{
unsigned lp_off:15, /* offset to tuple (from start of page) */
lp_flags:2, /* state of line pointer, see below */
lp_len:15; /* byte length of tuple */
} ItemIdData;
struct HeapTupleHeaderData
{
union
{
char * t_heap;
char * t_datum;
} t_choice;
char * t_ctid; /* current TID of this or newer tuple (or a
* speculative insertion token) */
/* Fields below here must match MinimalTupleData! */
#define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK2 2
uint16 t_infomask2; /* number of attributes + various flags */
#define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK 3
uint16 t_infomask; /* various flag bits, see below */
#define FIELDNO_HEAPTUPLEHEADERDATA_HOFF 4
uint8 t_hoff; /* sizeof header incl. bitmap, padding */
/* ^ - 23 bytes - ^ */
#define FIELDNO_HEAPTUPLEHEADERDATA_BITS 5
bits8 t_bits[FLEXIBLE_ARRAY_MEMBER]; /* bitmap of NULLs */
};
typedef struct HeapTupleHeaderData HeapTupleHeaderData;
typedef struct PageHeaderData
{
/* XXX LSN is member of *any* block, not only page-organized ones */
char * pd_lsn; /* LSN: next byte after last byte of xlog
* record for last change to this page */
uint16 pd_checksum; /* checksum */
uint16 pd_flags; /* flag bits, see below */
int * pd_lower; /* offset to start of free space */
int * pd_upper; /* offset to end of free space */
int * pd_special; /* offset to start of special space */
uint16 pd_pagesize_version;
char * pd_prune_xid; /* oldest prunable XID, or zero if none */
ItemIdData pd_linp[FLEXIBLE_ARRAY_MEMBER]; /* line pointer array */
} PageHeaderData;
#define SizeofHeapTupleHeader offsetof(HeapTupleHeaderData, t_bits)
// #define offsetof(t, d) __builtin_offsetof(t, d)
#define SizeOfPageHeaderData (offsetof(PageHeaderData, pd_linp))
#define TYPEALIGN(ALIGNVAL,LEN) \
(((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
#define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
#define MaxHeapTuplesPerPage \
((int) ((BLCKSZ - SizeOfPageHeaderData) / \
(MAXALIGN(SizeofHeapTupleHeader) + sizeof(ItemIdData))))
// #define myvalue 190
// #define MaxHeapTuplesPerPage myvalue + 100
#define MAX_TUPLES_PER_PAGE MaxHeapTuplesPerPage
typedef struct
{
int nredirected; /* numbers of entries in arrays below */
int ndead;
int nunused;
/*
* marked[i] is true if item i is entered in one of the above arrays.
*
* This needs to be MaxHeapTuplesPerPage + 1 long as FirstOffsetNumber is
* 1. Otherwise every access would need to subtract 1.
*/
bool marked[MaxHeapTuplesPerPage + 1];
} PruneState;
int
heap_page_prune()
{
PruneState prstate;
memset(prstate.marked, 0, sizeof(prstate.marked));
printf("====%ld\n", sizeof(prstate.marked));
ASSERT(291, sizeof(prstate.marked) );
printf("====%d\n", MaxHeapTuplesPerPage + 1);
ASSERT(291, MaxHeapTuplesPerPage + 1);
return 0;
}
int main() {
heap_page_prune();
return 0;
}
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