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/*
* Copyright (C) 2000, Imperial College
*
* This file is part of the Imperial College Exact Real Arithmetic Library.
* See the copyright notice included in the distribution for conditions
* of use.
*/
#include <stdio.h>
#include "real.h"
#include "real-impl.h"
/*
* For debugging purposes, we assign a unique identifier to each object in
* the heap. This identifier is invariant under copying in garbage collection.
* Also the names of the nodes in daVinci are strings formed from the
* assigned nodeId.
*/
int nodeId = 1;
/*
* For debugging purposes, nodes are assigned id's which (unlike the address
* of the node) is invariant under garbage collection.
*
* This file allocates ids and provides a function for mapping ids to
* heap addresses.
*/
void
newNodeId(Generic *node)
{
void addHashTableEntry(Generic *);
node->tag.nodeId = nodeId++;
addHashTableEntry(node);
}
/*
* We use a naive hash table to map node identifiers to heap cells.
*/
typedef struct HTE {
struct HTE *next;
Generic *node;
} HashTableEntry;
/*
* The following must be an integer power of 2
*/
#define HASH_TABLE_SIZE 512
#define HASH_TABLE_MASK (HASH_TABLE_SIZE - 1)
static HashTableEntry *hashTable[HASH_TABLE_SIZE] = {NULL};
void
addHashTableEntry(Generic *node)
{
HashTableEntry *new;
if ((new = (HashTableEntry *) malloc(sizeof(HashTableEntry))) == NULL)
Error(FATAL, E_INT, "addHashTableEntry", "malloc failed");
new->node = node;
new->next = hashTable[node->tag.nodeId & HASH_TABLE_MASK];
hashTable[node->tag.nodeId & HASH_TABLE_MASK] = new;
}
Generic *
mapNodeIdToHeapCell(int nodeId)
{
HashTableEntry *p;
p = hashTable[nodeId & HASH_TABLE_MASK];
while (p != NULL) {
if (p->node->tag.nodeId == nodeId)
return p->node;
else
p = p->next;
}
Error(FATAL, E_INT, "mapNodeIdToHeapCell", "failed to find nodeId %d", nodeId);
return NULL;
}
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