From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001
From: Duncan Wilkie <antigravityd@gmail.com>
Date: Sat, 18 Nov 2023 06:11:09 -0600
Subject: Initial commit.

---
 ic-reals-6.3/base/nodeId.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 ic-reals-6.3/base/nodeId.c

(limited to 'ic-reals-6.3/base/nodeId.c')

diff --git a/ic-reals-6.3/base/nodeId.c b/ic-reals-6.3/base/nodeId.c
new file mode 100644
index 0000000..035fa49
--- /dev/null
+++ b/ic-reals-6.3/base/nodeId.c
@@ -0,0 +1,81 @@
+/*
+ * 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;
+}
-- 
cgit v1.2.3