From 5c2b14ebb8a19a6e2d9e3c804649cc4eccf3d0ec Mon Sep 17 00:00:00 2001
From: Stefan Frederik <stefan.schippers@gmail.com>
Date: Sat, 8 Oct 2022 09:46:30 +0200
Subject: [PATCH] add generic pointer hash table

---
 src/spice_netlist.c | 100 ++++++++++++++++++++++++++++++++++++++++++++
 src/xschem.h        |  18 ++++++++
 2 files changed, 118 insertions(+)

diff --git a/src/spice_netlist.c b/src/spice_netlist.c
index 9255e550..f509bf2f 100644
--- a/src/spice_netlist.c
+++ b/src/spice_netlist.c
@@ -750,3 +750,103 @@ void int_hash_free(Int_hashtable *hashtable)
     hashtable->size = 0;
   }
 }
+
+
+
+/* GENERIC PURPOSE PTR HASH TABLE */
+
+/*    token        value      what    ... what ...
+ * --------------------------------------------------------------------------
+ * "whatever"    "whatever"  XINSERT     insert in hash table if not in.
+ *                                       if already present update value if not NULL,
+ *                                       return new entry address.
+ * "whatever"    "whatever"  XINSERT_NOREPLACE   same as XINSERT but do not replace existing value
+ *                                       return NULL if not found.
+ * "whatever"    "whatever"  XLOOKUP     lookup in hash table,return entry addr.
+ *                                       return NULL if not found
+ * "whatever"    "whatever"  XDELETE     delete entry if found,return NULL
+ */
+Ptr_hashentry *ptr_hash_lookup(Ptr_hashtable *hashtable, const char *token, void *const value, int what)
+{
+  unsigned int hashcode, idx;
+  Ptr_hashentry *entry, *saveptr, **preventry;
+  int s ;
+  int size = hashtable->size;
+  Ptr_hashentry **table = hashtable->table;
+
+  if(token==NULL || size == 0 || table == NULL) return NULL;
+  hashcode=str_hash(token);
+  idx=hashcode % size;
+  entry=table[idx];
+  preventry=&table[idx];
+  while(1)
+  {
+    if( !entry )          /* empty slot */
+    {
+      if(what==XINSERT || what == XINSERT_NOREPLACE)            /* insert data */
+      {
+        s=sizeof( Ptr_hashentry );
+        entry=(Ptr_hashentry *)my_malloc(659, s);
+        entry->next=NULL;
+        entry->token=NULL;
+        my_strdup(658, &entry->token, token);
+        entry->value = value;
+        entry->hash=hashcode;
+        *preventry=entry;
+      }
+      return NULL; /* if element inserted return NULL since it was not in table */
+    }
+    if( entry -> hash==hashcode && strcmp(token,entry->token)==0 ) /* found a matching token */
+    {
+      if(what==XDELETE)             /* remove token from the hash table ... */
+      {
+        saveptr=entry->next;
+        my_free(896, &entry->token);
+        my_free(897, &entry);
+        *preventry=saveptr;
+      }
+      else if(what == XINSERT ) {
+        entry->value = value;
+      }
+      return entry;   /* found matching entry, return the address */
+    }
+    preventry=&entry->next; /* descend into the list. */
+    entry = entry->next;
+  }
+}
+
+void ptr_hash_init(Ptr_hashtable *hashtable, int size)
+{
+  if(hashtable-,>size !=0 || hashtable->table != NULL) {
+    dbg(0, "ptr_hash_init(): Warning hash table not empty, possible data leak\n");
+  }
+  hashtable->size = size;
+  hashtable->table = my_calloc(1576, size, sizeof(Ptr_hashentry *));
+}
+
+static void ptr_hash_free_entry(Ptr_hashentry *entry)
+{
+  Ptr_hashentry *tmp;
+  while( entry ) {
+    tmp = entry -> next;
+    my_free(1171, &(entry->token));
+    my_free(1172, &entry);
+    entry = tmp;
+  }
+}
+
+
+void ptr_hash_free(Ptr_hashtable *hashtable)
+{
+  if(hashtable->table) {
+    int i;
+    Ptr_hashentry **table = hashtable->table;
+    for(i=0;i < hashtable->size;i++)
+    {
+      ptr_hash_free_entry( table[i] );
+      table[i] = NULL;
+    }
+    my_free(1575, &(hashtable->table));
+    hashtable->size = 0;
+  }
+}
diff --git a/src/xschem.h b/src/xschem.h
index 24facbe1..dd749ddc 100644
--- a/src/xschem.h
+++ b/src/xschem.h
@@ -629,6 +629,20 @@ typedef struct {
   int size;
 } Int_hashtable;
 
+/* generic pointer hash table */
+typedef struct ptr_hashentry Ptr_hashentry;
+struct ptr_hashentry
+{
+  struct ptr_hashentry *next;
+  unsigned int hash;
+  char *token;
+  void *value;
+};
+
+typedef struct {
+  Ptr_hashentry **table;
+  int size;
+} Ptr_hashtable;
 
 typedef struct node_hashentry Node_hashentry;
 struct node_hashentry
@@ -1299,6 +1313,10 @@ extern void int_hash_init(Int_hashtable *hashtable, int size);
 extern void int_hash_free(Int_hashtable *hashtable);
 extern Int_hashentry *int_hash_lookup(Int_hashtable *hashtable,
        const char *token, const int value, int what);
+extern void ptr_hash_init(Ptr_hashtable *hashtable, int size);
+extern void ptr_hash_free(Ptr_hashtable *hashtable);
+extern Ptr_hashentry *ptr_hash_lookup(Ptr_hashtable *hashtable,
+       const char *token,  void * const value, int what);
 
 extern char *find_nth(const char *str, const char *sep, int n);
 extern int isonlydigit(const char *s);