From 4f06b347b340c1c6308795e434283b25952fd23c Mon Sep 17 00:00:00 2001
From: Ken McMillan <kenmcmil@microsoft.com>
Date: Tue, 25 Feb 2014 18:21:06 -0800
Subject: [PATCH] new hastable implementation for interp/duality

---
 src/interp/iz3hash.h | 542 +++++++++++++++++++++++++++++++++----------
 1 file changed, 420 insertions(+), 122 deletions(-)
 mode change 100755 => 100644 src/interp/iz3hash.h

diff --git a/src/interp/iz3hash.h b/src/interp/iz3hash.h
old mode 100755
new mode 100644
index 94f282265..c628ef32b
--- a/src/interp/iz3hash.h
+++ b/src/interp/iz3hash.h
@@ -7,7 +7,16 @@ Module Name:
 
 Abstract:
 
-   Wrapper for stl hash tables
+   Simple implementation of bucket-list hash tables conforming to SGI
+   hash_map and hash_set interfaces. Just enough members are
+   implemented to support iz3 and duality.
+
+   iz3 and duality need this package because they assume that insert
+   preserves iterators and references to elements, which is not true
+   of the hashtable packages in util.
+
+   This package lives in namespace hash_space. Specializations of
+   class "hash" should be made in this namespace.
 
 Author:
 
@@ -17,66 +26,36 @@ Revision History:
 
 --*/
 
-// pull in the headers for has_map and hash_set
-// these live in non-standard places
-
 #ifndef IZ3_HASH_H
 #define IZ3_HASH_H
 
-//#define USE_UNORDERED_MAP
-#ifdef USE_UNORDERED_MAP
-
-#define stl_ext std
-#define hash_space std
-#include <unordered_map>
-#include <unordered_set>
-#define hash_map unordered_map
-#define hash_set unordered_set
-
-#else
-
-#if __GNUC__ >= 3
-#undef __DEPRECATED
-#define stl_ext __gnu_cxx
-#define hash_space stl_ext
-#include <ext/hash_map>
-#include <ext/hash_set>
-#else
-#ifdef WIN32
-#define stl_ext stdext
-#define hash_space std
-#include <hash_map>
-#include <hash_set>
-#else
-#define stl_ext std
-#define hash_space std
-#include <hash_map>
-#include <hash_set>
-#endif
-#endif
-
-#endif
-
 #include <string>
+#include <vector>
+#include <iterator>
+#include "hash.h"
 
-// stupid STL doesn't include hash function for class string
-
-#ifndef WIN32 
-
-namespace stl_ext {
-  template <>
-    class hash<std::string> {
-    stl_ext::hash<const char *> H;
-  public:
-    size_t operator()(const std::string &s) const {
-      return H(s.c_str());
-    }
-  };
-}
-
-#endif
+#define stl_ext hash_space
 
 namespace hash_space {
+
+  template <typename T> class hash {};
+
+  template <>
+    class hash<int> {
+  public:
+    size_t operator()(const int &s) const {
+      return s;
+    }
+  };
+
+  template <>
+    class hash<std::string> {
+  public:
+    size_t operator()(const std::string &s) const {
+      return string_hash(s.c_str(), s.size(), 0);
+    }
+  };
+
   template <>
     class hash<std::pair<int,int> > {
   public:
@@ -84,17 +63,7 @@ namespace hash_space {
       return p.first + p.second;
     }
   };
-}
 
-#ifdef WIN32 
-template <> inline
-size_t stdext::hash_value<std::pair<int,int> >(const std::pair<int,int>& p)
-{	// hash _Keyval to size_t value one-to-one
-	return p.first + p.second;
-}
-#endif
-
-namespace hash_space {
   template <class T>
     class hash<std::pair<T *, T *> > {
   public:
@@ -102,70 +71,399 @@ namespace hash_space {
       return (size_t)p.first + (size_t)p.second;
     }
   };
-}
 
-#if 0
-template <class T> inline
-size_t stdext::hash_value<std::pair<T *, T *> >(const std::pair<T *, T *>& p)
-{	// hash _Keyval to size_t value one-to-one
-  return (size_t)p.first + (size_t)p.second;
-}
-#endif
+  enum { num_primes = 29 };
 
-#ifdef WIN32
+  static const unsigned long primes[num_primes] =
+    {
+      7ul,
+      53ul,
+      97ul,
+      193ul,
+      389ul,
+      769ul,
+      1543ul,
+      3079ul,
+      6151ul,
+      12289ul,
+      24593ul,
+      49157ul,
+      98317ul,
+      196613ul,
+      393241ul,
+      786433ul,
+      1572869ul,
+      3145739ul,
+      6291469ul,
+      12582917ul,
+      25165843ul,
+      50331653ul,
+      100663319ul,
+      201326611ul,
+      402653189ul,
+      805306457ul,
+      1610612741ul,
+      3221225473ul,
+      4294967291ul
+    };
 
-namespace std {
-    template <>
-	   class less<std::pair<int,int> > {
-	   public:
-		   bool operator()(const pair<int,int> &x, const pair<int,int> &y) const {
-		      return x.first < y.first || x.first == y.first && x.second < y.second;
-		   }
-	   };
-	
-}
-  
-namespace std {
-    template <class T>
-	   class less<std::pair<T *,T *> > {
-	   public:
-		   bool operator()(const pair<T *,T *> &x, const pair<T *,T *> &y) const {
-		     return (size_t)x.first < (size_t)y.first || (size_t)x.first == (size_t)y.first && (size_t)x.second < (size_t)y.second;
-		   }
-	   };
-	
-}
+  inline unsigned long next_prime(unsigned long n) {
+    const unsigned long* to = primes + (int)num_primes;
+    for(const unsigned long* p = primes; p < to; p++)
+      if(*p >= n) return *p;
+    return primes[num_primes-1];
+  }
 
-#endif
-
-
-#ifndef WIN32
-
-#if 0
-namespace stl_ext {
-  template <class T>
-    class hash<T *> {
+  template<class Value, class Key, class HashFun, class GetKey, class KeyEqFun>
+    class hashtable
+  {
   public:
-    size_t operator()(const T *p) const {
-      return (size_t) p;
+
+    typedef Value &reference;
+    typedef const Value &const_reference;
+    
+    struct Entry
+    {
+      Entry* next;
+      Value val;
+      
+      Entry(const Value &_val) : val(_val) {next = 0;}
+    };
+    
+
+    struct iterator
+    {      
+      Entry* ent;
+      hashtable* tab;
+
+      typedef std::forward_iterator_tag iterator_category;
+      typedef Value value_type;
+      typedef std::ptrdiff_t difference_type;
+      typedef size_t size_type;
+      typedef Value& reference;
+      typedef Value* pointer;
+
+      iterator(Entry* _ent, hashtable* _tab) : ent(_ent), tab(_tab) { }
+
+      iterator() { }
+
+      Value &operator*() const { return ent->val; }
+
+      Value *operator->() const { return &(operator*()); }
+
+      iterator &operator++() {
+	Entry *old = ent;
+	ent = ent->next;
+	if (!ent) {
+	  size_t bucket = tab->get_bucket(old->val);
+	  while (!ent && ++bucket < tab->buckets.size())
+	    ent = tab->buckets[bucket];
+	}
+	return *this;
+      }
+
+      iterator operator++(int) {
+	iterator tmp = *this;
+	operator++();
+	return tmp;
+      }
+
+
+      bool operator==(const iterator& it) const { 
+	return ent == it.ent;
+      }
+
+      bool operator!=(const iterator& it) const {
+	return ent != it.ent;
+      }
+    };
+
+    struct const_iterator
+    {      
+      const Entry* ent;
+      const hashtable* tab;
+
+      typedef std::forward_iterator_tag iterator_category;
+      typedef Value value_type;
+      typedef std::ptrdiff_t difference_type;
+      typedef size_t size_type;
+      typedef const Value& reference;
+      typedef const Value* pointer;
+
+      const_iterator(const Entry* _ent, const hashtable* _tab) : ent(_ent), tab(_tab) { }
+
+      const_iterator() { }
+
+      const Value &operator*() const { return ent->val; }
+
+      const Value *operator->() const { return &(operator*()); }
+
+      const_iterator &operator++() {
+	Entry *old = ent;
+	ent = ent->next;
+	if (!ent) {
+	  size_t bucket = tab->get_bucket(old->val);
+	  while (!ent && ++bucket < tab->buckets.size())
+	    ent = tab->buckets[bucket];
+	}
+	return *this;
+      }
+
+      const_iterator operator++(int) {
+	const_iterator tmp = *this;
+	operator++();
+	return tmp;
+      }
+
+
+      bool operator==(const const_iterator& it) const { 
+	return ent == it.ent;
+      }
+
+      bool operator!=(const const_iterator& it) const {
+	return ent != it.ent;
+      }
+    };
+
+    private:
+
+    typedef std::vector<Entry*> Table;
+
+    Table buckets;
+    size_t entries;
+    HashFun hash_fun ;
+    GetKey get_key;
+    KeyEqFun key_eq_fun;
+    
+    public:
+
+    hashtable(size_t init_size) : buckets(init_size,(Entry *)0) {
+      entries = 0;
+    }
+    
+    hashtable(const hashtable& other) {
+      dup(other);
+    }
+
+    hashtable& operator= (const hashtable& other) {
+      if (&other != this)
+	dup(other);
+      return *this;
+    }
+
+    ~hashtable() {
+      clear();
+    }
+
+    size_t size() const { 
+      return entries;
+    }
+
+    bool empty() const { 
+      return size() == 0;
+    }
+
+    void swap(hashtable& other) {
+      buckets.swap(other.buckets);
+      std::swap(entries, other.entries);
+    }
+    
+    iterator begin() {
+      for (size_t i = 0; i < buckets.size(); ++i)
+	if (buckets[i])
+	  return iterator(buckets[i], this);
+      return end();
+    }
+    
+    iterator end() { 
+      return iterator(0, this);
+    }
+
+    const_iterator begin() const {
+      for (size_t i = 0; i < buckets.size(); ++i)
+	if (buckets[i])
+	  return const_iterator(buckets[i], this);
+      return end();
+    }
+    
+    const_iterator end() const { 
+      return const_iterator(0, this);
+    }
+    
+    size_t get_bucket(const Value& val, size_t n) const {
+      return hash_fun(get_key(val)) % n;
+    }
+    
+    size_t get_key_bucket(const Key& key) const {
+      return hash_fun(key) % buckets.size();
+    }
+
+    size_t get_bucket(const Value& val) const {
+      return get_bucket(val,buckets.size());
+    }
+
+    Entry *lookup(const Value& val, bool ins = false)
+    {
+      resize(entries + 1);
+
+      size_t n = get_bucket(val);
+      Entry* from = buckets[n];
+      
+      for (Entry* ent = from; ent; ent = ent->next)
+	if (key_eq_fun(get_key(ent->val), get_key(val)))
+	  return ent;
+      
+      if(!ins) return 0;
+
+      Entry* tmp = new Entry(val);
+      tmp->next = from;
+      buckets[n] = tmp;
+      ++entries;
+      return tmp;
+    }
+
+    Entry *lookup_key(const Key& key) const
+    {
+      size_t n = get_key_bucket(key);
+      Entry* from = buckets[n];
+      
+      for (Entry* ent = from; ent; ent = ent->next)
+	if (key_eq_fun(get_key(ent->val), key))
+	  return ent;
+      
+      return 0;
+    }
+
+    const_iterator find(const Key& key) const {
+      return const_iterator(lookup_key(key),this);
+    }
+
+    iterator find(const Key& key) {
+      return iterator(lookup_key(key),this);
+    }
+
+    std::pair<iterator,bool> insert(const Value& val){
+      size_t old_entries = entries;
+      Entry *ent = lookup(val,true);
+      return std::pair<iterator,bool>(iterator(ent,this),entries > old_entries);
+    }
+    
+    iterator insert(const iterator &it, const Value& val){
+      Entry *ent = lookup(val,true);
+      return iterator(ent,this);
+    }
+
+    size_t erase(const Key& key)
+    {
+      Entry** p = &(buckets[get_key_bucket(key)]);
+      size_t count = 0;
+      while(*p){
+	Entry *q = *p;
+	if (key_eq_fun(get_key(q->val), key)) {
+	  ++count;
+	  *p = q->next;
+	  delete q;
+	}
+	else
+	  p = &(q->next);
+      }
+      entries -= count;
+      return count;
+    }
+
+    void resize(size_t new_size) {
+      const size_t old_n = buckets.size();
+      if (new_size <= old_n) return;
+      const size_t n = next_prime(new_size);
+      if (n <= old_n) return;
+      Table tmp(n, (Entry*)(0));
+      for (size_t i = 0; i < old_n; ++i) {
+	Entry* ent = buckets[i];
+	while (ent) {
+	  size_t new_bucket = get_bucket(ent->val, n);
+	  buckets[i] = ent->next;
+	  ent->next = tmp[new_bucket];
+	  tmp[new_bucket] = ent;
+	  ent = buckets[i];
+	}
+      }
+      buckets.swap(tmp);
+    }
+    
+    void clear()
+    {
+      for (size_t i = 0; i < buckets.size(); ++i) {
+	for (Entry* ent = buckets[i]; ent != 0;) {
+	  Entry* next = ent->next;
+	  delete ent;
+	  ent = next;
+	}
+	buckets[i] = 0;
+      }
+      entries = 0;
+    }
+
+    void dup(const hashtable& other)
+    {
+      buckets.resize(other.buckets.size());
+      for (size_t i = 0; i < other.buckets.size(); ++i) {
+	Entry** to = &buckets[i];
+	for (Entry* from = other.buckets[i]; from; from = from->next)
+	  to = &((*to = new Entry(from->val))->next);
+      }
+      entries = other.entries;
     }
   };
+
+  template <typename T> 
+    class equal {
+  public:
+    bool operator()(const T& x, const T &y) const {
+      return x == y;
+    }
+  };
+
+  template <typename T>
+    class identity {
+  public:
+    const T &operator()(const T &x) const {
+      return x;
+    }
+  };
+
+  template <typename T, typename U>
+    class proj1 {
+  public:
+    const T &operator()(const std::pair<T,U> &x) const {
+      return x.first;
+    }
+  };
+
+  template <typename Element, class HashFun = hash<Element>, 
+            class EqFun = equal<Element> >
+    class hash_set
+    : public hashtable<Element,Element,HashFun,identity<Element>,EqFun> {
+
+  public:
+  hash_set()
+  : hashtable<Element,Element,HashFun,identity<Element>,EqFun>(7) {}
+  };
+
+  template <typename Key, typename Value, class HashFun = hash<Key>, 
+            class EqFun = equal<Key> >
+    class hash_map
+    : public hashtable<std::pair<Key,Value>,Key,HashFun,proj1<Key,Value>,EqFun> {
+
+  public:
+
+      hash_map()
+      : hashtable<std::pair<Key,Value>,Key,HashFun,proj1<Key,Value>,EqFun>(7) {}
+
+      Value &operator[](const Key& key) {
+	std::pair<Key,Value> kvp(key,Value());
+	return lookup(kvp,true)->val.second;
+      }
+  };
+
 }
 #endif
-
-#endif
-
-#ifdef WIN32
-
-
-
-
-template <class K, class T>
-class hash_map : public stl_ext::hash_map<K,T,stl_ext::hash_compare<K,std::less<K> > > {};
-
-template <class K>
-class hash_set : public stl_ext::hash_set<K,stl_ext::hash_compare<K,std::less<K> > > {};
-
-#endif
-
-#endif