X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2FStringMap.h;h=b4497a276d0e58331f54b528dd9b0e6353f87336;hb=ac24e251014de60a16558fc0a1f2340c334d2aa8;hp=ac2705574edc5ddd673d5d987c528a106dd2f66c;hpb=8bb5e9901346f448461289f2d0079ed6d534b571;p=oota-llvm.git

diff --git a/include/llvm/ADT/StringMap.h b/include/llvm/ADT/StringMap.h
index ac2705574ed..b4497a276d0 100644
--- a/include/llvm/ADT/StringMap.h
+++ b/include/llvm/ADT/StringMap.h
@@ -14,9 +14,9 @@
 #ifndef LLVM_ADT_STRINGMAP_H
 #define LLVM_ADT_STRINGMAP_H
 
+#include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Allocator.h"
 #include <cstring>
-#include <string>
 
 namespace llvm {
   template<typename ValueT>
@@ -34,6 +34,7 @@ class StringMapEntryInitializer {
 public:
   template <typename InitTy>
   static void Initialize(StringMapEntry<ValueTy> &T, InitTy InitVal) {
+    T.second = InitVal;
   }
 };
 
@@ -50,20 +51,11 @@ public:
 /// StringMapImpl - This is the base class of StringMap that is shared among
 /// all of its instantiations.
 class StringMapImpl {
-public:
-  /// ItemBucket - The hash table consists of an array of these.  If Item is
-  /// non-null, this is an extant entry, otherwise, it is a hole.
-  struct ItemBucket {
-    /// FullHashValue - This remembers the full hash value of the key for
-    /// easy scanning.
-    unsigned FullHashValue;
-
-    /// Item - This is a pointer to the actual item object.
-    StringMapEntryBase *Item;
-  };
-
 protected:
-  ItemBucket *TheTable;
+  // Array of NumBuckets pointers to entries, null pointers are holes.
+  // TheTable[NumBuckets] contains a sentinel value for easy iteration. Follwed
+  // by an array of the actual hash values as unsigned integers.
+  StringMapEntryBase **TheTable;
   unsigned NumBuckets;
   unsigned NumItems;
   unsigned NumTombstones;
@@ -79,27 +71,17 @@ protected:
   StringMapImpl(unsigned InitSize, unsigned ItemSize);
   void RehashTable();
 
-  /// ShouldRehash - Return true if the table should be rehashed after a new
-  /// element was recently inserted.
-  bool ShouldRehash() const {
-    // If the hash table is now more than 3/4 full, or if fewer than 1/8 of
-    // the buckets are empty (meaning that many are filled with tombstones),
-    // grow the table.
-    return NumItems*4 > NumBuckets*3 ||
-           NumBuckets-(NumItems+NumTombstones) < NumBuckets/8;
-  }
-
   /// LookupBucketFor - Look up the bucket that the specified string should end
   /// up in.  If it already exists as a key in the map, the Item pointer for the
   /// specified bucket will be non-null.  Otherwise, it will be null.  In either
   /// case, the FullHashValue field of the bucket will be set to the hash value
   /// of the string.
-  unsigned LookupBucketFor(const char *KeyStart, const char *KeyEnd);
+  unsigned LookupBucketFor(StringRef Key);
 
   /// FindKey - Look up the bucket that contains the specified key. If it exists
   /// in the map, return the bucket number of the key.  Otherwise return -1.
   /// This does not modify the map.
-  int FindKey(const char *KeyStart, const char *KeyEnd) const;
+  int FindKey(StringRef Key) const;
 
   /// RemoveKey - Remove the specified StringMapEntry from the table, but do not
   /// delete it.  This aborts if the value isn't in the table.
@@ -107,7 +89,7 @@ protected:
 
   /// RemoveKey - Remove the StringMapEntry for the specified key from the
   /// table, returning it.  If the key is not in the table, this returns null.
-  StringMapEntryBase *RemoveKey(const char *KeyStart, const char *KeyEnd);
+  StringMapEntryBase *RemoveKey(StringRef Key);
 private:
   void init(unsigned Size);
 public:
@@ -135,6 +117,10 @@ public:
   StringMapEntry(unsigned strLen, const ValueTy &V)
     : StringMapEntryBase(strLen), second(V) {}
 
+  StringRef getKey() const {
+    return StringRef(getKeyData(), getKeyLength());
+  }
+
   const ValueTy &getValue() const { return second; }
   ValueTy &getValue() { return second; }
 
@@ -145,7 +131,7 @@ public:
   /// StringMapEntry object.
   const char *getKeyData() const {return reinterpret_cast<const char*>(this+1);}
 
-  const char *first() const { return getKeyData(); }
+  StringRef first() const { return StringRef(getKeyData(), getKeyLength()); }
 
   /// Create - Create a StringMapEntry for the specified key and default
   /// construct the value.
@@ -161,7 +147,7 @@ public:
 
     unsigned AllocSize = static_cast<unsigned>(sizeof(StringMapEntry))+
       KeyLength+1;
-    unsigned Alignment = alignof<StringMapEntry>();
+    unsigned Alignment = alignOf<StringMapEntry>();
 
     StringMapEntry *NewItem =
       static_cast<StringMapEntry*>(Allocator.Allocate(AllocSize,Alignment));
@@ -182,7 +168,7 @@ public:
   template<typename AllocatorTy>
   static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd,
                                 AllocatorTy &Allocator) {
-    return Create(KeyStart, KeyEnd, Allocator, (void*)0);
+    return Create(KeyStart, KeyEnd, Allocator, 0);
   }
 
 
@@ -195,7 +181,7 @@ public:
   }
 
   static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd) {
-    return Create(KeyStart, KeyEnd, (void*)0);
+    return Create(KeyStart, KeyEnd, ValueTy());
   }
 
   /// GetStringMapEntryFromValue - Given a value that is known to be embedded
@@ -211,6 +197,14 @@ public:
     return GetStringMapEntryFromValue(const_cast<ValueTy&>(V));
   }
 
+  /// GetStringMapEntryFromKeyData - Given key data that is known to be embedded
+  /// into a StringMapEntry, return the StringMapEntry itself.
+  static StringMapEntry &GetStringMapEntryFromKeyData(const char *KeyData) {
+    char *Ptr = const_cast<char*>(KeyData) - sizeof(StringMapEntry<ValueTy>);
+    return *reinterpret_cast<StringMapEntry*>(Ptr);
+  }
+
+
   /// Destroy - Destroy this StringMapEntry, releasing memory back to the
   /// specified allocator.
   template<typename AllocatorTy>
@@ -235,14 +229,33 @@ public:
 template<typename ValueTy, typename AllocatorTy = MallocAllocator>
 class StringMap : public StringMapImpl {
   AllocatorTy Allocator;
-  typedef StringMapEntry<ValueTy> MapEntryTy;
 public:
+  typedef StringMapEntry<ValueTy> MapEntryTy;
+  
   StringMap() : StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))) {}
   explicit StringMap(unsigned InitialSize)
     : StringMapImpl(InitialSize, static_cast<unsigned>(sizeof(MapEntryTy))) {}
 
-  AllocatorTy &getAllocator() { return Allocator; }
-  const AllocatorTy &getAllocator() const { return Allocator; }
+  explicit StringMap(AllocatorTy A)
+    : StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))), Allocator(A) {}
+
+  StringMap(const StringMap &RHS)
+    : StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))) {
+    assert(RHS.empty() &&
+           "Copy ctor from non-empty stringmap not implemented yet!");
+    (void)RHS;
+  }
+  void operator=(const StringMap &RHS) {
+    assert(RHS.empty() &&
+           "assignment from non-empty stringmap not implemented yet!");
+    (void)RHS;
+    clear();
+  }
+
+  typedef typename ReferenceAdder<AllocatorTy>::result AllocatorRefTy;
+  typedef typename ReferenceAdder<const AllocatorTy>::result AllocatorCRefTy;
+  AllocatorRefTy getAllocator() { return Allocator; }
+  AllocatorCRefTy getAllocator() const { return Allocator; }
 
   typedef const char* key_type;
   typedef ValueTy mapped_type;
@@ -265,71 +278,51 @@ public:
     return const_iterator(TheTable+NumBuckets, true);
   }
 
-  iterator find(const char *KeyStart, const char *KeyEnd) {
-    int Bucket = FindKey(KeyStart, KeyEnd);
+  iterator find(StringRef Key) {
+    int Bucket = FindKey(Key);
     if (Bucket == -1) return end();
-    return iterator(TheTable+Bucket);
-  }
-  iterator find(const char *Key) {
-    return find(Key, Key + strlen(Key));
-  }
-  iterator find(const std::string &Key) {
-    const char* key_start = (Key.empty() ? NULL : &Key[0]);
-    return find(key_start, key_start + Key.size());
+    return iterator(TheTable+Bucket, true);
   }
 
-  const_iterator find(const char *KeyStart, const char *KeyEnd) const {
-    int Bucket = FindKey(KeyStart, KeyEnd);
+  const_iterator find(StringRef Key) const {
+    int Bucket = FindKey(Key);
     if (Bucket == -1) return end();
-    return const_iterator(TheTable+Bucket);
-  }
-  const_iterator find(const char *Key) const {
-    return find(Key, Key + strlen(Key));
-  }
-  const_iterator find(const std::string &Key) const {
-    const char* key_start = (Key.empty() ? NULL : &Key[0]);
-    return find(key_start, key_start + Key.size());
+    return const_iterator(TheTable+Bucket, true);
   }
 
-  ValueTy& operator[](const char *Key) {
-    value_type& entry = GetOrCreateValue(Key, Key + strlen(Key));
-    return entry.getValue();
-  }
-  ValueTy& operator[](const std::string &Key) {
-    const char* key_start = (Key.empty() ? NULL : &Key[0]);
-    value_type& entry = GetOrCreateValue(key_start, key_start + Key.size());
-    return entry.getValue();
+   /// lookup - Return the entry for the specified key, or a default
+  /// constructed value if no such entry exists.
+  ValueTy lookup(StringRef Key) const {
+    const_iterator it = find(Key);
+    if (it != end())
+      return it->second;
+    return ValueTy();
   }
 
-  size_type count(const char *KeyStart, const char *KeyEnd) const {
-    return find(KeyStart, KeyEnd) == end() ? 0 : 1;
+  ValueTy &operator[](StringRef Key) {
+    return GetOrCreateValue(Key).getValue();
   }
-  size_type count(const char *Key) const {
-    return count(Key, Key + strlen(Key));
-  }
-  size_type count(const std::string &Key) const {
-    const char* key_start = (Key.empty() ? NULL : &Key[0]);
-    return count(key_start, key_start + Key.size());
+
+  size_type count(StringRef Key) const {
+    return find(Key) == end() ? 0 : 1;
   }
 
   /// insert - Insert the specified key/value pair into the map.  If the key
   /// already exists in the map, return false and ignore the request, otherwise
   /// insert it and return true.
   bool insert(MapEntryTy *KeyValue) {
-    unsigned BucketNo =
-      LookupBucketFor(KeyValue->getKeyData(),
-                      KeyValue->getKeyData()+KeyValue->getKeyLength());
-    ItemBucket &Bucket = TheTable[BucketNo];
-    if (Bucket.Item && Bucket.Item != getTombstoneVal())
+    unsigned BucketNo = LookupBucketFor(KeyValue->getKey());
+    StringMapEntryBase *&Bucket = TheTable[BucketNo];
+    if (Bucket && Bucket != getTombstoneVal())
       return false;  // Already exists in map.
 
-    if (Bucket.Item == getTombstoneVal())
+    if (Bucket == getTombstoneVal())
       --NumTombstones;
-    Bucket.Item = KeyValue;
+    Bucket = KeyValue;
     ++NumItems;
+    assert(NumItems + NumTombstones <= NumBuckets);
 
-    if (ShouldRehash())
-      RehashTable();
+    RehashTable();
     return true;
   }
 
@@ -339,46 +332,46 @@ public:
 
     // Zap all values, resetting the keys back to non-present (not tombstone),
     // which is safe because we're removing all elements.
-    for (ItemBucket *I = TheTable, *E = TheTable+NumBuckets; I != E; ++I) {
-      if (I->Item && I->Item != getTombstoneVal()) {
-        static_cast<MapEntryTy*>(I->Item)->Destroy(Allocator);
-        I->Item = 0;
+    for (unsigned I = 0, E = NumBuckets; I != E; ++I) {
+      StringMapEntryBase *&Bucket = TheTable[I];
+      if (Bucket && Bucket != getTombstoneVal()) {
+        static_cast<MapEntryTy*>(Bucket)->Destroy(Allocator);
+        Bucket = 0;
       }
     }
 
     NumItems = 0;
+    NumTombstones = 0;
   }
 
   /// GetOrCreateValue - Look up the specified key in the table.  If a value
   /// exists, return it.  Otherwise, default construct a value, insert it, and
   /// return.
   template <typename InitTy>
-  StringMapEntry<ValueTy> &GetOrCreateValue(const char *KeyStart,
-                                            const char *KeyEnd,
-                                            InitTy Val) {
-    unsigned BucketNo = LookupBucketFor(KeyStart, KeyEnd);
-    ItemBucket &Bucket = TheTable[BucketNo];
-    if (Bucket.Item && Bucket.Item != getTombstoneVal())
-      return *static_cast<MapEntryTy*>(Bucket.Item);
+  MapEntryTy &GetOrCreateValue(StringRef Key, InitTy Val) {
+    unsigned BucketNo = LookupBucketFor(Key);
+    StringMapEntryBase *&Bucket = TheTable[BucketNo];
+    if (Bucket && Bucket != getTombstoneVal())
+      return *static_cast<MapEntryTy*>(Bucket);
 
-    MapEntryTy *NewItem = MapEntryTy::Create(KeyStart, KeyEnd, Allocator, Val);
+    MapEntryTy *NewItem =
+      MapEntryTy::Create(Key.begin(), Key.end(), Allocator, Val);
 
-    if (Bucket.Item == getTombstoneVal())
+    if (Bucket == getTombstoneVal())
       --NumTombstones;
     ++NumItems;
+    assert(NumItems + NumTombstones <= NumBuckets);
 
     // Fill in the bucket for the hash table.  The FullHashValue was already
     // filled in by LookupBucketFor.
-    Bucket.Item = NewItem;
+    Bucket = NewItem;
 
-    if (ShouldRehash())
-      RehashTable();
+    RehashTable();
     return *NewItem;
   }
 
-  StringMapEntry<ValueTy> &GetOrCreateValue(const char *KeyStart,
-                                            const char *KeyEnd) {
-    return GetOrCreateValue(KeyStart, KeyEnd, (void*)0);
+  MapEntryTy &GetOrCreateValue(StringRef Key) {
+    return GetOrCreateValue(Key, ValueTy());
   }
 
   /// remove - Remove the specified key/value pair from the map, but do not
@@ -393,14 +386,7 @@ public:
     V.Destroy(Allocator);
   }
 
-  bool erase(const char *Key) {
-    iterator I = find(Key);
-    if (I == end()) return false;
-    erase(I);
-    return true;
-  }
-
-  bool erase(const std::string &Key) {
+  bool erase(StringRef Key) {
     iterator I = find(Key);
     if (I == end()) return false;
     erase(I);
@@ -411,30 +397,27 @@ public:
     clear();
     free(TheTable);
   }
-private:
-  StringMap(const StringMap &);  // FIXME: Implement.
-  void operator=(const StringMap &);  // FIXME: Implement.
 };
 
 
 template<typename ValueTy>
 class StringMapConstIterator {
 protected:
-  StringMapImpl::ItemBucket *Ptr;
+  StringMapEntryBase **Ptr;
 public:
   typedef StringMapEntry<ValueTy> value_type;
 
-  explicit StringMapConstIterator(StringMapImpl::ItemBucket *Bucket,
+  explicit StringMapConstIterator(StringMapEntryBase **Bucket,
                                   bool NoAdvance = false)
   : Ptr(Bucket) {
     if (!NoAdvance) AdvancePastEmptyBuckets();
   }
 
   const value_type &operator*() const {
-    return *static_cast<StringMapEntry<ValueTy>*>(Ptr->Item);
+    return *static_cast<StringMapEntry<ValueTy>*>(*Ptr);
   }
   const value_type *operator->() const {
-    return static_cast<StringMapEntry<ValueTy>*>(Ptr->Item);
+    return static_cast<StringMapEntry<ValueTy>*>(*Ptr);
   }
 
   bool operator==(const StringMapConstIterator &RHS) const {
@@ -455,7 +438,7 @@ public:
 
 private:
   void AdvancePastEmptyBuckets() {
-    while (Ptr->Item == 0 || Ptr->Item == StringMapImpl::getTombstoneVal())
+    while (*Ptr == 0 || *Ptr == StringMapImpl::getTombstoneVal())
       ++Ptr;
   }
 };
@@ -463,15 +446,15 @@ private:
 template<typename ValueTy>
 class StringMapIterator : public StringMapConstIterator<ValueTy> {
 public:
-  explicit StringMapIterator(StringMapImpl::ItemBucket *Bucket,
+  explicit StringMapIterator(StringMapEntryBase **Bucket,
                              bool NoAdvance = false)
     : StringMapConstIterator<ValueTy>(Bucket, NoAdvance) {
   }
   StringMapEntry<ValueTy> &operator*() const {
-    return *static_cast<StringMapEntry<ValueTy>*>(this->Ptr->Item);
+    return *static_cast<StringMapEntry<ValueTy>*>(*this->Ptr);
   }
   StringMapEntry<ValueTy> *operator->() const {
-    return static_cast<StringMapEntry<ValueTy>*>(this->Ptr->Item);
+    return static_cast<StringMapEntry<ValueTy>*>(*this->Ptr);
   }
 };