-//===--- CStringMap.h - CString Hash table map interface --------*- C++ -*-===//
+//===--- StringMap.h - String Hash table map interface ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Chris Lattner and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
-// This file defines the CStringMap class.
+// This file defines the StringMap class.
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_ADT_CSTRINGMAP_H
-#define LLVM_ADT_CSTRINGMAP_H
+#ifndef LLVM_ADT_STRINGMAP_H
+#define LLVM_ADT_STRINGMAP_H
+#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Allocator.h"
#include <cstring>
namespace llvm {
-
-/// CStringMapVisitor - Subclasses of this class may be implemented to walk all
-/// of the items in a CStringMap.
-class CStringMapVisitor {
+ template<typename ValueT>
+ class StringMapConstIterator;
+ template<typename ValueT>
+ class StringMapIterator;
+ template<typename ValueTy>
+ class StringMapEntry;
+
+/// StringMapEntryInitializer - This datatype can be partially specialized for
+/// various datatypes in a stringmap to allow them to be initialized when an
+/// entry is default constructed for the map.
+template<typename ValueTy>
+class StringMapEntryInitializer {
public:
- virtual ~CStringMapVisitor();
- virtual void Visit(const char *Key, void *Value) const = 0;
+ template <typename InitTy>
+ static void Initialize(StringMapEntry<ValueTy> &T, InitTy InitVal) {
+ T.second = InitVal;
+ }
};
-
-/// CStringMapImpl - This is the base class of CStringMap that is shared among
+
+
+/// StringMapEntryBase - Shared base class of StringMapEntry instances.
+class StringMapEntryBase {
+ unsigned StrLen;
+public:
+ explicit StringMapEntryBase(unsigned Len) : StrLen(Len) {}
+
+ unsigned getKeyLength() const { return StrLen; }
+};
+
+/// StringMapImpl - This is the base class of StringMap that is shared among
/// all of its instantiations.
-class CStringMapImpl {
+class StringMapImpl {
protected:
- /// 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.
- void *Item;
- };
-
- ItemBucket *TheTable;
+ // Array of NumBuckets pointers to entries, null pointers are holes.
+ // TheTable[NumBuckets] contains a sentinel value for easy iteration. Followed
+ // by an array of the actual hash values as unsigned integers.
+ StringMapEntryBase **TheTable;
unsigned NumBuckets;
unsigned NumItems;
+ unsigned NumTombstones;
unsigned ItemSize;
protected:
- CStringMapImpl(unsigned InitSize, unsigned ItemSize);
+ explicit StringMapImpl(unsigned itemSize) : ItemSize(itemSize) {
+ // Initialize the map with zero buckets to allocation.
+ TheTable = 0;
+ NumBuckets = 0;
+ NumItems = 0;
+ NumTombstones = 0;
+ }
+ StringMapImpl(unsigned InitSize, unsigned ItemSize);
void RehashTable();
-
+
/// 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(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.
+ void RemoveKey(StringMapEntryBase *V);
+
+ /// 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(StringRef Key);
+private:
+ void init(unsigned Size);
public:
+ static StringMapEntryBase *getTombstoneVal() {
+ return (StringMapEntryBase*)-1;
+ }
+
unsigned getNumBuckets() const { return NumBuckets; }
unsigned getNumItems() const { return NumItems; }
- void VisitEntries(const CStringMapVisitor &Visitor) const;
+ bool empty() const { return NumItems == 0; }
+ unsigned size() const { return NumItems; }
};
+/// StringMapEntry - This is used to represent one value that is inserted into
+/// a StringMap. It contains the Value itself and the key: the string length
+/// and data.
+template<typename ValueTy>
+class StringMapEntry : public StringMapEntryBase {
+public:
+ ValueTy second;
+
+ explicit StringMapEntry(unsigned strLen)
+ : StringMapEntryBase(strLen), second() {}
+ 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; }
+
+ void setValue(const ValueTy &V) { second = V; }
-/// CStringMap - This is an unconventional map that is specialized for handling
-/// keys that are "C strings", that is, null-terminated strings. This does some
+ /// getKeyData - Return the start of the string data that is the key for this
+ /// value. The string data is always stored immediately after the
+ /// StringMapEntry object.
+ const char *getKeyData() const {return reinterpret_cast<const char*>(this+1);}
+
+ StringRef first() const { return StringRef(getKeyData(), getKeyLength()); }
+
+ /// Create - Create a StringMapEntry for the specified key and default
+ /// construct the value.
+ template<typename AllocatorTy, typename InitType>
+ static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd,
+ AllocatorTy &Allocator,
+ InitType InitVal) {
+ unsigned KeyLength = static_cast<unsigned>(KeyEnd-KeyStart);
+
+ // Okay, the item doesn't already exist, and 'Bucket' is the bucket to fill
+ // in. Allocate a new item with space for the string at the end and a null
+ // terminator.
+
+ unsigned AllocSize = static_cast<unsigned>(sizeof(StringMapEntry))+
+ KeyLength+1;
+ unsigned Alignment = alignOf<StringMapEntry>();
+
+ StringMapEntry *NewItem =
+ static_cast<StringMapEntry*>(Allocator.Allocate(AllocSize,Alignment));
+
+ // Default construct the value.
+ new (NewItem) StringMapEntry(KeyLength);
+
+ // Copy the string information.
+ char *StrBuffer = const_cast<char*>(NewItem->getKeyData());
+ memcpy(StrBuffer, KeyStart, KeyLength);
+ StrBuffer[KeyLength] = 0; // Null terminate for convenience of clients.
+
+ // Initialize the value if the client wants to.
+ StringMapEntryInitializer<ValueTy>::Initialize(*NewItem, InitVal);
+ return NewItem;
+ }
+
+ template<typename AllocatorTy>
+ static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd,
+ AllocatorTy &Allocator) {
+ return Create(KeyStart, KeyEnd, Allocator, 0);
+ }
+
+ /// Create - Create a StringMapEntry with normal malloc/free.
+ template<typename InitType>
+ static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd,
+ InitType InitVal) {
+ MallocAllocator A;
+ return Create(KeyStart, KeyEnd, A, InitVal);
+ }
+
+ static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd) {
+ return Create(KeyStart, KeyEnd, ValueTy());
+ }
+
+ /// GetStringMapEntryFromValue - Given a value that is known to be embedded
+ /// into a StringMapEntry, return the StringMapEntry itself.
+ static StringMapEntry &GetStringMapEntryFromValue(ValueTy &V) {
+ StringMapEntry *EPtr = 0;
+ char *Ptr = reinterpret_cast<char*>(&V) -
+ (reinterpret_cast<char*>(&EPtr->second) -
+ reinterpret_cast<char*>(EPtr));
+ return *reinterpret_cast<StringMapEntry*>(Ptr);
+ }
+ static const StringMapEntry &GetStringMapEntryFromValue(const ValueTy &V) {
+ 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>
+ void Destroy(AllocatorTy &Allocator) {
+ // Free memory referenced by the item.
+ this->~StringMapEntry();
+ Allocator.Deallocate(this);
+ }
+
+ /// Destroy this object, releasing memory back to the malloc allocator.
+ void Destroy() {
+ MallocAllocator A;
+ Destroy(A);
+ }
+};
+
+
+/// StringMap - This is an unconventional map that is specialized for handling
+/// keys that are "strings", which are basically ranges of bytes. This does some
/// funky memory allocation and hashing things to make it extremely efficient,
/// storing the string data *after* the value in the map.
template<typename ValueTy, typename AllocatorTy = MallocAllocator>
-class CStringMap : public CStringMapImpl {
+class StringMap : public StringMapImpl {
AllocatorTy Allocator;
public:
- CStringMap(unsigned InitialSize = 0)
- : CStringMapImpl(InitialSize, sizeof(ValueTy)) {}
+ typedef StringMapEntry<ValueTy> MapEntryTy;
- AllocatorTy &getAllocator() { return Allocator; }
- const AllocatorTy &getAllocator() const { return Allocator; }
+ StringMap() : StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))) {}
+ explicit StringMap(unsigned InitialSize)
+ : StringMapImpl(InitialSize, static_cast<unsigned>(sizeof(MapEntryTy))) {}
- /// FindValue - Look up the specified key in the map. If it exists, return a
- /// pointer to the element, otherwise return null.
- ValueTy *FindValue(const char *KeyStart, const char *KeyEnd) {
- unsigned BucketNo = LookupBucketFor(KeyStart, KeyEnd);
- return static_cast<ValueTy*>(TheTable[BucketNo].Item);
+ 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;
}
-
- /// GetKeyForValueInMap - Given a value that is inserted into this map, return
- /// the string that corresponds to it. This is an efficient operation that
- /// is provided by CStringMap. The string is live as long as the value is in
- /// the map.
- static const char *GetKeyForValueInMap(const ValueTy &Val) {
- return reinterpret_cast<const char*>(&Val+1);
+ 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;
+ typedef StringMapEntry<ValueTy> value_type;
+ typedef size_t size_type;
+
+ typedef StringMapConstIterator<ValueTy> const_iterator;
+ typedef StringMapIterator<ValueTy> iterator;
+
+ iterator begin() {
+ return iterator(TheTable, NumBuckets == 0);
+ }
+ iterator end() {
+ return iterator(TheTable+NumBuckets, true);
+ }
+ const_iterator begin() const {
+ return const_iterator(TheTable, NumBuckets == 0);
+ }
+ const_iterator end() const {
+ return const_iterator(TheTable+NumBuckets, true);
+ }
+
+ iterator find(StringRef Key) {
+ int Bucket = FindKey(Key);
+ if (Bucket == -1) return end();
+ return iterator(TheTable+Bucket, true);
+ }
+
+ const_iterator find(StringRef Key) const {
+ int Bucket = FindKey(Key);
+ if (Bucket == -1) return end();
+ return const_iterator(TheTable+Bucket, true);
+ }
+
+ /// 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();
+ }
+
+ ValueTy &operator[](StringRef Key) {
+ return GetOrCreateValue(Key).getValue();
+ }
+
+ 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->getKey());
+ StringMapEntryBase *&Bucket = TheTable[BucketNo];
+ if (Bucket && Bucket != getTombstoneVal())
+ return false; // Already exists in map.
+
+ if (Bucket == getTombstoneVal())
+ --NumTombstones;
+ Bucket = KeyValue;
+ ++NumItems;
+ assert(NumItems + NumTombstones <= NumBuckets);
+
+ RehashTable();
+ return true;
+ }
+
+ // clear - Empties out the StringMap
+ void clear() {
+ if (empty()) return;
+
+ // Zap all values, resetting the keys back to non-present (not tombstone),
+ // which is safe because we're removing all elements.
+ 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.
- ValueTy &GetOrCreateValue(const char *KeyStart, const char *KeyEnd) {
- unsigned BucketNo = LookupBucketFor(KeyStart, KeyEnd);
- ItemBucket &Bucket = TheTable[BucketNo];
- if (Bucket.Item)
- return *static_cast<ValueTy*>(Bucket.Item);
-
- unsigned KeyLength = KeyEnd-KeyStart;
-
- // Okay, the item doesn't already exist, and Bucket is the bucket to fill
- // in. Allocate a new item with space for the null-terminated string at the
- // end.
- unsigned AllocSize = sizeof(ValueTy)+KeyLength+1;
-
-#ifdef __GNUC__
- unsigned Alignment = __alignof__(ValueTy);
-#else
- // FIXME: ugly.
- unsigned Alignment = 8;
-#endif
- ValueTy *NewItem = (ValueTy*)Allocator.Allocate(AllocSize, Alignment);
- new (NewItem) ValueTy();
+ template <typename InitTy>
+ 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(Key.begin(), Key.end(), Allocator, Val);
+
+ if (Bucket == getTombstoneVal())
+ --NumTombstones;
++NumItems;
-
- // Copy the string information.
- char *StrBuffer = (char*)(NewItem+1);
- memcpy(StrBuffer, KeyStart, KeyLength);
- StrBuffer[KeyLength] = 0; // Null terminate string.
-
+ assert(NumItems + NumTombstones <= NumBuckets);
+
// Fill in the bucket for the hash table. The FullHashValue was already
// filled in by LookupBucketFor.
- Bucket.Item = NewItem;
-
- // If the hash table is now more than 3/4 full, rehash into a larger table.
- if (NumItems > NumBuckets*3/4)
- RehashTable();
+ Bucket = NewItem;
+
+ RehashTable();
return *NewItem;
}
-
- ~CStringMap() {
- for (ItemBucket *I = TheTable, *E = TheTable+NumBuckets; I != E; ++I) {
- if (ValueTy *Id = static_cast<ValueTy*>(I->Item)) {
- // Free memory referenced by the item.
- Id->~ValueTy();
- Allocator.Deallocate(Id);
- }
- }
- delete [] TheTable;
+
+ MapEntryTy &GetOrCreateValue(StringRef Key) {
+ return GetOrCreateValue(Key, ValueTy());
+ }
+
+ /// remove - Remove the specified key/value pair from the map, but do not
+ /// erase it. This aborts if the key is not in the map.
+ void remove(MapEntryTy *KeyValue) {
+ RemoveKey(KeyValue);
+ }
+
+ void erase(iterator I) {
+ MapEntryTy &V = *I;
+ remove(&V);
+ V.Destroy(Allocator);
+ }
+
+ bool erase(StringRef Key) {
+ iterator I = find(Key);
+ if (I == end()) return false;
+ erase(I);
+ return true;
+ }
+
+ ~StringMap() {
+ clear();
+ free(TheTable);
}
};
-
+
+
+template<typename ValueTy>
+class StringMapConstIterator {
+protected:
+ StringMapEntryBase **Ptr;
+public:
+ typedef StringMapEntry<ValueTy> value_type;
+
+ explicit StringMapConstIterator(StringMapEntryBase **Bucket,
+ bool NoAdvance = false)
+ : Ptr(Bucket) {
+ if (!NoAdvance) AdvancePastEmptyBuckets();
+ }
+
+ const value_type &operator*() const {
+ return *static_cast<StringMapEntry<ValueTy>*>(*Ptr);
+ }
+ const value_type *operator->() const {
+ return static_cast<StringMapEntry<ValueTy>*>(*Ptr);
+ }
+
+ bool operator==(const StringMapConstIterator &RHS) const {
+ return Ptr == RHS.Ptr;
+ }
+ bool operator!=(const StringMapConstIterator &RHS) const {
+ return Ptr != RHS.Ptr;
+ }
+
+ inline StringMapConstIterator& operator++() { // Preincrement
+ ++Ptr;
+ AdvancePastEmptyBuckets();
+ return *this;
+ }
+ StringMapConstIterator operator++(int) { // Postincrement
+ StringMapConstIterator tmp = *this; ++*this; return tmp;
+ }
+
+private:
+ void AdvancePastEmptyBuckets() {
+ while (*Ptr == 0 || *Ptr == StringMapImpl::getTombstoneVal())
+ ++Ptr;
+ }
+};
+
+template<typename ValueTy>
+class StringMapIterator : public StringMapConstIterator<ValueTy> {
+public:
+ explicit StringMapIterator(StringMapEntryBase **Bucket,
+ bool NoAdvance = false)
+ : StringMapConstIterator<ValueTy>(Bucket, NoAdvance) {
+ }
+ StringMapEntry<ValueTy> &operator*() const {
+ return *static_cast<StringMapEntry<ValueTy>*>(*this->Ptr);
+ }
+ StringMapEntry<ValueTy> *operator->() const {
+ return static_cast<StringMapEntry<ValueTy>*>(*this->Ptr);
+ }
+};
+
}
#endif
-
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