#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Allocator.h"
#include <cstring>
-#include <string>
+#include <utility>
namespace llvm {
template<typename ValueT>
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:
- template <typename InitTy>
- static void Initialize(StringMapEntry<ValueTy> &T, InitTy InitVal) {
- T.second = InitVal;
- }
-};
-
-
/// StringMapEntryBase - Shared base class of StringMapEntry instances.
class StringMapEntryBase {
unsigned StrLen;
+
public:
explicit StringMapEntryBase(unsigned Len) : StrLen(Len) {}
/// 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. Followed
+ // by an array of the actual hash values as unsigned integers.
+ StringMapEntryBase **TheTable;
unsigned NumBuckets;
unsigned NumItems;
unsigned NumTombstones;
unsigned ItemSize;
+
protected:
- explicit StringMapImpl(unsigned itemSize) : ItemSize(itemSize) {
- // Initialize the map with zero buckets to allocation.
- TheTable = 0;
- NumBuckets = 0;
- NumItems = 0;
- NumTombstones = 0;
+ explicit StringMapImpl(unsigned itemSize)
+ : TheTable(nullptr),
+ // Initialize the map with zero buckets to allocation.
+ NumBuckets(0), NumItems(0), NumTombstones(0), ItemSize(itemSize) {}
+ StringMapImpl(StringMapImpl &&RHS)
+ : TheTable(RHS.TheTable), NumBuckets(RHS.NumBuckets),
+ NumItems(RHS.NumItems), NumTombstones(RHS.NumTombstones),
+ ItemSize(RHS.ItemSize) {
+ RHS.TheTable = nullptr;
+ RHS.NumBuckets = 0;
+ RHS.NumItems = 0;
+ RHS.NumTombstones = 0;
}
- 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;
- }
+ StringMapImpl(unsigned InitSize, unsigned ItemSize);
+ unsigned RehashTable(unsigned BucketNo = 0);
/// 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
/// 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;
bool empty() const { return NumItems == 0; }
unsigned size() const { return NumItems; }
+
+ void swap(StringMapImpl &Other) {
+ std::swap(TheTable, Other.TheTable);
+ std::swap(NumBuckets, Other.NumBuckets);
+ std::swap(NumItems, Other.NumItems);
+ std::swap(NumTombstones, Other.NumTombstones);
+ }
};
/// StringMapEntry - This is used to represent one value that is inserted into
/// and data.
template<typename ValueTy>
class StringMapEntry : public StringMapEntryBase {
+ StringMapEntry(StringMapEntry &E) = delete;
+
public:
ValueTy second;
explicit StringMapEntry(unsigned strLen)
: StringMapEntryBase(strLen), second() {}
- StringMapEntry(unsigned strLen, const ValueTy &V)
- : StringMapEntryBase(strLen), second(V) {}
+ template <class InitTy>
+ StringMapEntry(unsigned strLen, InitTy &&V)
+ : StringMapEntryBase(strLen), second(std::forward<InitTy>(V)) {}
StringRef getKey() const {
return StringRef(getKeyData(), getKeyLength());
/// 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.
- 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.
+ template <typename AllocatorTy, typename InitType>
+ static StringMapEntry *Create(StringRef Key, AllocatorTy &Allocator,
+ InitType &&InitVal) {
+ unsigned KeyLength = Key.size();
+ // 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>();
static_cast<StringMapEntry*>(Allocator.Allocate(AllocSize,Alignment));
// Default construct the value.
- new (NewItem) StringMapEntry(KeyLength);
+ new (NewItem) StringMapEntry(KeyLength, std::forward<InitType>(InitVal));
// Copy the string information.
char *StrBuffer = const_cast<char*>(NewItem->getKeyData());
- memcpy(StrBuffer, KeyStart, KeyLength);
+ if (KeyLength > 0)
+ memcpy(StrBuffer, Key.data(), 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);
+ static StringMapEntry *Create(StringRef Key, AllocatorTy &Allocator) {
+ return Create(Key, Allocator, ValueTy());
}
-
/// Create - Create a StringMapEntry with normal malloc/free.
template<typename InitType>
- static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd,
- InitType InitVal) {
+ static StringMapEntry *Create(StringRef Key, InitType &&InitVal) {
MallocAllocator A;
- return Create(KeyStart, KeyEnd, A, InitVal);
+ return Create(Key, A, std::forward<InitType>(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));
+ static StringMapEntry *Create(StringRef Key) {
+ return Create(Key, ValueTy());
}
/// GetStringMapEntryFromKeyData - Given key data that is known to be embedded
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.
+ unsigned AllocSize =
+ static_cast<unsigned>(sizeof(StringMapEntry)) + getKeyLength() + 1;
this->~StringMapEntry();
- Allocator.Deallocate(this);
+ Allocator.Deallocate(static_cast<void *>(this), AllocSize);
}
/// Destroy this object, releasing memory back to the malloc allocator.
}
};
-
-template <typename T> struct ReferenceAdder { typedef T& result; };
-template <typename T> struct ReferenceAdder<T&> { typedef T result; };
-
/// 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,
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))) {}
explicit StringMap(AllocatorTy A)
: StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))), Allocator(A) {}
- explicit StringMap(const StringMap &RHS)
- : StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))) {
- assert(RHS.empty() &&
- "Copy ctor from non-empty stringmap not implemented yet!");
- }
- void operator=(const StringMap &RHS) {
- assert(RHS.empty() &&
- "assignment from non-empty stringmap not implemented yet!");
- clear();
+ StringMap(unsigned InitialSize, AllocatorTy A)
+ : StringMapImpl(InitialSize, static_cast<unsigned>(sizeof(MapEntryTy))),
+ Allocator(A) {}
+
+ StringMap(StringMap &&RHS)
+ : StringMapImpl(std::move(RHS)), Allocator(std::move(RHS.Allocator)) {}
+
+ StringMap &operator=(StringMap RHS) {
+ StringMapImpl::swap(RHS);
+ std::swap(Allocator, RHS.Allocator);
+ return *this;
}
- typedef typename ReferenceAdder<AllocatorTy>::result AllocatorRefTy;
- typedef typename ReferenceAdder<const AllocatorTy>::result AllocatorCRefTy;
- AllocatorRefTy getAllocator() { return Allocator; }
- AllocatorCRefTy getAllocator() const { return Allocator; }
+ // FIXME: Implement copy operations if/when they're needed.
+
+ AllocatorTy &getAllocator() { return Allocator; }
+ const AllocatorTy &getAllocator() const { return Allocator; }
typedef const char* key_type;
typedef ValueTy mapped_type;
iterator find(StringRef Key) {
int Bucket = FindKey(Key);
if (Bucket == -1) return end();
- return iterator(TheTable+Bucket);
+ 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);
+ return const_iterator(TheTable+Bucket, true);
}
- /// lookup - Return the entry for the specified key, or a default
+ /// 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);
return ValueTy();
}
- ValueTy& operator[](StringRef Key) {
- return GetOrCreateValue(Key).getValue();
+ ValueTy &operator[](StringRef Key) {
+ return insert(std::make_pair(Key, ValueTy())).first->second;
}
+ /// count - Return 1 if the element is in the map, 0 otherwise.
size_type count(StringRef Key) const {
return find(Key) == end() ? 0 : 1;
}
/// insert it and return true.
bool insert(MapEntryTy *KeyValue) {
unsigned BucketNo = LookupBucketFor(KeyValue->getKey());
- ItemBucket &Bucket = TheTable[BucketNo];
- if (Bucket.Item && Bucket.Item != getTombstoneVal())
+ 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;
}
+ /// insert - Inserts the specified key/value pair into the map if the key
+ /// isn't already in the map. The bool component of the returned pair is true
+ /// if and only if the insertion takes place, and the iterator component of
+ /// the pair points to the element with key equivalent to the key of the pair.
+ std::pair<iterator, bool> insert(std::pair<StringRef, ValueTy> KV) {
+ unsigned BucketNo = LookupBucketFor(KV.first);
+ StringMapEntryBase *&Bucket = TheTable[BucketNo];
+ if (Bucket && Bucket != getTombstoneVal())
+ return std::make_pair(iterator(TheTable + BucketNo, false),
+ false); // Already exists in map.
+
+ if (Bucket == getTombstoneVal())
+ --NumTombstones;
+ Bucket =
+ MapEntryTy::Create(KV.first, Allocator, std::move(KV.second));
+ ++NumItems;
+ assert(NumItems + NumTombstones <= NumBuckets);
+
+ BucketNo = RehashTable(BucketNo);
+ return std::make_pair(iterator(TheTable + BucketNo, false), 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 (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 = nullptr;
}
NumItems = 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(StringRef Key,
- InitTy Val) {
- unsigned BucketNo = LookupBucketFor(Key);
- ItemBucket &Bucket = TheTable[BucketNo];
- if (Bucket.Item && Bucket.Item != getTombstoneVal())
- return *static_cast<MapEntryTy*>(Bucket.Item);
-
- MapEntryTy *NewItem =
- MapEntryTy::Create(Key.begin(), Key.end(), Allocator, Val);
-
- if (Bucket.Item == getTombstoneVal())
- --NumTombstones;
- ++NumItems;
-
- // Fill in the bucket for the hash table. The FullHashValue was already
- // filled in by LookupBucketFor.
- Bucket.Item = NewItem;
-
- if (ShouldRehash())
- RehashTable();
- return *NewItem;
- }
-
- StringMapEntry<ValueTy> &GetOrCreateValue(StringRef Key) {
- return GetOrCreateValue(Key, ValueTy());
- }
-
- template <typename InitTy>
- StringMapEntry<ValueTy> &GetOrCreateValue(const char *KeyStart,
- const char *KeyEnd,
- InitTy Val) {
- return GetOrCreateValue(StringRef(KeyStart, KeyEnd - KeyStart), Val);
- }
-
- StringMapEntry<ValueTy> &GetOrCreateValue(const char *KeyStart,
- const char *KeyEnd) {
- return GetOrCreateValue(StringRef(KeyStart, KeyEnd - KeyStart));
+ NumTombstones = 0;
}
/// remove - Remove the specified key/value pair from the map, but do not
}
~StringMap() {
- clear();
+ // Delete all the elements in the map, but don't reset the elements
+ // to default values. This is a copy of clear(), but avoids unnecessary
+ // work not required in the destructor.
+ if (!empty()) {
+ for (unsigned I = 0, E = NumBuckets; I != E; ++I) {
+ StringMapEntryBase *Bucket = TheTable[I];
+ if (Bucket && Bucket != getTombstoneVal()) {
+ static_cast<MapEntryTy*>(Bucket)->Destroy(Allocator);
+ }
+ }
+ }
free(TheTable);
}
};
-
template<typename ValueTy>
class StringMapConstIterator {
protected:
- StringMapImpl::ItemBucket *Ptr;
+ StringMapEntryBase **Ptr;
+
public:
typedef StringMapEntry<ValueTy> value_type;
- explicit StringMapConstIterator(StringMapImpl::ItemBucket *Bucket,
+ StringMapConstIterator() : Ptr(nullptr) { }
+
+ 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 {
return Ptr != RHS.Ptr;
}
- inline StringMapConstIterator& operator++() { // Preincrement
+ inline StringMapConstIterator& operator++() { // Preincrement
++Ptr;
AdvancePastEmptyBuckets();
return *this;
private:
void AdvancePastEmptyBuckets() {
- while (Ptr->Item == 0 || Ptr->Item == StringMapImpl::getTombstoneVal())
+ while (*Ptr == nullptr || *Ptr == StringMapImpl::getTombstoneVal())
++Ptr;
}
};
template<typename ValueTy>
class StringMapIterator : public StringMapConstIterator<ValueTy> {
public:
- explicit StringMapIterator(StringMapImpl::ItemBucket *Bucket,
+ StringMapIterator() {}
+ 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);
}
};
-
}
#endif
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