| /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- |
| * vim: set ts=8 sts=4 et sw=4 tw=99: |
| * This Source Code Form is subject to the terms of the Mozilla Public |
| * License, v. 2.0. If a copy of the MPL was not distributed with this |
| * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| |
| #ifndef js_HashTable_h |
| #define js_HashTable_h |
| |
| #include "mozilla/Assertions.h" |
| #include "mozilla/Attributes.h" |
| #include "mozilla/Casting.h" |
| #include "mozilla/DebugOnly.h" |
| #include "mozilla/PodOperations.h" |
| #include "mozilla/TypeTraits.h" |
| #include "mozilla/Util.h" |
| |
| #include "js/TemplateLib.h" |
| #include "js/Utility.h" |
| |
| namespace js { |
| |
| class TempAllocPolicy; |
| template <class> struct DefaultHasher; |
| template <class, class> class HashMapEntry; |
| namespace detail { |
| template <class T> class HashTableEntry; |
| template <class T, class HashPolicy, class AllocPolicy> class HashTable; |
| } |
| |
| /*****************************************************************************/ |
| |
| // A JS-friendly, STL-like container providing a hash-based map from keys to |
| // values. In particular, HashMap calls constructors and destructors of all |
| // objects added so non-PODs may be used safely. |
| // |
| // Key/Value requirements: |
| // - movable, destructible, assignable |
| // HashPolicy requirements: |
| // - see Hash Policy section below |
| // AllocPolicy: |
| // - see jsalloc.h |
| // |
| // Note: |
| // - HashMap is not reentrant: Key/Value/HashPolicy/AllocPolicy members |
| // called by HashMap must not call back into the same HashMap object. |
| // - Due to the lack of exception handling, the user must call |init()|. |
| template <class Key, |
| class Value, |
| class HashPolicy = DefaultHasher<Key>, |
| class AllocPolicy = TempAllocPolicy> |
| class HashMap |
| { |
| typedef HashMapEntry<Key, Value> TableEntry; |
| |
| struct MapHashPolicy : HashPolicy |
| { |
| typedef Key KeyType; |
| static const Key &getKey(TableEntry &e) { return e.key; } |
| static void setKey(TableEntry &e, Key &k) { const_cast<Key &>(e.key) = k; } |
| }; |
| |
| typedef detail::HashTable<TableEntry, MapHashPolicy, AllocPolicy> Impl; |
| Impl impl; |
| |
| public: |
| typedef typename HashPolicy::Lookup Lookup; |
| typedef TableEntry Entry; |
| |
| // HashMap construction is fallible (due to OOM); thus the user must call |
| // init after constructing a HashMap and check the return value. |
| HashMap(AllocPolicy a = AllocPolicy()) |
| : impl(a) |
| { |
| MOZ_STATIC_ASSERT(tl::IsRelocatableHeapType<Key>::result, |
| "Key type must be relocatable"); |
| MOZ_STATIC_ASSERT(tl::IsRelocatableHeapType<Value>::result, |
| "Value type must be relocatable"); |
| } |
| |
| bool init(uint32_t len = 16) { return impl.init(len); } |
| bool initialized() const { return impl.initialized(); } |
| |
| // Return whether the given lookup value is present in the map. E.g.: |
| // |
| // typedef HashMap<int,char> HM; |
| // HM h; |
| // if (HM::Ptr p = h.lookup(3)) { |
| // const HM::Entry &e = *p; // p acts like a pointer to Entry |
| // assert(p->key == 3); // Entry contains the key |
| // char val = p->value; // and value |
| // } |
| // |
| // Also see the definition of Ptr in HashTable above (with T = Entry). |
| typedef typename Impl::Ptr Ptr; |
| Ptr lookup(const Lookup &l) const { return impl.lookup(l); } |
| |
| // Like lookup, but does not assert if two threads call lookup at the same |
| // time. Only use this method when none of the threads will modify the map. |
| Ptr readonlyThreadsafeLookup(const Lookup &l) const { return impl.readonlyThreadsafeLookup(l); } |
| |
| // Assuming |p.found()|, remove |*p|. |
| void remove(Ptr p) { impl.remove(p); } |
| |
| // Like |lookup(l)|, but on miss, |p = lookupForAdd(l)| allows efficient |
| // insertion of Key |k| (where |HashPolicy::match(k,l) == true|) using |
| // |add(p,k,v)|. After |add(p,k,v)|, |p| points to the new Entry. E.g.: |
| // |
| // typedef HashMap<int,char> HM; |
| // HM h; |
| // HM::AddPtr p = h.lookupForAdd(3); |
| // if (!p) { |
| // if (!h.add(p, 3, 'a')) |
| // return false; |
| // } |
| // const HM::Entry &e = *p; // p acts like a pointer to Entry |
| // assert(p->key == 3); // Entry contains the key |
| // char val = p->value; // and value |
| // |
| // Also see the definition of AddPtr in HashTable above (with T = Entry). |
| // |
| // N.B. The caller must ensure that no mutating hash table operations |
| // occur between a pair of |lookupForAdd| and |add| calls. To avoid |
| // looking up the key a second time, the caller may use the more efficient |
| // relookupOrAdd method. This method reuses part of the hashing computation |
| // to more efficiently insert the key if it has not been added. For |
| // example, a mutation-handling version of the previous example: |
| // |
| // HM::AddPtr p = h.lookupForAdd(3); |
| // if (!p) { |
| // call_that_may_mutate_h(); |
| // if (!h.relookupOrAdd(p, 3, 'a')) |
| // return false; |
| // } |
| // const HM::Entry &e = *p; |
| // assert(p->key == 3); |
| // char val = p->value; |
| typedef typename Impl::AddPtr AddPtr; |
| AddPtr lookupForAdd(const Lookup &l) const { |
| return impl.lookupForAdd(l); |
| } |
| |
| template<typename KeyInput, typename ValueInput> |
| bool add(AddPtr &p, const KeyInput &k, const ValueInput &v) { |
| Entry e(k, v); |
| return impl.add(p, Move(e)); |
| } |
| |
| bool add(AddPtr &p, const Key &k) { |
| Entry e(k, Value()); |
| return impl.add(p, Move(e)); |
| } |
| |
| template<typename KeyInput, typename ValueInput> |
| bool relookupOrAdd(AddPtr &p, const KeyInput &k, const ValueInput &v) { |
| Entry e(k, v); |
| return impl.relookupOrAdd(p, k, Move(e)); |
| } |
| |
| // |all()| returns a Range containing |count()| elements. E.g.: |
| // |
| // typedef HashMap<int,char> HM; |
| // HM h; |
| // for (HM::Range r = h.all(); !r.empty(); r.popFront()) |
| // char c = r.front().value; |
| // |
| // Also see the definition of Range in HashTable above (with T = Entry). |
| typedef typename Impl::Range Range; |
| Range all() const { return impl.all(); } |
| |
| // Typedef for the enumeration class. An Enum may be used to examine and |
| // remove table entries: |
| // |
| // typedef HashMap<int,char> HM; |
| // HM s; |
| // for (HM::Enum e(s); !e.empty(); e.popFront()) |
| // if (e.front().value == 'l') |
| // e.removeFront(); |
| // |
| // Table resize may occur in Enum's destructor. Also see the definition of |
| // Enum in HashTable above (with T = Entry). |
| typedef typename Impl::Enum Enum; |
| |
| // Remove all entries. This does not shrink the table. For that consider |
| // using the finish() method. |
| void clear() { impl.clear(); } |
| |
| // Remove all entries without triggering destructors. This method is unsafe. |
| void clearWithoutCallingDestructors() { impl.clearWithoutCallingDestructors(); } |
| |
| // Remove all the entries and release all internal buffers. The map must |
| // be initialized again before any use. |
| void finish() { impl.finish(); } |
| |
| // Does the table contain any entries? |
| bool empty() const { return impl.empty(); } |
| |
| // Number of live elements in the map. |
| uint32_t count() const { return impl.count(); } |
| |
| // Total number of allocation in the dynamic table. Note: resize will |
| // happen well before count() == capacity(). |
| size_t capacity() const { return impl.capacity(); } |
| |
| // Don't just call |impl.sizeOfExcludingThis()| because there's no |
| // guarantee that |impl| is the first field in HashMap. |
| size_t sizeOfExcludingThis(JSMallocSizeOfFun mallocSizeOf) const { |
| return impl.sizeOfExcludingThis(mallocSizeOf); |
| } |
| size_t sizeOfIncludingThis(JSMallocSizeOfFun mallocSizeOf) const { |
| return mallocSizeOf(this) + impl.sizeOfExcludingThis(mallocSizeOf); |
| } |
| |
| // If |generation()| is the same before and after a HashMap operation, |
| // pointers into the table remain valid. |
| unsigned generation() const { return impl.generation(); } |
| |
| /************************************************** Shorthand operations */ |
| |
| bool has(const Lookup &l) const { |
| return impl.lookup(l) != NULL; |
| } |
| |
| // Overwrite existing value with v. Return false on oom. |
| template<typename KeyInput, typename ValueInput> |
| bool put(const KeyInput &k, const ValueInput &v) { |
| AddPtr p = lookupForAdd(k); |
| if (p) { |
| p->value = v; |
| return true; |
| } |
| return add(p, k, v); |
| } |
| |
| // Like put, but assert that the given key is not already present. |
| template<typename KeyInput, typename ValueInput> |
| bool putNew(const KeyInput &k, const ValueInput &v) { |
| Entry e(k, v); |
| return impl.putNew(k, Move(e)); |
| } |
| |
| // Add (k,defaultValue) if |k| is not found. Return a false-y Ptr on oom. |
| Ptr lookupWithDefault(const Key &k, const Value &defaultValue) { |
| AddPtr p = lookupForAdd(k); |
| if (p) |
| return p; |
| (void)add(p, k, defaultValue); // p is left false-y on oom. |
| return p; |
| } |
| |
| // Remove if present. |
| void remove(const Lookup &l) { |
| if (Ptr p = lookup(l)) |
| remove(p); |
| } |
| |
| // HashMap is movable |
| HashMap(MoveRef<HashMap> rhs) : impl(Move(rhs->impl)) {} |
| void operator=(MoveRef<HashMap> rhs) { impl = Move(rhs->impl); } |
| |
| private: |
| // HashMap is not copyable or assignable |
| HashMap(const HashMap &hm) MOZ_DELETE; |
| HashMap &operator=(const HashMap &hm) MOZ_DELETE; |
| |
| friend class Impl::Enum; |
| }; |
| |
| /*****************************************************************************/ |
| |
| // A JS-friendly, STL-like container providing a hash-based set of values. In |
| // particular, HashSet calls constructors and destructors of all objects added |
| // so non-PODs may be used safely. |
| // |
| // T requirements: |
| // - movable, destructible, assignable |
| // HashPolicy requirements: |
| // - see Hash Policy section below |
| // AllocPolicy: |
| // - see jsalloc.h |
| // |
| // Note: |
| // - HashSet is not reentrant: T/HashPolicy/AllocPolicy members called by |
| // HashSet must not call back into the same HashSet object. |
| // - Due to the lack of exception handling, the user must call |init()|. |
| template <class T, |
| class HashPolicy = DefaultHasher<T>, |
| class AllocPolicy = TempAllocPolicy> |
| class HashSet |
| { |
| struct SetOps : HashPolicy |
| { |
| typedef T KeyType; |
| static const KeyType &getKey(const T &t) { return t; } |
| static void setKey(T &t, KeyType &k) { t = k; } |
| }; |
| |
| typedef detail::HashTable<const T, SetOps, AllocPolicy> Impl; |
| Impl impl; |
| |
| public: |
| typedef typename HashPolicy::Lookup Lookup; |
| typedef T Entry; |
| |
| // HashSet construction is fallible (due to OOM); thus the user must call |
| // init after constructing a HashSet and check the return value. |
| HashSet(AllocPolicy a = AllocPolicy()) : impl(a) |
| { |
| MOZ_STATIC_ASSERT(tl::IsRelocatableHeapType<T>::result, |
| "Set element type must be relocatable"); |
| } |
| bool init(uint32_t len = 16) { return impl.init(len); } |
| bool initialized() const { return impl.initialized(); } |
| |
| // Return whether the given lookup value is present in the map. E.g.: |
| // |
| // typedef HashSet<int> HS; |
| // HS h; |
| // if (HS::Ptr p = h.lookup(3)) { |
| // assert(*p == 3); // p acts like a pointer to int |
| // } |
| // |
| // Also see the definition of Ptr in HashTable above. |
| typedef typename Impl::Ptr Ptr; |
| Ptr lookup(const Lookup &l) const { return impl.lookup(l); } |
| |
| // Assuming |p.found()|, remove |*p|. |
| void remove(Ptr p) { impl.remove(p); } |
| |
| // Like |lookup(l)|, but on miss, |p = lookupForAdd(l)| allows efficient |
| // insertion of T value |t| (where |HashPolicy::match(t,l) == true|) using |
| // |add(p,t)|. After |add(p,t)|, |p| points to the new element. E.g.: |
| // |
| // typedef HashSet<int> HS; |
| // HS h; |
| // HS::AddPtr p = h.lookupForAdd(3); |
| // if (!p) { |
| // if (!h.add(p, 3)) |
| // return false; |
| // } |
| // assert(*p == 3); // p acts like a pointer to int |
| // |
| // Also see the definition of AddPtr in HashTable above. |
| // |
| // N.B. The caller must ensure that no mutating hash table operations |
| // occur between a pair of |lookupForAdd| and |add| calls. To avoid |
| // looking up the key a second time, the caller may use the more efficient |
| // relookupOrAdd method. This method reuses part of the hashing computation |
| // to more efficiently insert the key if it has not been added. For |
| // example, a mutation-handling version of the previous example: |
| // |
| // HS::AddPtr p = h.lookupForAdd(3); |
| // if (!p) { |
| // call_that_may_mutate_h(); |
| // if (!h.relookupOrAdd(p, 3, 3)) |
| // return false; |
| // } |
| // assert(*p == 3); |
| // |
| // Note that relookupOrAdd(p,l,t) performs Lookup using |l| and adds the |
| // entry |t|, where the caller ensures match(l,t). |
| typedef typename Impl::AddPtr AddPtr; |
| AddPtr lookupForAdd(const Lookup &l) const { return impl.lookupForAdd(l); } |
| |
| bool add(AddPtr &p, const T &t) { return impl.add(p, t); } |
| |
| bool relookupOrAdd(AddPtr &p, const Lookup &l, const T &t) { |
| return impl.relookupOrAdd(p, l, t); |
| } |
| |
| // |all()| returns a Range containing |count()| elements: |
| // |
| // typedef HashSet<int> HS; |
| // HS h; |
| // for (HS::Range r = h.all(); !r.empty(); r.popFront()) |
| // int i = r.front(); |
| // |
| // Also see the definition of Range in HashTable above. |
| typedef typename Impl::Range Range; |
| Range all() const { return impl.all(); } |
| |
| // Typedef for the enumeration class. An Enum may be used to examine and |
| // remove table entries: |
| // |
| // typedef HashSet<int> HS; |
| // HS s; |
| // for (HS::Enum e(s); !e.empty(); e.popFront()) |
| // if (e.front() == 42) |
| // e.removeFront(); |
| // |
| // Table resize may occur in Enum's destructor. Also see the definition of |
| // Enum in HashTable above. |
| typedef typename Impl::Enum Enum; |
| |
| // Remove all entries. This does not shrink the table. For that consider |
| // using the finish() method. |
| void clear() { impl.clear(); } |
| |
| // Remove all the entries and release all internal buffers. The set must |
| // be initialized again before any use. |
| void finish() { impl.finish(); } |
| |
| // Does the table contain any entries? |
| bool empty() const { return impl.empty(); } |
| |
| // Number of live elements in the map. |
| uint32_t count() const { return impl.count(); } |
| |
| // Total number of allocation in the dynamic table. Note: resize will |
| // happen well before count() == capacity(). |
| size_t capacity() const { return impl.capacity(); } |
| |
| // Don't just call |impl.sizeOfExcludingThis()| because there's no |
| // guarantee that |impl| is the first field in HashSet. |
| size_t sizeOfExcludingThis(JSMallocSizeOfFun mallocSizeOf) const { |
| return impl.sizeOfExcludingThis(mallocSizeOf); |
| } |
| size_t sizeOfIncludingThis(JSMallocSizeOfFun mallocSizeOf) const { |
| return mallocSizeOf(this) + impl.sizeOfExcludingThis(mallocSizeOf); |
| } |
| |
| // If |generation()| is the same before and after a HashSet operation, |
| // pointers into the table remain valid. |
| unsigned generation() const { return impl.generation(); } |
| |
| /************************************************** Shorthand operations */ |
| |
| bool has(const Lookup &l) const { |
| return impl.lookup(l) != NULL; |
| } |
| |
| // Overwrite existing value with v. Return false on oom. |
| bool put(const T &t) { |
| AddPtr p = lookupForAdd(t); |
| return p ? true : add(p, t); |
| } |
| |
| // Like put, but assert that the given key is not already present. |
| bool putNew(const T &t) { |
| return impl.putNew(t, t); |
| } |
| |
| bool putNew(const Lookup &l, const T &t) { |
| return impl.putNew(l, t); |
| } |
| |
| void remove(const Lookup &l) { |
| if (Ptr p = lookup(l)) |
| remove(p); |
| } |
| |
| // HashSet is movable |
| HashSet(MoveRef<HashSet> rhs) : impl(Move(rhs->impl)) {} |
| void operator=(MoveRef<HashSet> rhs) { impl = Move(rhs->impl); } |
| |
| private: |
| // HashSet is not copyable or assignable |
| HashSet(const HashSet &hs) MOZ_DELETE; |
| HashSet &operator=(const HashSet &hs) MOZ_DELETE; |
| |
| friend class Impl::Enum; |
| }; |
| |
| /*****************************************************************************/ |
| |
| // Hash Policy |
| // |
| // A hash policy P for a hash table with key-type Key must provide: |
| // - a type |P::Lookup| to use to lookup table entries; |
| // - a static member function |P::hash| with signature |
| // |
| // static js::HashNumber hash(Lookup) |
| // |
| // to use to hash the lookup type; and |
| // - a static member function |P::match| with signature |
| // |
| // static bool match(Key, Lookup) |
| // |
| // to use to test equality of key and lookup values. |
| // |
| // Normally, Lookup = Key. In general, though, different values and types of |
| // values can be used to lookup and store. If a Lookup value |l| is != to the |
| // added Key value |k|, the user must ensure that |P::match(k,l)|. E.g.: |
| // |
| // js::HashSet<Key, P>::AddPtr p = h.lookup(l); |
| // if (!p) { |
| // assert(P::match(k, l)); // must hold |
| // h.add(p, k); |
| // } |
| |
| // Pointer hashing policy that strips the lowest zeroBits when calculating the |
| // hash to improve key distribution. |
| template <typename Key, size_t zeroBits> |
| struct PointerHasher |
| { |
| typedef Key Lookup; |
| static HashNumber hash(const Lookup &l) { |
| JS_ASSERT(!JS::IsPoisonedPtr(l)); |
| size_t word = reinterpret_cast<size_t>(l) >> zeroBits; |
| JS_STATIC_ASSERT(sizeof(HashNumber) == 4); |
| #if JS_BYTES_PER_WORD == 4 |
| return HashNumber(word); |
| #else |
| JS_STATIC_ASSERT(sizeof word == 8); |
| return HashNumber((word >> 32) ^ word); |
| #endif |
| } |
| static bool match(const Key &k, const Lookup &l) { |
| JS_ASSERT(!JS::IsPoisonedPtr(k)); |
| JS_ASSERT(!JS::IsPoisonedPtr(l)); |
| return k == l; |
| } |
| }; |
| |
| // Default hash policy: just use the 'lookup' value. This of course only |
| // works if the lookup value is integral. HashTable applies ScrambleHashCode to |
| // the result of the 'hash' which means that it is 'ok' if the lookup value is |
| // not well distributed over the HashNumber domain. |
| template <class Key> |
| struct DefaultHasher |
| { |
| typedef Key Lookup; |
| static HashNumber hash(const Lookup &l) { |
| // Hash if can implicitly cast to hash number type. |
| return l; |
| } |
| static bool match(const Key &k, const Lookup &l) { |
| // Use builtin or overloaded operator==. |
| return k == l; |
| } |
| }; |
| |
| // Specialize hashing policy for pointer types. It assumes that the type is |
| // at least word-aligned. For types with smaller size use PointerHasher. |
| template <class T> |
| struct DefaultHasher<T *> : PointerHasher<T *, tl::FloorLog2<sizeof(void *)>::result> |
| {}; |
| |
| // For doubles, we can xor the two uint32s. |
| template <> |
| struct DefaultHasher<double> |
| { |
| typedef double Lookup; |
| static HashNumber hash(double d) { |
| JS_STATIC_ASSERT(sizeof(HashNumber) == 4); |
| uint64_t u = mozilla::BitwiseCast<uint64_t>(d); |
| return HashNumber(u ^ (u >> 32)); |
| } |
| static bool match(double lhs, double rhs) { |
| return mozilla::BitwiseCast<uint64_t>(lhs) == mozilla::BitwiseCast<uint64_t>(rhs); |
| } |
| }; |
| |
| /*****************************************************************************/ |
| |
| // Both HashMap and HashSet are implemented by a single HashTable that is even |
| // more heavily parameterized than the other two. This leaves HashTable gnarly |
| // and extremely coupled to HashMap and HashSet; thus code should not use |
| // HashTable directly. |
| |
| template <class Key, class Value> |
| class HashMapEntry |
| { |
| template <class, class, class> friend class detail::HashTable; |
| template <class> friend class detail::HashTableEntry; |
| |
| HashMapEntry(const HashMapEntry &) MOZ_DELETE; |
| void operator=(const HashMapEntry &) MOZ_DELETE; |
| |
| public: |
| template<typename KeyInput, typename ValueInput> |
| HashMapEntry(const KeyInput &k, const ValueInput &v) : key(k), value(v) {} |
| |
| HashMapEntry(MoveRef<HashMapEntry> rhs) |
| : key(Move(rhs->key)), value(Move(rhs->value)) { } |
| |
| typedef Key KeyType; |
| typedef Value ValueType; |
| |
| const Key key; |
| Value value; |
| }; |
| |
| } // namespace js |
| |
| namespace mozilla { |
| |
| template <typename T> |
| struct IsPod<js::detail::HashTableEntry<T> > : IsPod<T> {}; |
| |
| template <typename K, typename V> |
| struct IsPod<js::HashMapEntry<K, V> > |
| : IntegralConstant<bool, IsPod<K>::value && IsPod<V>::value> |
| {}; |
| |
| } // namespace mozilla |
| |
| namespace js { |
| |
| namespace detail { |
| |
| template <class T, class HashPolicy, class AllocPolicy> |
| class HashTable; |
| |
| template <class T> |
| class HashTableEntry |
| { |
| template <class, class, class> friend class HashTable; |
| typedef typename mozilla::RemoveConst<T>::Type NonConstT; |
| |
| HashNumber keyHash; |
| mozilla::AlignedStorage2<NonConstT> mem; |
| |
| static const HashNumber sFreeKey = 0; |
| static const HashNumber sRemovedKey = 1; |
| static const HashNumber sCollisionBit = 1; |
| |
| // Assumed by calloc in createTable. |
| JS_STATIC_ASSERT(sFreeKey == 0); |
| |
| static bool isLiveHash(HashNumber hash) |
| { |
| return hash > sRemovedKey; |
| } |
| |
| HashTableEntry(const HashTableEntry &) MOZ_DELETE; |
| void operator=(const HashTableEntry &) MOZ_DELETE; |
| ~HashTableEntry() MOZ_DELETE; |
| |
| public: |
| // NB: HashTableEntry is treated as a POD: no constructor or destructor calls. |
| |
| void destroyIfLive() { |
| if (isLive()) |
| mem.addr()->~T(); |
| } |
| |
| void destroy() { |
| JS_ASSERT(isLive()); |
| mem.addr()->~T(); |
| } |
| |
| void swap(HashTableEntry *other) { |
| Swap(keyHash, other->keyHash); |
| Swap(mem, other->mem); |
| } |
| |
| T &get() { JS_ASSERT(isLive()); return *mem.addr(); } |
| |
| bool isFree() const { return keyHash == sFreeKey; } |
| void clearLive() { JS_ASSERT(isLive()); keyHash = sFreeKey; mem.addr()->~T(); } |
| void clear() { if (isLive()) mem.addr()->~T(); keyHash = sFreeKey; } |
| bool isRemoved() const { return keyHash == sRemovedKey; } |
| void removeLive() { JS_ASSERT(isLive()); keyHash = sRemovedKey; mem.addr()->~T(); } |
| bool isLive() const { return isLiveHash(keyHash); } |
| void setCollision() { JS_ASSERT(isLive()); keyHash |= sCollisionBit; } |
| void setCollision(HashNumber bit) { JS_ASSERT(isLive()); keyHash |= bit; } |
| void unsetCollision() { keyHash &= ~sCollisionBit; } |
| bool hasCollision() const { return keyHash & sCollisionBit; } |
| bool matchHash(HashNumber hn) { return (keyHash & ~sCollisionBit) == hn; } |
| HashNumber getKeyHash() const { return keyHash & ~sCollisionBit; } |
| |
| template <class U> |
| void setLive(HashNumber hn, const U &u) |
| { |
| JS_ASSERT(!isLive()); |
| keyHash = hn; |
| new(mem.addr()) T(u); |
| JS_ASSERT(isLive()); |
| } |
| }; |
| |
| template <class T, class HashPolicy, class AllocPolicy> |
| class HashTable : private AllocPolicy |
| { |
| typedef typename mozilla::RemoveConst<T>::Type NonConstT; |
| typedef typename HashPolicy::KeyType Key; |
| typedef typename HashPolicy::Lookup Lookup; |
| |
| public: |
| typedef HashTableEntry<T> Entry; |
| |
| // A nullable pointer to a hash table element. A Ptr |p| can be tested |
| // either explicitly |if (p.found()) p->...| or using boolean conversion |
| // |if (p) p->...|. Ptr objects must not be used after any mutating hash |
| // table operations unless |generation()| is tested. |
| class Ptr |
| { |
| friend class HashTable; |
| typedef void (Ptr::* ConvertibleToBool)(); |
| void nonNull() {} |
| |
| Entry *entry_; |
| |
| protected: |
| Ptr(Entry &entry) : entry_(&entry) {} |
| |
| public: |
| // Leaves Ptr uninitialized. |
| Ptr() { |
| #ifdef JS_DEBUG |
| entry_ = (Entry *)0xbad; |
| #endif |
| } |
| |
| bool found() const { return entry_->isLive(); } |
| operator ConvertibleToBool() const { return found() ? &Ptr::nonNull : 0; } |
| bool operator==(const Ptr &rhs) const { JS_ASSERT(found() && rhs.found()); return entry_ == rhs.entry_; } |
| bool operator!=(const Ptr &rhs) const { return !(*this == rhs); } |
| |
| T &operator*() const { return entry_->get(); } |
| T *operator->() const { return &entry_->get(); } |
| }; |
| |
| // A Ptr that can be used to add a key after a failed lookup. |
| class AddPtr : public Ptr |
| { |
| friend class HashTable; |
| HashNumber keyHash; |
| mozilla::DebugOnly<uint64_t> mutationCount; |
| |
| AddPtr(Entry &entry, HashNumber hn) : Ptr(entry), keyHash(hn) {} |
| public: |
| // Leaves AddPtr uninitialized. |
| AddPtr() {} |
| }; |
| |
| // A collection of hash table entries. The collection is enumerated by |
| // calling |front()| followed by |popFront()| as long as |!empty()|. As |
| // with Ptr/AddPtr, Range objects must not be used after any mutating hash |
| // table operation unless the |generation()| is tested. |
| class Range |
| { |
| protected: |
| friend class HashTable; |
| |
| Range(Entry *c, Entry *e) : cur(c), end(e), validEntry(true) { |
| while (cur < end && !cur->isLive()) |
| ++cur; |
| } |
| |
| Entry *cur, *end; |
| mozilla::DebugOnly<bool> validEntry; |
| |
| public: |
| Range() : cur(NULL), end(NULL), validEntry(false) {} |
| |
| bool empty() const { |
| return cur == end; |
| } |
| |
| T &front() const { |
| JS_ASSERT(validEntry); |
| JS_ASSERT(!empty()); |
| return cur->get(); |
| } |
| |
| void popFront() { |
| JS_ASSERT(!empty()); |
| while (++cur < end && !cur->isLive()) |
| continue; |
| validEntry = true; |
| } |
| }; |
| |
| // A Range whose lifetime delimits a mutating enumeration of a hash table. |
| // Since rehashing when elements were removed during enumeration would be |
| // bad, it is postponed until the Enum is destructed. Since the Enum's |
| // destructor touches the hash table, the user must ensure that the hash |
| // table is still alive when the destructor runs. |
| class Enum : public Range |
| { |
| friend class HashTable; |
| |
| HashTable &table; |
| bool rekeyed; |
| bool removed; |
| |
| /* Not copyable. */ |
| Enum(const Enum &); |
| void operator=(const Enum &); |
| |
| public: |
| template<class Map> explicit |
| Enum(Map &map) : Range(map.all()), table(map.impl), rekeyed(false), removed(false) {} |
| |
| // Removes the |front()| element from the table, leaving |front()| |
| // invalid until the next call to |popFront()|. For example: |
| // |
| // HashSet<int> s; |
| // for (HashSet<int>::Enum e(s); !e.empty(); e.popFront()) |
| // if (e.front() == 42) |
| // e.removeFront(); |
| void removeFront() { |
| table.remove(*this->cur); |
| removed = true; |
| this->validEntry = false; |
| } |
| |
| // Removes the |front()| element and re-inserts it into the table with |
| // a new key at the new Lookup position. |front()| is invalid after |
| // this operation until the next call to |popFront()|. |
| void rekeyFront(const Lookup &l, const Key &k) { |
| typename HashTableEntry<T>::NonConstT t(Move(this->cur->get())); |
| HashPolicy::setKey(t, const_cast<Key &>(k)); |
| table.remove(*this->cur); |
| table.putNewInfallible(l, Move(t)); |
| rekeyed = true; |
| this->validEntry = false; |
| } |
| |
| void rekeyFront(const Key &k) { |
| rekeyFront(k, k); |
| } |
| |
| // Potentially rehashes the table. |
| ~Enum() { |
| if (rekeyed) { |
| table.gen++; |
| table.checkOverRemoved(); |
| } |
| |
| if (removed) |
| table.compactIfUnderloaded(); |
| } |
| }; |
| |
| // HashTable is movable |
| HashTable(MoveRef<HashTable> rhs) |
| : AllocPolicy(*rhs) |
| { |
| mozilla::PodAssign(this, &*rhs); |
| rhs->table = NULL; |
| } |
| void operator=(MoveRef<HashTable> rhs) { |
| if (table) |
| destroyTable(*this, table, capacity()); |
| mozilla::PodAssign(this, &*rhs); |
| rhs->table = NULL; |
| } |
| |
| private: |
| // HashTable is not copyable or assignable |
| HashTable(const HashTable &) MOZ_DELETE; |
| void operator=(const HashTable &) MOZ_DELETE; |
| |
| private: |
| uint32_t hashShift; // multiplicative hash shift |
| uint32_t entryCount; // number of entries in table |
| uint32_t gen; // entry storage generation number |
| uint32_t removedCount; // removed entry sentinels in table |
| Entry *table; // entry storage |
| |
| void setTableSizeLog2(unsigned sizeLog2) |
| { |
| hashShift = sHashBits - sizeLog2; |
| } |
| |
| #ifdef JS_DEBUG |
| mutable struct Stats |
| { |
| uint32_t searches; // total number of table searches |
| uint32_t steps; // hash chain links traversed |
| uint32_t hits; // searches that found key |
| uint32_t misses; // searches that didn't find key |
| uint32_t addOverRemoved; // adds that recycled a removed entry |
| uint32_t removes; // calls to remove |
| uint32_t removeFrees; // calls to remove that freed the entry |
| uint32_t grows; // table expansions |
| uint32_t shrinks; // table contractions |
| uint32_t compresses; // table compressions |
| uint32_t rehashes; // tombstone decontaminations |
| } stats; |
| # define METER(x) x |
| #else |
| # define METER(x) |
| #endif |
| |
| friend class js::ReentrancyGuard; |
| mutable mozilla::DebugOnly<bool> entered; |
| mozilla::DebugOnly<uint64_t> mutationCount; |
| |
| // The default initial capacity is 32 (enough to hold 16 elements), but it |
| // can be as low as 4. |
| static const unsigned sMinCapacityLog2 = 2; |
| static const unsigned sMinCapacity = 1 << sMinCapacityLog2; |
| static const unsigned sMaxInit = JS_BIT(23); |
| static const unsigned sMaxCapacity = JS_BIT(24); |
| static const unsigned sHashBits = tl::BitSize<HashNumber>::result; |
| static const uint8_t sMinAlphaFrac = 64; // (0x100 * .25) |
| static const uint8_t sMaxAlphaFrac = 192; // (0x100 * .75) |
| static const uint8_t sInvMaxAlpha = 171; // (ceil(0x100 / .75) >> 1) |
| static const HashNumber sFreeKey = Entry::sFreeKey; |
| static const HashNumber sRemovedKey = Entry::sRemovedKey; |
| static const HashNumber sCollisionBit = Entry::sCollisionBit; |
| |
| static void staticAsserts() |
| { |
| // Rely on compiler "constant overflow warnings". |
| JS_STATIC_ASSERT(((sMaxInit * sInvMaxAlpha) >> 7) < sMaxCapacity); |
| JS_STATIC_ASSERT((sMaxCapacity * sInvMaxAlpha) <= UINT32_MAX); |
| JS_STATIC_ASSERT((sMaxCapacity * sizeof(Entry)) <= UINT32_MAX); |
| } |
| |
| static bool isLiveHash(HashNumber hash) |
| { |
| return Entry::isLiveHash(hash); |
| } |
| |
| static HashNumber prepareHash(const Lookup& l) |
| { |
| HashNumber keyHash = ScrambleHashCode(HashPolicy::hash(l)); |
| |
| // Avoid reserved hash codes. |
| if (!isLiveHash(keyHash)) |
| keyHash -= (sRemovedKey + 1); |
| return keyHash & ~sCollisionBit; |
| } |
| |
| static Entry *createTable(AllocPolicy &alloc, uint32_t capacity) |
| { |
| // See JS_STATIC_ASSERT(sFreeKey == 0) in HashTableEntry. |
| return (Entry *)alloc.calloc_(capacity * sizeof(Entry)); |
| } |
| |
| static void destroyTable(AllocPolicy &alloc, Entry *oldTable, uint32_t capacity) |
| { |
| for (Entry *e = oldTable, *end = e + capacity; e < end; ++e) |
| e->destroyIfLive(); |
| alloc.free_(oldTable); |
| } |
| |
| public: |
| HashTable(AllocPolicy ap) |
| : AllocPolicy(ap), |
| hashShift(sHashBits), |
| entryCount(0), |
| gen(0), |
| removedCount(0), |
| table(NULL), |
| entered(false), |
| mutationCount(0) |
| {} |
| |
| MOZ_WARN_UNUSED_RESULT bool init(uint32_t length) |
| { |
| JS_ASSERT(!initialized()); |
| |
| // Correct for sMaxAlphaFrac such that the table will not resize |
| // when adding 'length' entries. |
| if (length > sMaxInit) { |
| this->reportAllocOverflow(); |
| return false; |
| } |
| uint32_t newCapacity = (length * sInvMaxAlpha) >> 7; |
| |
| if (newCapacity < sMinCapacity) |
| newCapacity = sMinCapacity; |
| |
| // FIXME: use JS_CEILING_LOG2 when PGO stops crashing (bug 543034). |
| uint32_t roundUp = sMinCapacity, roundUpLog2 = sMinCapacityLog2; |
| while (roundUp < newCapacity) { |
| roundUp <<= 1; |
| ++roundUpLog2; |
| } |
| |
| newCapacity = roundUp; |
| JS_ASSERT(newCapacity <= sMaxCapacity); |
| |
| table = createTable(*this, newCapacity); |
| if (!table) |
| return false; |
| |
| setTableSizeLog2(roundUpLog2); |
| METER(memset(&stats, 0, sizeof(stats))); |
| return true; |
| } |
| |
| bool initialized() const |
| { |
| return !!table; |
| } |
| |
| ~HashTable() |
| { |
| if (table) |
| destroyTable(*this, table, capacity()); |
| } |
| |
| private: |
| HashNumber hash1(HashNumber hash0) const |
| { |
| return hash0 >> hashShift; |
| } |
| |
| struct DoubleHash |
| { |
| HashNumber h2; |
| HashNumber sizeMask; |
| }; |
| |
| DoubleHash hash2(HashNumber curKeyHash) const |
| { |
| unsigned sizeLog2 = sHashBits - hashShift; |
| DoubleHash dh = { |
| ((curKeyHash << sizeLog2) >> hashShift) | 1, |
| (HashNumber(1) << sizeLog2) - 1 |
| }; |
| return dh; |
| } |
| |
| static HashNumber applyDoubleHash(HashNumber h1, const DoubleHash &dh) |
| { |
| return (h1 - dh.h2) & dh.sizeMask; |
| } |
| |
| bool overloaded() |
| { |
| return entryCount + removedCount >= ((sMaxAlphaFrac * capacity()) >> 8); |
| } |
| |
| // Would the table be underloaded if it had the given capacity and entryCount? |
| static bool wouldBeUnderloaded(uint32_t capacity, uint32_t entryCount) |
| { |
| return capacity > sMinCapacity && entryCount <= ((sMinAlphaFrac * capacity) >> 8); |
| } |
| |
| bool underloaded() |
| { |
| return wouldBeUnderloaded(capacity(), entryCount); |
| } |
| |
| static bool match(Entry &e, const Lookup &l) |
| { |
| return HashPolicy::match(HashPolicy::getKey(e.get()), l); |
| } |
| |
| Entry &lookup(const Lookup &l, HashNumber keyHash, unsigned collisionBit) const |
| { |
| JS_ASSERT(isLiveHash(keyHash)); |
| JS_ASSERT(!(keyHash & sCollisionBit)); |
| JS_ASSERT(collisionBit == 0 || collisionBit == sCollisionBit); |
| JS_ASSERT(table); |
| METER(stats.searches++); |
| |
| // Compute the primary hash address. |
| HashNumber h1 = hash1(keyHash); |
| Entry *entry = &table[h1]; |
| |
| // Miss: return space for a new entry. |
| if (entry->isFree()) { |
| METER(stats.misses++); |
| return *entry; |
| } |
| |
| // Hit: return entry. |
| if (entry->matchHash(keyHash) && match(*entry, l)) { |
| METER(stats.hits++); |
| return *entry; |
| } |
| |
| // Collision: double hash. |
| DoubleHash dh = hash2(keyHash); |
| |
| // Save the first removed entry pointer so we can recycle later. |
| Entry *firstRemoved = NULL; |
| |
| while(true) { |
| if (JS_UNLIKELY(entry->isRemoved())) { |
| if (!firstRemoved) |
| firstRemoved = entry; |
| } else { |
| entry->setCollision(collisionBit); |
| } |
| |
| METER(stats.steps++); |
| h1 = applyDoubleHash(h1, dh); |
| |
| entry = &table[h1]; |
| if (entry->isFree()) { |
| METER(stats.misses++); |
| return firstRemoved ? *firstRemoved : *entry; |
| } |
| |
| if (entry->matchHash(keyHash) && match(*entry, l)) { |
| METER(stats.hits++); |
| return *entry; |
| } |
| } |
| } |
| |
| // This is a copy of lookup hardcoded to the assumptions: |
| // 1. the lookup is a lookupForAdd |
| // 2. the key, whose |keyHash| has been passed is not in the table, |
| // 3. no entries have been removed from the table. |
| // This specialized search avoids the need for recovering lookup values |
| // from entries, which allows more flexible Lookup/Key types. |
| Entry &findFreeEntry(HashNumber keyHash) |
| { |
| JS_ASSERT(!(keyHash & sCollisionBit)); |
| JS_ASSERT(table); |
| METER(stats.searches++); |
| |
| // We assume 'keyHash' has already been distributed. |
| |
| // Compute the primary hash address. |
| HashNumber h1 = hash1(keyHash); |
| Entry *entry = &table[h1]; |
| |
| // Miss: return space for a new entry. |
| if (!entry->isLive()) { |
| METER(stats.misses++); |
| return *entry; |
| } |
| |
| // Collision: double hash. |
| DoubleHash dh = hash2(keyHash); |
| |
| while(true) { |
| JS_ASSERT(!entry->isRemoved()); |
| entry->setCollision(); |
| |
| METER(stats.steps++); |
| h1 = applyDoubleHash(h1, dh); |
| |
| entry = &table[h1]; |
| if (!entry->isLive()) { |
| METER(stats.misses++); |
| return *entry; |
| } |
| } |
| } |
| |
| enum RebuildStatus { NotOverloaded, Rehashed, RehashFailed }; |
| |
| RebuildStatus changeTableSize(int deltaLog2) |
| { |
| // Look, but don't touch, until we succeed in getting new entry store. |
| Entry *oldTable = table; |
| uint32_t oldCap = capacity(); |
| uint32_t newLog2 = sHashBits - hashShift + deltaLog2; |
| uint32_t newCapacity = JS_BIT(newLog2); |
| if (newCapacity > sMaxCapacity) { |
| this->reportAllocOverflow(); |
| return RehashFailed; |
| } |
| |
| Entry *newTable = createTable(*this, newCapacity); |
| if (!newTable) |
| return RehashFailed; |
| |
| // We can't fail from here on, so update table parameters. |
| setTableSizeLog2(newLog2); |
| removedCount = 0; |
| gen++; |
| table = newTable; |
| |
| // Copy only live entries, leaving removed ones behind. |
| for (Entry *src = oldTable, *end = src + oldCap; src < end; ++src) { |
| if (src->isLive()) { |
| HashNumber hn = src->getKeyHash(); |
| findFreeEntry(hn).setLive(hn, Move(src->get())); |
| src->destroy(); |
| } |
| } |
| |
| // All entries have been destroyed, no need to destroyTable. |
| this->free_(oldTable); |
| return Rehashed; |
| } |
| |
| RebuildStatus checkOverloaded() |
| { |
| if (!overloaded()) |
| return NotOverloaded; |
| |
| // Compress if a quarter or more of all entries are removed. |
| int deltaLog2; |
| if (removedCount >= (capacity() >> 2)) { |
| METER(stats.compresses++); |
| deltaLog2 = 0; |
| } else { |
| METER(stats.grows++); |
| deltaLog2 = 1; |
| } |
| |
| return changeTableSize(deltaLog2); |
| } |
| |
| // Infallibly rehash the table if we are overloaded with removals. |
| void checkOverRemoved() |
| { |
| if (overloaded()) { |
| if (checkOverloaded() == RehashFailed) |
| rehashTableInPlace(); |
| } |
| } |
| |
| void remove(Entry &e) |
| { |
| JS_ASSERT(table); |
| METER(stats.removes++); |
| |
| if (e.hasCollision()) { |
| e.removeLive(); |
| removedCount++; |
| } else { |
| METER(stats.removeFrees++); |
| e.clearLive(); |
| } |
| entryCount--; |
| mutationCount++; |
| } |
| |
| void checkUnderloaded() |
| { |
| if (underloaded()) { |
| METER(stats.shrinks++); |
| (void) changeTableSize(-1); |
| } |
| } |
| |
| // Resize the table down to the largest capacity which doesn't underload the |
| // table. Since we call checkUnderloaded() on every remove, you only need |
| // to call this after a bulk removal of items done without calling remove(). |
| void compactIfUnderloaded() |
| { |
| int32_t resizeLog2 = 0; |
| uint32_t newCapacity = capacity(); |
| while (wouldBeUnderloaded(newCapacity, entryCount)) { |
| newCapacity = newCapacity >> 1; |
| resizeLog2--; |
| } |
| |
| if (resizeLog2 != 0) { |
| changeTableSize(resizeLog2); |
| } |
| } |
| |
| // This is identical to changeTableSize(currentSize), but without requiring |
| // a second table. We do this by recycling the collision bits to tell us if |
| // the element is already inserted or still waiting to be inserted. Since |
| // already-inserted elements win any conflicts, we get the same table as we |
| // would have gotten through random insertion order. |
| void rehashTableInPlace() |
| { |
| METER(stats.rehashes++); |
| removedCount = 0; |
| for (size_t i = 0; i < capacity(); ++i) |
| table[i].unsetCollision(); |
| |
| for (size_t i = 0; i < capacity();) { |
| Entry *src = &table[i]; |
| |
| if (!src->isLive() || src->hasCollision()) { |
| ++i; |
| continue; |
| } |
| |
| HashNumber keyHash = src->getKeyHash(); |
| HashNumber h1 = hash1(keyHash); |
| DoubleHash dh = hash2(keyHash); |
| Entry *tgt = &table[h1]; |
| while (true) { |
| if (!tgt->hasCollision()) { |
| src->swap(tgt); |
| tgt->setCollision(); |
| break; |
| } |
| |
| h1 = applyDoubleHash(h1, dh); |
| tgt = &table[h1]; |
| } |
| } |
| |
| // TODO: this algorithm leaves collision bits on *all* elements, even if |
| // they are on no collision path. We have the option of setting the |
| // collision bits correctly on a subsequent pass or skipping the rehash |
| // unless we are totally filled with tombstones: benchmark to find out |
| // which approach is best. |
| } |
| |
| public: |
| void clear() |
| { |
| if (mozilla::IsPod<Entry>::value) { |
| memset(table, 0, sizeof(*table) * capacity()); |
| } else { |
| uint32_t tableCapacity = capacity(); |
| for (Entry *e = table, *end = table + tableCapacity; e < end; ++e) |
| e->clear(); |
| } |
| removedCount = 0; |
| entryCount = 0; |
| mutationCount++; |
| } |
| |
| void finish() |
| { |
| JS_ASSERT(!entered); |
| |
| if (!table) |
| return; |
| |
| destroyTable(*this, table, capacity()); |
| table = NULL; |
| gen++; |
| entryCount = 0; |
| removedCount = 0; |
| mutationCount++; |
| } |
| |
| Range all() const |
| { |
| JS_ASSERT(table); |
| return Range(table, table + capacity()); |
| } |
| |
| bool empty() const |
| { |
| JS_ASSERT(table); |
| return !entryCount; |
| } |
| |
| uint32_t count() const |
| { |
| JS_ASSERT(table); |
| return entryCount; |
| } |
| |
| uint32_t capacity() const |
| { |
| JS_ASSERT(table); |
| return JS_BIT(sHashBits - hashShift); |
| } |
| |
| uint32_t generation() const |
| { |
| JS_ASSERT(table); |
| return gen; |
| } |
| |
| size_t sizeOfExcludingThis(JSMallocSizeOfFun mallocSizeOf) const |
| { |
| return mallocSizeOf(table); |
| } |
| |
| size_t sizeOfIncludingThis(JSMallocSizeOfFun mallocSizeOf) const |
| { |
| return mallocSizeOf(this) + sizeOfExcludingThis(mallocSizeOf); |
| } |
| |
| Ptr lookup(const Lookup &l) const |
| { |
| ReentrancyGuard g(*this); |
| HashNumber keyHash = prepareHash(l); |
| return Ptr(lookup(l, keyHash, 0)); |
| } |
| |
| Ptr readonlyThreadsafeLookup(const Lookup &l) const |
| { |
| HashNumber keyHash = prepareHash(l); |
| return Ptr(lookup(l, keyHash, 0)); |
| } |
| |
| AddPtr lookupForAdd(const Lookup &l) const |
| { |
| ReentrancyGuard g(*this); |
| HashNumber keyHash = prepareHash(l); |
| Entry &entry = lookup(l, keyHash, sCollisionBit); |
| AddPtr p(entry, keyHash); |
| p.mutationCount = mutationCount; |
| return p; |
| } |
| |
| template <class U> |
| bool add(AddPtr &p, const U &rhs) |
| { |
| ReentrancyGuard g(*this); |
| JS_ASSERT(mutationCount == p.mutationCount); |
| JS_ASSERT(table); |
| JS_ASSERT(!p.found()); |
| JS_ASSERT(!(p.keyHash & sCollisionBit)); |
| |
| // Changing an entry from removed to live does not affect whether we |
| // are overloaded and can be handled separately. |
| if (p.entry_->isRemoved()) { |
| METER(stats.addOverRemoved++); |
| removedCount--; |
| p.keyHash |= sCollisionBit; |
| } else { |
| // Preserve the validity of |p.entry_|. |
| RebuildStatus status = checkOverloaded(); |
| if (status == RehashFailed) |
| return false; |
| if (status == Rehashed) |
| p.entry_ = &findFreeEntry(p.keyHash); |
| } |
| |
| p.entry_->setLive(p.keyHash, rhs); |
| entryCount++; |
| mutationCount++; |
| return true; |
| } |
| |
| template <class U> |
| void putNewInfallible(const Lookup &l, const U &u) |
| { |
| JS_ASSERT(table); |
| |
| HashNumber keyHash = prepareHash(l); |
| Entry *entry = &findFreeEntry(keyHash); |
| |
| if (entry->isRemoved()) { |
| METER(stats.addOverRemoved++); |
| removedCount--; |
| keyHash |= sCollisionBit; |
| } |
| |
| entry->setLive(keyHash, u); |
| entryCount++; |
| mutationCount++; |
| } |
| |
| template <class U> |
| bool putNew(const Lookup &l, const U &u) |
| { |
| if (checkOverloaded() == RehashFailed) |
| return false; |
| |
| putNewInfallible(l, u); |
| return true; |
| } |
| |
| template <class U> |
| bool relookupOrAdd(AddPtr& p, const Lookup &l, const U &u) |
| { |
| p.mutationCount = mutationCount; |
| { |
| ReentrancyGuard g(*this); |
| p.entry_ = &lookup(l, p.keyHash, sCollisionBit); |
| } |
| return p.found() || add(p, u); |
| } |
| |
| void remove(Ptr p) |
| { |
| JS_ASSERT(table); |
| ReentrancyGuard g(*this); |
| JS_ASSERT(p.found()); |
| remove(*p.entry_); |
| checkUnderloaded(); |
| } |
| |
| #undef METER |
| }; |
| |
| } // namespace detail |
| } // namespace js |
| |
| #endif /* js_HashTable_h */ |
