mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-10-30 21:55:31 +00:00
547 lines
17 KiB
C++
547 lines
17 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* 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 nsTHashtable_h__
|
|
#define nsTHashtable_h__
|
|
|
|
#include "nscore.h"
|
|
#include "pldhash.h"
|
|
#include "nsDebug.h"
|
|
#include "mozilla/MemoryChecking.h"
|
|
#include "mozilla/MemoryReporting.h"
|
|
#include "mozilla/Move.h"
|
|
#include "mozilla/fallible.h"
|
|
#include "mozilla/PodOperations.h"
|
|
|
|
#include <new>
|
|
|
|
// helper function for nsTHashtable::Clear()
|
|
NS_COM_GLUE PLDHashOperator
|
|
PL_DHashStubEnumRemove(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry,
|
|
uint32_t ordinal,
|
|
void *userArg);
|
|
|
|
|
|
/**
|
|
* a base class for templated hashtables.
|
|
*
|
|
* Clients will rarely need to use this class directly. Check the derived
|
|
* classes first, to see if they will meet your needs.
|
|
*
|
|
* @param EntryType the templated entry-type class that is managed by the
|
|
* hashtable. <code>EntryType</code> must extend the following declaration,
|
|
* and <strong>must not declare any virtual functions or derive from classes
|
|
* with virtual functions.</strong> Any vtable pointer would break the
|
|
* PLDHashTable code.
|
|
*<pre> class EntryType : public PLDHashEntryHdr
|
|
* {
|
|
* public: or friend nsTHashtable<EntryType>;
|
|
* // KeyType is what we use when Get()ing or Put()ing this entry
|
|
* // this should either be a simple datatype (uint32_t, nsISupports*) or
|
|
* // a const reference (const nsAString&)
|
|
* typedef something KeyType;
|
|
* // KeyTypePointer is the pointer-version of KeyType, because pldhash.h
|
|
* // requires keys to cast to <code>const void*</code>
|
|
* typedef const something* KeyTypePointer;
|
|
*
|
|
* EntryType(KeyTypePointer aKey);
|
|
*
|
|
* // A copy or C++11 Move constructor must be defined, even if
|
|
* // AllowMemMove() == true, otherwise you will cause link errors.
|
|
* EntryType(const EntryType& aEnt); // Either this...
|
|
* EntryType(EntryType&& aEnt); // ...or this
|
|
*
|
|
* // the destructor must be defined... or you will cause link errors!
|
|
* ~EntryType();
|
|
*
|
|
* // KeyEquals(): does this entry match this key?
|
|
* bool KeyEquals(KeyTypePointer aKey) const;
|
|
*
|
|
* // KeyToPointer(): Convert KeyType to KeyTypePointer
|
|
* static KeyTypePointer KeyToPointer(KeyType aKey);
|
|
*
|
|
* // HashKey(): calculate the hash number
|
|
* static PLDHashNumber HashKey(KeyTypePointer aKey);
|
|
*
|
|
* // ALLOW_MEMMOVE can we move this class with memmove(), or do we have
|
|
* // to use the copy constructor?
|
|
* enum { ALLOW_MEMMOVE = true/false };
|
|
* }</pre>
|
|
*
|
|
* @see nsInterfaceHashtable
|
|
* @see nsDataHashtable
|
|
* @see nsClassHashtable
|
|
* @author "Benjamin Smedberg <bsmedberg@covad.net>"
|
|
*/
|
|
|
|
template<class EntryType>
|
|
class nsTHashtable
|
|
{
|
|
typedef mozilla::fallible_t fallible_t;
|
|
|
|
public:
|
|
// Separate constructors instead of default aInitSize parameter since
|
|
// otherwise the default no-arg constructor isn't found.
|
|
nsTHashtable()
|
|
{
|
|
Init(PL_DHASH_MIN_SIZE);
|
|
}
|
|
explicit nsTHashtable(uint32_t aInitSize)
|
|
{
|
|
Init(aInitSize);
|
|
}
|
|
|
|
/**
|
|
* destructor, cleans up and deallocates
|
|
*/
|
|
~nsTHashtable();
|
|
|
|
nsTHashtable(nsTHashtable<EntryType>&& aOther);
|
|
|
|
/**
|
|
* Return the generation number for the table. This increments whenever
|
|
* the table data items are moved.
|
|
*/
|
|
uint32_t GetGeneration() const { return mTable.generation; }
|
|
|
|
/**
|
|
* KeyType is typedef'ed for ease of use.
|
|
*/
|
|
typedef typename EntryType::KeyType KeyType;
|
|
|
|
/**
|
|
* KeyTypePointer is typedef'ed for ease of use.
|
|
*/
|
|
typedef typename EntryType::KeyTypePointer KeyTypePointer;
|
|
|
|
/**
|
|
* Return the number of entries in the table.
|
|
* @return number of entries
|
|
*/
|
|
uint32_t Count() const { return mTable.entryCount; }
|
|
|
|
/**
|
|
* Get the entry associated with a key.
|
|
* @param aKey the key to retrieve
|
|
* @return pointer to the entry class, if the key exists; nullptr if the
|
|
* key doesn't exist
|
|
*/
|
|
EntryType* GetEntry(KeyType aKey) const
|
|
{
|
|
NS_ASSERTION(mTable.entrySize, "nsTHashtable was not initialized properly.");
|
|
|
|
EntryType* entry =
|
|
reinterpret_cast<EntryType*>
|
|
(PL_DHashTableOperate(
|
|
const_cast<PLDHashTable*>(&mTable),
|
|
EntryType::KeyToPointer(aKey),
|
|
PL_DHASH_LOOKUP));
|
|
return PL_DHASH_ENTRY_IS_BUSY(entry) ? entry : nullptr;
|
|
}
|
|
|
|
/**
|
|
* Return true if an entry for the given key exists, false otherwise.
|
|
* @param aKey the key to retrieve
|
|
* @return true if the key exists, false if the key doesn't exist
|
|
*/
|
|
bool Contains(KeyType aKey) const
|
|
{
|
|
return !!GetEntry(aKey);
|
|
}
|
|
|
|
/**
|
|
* Get the entry associated with a key, or create a new entry,
|
|
* @param aKey the key to retrieve
|
|
* @return pointer to the entry class retreived; nullptr only if memory
|
|
can't be allocated
|
|
*/
|
|
EntryType* PutEntry(KeyType aKey)
|
|
{
|
|
EntryType* e = PutEntry(aKey, fallible_t());
|
|
if (!e)
|
|
NS_RUNTIMEABORT("OOM");
|
|
return e;
|
|
}
|
|
|
|
EntryType* PutEntry(KeyType aKey, const fallible_t&) NS_WARN_UNUSED_RESULT
|
|
{
|
|
NS_ASSERTION(mTable.entrySize, "nsTHashtable was not initialized properly.");
|
|
|
|
return static_cast<EntryType*>
|
|
(PL_DHashTableOperate(
|
|
&mTable,
|
|
EntryType::KeyToPointer(aKey),
|
|
PL_DHASH_ADD));
|
|
}
|
|
|
|
/**
|
|
* Remove the entry associated with a key.
|
|
* @param aKey of the entry to remove
|
|
*/
|
|
void RemoveEntry(KeyType aKey)
|
|
{
|
|
NS_ASSERTION(mTable.entrySize, "nsTHashtable was not initialized properly.");
|
|
|
|
PL_DHashTableOperate(&mTable,
|
|
EntryType::KeyToPointer(aKey),
|
|
PL_DHASH_REMOVE);
|
|
}
|
|
|
|
/**
|
|
* Remove the entry associated with a key, but don't resize the hashtable.
|
|
* This is a low-level method, and is not recommended unless you know what
|
|
* you're doing and you need the extra performance. This method can be used
|
|
* during enumeration, while RemoveEntry() cannot.
|
|
* @param aEntry the entry-pointer to remove (obtained from GetEntry or
|
|
* the enumerator
|
|
*/
|
|
void RawRemoveEntry(EntryType* aEntry)
|
|
{
|
|
PL_DHashTableRawRemove(&mTable, aEntry);
|
|
}
|
|
|
|
/**
|
|
* client must provide an <code>Enumerator</code> function for
|
|
* EnumerateEntries
|
|
* @param aEntry the entry being enumerated
|
|
* @param userArg passed unchanged from <code>EnumerateEntries</code>
|
|
* @return combination of flags
|
|
* @link PLDHashOperator::PL_DHASH_NEXT PL_DHASH_NEXT @endlink ,
|
|
* @link PLDHashOperator::PL_DHASH_STOP PL_DHASH_STOP @endlink ,
|
|
* @link PLDHashOperator::PL_DHASH_REMOVE PL_DHASH_REMOVE @endlink
|
|
*/
|
|
typedef PLDHashOperator (* Enumerator)(EntryType* aEntry, void* userArg);
|
|
|
|
/**
|
|
* Enumerate all the entries of the function.
|
|
* @param enumFunc the <code>Enumerator</code> function to call
|
|
* @param userArg a pointer to pass to the
|
|
* <code>Enumerator</code> function
|
|
* @return the number of entries actually enumerated
|
|
*/
|
|
uint32_t EnumerateEntries(Enumerator enumFunc, void* userArg)
|
|
{
|
|
NS_ASSERTION(mTable.entrySize, "nsTHashtable was not initialized properly.");
|
|
|
|
s_EnumArgs args = { enumFunc, userArg };
|
|
return PL_DHashTableEnumerate(&mTable, s_EnumStub, &args);
|
|
}
|
|
|
|
/**
|
|
* remove all entries, return hashtable to "pristine" state ;)
|
|
*/
|
|
void Clear()
|
|
{
|
|
NS_ASSERTION(mTable.entrySize, "nsTHashtable was not initialized properly.");
|
|
|
|
PL_DHashTableEnumerate(&mTable, PL_DHashStubEnumRemove, nullptr);
|
|
}
|
|
|
|
/**
|
|
* client must provide a <code>SizeOfEntryExcludingThisFun</code> function for
|
|
* SizeOfExcludingThis.
|
|
* @param aEntry the entry being enumerated
|
|
* @param mallocSizeOf the function used to measure heap-allocated blocks
|
|
* @param arg passed unchanged from <code>SizeOf{In,Ex}cludingThis</code>
|
|
* @return summed size of the things pointed to by the entries
|
|
*/
|
|
typedef size_t (* SizeOfEntryExcludingThisFun)(EntryType* aEntry,
|
|
mozilla::MallocSizeOf mallocSizeOf,
|
|
void *arg);
|
|
|
|
/**
|
|
* Measure the size of the table's entry storage, and if
|
|
* |sizeOfEntryExcludingThis| is non-nullptr, measure the size of things
|
|
* pointed to by entries.
|
|
*
|
|
* @param sizeOfEntryExcludingThis the
|
|
* <code>SizeOfEntryExcludingThisFun</code> function to call
|
|
* @param mallocSizeOf the function used to measure heap-allocated blocks
|
|
* @param userArg a pointer to pass to the
|
|
* <code>SizeOfEntryExcludingThisFun</code> function
|
|
* @return the summed size of all the entries
|
|
*/
|
|
size_t SizeOfExcludingThis(SizeOfEntryExcludingThisFun sizeOfEntryExcludingThis,
|
|
mozilla::MallocSizeOf mallocSizeOf,
|
|
void *userArg = nullptr) const
|
|
{
|
|
if (sizeOfEntryExcludingThis) {
|
|
s_SizeOfArgs args = { sizeOfEntryExcludingThis, userArg };
|
|
return PL_DHashTableSizeOfExcludingThis(&mTable, s_SizeOfStub, mallocSizeOf, &args);
|
|
}
|
|
return PL_DHashTableSizeOfExcludingThis(&mTable, nullptr, mallocSizeOf);
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
/**
|
|
* Mark the table as constant after initialization.
|
|
*
|
|
* This will prevent assertions when a read-only hash is accessed on multiple
|
|
* threads without synchronization.
|
|
*/
|
|
void MarkImmutable()
|
|
{
|
|
NS_ASSERTION(mTable.entrySize, "nsTHashtable was not initialized properly.");
|
|
|
|
PL_DHashMarkTableImmutable(&mTable);
|
|
}
|
|
#endif
|
|
|
|
protected:
|
|
PLDHashTable mTable;
|
|
|
|
static const void* s_GetKey(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry);
|
|
|
|
static PLDHashNumber s_HashKey(PLDHashTable *table,
|
|
const void *key);
|
|
|
|
static bool s_MatchEntry(PLDHashTable *table,
|
|
const PLDHashEntryHdr *entry,
|
|
const void *key);
|
|
|
|
static void s_CopyEntry(PLDHashTable *table,
|
|
const PLDHashEntryHdr *from,
|
|
PLDHashEntryHdr *to);
|
|
|
|
static void s_ClearEntry(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry);
|
|
|
|
static bool s_InitEntry(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry,
|
|
const void *key);
|
|
|
|
/**
|
|
* passed internally during enumeration. Allocated on the stack.
|
|
*
|
|
* @param userFunc the Enumerator function passed to
|
|
* EnumerateEntries by the client
|
|
* @param userArg the userArg passed unaltered
|
|
*/
|
|
struct s_EnumArgs
|
|
{
|
|
Enumerator userFunc;
|
|
void* userArg;
|
|
};
|
|
|
|
static PLDHashOperator s_EnumStub(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry,
|
|
uint32_t number,
|
|
void *arg);
|
|
|
|
/**
|
|
* passed internally during sizeOf counting. Allocated on the stack.
|
|
*
|
|
* @param userFunc the SizeOfEntryExcludingThisFun passed to
|
|
* SizeOf{In,Ex}cludingThis by the client
|
|
* @param userArg the userArg passed unaltered
|
|
*/
|
|
struct s_SizeOfArgs
|
|
{
|
|
SizeOfEntryExcludingThisFun userFunc;
|
|
void* userArg;
|
|
};
|
|
|
|
static size_t s_SizeOfStub(PLDHashEntryHdr *entry,
|
|
mozilla::MallocSizeOf mallocSizeOf,
|
|
void *arg);
|
|
|
|
private:
|
|
// copy constructor, not implemented
|
|
nsTHashtable(nsTHashtable<EntryType>& toCopy) MOZ_DELETE;
|
|
|
|
/**
|
|
* Initialize the table.
|
|
* @param initSize the initial number of buckets in the hashtable
|
|
*/
|
|
void Init(uint32_t aInitSize);
|
|
|
|
// assignment operator, not implemented
|
|
nsTHashtable<EntryType>& operator= (nsTHashtable<EntryType>& toEqual) MOZ_DELETE;
|
|
};
|
|
|
|
//
|
|
// template definitions
|
|
//
|
|
|
|
template<class EntryType>
|
|
nsTHashtable<EntryType>::nsTHashtable(
|
|
nsTHashtable<EntryType>&& aOther)
|
|
: mTable(mozilla::Move(aOther.mTable))
|
|
{
|
|
// aOther shouldn't touch mTable after this, because we've stolen the table's
|
|
// pointers but not overwitten them.
|
|
MOZ_MAKE_MEM_UNDEFINED(aOther.mTable, sizeof(aOther.mTable));
|
|
|
|
// Indicate that aOther is not initialized. This will make its destructor a
|
|
// nop, which is what we want.
|
|
aOther.mTable.entrySize = 0;
|
|
}
|
|
|
|
template<class EntryType>
|
|
nsTHashtable<EntryType>::~nsTHashtable()
|
|
{
|
|
if (mTable.entrySize)
|
|
PL_DHashTableFinish(&mTable);
|
|
}
|
|
|
|
template<class EntryType>
|
|
void
|
|
nsTHashtable<EntryType>::Init(uint32_t aInitSize)
|
|
{
|
|
static PLDHashTableOps sOps =
|
|
{
|
|
::PL_DHashAllocTable,
|
|
::PL_DHashFreeTable,
|
|
s_HashKey,
|
|
s_MatchEntry,
|
|
::PL_DHashMoveEntryStub,
|
|
s_ClearEntry,
|
|
::PL_DHashFinalizeStub,
|
|
s_InitEntry
|
|
};
|
|
|
|
if (!EntryType::ALLOW_MEMMOVE) {
|
|
sOps.moveEntry = s_CopyEntry;
|
|
}
|
|
|
|
if (!PL_DHashTableInit(&mTable, &sOps, nullptr, sizeof(EntryType), aInitSize)) {
|
|
NS_RUNTIMEABORT("OOM");
|
|
}
|
|
}
|
|
|
|
// static definitions
|
|
|
|
template<class EntryType>
|
|
PLDHashNumber
|
|
nsTHashtable<EntryType>::s_HashKey(PLDHashTable *table,
|
|
const void *key)
|
|
{
|
|
return EntryType::HashKey(reinterpret_cast<const KeyTypePointer>(key));
|
|
}
|
|
|
|
template<class EntryType>
|
|
bool
|
|
nsTHashtable<EntryType>::s_MatchEntry(PLDHashTable *table,
|
|
const PLDHashEntryHdr *entry,
|
|
const void *key)
|
|
{
|
|
return ((const EntryType*) entry)->KeyEquals(
|
|
reinterpret_cast<const KeyTypePointer>(key));
|
|
}
|
|
|
|
template<class EntryType>
|
|
void
|
|
nsTHashtable<EntryType>::s_CopyEntry(PLDHashTable *table,
|
|
const PLDHashEntryHdr *from,
|
|
PLDHashEntryHdr *to)
|
|
{
|
|
EntryType* fromEntry =
|
|
const_cast<EntryType*>(reinterpret_cast<const EntryType*>(from));
|
|
|
|
new(to) EntryType(mozilla::Move(*fromEntry));
|
|
|
|
fromEntry->~EntryType();
|
|
}
|
|
|
|
template<class EntryType>
|
|
void
|
|
nsTHashtable<EntryType>::s_ClearEntry(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry)
|
|
{
|
|
reinterpret_cast<EntryType*>(entry)->~EntryType();
|
|
}
|
|
|
|
template<class EntryType>
|
|
bool
|
|
nsTHashtable<EntryType>::s_InitEntry(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry,
|
|
const void *key)
|
|
{
|
|
new(entry) EntryType(reinterpret_cast<KeyTypePointer>(key));
|
|
return true;
|
|
}
|
|
|
|
template<class EntryType>
|
|
PLDHashOperator
|
|
nsTHashtable<EntryType>::s_EnumStub(PLDHashTable *table,
|
|
PLDHashEntryHdr *entry,
|
|
uint32_t number,
|
|
void *arg)
|
|
{
|
|
// dereferences the function-pointer to the user's enumeration function
|
|
return (* reinterpret_cast<s_EnumArgs*>(arg)->userFunc)(
|
|
reinterpret_cast<EntryType*>(entry),
|
|
reinterpret_cast<s_EnumArgs*>(arg)->userArg);
|
|
}
|
|
|
|
template<class EntryType>
|
|
size_t
|
|
nsTHashtable<EntryType>::s_SizeOfStub(PLDHashEntryHdr *entry,
|
|
mozilla::MallocSizeOf mallocSizeOf,
|
|
void *arg)
|
|
{
|
|
// dereferences the function-pointer to the user's enumeration function
|
|
return (* reinterpret_cast<s_SizeOfArgs*>(arg)->userFunc)(
|
|
reinterpret_cast<EntryType*>(entry),
|
|
mallocSizeOf,
|
|
reinterpret_cast<s_SizeOfArgs*>(arg)->userArg);
|
|
}
|
|
|
|
class nsCycleCollectionTraversalCallback;
|
|
|
|
struct MOZ_STACK_CLASS nsTHashtableCCTraversalData
|
|
{
|
|
nsTHashtableCCTraversalData(nsCycleCollectionTraversalCallback& aCallback,
|
|
const char* aName,
|
|
uint32_t aFlags)
|
|
: mCallback(aCallback),
|
|
mName(aName),
|
|
mFlags(aFlags)
|
|
{
|
|
}
|
|
|
|
nsCycleCollectionTraversalCallback& mCallback;
|
|
const char* mName;
|
|
uint32_t mFlags;
|
|
};
|
|
|
|
template <class EntryType>
|
|
PLDHashOperator
|
|
ImplCycleCollectionTraverse_EnumFunc(EntryType *aEntry,
|
|
void* aUserData)
|
|
{
|
|
auto userData = static_cast<nsTHashtableCCTraversalData*>(aUserData);
|
|
|
|
ImplCycleCollectionTraverse(userData->mCallback,
|
|
*aEntry,
|
|
userData->mName,
|
|
userData->mFlags);
|
|
return PL_DHASH_NEXT;
|
|
}
|
|
|
|
template <class EntryType>
|
|
inline void
|
|
ImplCycleCollectionUnlink(nsTHashtable<EntryType>& aField)
|
|
{
|
|
aField.Clear();
|
|
}
|
|
|
|
template <class EntryType>
|
|
inline void
|
|
ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
|
|
nsTHashtable<EntryType>& aField,
|
|
const char* aName,
|
|
uint32_t aFlags = 0)
|
|
{
|
|
nsTHashtableCCTraversalData userData(aCallback, aName, aFlags);
|
|
|
|
aField.EnumerateEntries(ImplCycleCollectionTraverse_EnumFunc<EntryType>,
|
|
&userData);
|
|
}
|
|
|
|
#endif // nsTHashtable_h__
|