mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-10-30 21:55:31 +00:00
330 lines
9.9 KiB
C++
330 lines
9.9 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* 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 nsBaseHashtable_h__
|
|
#define nsBaseHashtable_h__
|
|
|
|
#include "mozilla/MemoryReporting.h"
|
|
#include "mozilla/Move.h"
|
|
#include "nsTHashtable.h"
|
|
#include "prlock.h"
|
|
#include "nsDebug.h"
|
|
|
|
// These are the codes returned by |EnumReadFunction| and |EnumFunction|, which
|
|
// control the behavior of EnumerateRead() and Enumerate(). The PLD/PL_D prefix
|
|
// is because they originated in PLDHashTable, but that class no longer uses
|
|
// them.
|
|
enum PLDHashOperator
|
|
{
|
|
PL_DHASH_NEXT = 0, // enumerator says continue
|
|
PL_DHASH_STOP = 1, // enumerator says stop
|
|
PL_DHASH_REMOVE = 2 // enumerator says remove
|
|
};
|
|
|
|
template<class KeyClass, class DataType, class UserDataType>
|
|
class nsBaseHashtable; // forward declaration
|
|
|
|
/**
|
|
* the private nsTHashtable::EntryType class used by nsBaseHashtable
|
|
* @see nsTHashtable for the specification of this class
|
|
* @see nsBaseHashtable for template parameters
|
|
*/
|
|
template<class KeyClass, class DataType>
|
|
class nsBaseHashtableET : public KeyClass
|
|
{
|
|
public:
|
|
DataType mData;
|
|
friend class nsTHashtable<nsBaseHashtableET<KeyClass, DataType>>;
|
|
|
|
private:
|
|
typedef typename KeyClass::KeyType KeyType;
|
|
typedef typename KeyClass::KeyTypePointer KeyTypePointer;
|
|
|
|
explicit nsBaseHashtableET(KeyTypePointer aKey);
|
|
nsBaseHashtableET(nsBaseHashtableET<KeyClass, DataType>&& aToMove);
|
|
~nsBaseHashtableET();
|
|
};
|
|
|
|
/**
|
|
* templated hashtable for simple data types
|
|
* This class manages simple data types that do not need construction or
|
|
* destruction.
|
|
*
|
|
* @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
|
|
* for a complete specification.
|
|
* @param DataType the datatype stored in the hashtable,
|
|
* for example, uint32_t or nsCOMPtr. If UserDataType is not the same,
|
|
* DataType must implicitly cast to UserDataType
|
|
* @param UserDataType the user sees, for example uint32_t or nsISupports*
|
|
*/
|
|
template<class KeyClass, class DataType, class UserDataType>
|
|
class nsBaseHashtable
|
|
: protected nsTHashtable<nsBaseHashtableET<KeyClass, DataType>>
|
|
{
|
|
typedef mozilla::fallible_t fallible_t;
|
|
|
|
public:
|
|
typedef typename KeyClass::KeyType KeyType;
|
|
typedef nsBaseHashtableET<KeyClass, DataType> EntryType;
|
|
|
|
using nsTHashtable<EntryType>::Contains;
|
|
|
|
nsBaseHashtable() {}
|
|
explicit nsBaseHashtable(uint32_t aInitLength)
|
|
: nsTHashtable<EntryType>(aInitLength)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* Return the number of entries in the table.
|
|
* @return number of entries
|
|
*/
|
|
uint32_t Count() const { return nsTHashtable<EntryType>::Count(); }
|
|
|
|
/**
|
|
* retrieve the value for a key.
|
|
* @param aKey the key to retreive
|
|
* @param aData data associated with this key will be placed at this
|
|
* pointer. If you only need to check if the key exists, aData
|
|
* may be null.
|
|
* @return true if the key exists. If key does not exist, aData is not
|
|
* modified.
|
|
*/
|
|
bool Get(KeyType aKey, UserDataType* aData) const
|
|
{
|
|
EntryType* ent = this->GetEntry(aKey);
|
|
if (!ent) {
|
|
return false;
|
|
}
|
|
|
|
if (aData) {
|
|
*aData = ent->mData;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* For pointer types, get the value, returning nullptr if the entry is not
|
|
* present in the table.
|
|
*
|
|
* @param aKey the key to retrieve
|
|
* @return The found value, or nullptr if no entry was found with the given key.
|
|
* @note If nullptr values are stored in the table, it is not possible to
|
|
* distinguish between a nullptr value and a missing entry.
|
|
*/
|
|
UserDataType Get(KeyType aKey) const
|
|
{
|
|
EntryType* ent = this->GetEntry(aKey);
|
|
if (!ent) {
|
|
return 0;
|
|
}
|
|
|
|
return ent->mData;
|
|
}
|
|
|
|
/**
|
|
* put a new value for the associated key
|
|
* @param aKey the key to put
|
|
* @param aData the new data
|
|
* @return always true, unless memory allocation failed
|
|
*/
|
|
void Put(KeyType aKey, const UserDataType& aData)
|
|
{
|
|
if (!Put(aKey, aData, mozilla::fallible)) {
|
|
NS_ABORT_OOM(this->mTable.EntrySize() * this->mTable.EntryCount());
|
|
}
|
|
}
|
|
|
|
MOZ_WARN_UNUSED_RESULT bool Put(KeyType aKey, const UserDataType& aData,
|
|
const fallible_t&)
|
|
{
|
|
EntryType* ent = this->PutEntry(aKey);
|
|
if (!ent) {
|
|
return false;
|
|
}
|
|
|
|
ent->mData = aData;
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* remove the data for the associated key
|
|
* @param aKey the key to remove from the hashtable
|
|
*/
|
|
void Remove(KeyType aKey) { this->RemoveEntry(aKey); }
|
|
|
|
/**
|
|
* function type provided by the application for enumeration.
|
|
* @param aKey the key being enumerated
|
|
* @param aData data being enumerated
|
|
* @param aUserArg passed unchanged from Enumerate
|
|
* @return either
|
|
* @link PLDHashOperator::PL_DHASH_NEXT PL_DHASH_NEXT @endlink or
|
|
* @link PLDHashOperator::PL_DHASH_STOP PL_DHASH_STOP @endlink
|
|
*/
|
|
typedef PLDHashOperator (*EnumReadFunction)(KeyType aKey,
|
|
UserDataType aData,
|
|
void* aUserArg);
|
|
|
|
/**
|
|
* enumerate entries in the hashtable, without allowing changes
|
|
* WARNING: this function is deprecated. Please use Iterator instead.
|
|
* @param aEnumFunc enumeration callback
|
|
* @param aUserArg passed unchanged to the EnumReadFunction
|
|
*/
|
|
uint32_t EnumerateRead(EnumReadFunction aEnumFunc, void* aUserArg) const
|
|
{
|
|
uint32_t n = 0;
|
|
for (auto iter = this->mTable.ConstIter(); !iter.Done(); iter.Next()) {
|
|
auto entry = static_cast<EntryType*>(iter.Get());
|
|
PLDHashOperator op = aEnumFunc(entry->GetKey(), entry->mData, aUserArg);
|
|
n++;
|
|
MOZ_ASSERT(!(op & PL_DHASH_REMOVE));
|
|
if (op & PL_DHASH_STOP) {
|
|
break;
|
|
}
|
|
}
|
|
return n;
|
|
}
|
|
|
|
/**
|
|
* function type provided by the application for enumeration.
|
|
* @param aKey the key being enumerated
|
|
* @param aData Reference to data being enumerated, may be altered. e.g. for
|
|
* nsInterfaceHashtable this is an nsCOMPtr reference...
|
|
* @parm aUserArg passed unchanged from Enumerate
|
|
* @return bitflag combination of
|
|
* @link PLDHashOperator::PL_DHASH_REMOVE @endlink,
|
|
* @link PLDHashOperator::PL_DHASH_NEXT PL_DHASH_NEXT @endlink, or
|
|
* @link PLDHashOperator::PL_DHASH_STOP PL_DHASH_STOP @endlink
|
|
*/
|
|
typedef PLDHashOperator (*EnumFunction)(KeyType aKey,
|
|
DataType& aData,
|
|
void* aUserArg);
|
|
|
|
/**
|
|
* enumerate entries in the hashtable, allowing changes.
|
|
* WARNING: this function is deprecated. Please use Iterator and/or
|
|
* MutatingIterator instead.
|
|
* @param aEnumFunc enumeration callback
|
|
* @param aUserArg passed unchanged to the EnumFunction
|
|
*/
|
|
uint32_t Enumerate(EnumFunction aEnumFunc, void* aUserArg)
|
|
{
|
|
uint32_t n = 0;
|
|
for (auto iter = this->mTable.Iter(); !iter.Done(); iter.Next()) {
|
|
auto entry = static_cast<EntryType*>(iter.Get());
|
|
PLDHashOperator op = aEnumFunc(entry->GetKey(), entry->mData, aUserArg);
|
|
n++;
|
|
if (op & PL_DHASH_REMOVE) {
|
|
iter.Remove();
|
|
}
|
|
if (op & PL_DHASH_STOP) {
|
|
break;
|
|
}
|
|
}
|
|
return n;
|
|
}
|
|
|
|
// This is an iterator that also allows entry removal. Example usage:
|
|
//
|
|
// for (auto iter = table.Iter(); !iter.Done(); iter.Next()) {
|
|
// const KeyType key = iter.Key();
|
|
// const UserDataType data = iter.UserData();
|
|
// // or
|
|
// const DataType& data = iter.Data();
|
|
// // ... do stuff with |key| and/or |data| ...
|
|
// // ... possibly call iter.Remove() once ...
|
|
// }
|
|
//
|
|
class Iterator : public PLDHashTable::Iterator
|
|
{
|
|
public:
|
|
typedef PLDHashTable::Iterator Base;
|
|
|
|
explicit Iterator(nsBaseHashtable* aTable) : Base(&aTable->mTable) {}
|
|
Iterator(Iterator&& aOther) : Base(aOther.mTable) {}
|
|
~Iterator() {}
|
|
|
|
KeyType Key() const { return static_cast<EntryType*>(Get())->GetKey(); }
|
|
UserDataType UserData() const
|
|
{
|
|
return static_cast<EntryType*>(Get())->mData;
|
|
}
|
|
DataType& Data() const { return static_cast<EntryType*>(Get())->mData; }
|
|
|
|
private:
|
|
Iterator() = delete;
|
|
Iterator(const Iterator&) = delete;
|
|
Iterator& operator=(const Iterator&) = delete;
|
|
Iterator& operator=(const Iterator&&) = delete;
|
|
};
|
|
|
|
Iterator Iter() { return Iterator(this); }
|
|
|
|
Iterator ConstIter() const
|
|
{
|
|
return Iterator(const_cast<nsBaseHashtable*>(this));
|
|
}
|
|
|
|
/**
|
|
* reset the hashtable, removing all entries
|
|
*/
|
|
void Clear() { nsTHashtable<EntryType>::Clear(); }
|
|
|
|
/**
|
|
* Measure the size of the table's entry storage. The size of things pointed
|
|
* to by entries must be measured separately; hence the "Shallow" prefix.
|
|
*
|
|
* @param aMallocSizeOf the function used to measure heap-allocated blocks
|
|
* @return the summed size of the table's storage
|
|
*/
|
|
size_t ShallowSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
|
|
{
|
|
return this->mTable.ShallowSizeOfExcludingThis(aMallocSizeOf);
|
|
}
|
|
|
|
/**
|
|
* Like ShallowSizeOfExcludingThis, but includes sizeof(*this).
|
|
*/
|
|
size_t ShallowSizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
|
|
{
|
|
return aMallocSizeOf(this) + ShallowSizeOfExcludingThis(aMallocSizeOf);
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
using nsTHashtable<EntryType>::MarkImmutable;
|
|
#endif
|
|
};
|
|
|
|
//
|
|
// nsBaseHashtableET definitions
|
|
//
|
|
|
|
template<class KeyClass, class DataType>
|
|
nsBaseHashtableET<KeyClass, DataType>::nsBaseHashtableET(KeyTypePointer aKey)
|
|
: KeyClass(aKey)
|
|
, mData()
|
|
{
|
|
}
|
|
|
|
template<class KeyClass, class DataType>
|
|
nsBaseHashtableET<KeyClass, DataType>::nsBaseHashtableET(
|
|
nsBaseHashtableET<KeyClass, DataType>&& aToMove)
|
|
: KeyClass(mozilla::Move(aToMove))
|
|
, mData(mozilla::Move(aToMove.mData))
|
|
{
|
|
}
|
|
|
|
template<class KeyClass, class DataType>
|
|
nsBaseHashtableET<KeyClass, DataType>::~nsBaseHashtableET()
|
|
{
|
|
}
|
|
|
|
#endif // nsBaseHashtable_h__
|