1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/glue/nsClassHashtable.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,117 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsClassHashtable_h__
1.10 +#define nsClassHashtable_h__
1.11 +
1.12 +#include "nsBaseHashtable.h"
1.13 +#include "nsHashKeys.h"
1.14 +#include "nsAutoPtr.h"
1.15 +
1.16 +/**
1.17 + * templated hashtable class maps keys to C++ object pointers.
1.18 + * See nsBaseHashtable for complete declaration.
1.19 + * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
1.20 + * for a complete specification.
1.21 + * @param Class the class-type being wrapped
1.22 + * @see nsInterfaceHashtable, nsClassHashtable
1.23 + */
1.24 +template<class KeyClass,class T>
1.25 +class nsClassHashtable :
1.26 + public nsBaseHashtable< KeyClass, nsAutoPtr<T>, T* >
1.27 +{
1.28 +public:
1.29 + typedef typename KeyClass::KeyType KeyType;
1.30 + typedef T* UserDataType;
1.31 + typedef nsBaseHashtable< KeyClass, nsAutoPtr<T>, T* > base_type;
1.32 +
1.33 + nsClassHashtable()
1.34 + {
1.35 + }
1.36 + explicit nsClassHashtable(uint32_t aInitSize)
1.37 + : nsBaseHashtable<KeyClass,nsAutoPtr<T>,T*>(aInitSize)
1.38 + {
1.39 + }
1.40 +
1.41 + /**
1.42 + * @copydoc nsBaseHashtable::Get
1.43 + * @param pData if the key doesn't exist, pData will be set to nullptr.
1.44 + */
1.45 + bool Get(KeyType aKey, UserDataType* pData) const;
1.46 +
1.47 + /**
1.48 + * @copydoc nsBaseHashtable::Get
1.49 + * @returns nullptr if the key is not present.
1.50 + */
1.51 + UserDataType Get(KeyType aKey) const;
1.52 +
1.53 + /**
1.54 + * Remove the entry for the given key from the hashtable and return it in
1.55 + * aOut. If the key is not in the hashtable, aOut's pointer is set to
1.56 + * nullptr.
1.57 + *
1.58 + * Normally, an entry is deleted when it's removed from an nsClassHashtable,
1.59 + * but this function transfers ownership of the entry back to the caller
1.60 + * through aOut -- the entry will be deleted when aOut goes out of scope.
1.61 + *
1.62 + * @param aKey the key to get and remove from the hashtable
1.63 + */
1.64 + void RemoveAndForget(KeyType aKey, nsAutoPtr<T> &aOut);
1.65 +};
1.66 +
1.67 +//
1.68 +// nsClassHashtable definitions
1.69 +//
1.70 +
1.71 +template<class KeyClass,class T>
1.72 +bool
1.73 +nsClassHashtable<KeyClass,T>::Get(KeyType aKey, T** retVal) const
1.74 +{
1.75 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.76 +
1.77 + if (ent)
1.78 + {
1.79 + if (retVal)
1.80 + *retVal = ent->mData;
1.81 +
1.82 + return true;
1.83 + }
1.84 +
1.85 + if (retVal)
1.86 + *retVal = nullptr;
1.87 +
1.88 + return false;
1.89 +}
1.90 +
1.91 +template<class KeyClass,class T>
1.92 +T*
1.93 +nsClassHashtable<KeyClass,T>::Get(KeyType aKey) const
1.94 +{
1.95 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.96 +
1.97 + if (!ent)
1.98 + return nullptr;
1.99 +
1.100 + return ent->mData;
1.101 +}
1.102 +
1.103 +template<class KeyClass,class T>
1.104 +void
1.105 +nsClassHashtable<KeyClass,T>::RemoveAndForget(KeyType aKey, nsAutoPtr<T> &aOut)
1.106 +{
1.107 + aOut = nullptr;
1.108 + nsAutoPtr<T> ptr;
1.109 +
1.110 + typename base_type::EntryType *ent = this->GetEntry(aKey);
1.111 + if (!ent)
1.112 + return;
1.113 +
1.114 + // Transfer ownership from ent->mData into aOut.
1.115 + aOut = ent->mData;
1.116 +
1.117 + this->Remove(aKey);
1.118 +}
1.119 +
1.120 +#endif // nsClassHashtable_h__
