michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=8 sts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * Class for representing MozMap arguments.  This is an nsTHashtable
michael@0:  * under the hood, but we don't want to leak that implementation
michael@0:  * detail.
michael@0:  */
michael@0: 
michael@0: #ifndef mozilla_dom_MozMap_h
michael@0: #define mozilla_dom_MozMap_h
michael@0: 
michael@0: #include "nsTHashtable.h"
michael@0: #include "nsHashKeys.h"
michael@0: #include "nsStringGlue.h"
michael@0: #include "nsTArray.h"
michael@0: #include "mozilla/Move.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: namespace binding_detail {
michael@0: template<typename DataType>
michael@0: class MozMapEntry : public nsStringHashKey
michael@0: {
michael@0: public:
michael@0:   MozMapEntry(const nsAString* aKeyTypePointer)
michael@0:     : nsStringHashKey(aKeyTypePointer)
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   // Move constructor so we can do MozMaps of MozMaps.
michael@0:   MozMapEntry(MozMapEntry<DataType>&& aOther)
michael@0:     : nsStringHashKey(aOther),
michael@0:       mData(Move(aOther.mData))
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   DataType mData;
michael@0: };
michael@0: } // namespace binding_detail
michael@0: 
michael@0: template<typename DataType>
michael@0: class MozMap : protected nsTHashtable<binding_detail::MozMapEntry<DataType>>
michael@0: {
michael@0: public:
michael@0:   typedef typename binding_detail::MozMapEntry<DataType> EntryType;
michael@0:   typedef nsTHashtable<EntryType> Base;
michael@0:   typedef MozMap<DataType> SelfType;
michael@0: 
michael@0:   MozMap()
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   // Move constructor so we can do MozMap of MozMap.
michael@0:   MozMap(SelfType&& aOther) :
michael@0:     Base(Move(aOther))
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   // The return value is only safe to use until an AddEntry call.
michael@0:   const DataType& Get(const nsAString& aKey) const
michael@0:   {
michael@0:     const EntryType* ent = this->GetEntry(aKey);
michael@0:     MOZ_ASSERT(ent, "Why are you using a key we didn't claim to have?");
michael@0:     return ent->mData;
michael@0:   }
michael@0: 
michael@0:   // The return value is only safe to use until an AddEntry call.
michael@0:   const DataType* GetIfExists(const nsAString& aKey) const
michael@0:   {
michael@0:     const EntryType* ent = this->GetEntry(aKey);
michael@0:     if (!ent) {
michael@0:       return nullptr;
michael@0:     }
michael@0:     return &ent->mData;
michael@0:   }
michael@0: 
michael@0:   void GetKeys(nsTArray<nsString>& aKeys) const {
michael@0:     // Sadly, EnumerateEntries is not a const method
michael@0:     const_cast<SelfType*>(this)->EnumerateEntries(KeyEnumerator, &aKeys);
michael@0:   }
michael@0: 
michael@0:   // XXXbz we expose this generic enumerator for tracing.  Otherwise we'd end up
michael@0:   // with a dependency on BindingUtils.h here for the SequenceTracer bits.
michael@0:   typedef PLDHashOperator (* Enumerator)(DataType* aValue, void* aClosure);
michael@0:   void EnumerateValues(Enumerator aEnumerator, void *aClosure)
michael@0:   {
michael@0:     ValueEnumClosure args = { aEnumerator, aClosure };
michael@0:     this->EnumerateEntries(ValueEnumerator, &args);
michael@0:   }
michael@0: 
michael@0:   DataType* AddEntry(const nsAString& aKey) NS_WARN_UNUSED_RESULT
michael@0:   {
michael@0:     // XXXbz can't just use fallible_t() because our superclass has a
michael@0:     // private typedef by that name.
michael@0:     EntryType* ent = this->PutEntry(aKey, mozilla::fallible_t());
michael@0:     if (!ent) {
michael@0:       return nullptr;
michael@0:     }
michael@0:     return &ent->mData;
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   static PLDHashOperator
michael@0:   KeyEnumerator(EntryType* aEntry, void* aClosure)
michael@0:   {
michael@0:     nsTArray<nsString>& keys = *static_cast<nsTArray<nsString>*>(aClosure);
michael@0:     keys.AppendElement(aEntry->GetKey());
michael@0:     return PL_DHASH_NEXT;
michael@0:   }
michael@0: 
michael@0:   struct ValueEnumClosure {
michael@0:     Enumerator mEnumerator;
michael@0:     void* mClosure;
michael@0:   };
michael@0: 
michael@0:   static PLDHashOperator
michael@0:   ValueEnumerator(EntryType* aEntry, void* aClosure)
michael@0:   {
michael@0:     ValueEnumClosure* enumClosure = static_cast<ValueEnumClosure*>(aClosure);
michael@0:     return enumClosure->mEnumerator(&aEntry->mData, enumClosure->mClosure);
michael@0:   }
michael@0: };
michael@0: 
michael@0: } // namespace dom
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // mozilla_dom_MozMap_h