1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/bindings/MozMap.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,132 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/**
1.11 + * Class for representing MozMap arguments. This is an nsTHashtable
1.12 + * under the hood, but we don't want to leak that implementation
1.13 + * detail.
1.14 + */
1.15 +
1.16 +#ifndef mozilla_dom_MozMap_h
1.17 +#define mozilla_dom_MozMap_h
1.18 +
1.19 +#include "nsTHashtable.h"
1.20 +#include "nsHashKeys.h"
1.21 +#include "nsStringGlue.h"
1.22 +#include "nsTArray.h"
1.23 +#include "mozilla/Move.h"
1.24 +
1.25 +namespace mozilla {
1.26 +namespace dom {
1.27 +
1.28 +namespace binding_detail {
1.29 +template<typename DataType>
1.30 +class MozMapEntry : public nsStringHashKey
1.31 +{
1.32 +public:
1.33 + MozMapEntry(const nsAString* aKeyTypePointer)
1.34 + : nsStringHashKey(aKeyTypePointer)
1.35 + {
1.36 + }
1.37 +
1.38 + // Move constructor so we can do MozMaps of MozMaps.
1.39 + MozMapEntry(MozMapEntry<DataType>&& aOther)
1.40 + : nsStringHashKey(aOther),
1.41 + mData(Move(aOther.mData))
1.42 + {
1.43 + }
1.44 +
1.45 + DataType mData;
1.46 +};
1.47 +} // namespace binding_detail
1.48 +
1.49 +template<typename DataType>
1.50 +class MozMap : protected nsTHashtable<binding_detail::MozMapEntry<DataType>>
1.51 +{
1.52 +public:
1.53 + typedef typename binding_detail::MozMapEntry<DataType> EntryType;
1.54 + typedef nsTHashtable<EntryType> Base;
1.55 + typedef MozMap<DataType> SelfType;
1.56 +
1.57 + MozMap()
1.58 + {
1.59 + }
1.60 +
1.61 + // Move constructor so we can do MozMap of MozMap.
1.62 + MozMap(SelfType&& aOther) :
1.63 + Base(Move(aOther))
1.64 + {
1.65 + }
1.66 +
1.67 + // The return value is only safe to use until an AddEntry call.
1.68 + const DataType& Get(const nsAString& aKey) const
1.69 + {
1.70 + const EntryType* ent = this->GetEntry(aKey);
1.71 + MOZ_ASSERT(ent, "Why are you using a key we didn't claim to have?");
1.72 + return ent->mData;
1.73 + }
1.74 +
1.75 + // The return value is only safe to use until an AddEntry call.
1.76 + const DataType* GetIfExists(const nsAString& aKey) const
1.77 + {
1.78 + const EntryType* ent = this->GetEntry(aKey);
1.79 + if (!ent) {
1.80 + return nullptr;
1.81 + }
1.82 + return &ent->mData;
1.83 + }
1.84 +
1.85 + void GetKeys(nsTArray<nsString>& aKeys) const {
1.86 + // Sadly, EnumerateEntries is not a const method
1.87 + const_cast<SelfType*>(this)->EnumerateEntries(KeyEnumerator, &aKeys);
1.88 + }
1.89 +
1.90 + // XXXbz we expose this generic enumerator for tracing. Otherwise we'd end up
1.91 + // with a dependency on BindingUtils.h here for the SequenceTracer bits.
1.92 + typedef PLDHashOperator (* Enumerator)(DataType* aValue, void* aClosure);
1.93 + void EnumerateValues(Enumerator aEnumerator, void *aClosure)
1.94 + {
1.95 + ValueEnumClosure args = { aEnumerator, aClosure };
1.96 + this->EnumerateEntries(ValueEnumerator, &args);
1.97 + }
1.98 +
1.99 + DataType* AddEntry(const nsAString& aKey) NS_WARN_UNUSED_RESULT
1.100 + {
1.101 + // XXXbz can't just use fallible_t() because our superclass has a
1.102 + // private typedef by that name.
1.103 + EntryType* ent = this->PutEntry(aKey, mozilla::fallible_t());
1.104 + if (!ent) {
1.105 + return nullptr;
1.106 + }
1.107 + return &ent->mData;
1.108 + }
1.109 +
1.110 +private:
1.111 + static PLDHashOperator
1.112 + KeyEnumerator(EntryType* aEntry, void* aClosure)
1.113 + {
1.114 + nsTArray<nsString>& keys = *static_cast<nsTArray<nsString>*>(aClosure);
1.115 + keys.AppendElement(aEntry->GetKey());
1.116 + return PL_DHASH_NEXT;
1.117 + }
1.118 +
1.119 + struct ValueEnumClosure {
1.120 + Enumerator mEnumerator;
1.121 + void* mClosure;
1.122 + };
1.123 +
1.124 + static PLDHashOperator
1.125 + ValueEnumerator(EntryType* aEntry, void* aClosure)
1.126 + {
1.127 + ValueEnumClosure* enumClosure = static_cast<ValueEnumClosure*>(aClosure);
1.128 + return enumClosure->mEnumerator(&aEntry->mData, enumClosure->mClosure);
1.129 + }
1.130 +};
1.131 +
1.132 +} // namespace dom
1.133 +} // namespace mozilla
1.134 +
1.135 +#endif // mozilla_dom_MozMap_h
