/usr/include/thunderbird/nsCheapSets.h is in thunderbird-dev 1:52.8.0-1~deb8u1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 | /* -*- 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 __nsCheapSets_h__
#define __nsCheapSets_h__
#include "nsTHashtable.h"
#include <stdint.h>
enum nsCheapSetOperator
{
OpNext = 0, // enumerator says continue
OpRemove = 1, // enumerator says remove and continue
};
/**
* A set that takes up minimal size when there are 0 or 1 entries in the set.
* Use for cases where sizes of 0 and 1 are even slightly common.
*/
template<typename EntryType>
class nsCheapSet
{
public:
typedef typename EntryType::KeyType KeyType;
typedef nsCheapSetOperator (*Enumerator)(EntryType* aEntry, void* userArg);
nsCheapSet() : mState(ZERO) {}
~nsCheapSet() { Clear(); }
/**
* Remove all entries.
*/
void Clear()
{
switch (mState) {
case ZERO:
break;
case ONE:
GetSingleEntry()->~EntryType();
break;
case MANY:
delete mUnion.table;
break;
default:
NS_NOTREACHED("bogus state");
break;
}
mState = ZERO;
}
void Put(const KeyType aVal);
void Remove(const KeyType aVal);
bool Contains(const KeyType aVal)
{
switch (mState) {
case ZERO:
return false;
case ONE:
return GetSingleEntry()->KeyEquals(EntryType::KeyToPointer(aVal));
case MANY:
return !!mUnion.table->GetEntry(aVal);
default:
NS_NOTREACHED("bogus state");
return false;
}
}
uint32_t EnumerateEntries(Enumerator aEnumFunc, void* aUserArg)
{
switch (mState) {
case ZERO:
return 0;
case ONE:
if (aEnumFunc(GetSingleEntry(), aUserArg) == OpRemove) {
GetSingleEntry()->~EntryType();
mState = ZERO;
}
return 1;
case MANY: {
uint32_t n = mUnion.table->Count();
for (auto iter = mUnion.table->Iter(); !iter.Done(); iter.Next()) {
auto entry = static_cast<EntryType*>(iter.Get());
if (aEnumFunc(entry, aUserArg) == OpRemove) {
iter.Remove();
}
}
return n;
}
default:
NS_NOTREACHED("bogus state");
return 0;
}
}
private:
EntryType* GetSingleEntry()
{
return reinterpret_cast<EntryType*>(&mUnion.singleEntry[0]);
}
enum SetState
{
ZERO,
ONE,
MANY
};
union
{
nsTHashtable<EntryType>* table;
char singleEntry[sizeof(EntryType)];
} mUnion;
enum SetState mState;
};
template<typename EntryType>
void
nsCheapSet<EntryType>::Put(const KeyType aVal)
{
switch (mState) {
case ZERO:
new (GetSingleEntry()) EntryType(EntryType::KeyToPointer(aVal));
mState = ONE;
return;
case ONE: {
nsTHashtable<EntryType>* table = new nsTHashtable<EntryType>();
EntryType* entry = GetSingleEntry();
table->PutEntry(entry->GetKey());
entry->~EntryType();
mUnion.table = table;
mState = MANY;
}
MOZ_FALLTHROUGH;
case MANY:
mUnion.table->PutEntry(aVal);
return;
default:
NS_NOTREACHED("bogus state");
return;
}
}
template<typename EntryType>
void
nsCheapSet<EntryType>::Remove(const KeyType aVal)
{
switch (mState) {
case ZERO:
break;
case ONE:
if (Contains(aVal)) {
GetSingleEntry()->~EntryType();
mState = ZERO;
}
break;
case MANY:
mUnion.table->RemoveEntry(aVal);
break;
default:
NS_NOTREACHED("bogus state");
break;
}
}
#endif
|