1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_CMDLINE_MEMORY_REPRESENTATION_H_
18 #define ART_CMDLINE_MEMORY_REPRESENTATION_H_
19 
20 #include <assert.h>
21 #include <ostream>
22 #include <string>
23 
24 #include "base/bit_utils.h"
25 
26 namespace art {
27 
28 // An integral representation of bytes of memory.
29 // The underlying runtime size_t value is guaranteed to be a multiple of Divisor.
30 template <size_t kDivisor = 1024>
31 struct Memory {
32   static_assert(IsPowerOfTwo(kDivisor), "Divisor must be a power of 2");
33 
FromBytesMemory34   static Memory<kDivisor> FromBytes(size_t bytes) {
35     assert(bytes % kDivisor == 0);
36     return Memory<kDivisor>(bytes);
37   }
38 
MemoryMemory39   Memory() : Value(0u) {}
MemoryMemory40   Memory(size_t value) : Value(value) {  // NOLINT [runtime/explicit] [5]
41     assert(value % kDivisor == 0);
42   }
size_tMemory43   operator size_t() const { return Value; }
44 
ToBytesMemory45   size_t ToBytes() const {
46     return Value;
47   }
48 
NameMemory49   static const char* Name() {
50     static std::string str;
51     if (str.empty()) {
52       str = "Memory<" + std::to_string(kDivisor) + '>';
53     }
54 
55     return str.c_str();
56   }
57 
58   size_t Value;
59 };
60 
61 template <size_t kDivisor>
62 std::ostream& operator<<(std::ostream& stream, Memory<kDivisor> memory) {
63   return stream << memory.Value << '*' << kDivisor;
64 }
65 
66 using MemoryKiB = Memory<1024>;
67 
68 }  // namespace art
69 
70 #endif  // ART_CMDLINE_MEMORY_REPRESENTATION_H_
71