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
|
/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <stddef.h>
#include <string>
#include <utility>
#include <vector>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/strings.h>
using Range = std::pair<size_t, size_t>;
class RangeSet {
public:
RangeSet() : blocks_(0) {}
explicit RangeSet(std::vector<Range>&& pairs) {
CHECK_NE(pairs.size(), static_cast<size_t>(0)) << "Invalid number of tokens";
// Sanity check the input.
size_t result = 0;
for (const auto& range : pairs) {
CHECK_LT(range.first, range.second)
<< "Empty or negative range: " << range.first << ", " << range.second;
size_t sz = range.second - range.first;
CHECK_LE(result, SIZE_MAX - sz) << "RangeSet size overflow";
result += sz;
}
ranges_ = pairs;
blocks_ = result;
}
static RangeSet Parse(const std::string& range_text) {
std::vector<std::string> pieces = android::base::Split(range_text, ",");
CHECK_GE(pieces.size(), static_cast<size_t>(3)) << "Invalid range text: " << range_text;
size_t num;
CHECK(android::base::ParseUint(pieces[0], &num, static_cast<size_t>(INT_MAX)))
<< "Failed to parse the number of tokens: " << range_text;
CHECK_NE(num, static_cast<size_t>(0)) << "Invalid number of tokens: " << range_text;
CHECK_EQ(num % 2, static_cast<size_t>(0)) << "Number of tokens must be even: " << range_text;
CHECK_EQ(num, pieces.size() - 1) << "Mismatching number of tokens: " << range_text;
std::vector<Range> pairs;
for (size_t i = 0; i < num; i += 2) {
size_t first;
CHECK(android::base::ParseUint(pieces[i + 1], &first, static_cast<size_t>(INT_MAX)));
size_t second;
CHECK(android::base::ParseUint(pieces[i + 2], &second, static_cast<size_t>(INT_MAX)));
pairs.emplace_back(first, second);
}
return RangeSet(std::move(pairs));
}
// Get the block number for the i-th (starting from 0) block in the RangeSet.
size_t GetBlockNumber(size_t idx) const {
CHECK_LT(idx, blocks_) << "Out of bound index " << idx << " (total blocks: " << blocks_ << ")";
for (const auto& range : ranges_) {
if (idx < range.second - range.first) {
return range.first + idx;
}
idx -= (range.second - range.first);
}
CHECK(false) << "Failed to find block number for index " << idx;
return 0; // Unreachable, but to make compiler happy.
}
// RangeSet has half-closed half-open bounds. For example, "3,5" contains blocks 3 and 4. So "3,5"
// and "5,7" are not overlapped.
bool Overlaps(const RangeSet& other) const {
for (const auto& range : ranges_) {
size_t start = range.first;
size_t end = range.second;
for (const auto& other_range : other.ranges_) {
size_t other_start = other_range.first;
size_t other_end = other_range.second;
// [start, end) vs [other_start, other_end)
if (!(other_start >= end || start >= other_end)) {
return true;
}
}
}
return false;
}
// size() gives the number of Range's in this RangeSet.
size_t size() const {
return ranges_.size();
}
// blocks() gives the number of all blocks in this RangeSet.
size_t blocks() const {
return blocks_;
}
// We provide const iterators only.
std::vector<Range>::const_iterator cbegin() const {
return ranges_.cbegin();
}
std::vector<Range>::const_iterator cend() const {
return ranges_.cend();
}
// Need to provide begin()/end() since range-based loop expects begin()/end().
std::vector<Range>::const_iterator begin() const {
return ranges_.cbegin();
}
std::vector<Range>::const_iterator end() const {
return ranges_.cend();
}
// Reverse const iterators for MoveRange().
std::vector<Range>::const_reverse_iterator crbegin() const {
return ranges_.crbegin();
}
std::vector<Range>::const_reverse_iterator crend() const {
return ranges_.crend();
}
const Range& operator[](size_t i) const {
return ranges_[i];
}
bool operator==(const RangeSet& other) const {
// The orders of Range's matter. "4,1,5,8,10" != "4,8,10,1,5".
return (ranges_ == other.ranges_);
}
bool operator!=(const RangeSet& other) const {
return ranges_ != other.ranges_;
}
private:
// Actual limit for each value and the total number are both INT_MAX.
std::vector<Range> ranges_;
size_t blocks_;
};
|
