GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/bigqueue.h
Date: 2025-12-28 02:35:52
Exec Total Coverage
Lines: 76 77 98.7%
Branches: 23 32 71.9%
Line Branch Exec Source
1 /**
2 * This file is part of the CernVM File System.
3 *
4 * Similar to bigvector, but queue semantics. Used by the negative entry
5 * tracker. Allocates with mmap in order to avoid memory fragmentation.
6 */
7
8 #ifndef CVMFS_BIGQUEUE_H_
9 #define CVMFS_BIGQUEUE_H_
10
11 #include <algorithm>
12 #include <cassert>
13 #include <cstdlib>
14 #include <new>
15
16 #include "util/smalloc.h"
17
18 template<class Item>
19 class BigQueue {
20 public:
21 663 BigQueue() {
22 663 Alloc(kNumInit);
23 663 size_ = 0;
24 663 }
25
26 explicit BigQueue(const size_t num_items) {
27 const size_t min_items = kNumInit;
28 Alloc(std::max(num_items, min_items));
29 size_ = 0;
30 }
31
32 2 BigQueue(const BigQueue<Item> &other) { CopyFrom(other); }
33
34 138 BigQueue<Item> &operator=(const BigQueue<Item> &other) {
35
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 138 if (&other == this)
36 ✗ return *this;
37
38 138 Dealloc();
39 138 CopyFrom(other);
40 138 return *this;
41 }
42
43 650 ~BigQueue() { Dealloc(); }
44
45 40088028 void PushBack(const Item &item) {
46
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 40088028 if (GetAvailableSpace() == 0) {
47 506 Migrate(1.9 * static_cast<float>(capacity_));
48
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 506 assert(GetAvailableSpace() > 0);
49 }
50
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 40088028 new (head_ + size_) Item(item);
51 40088028 size_++;
52 40088028 }
53
54 40003045 void PopFront() {
55
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 40003045 assert(!IsEmpty());
56 40003045 head_++;
57 40003045 size_--;
58
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 40003045 if ((size_ > kCompactThreshold) && (size_ < (capacity_ / 2)))
59 102 Migrate(static_cast<int>(static_cast<float>(capacity_ * 0.6)));
60 40003045 }
61
62 40087505 bool Peek(Item **item) {
63
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 40087505 if (IsEmpty())
64 223 return false;
65 40087282 *item = head_;
66 40087282 return true;
67 }
68
69 80090550 bool IsEmpty() const { return size_ == 0; }
70
71 138 void Clear() {
72 138 Dealloc();
73 138 Alloc(kNumInit);
74 138 }
75
76 52780 size_t size() const { return size_; }
77 20 size_t capacity() const { return capacity_; }
78
79 private:
80 static const size_t kNumInit = 64;
81 static const size_t kCompactThreshold = 64;
82
83 50174051 size_t GetHeadOffset() const { return head_ - buffer_; }
84 40088534 size_t GetAvailableSpace() const {
85 40088534 return capacity_ - (size_ + GetHeadOffset());
86 }
87
88 1549 void Alloc(const size_t num_elements) {
89 1549 size_t num_bytes = sizeof(Item) * num_elements;
90 1549 buffer_ = static_cast<Item *>(smmap(num_bytes));
91 1549 capacity_ = num_elements;
92 1549 head_ = buffer_;
93 1549 }
94
95 926 void Dealloc() {
96 926 FreeBuffer(buffer_, GetHeadOffset() + size_);
97 926 buffer_ = NULL;
98 926 head_ = NULL;
99 926 capacity_ = 0;
100 926 size_ = 0;
101 926 }
102
103 608 void Migrate(size_t new_capacity) {
104
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 608 assert(new_capacity > 0);
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 608 assert(new_capacity >= size_);
106
107 608 size_t head_offset = GetHeadOffset();
108 608 Item *old_buffer = buffer_;
109
110 608 Alloc(new_capacity);
111
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 112213064 for (size_t i = 0; i < size_; ++i)
112
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 112212456 new (buffer_ + i) Item(old_buffer[head_offset + i]);
113
114 608 FreeBuffer(old_buffer, head_offset + size_);
115 608 }
116
117 1534 void FreeBuffer(Item *buf, const size_t nitems) {
118
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 162385986 for (size_t i = 0; i < nitems; ++i)
119 162384452 buf[i].~Item();
120
121
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 1534 if (buf)
122 1534 smunmap(buf);
123 1534 }
124
125 140 void CopyFrom(const BigQueue<Item> &other) {
126 140 size_t min_items = kNumInit;
127 140 Alloc(std::max(other.size_, min_items));
128
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 10084123 for (size_t i = 0; i < other.size_; ++i) {
129
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 10083983 new (buffer_ + i) Item(*(other.buffer_ + other.GetHeadOffset() + i));
130 }
131 140 size_ = other.size_;
132 140 }
133
134 Item *buffer_;
135 Item *head_;
136 size_t size_;
137 size_t capacity_;
138 };
139
140 #endif // CVMFS_BIGQUEUE_H_
141