GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/bigqueue.h
Date: 2025-12-07 02:35:36
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:
21 369 BigQueue() {
22 369 Alloc(kNumInit);
23 369 size_ = 0;
24 369 }
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 49 BigQueue(const BigQueue<Item> &other) { CopyFrom(other); }
33
34 38 BigQueue<Item> &operator=(const BigQueue<Item> &other) {
35
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 38 if (&other == this)
36 ✗ return *this;
37
38 38 Dealloc();
39 38 CopyFrom(other);
40 38 return *this;
41 }
42
43 386 ~BigQueue() { Dealloc(); }
44
45 980102220 void PushBack(const Item &item) {
46
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 980102220 if (GetAvailableSpace() == 0) {
47 2372 Migrate(1.9 * static_cast<float>(capacity_));
48
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 2372 assert(GetAvailableSpace() > 0);
49 }
50
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 980102220 new (head_ + size_) Item(item);
51 980102220 size_++;
52 980102220 }
53
54 980073592 void PopFront() {
55
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 980073592 assert(!IsEmpty());
56 980073592 head_++;
57 980073592 size_--;
58
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 980073592 if ((size_ > kCompactThreshold) && (size_ < (capacity_ / 2)))
59 2499 Migrate(static_cast<int>(static_cast<float>(capacity_ * 0.6)));
60 980073592 }
61
62 980078345 bool Peek(Item **item) {
63
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 980078345 if (IsEmpty())
64 431 return false;
65 980077914 *item = head_;
66 980077914 return true;
67 }
68
69 1960151937 bool IsEmpty() const { return size_ == 0; }
70
71 38 void Clear() {
72 38 Dealloc();
73 38 Alloc(kNumInit);
74 38 }
75
76 3881 size_t size() const { return size_; }
77 490 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 1225114053 size_t GetHeadOffset() const { return head_ - buffer_; }
84 980104592 size_t GetAvailableSpace() const {
85 980104592 return capacity_ - (size_ + GetHeadOffset());
86 }
87
88 5365 void Alloc(const size_t num_elements) {
89 5365 size_t num_bytes = sizeof(Item) * num_elements;
90 5365 buffer_ = static_cast<Item *>(smmap(num_bytes));
91 5365 capacity_ = num_elements;
92 5365 head_ = buffer_;
93 5365 }
94
95 462 void Dealloc() {
96 462 FreeBuffer(buffer_, GetHeadOffset() + size_);
97 462 buffer_ = NULL;
98 462 head_ = NULL;
99 462 capacity_ = 0;
100 462 size_ = 0;
101 462 }
102
103 4871 void Migrate(size_t new_capacity) {
104
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 4871 assert(new_capacity > 0);
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 4871 assert(new_capacity >= size_);
106
107 4871 size_t head_offset = GetHeadOffset();
108 4871 Item *old_buffer = buffer_;
109
110 4871 Alloc(new_capacity);
111
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 2745851668 for (size_t i = 0; i < size_; ++i)
112
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 2745846797 new (buffer_ + i) Item(old_buffer[head_offset + i]);
113
114 4871 FreeBuffer(old_buffer, head_offset + size_);
115 4871 }
116
117 5333 void FreeBuffer(Item *buf, const size_t nitems) {
118
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 3970958446 for (size_t i = 0; i < nitems; ++i)
119 3970953113 buf[i].~Item();
120
121
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 5333 if (buf)
122 5333 smunmap(buf);
123 5333 }
124
125 87 void CopyFrom(const BigQueue<Item> &other) {
126 87 size_t min_items = kNumInit;
127 87 Alloc(std::max(other.size_, min_items));
128
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 245004215 for (size_t i = 0; i < other.size_; ++i) {
129
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 245004128 new (buffer_ + i) Item(*(other.buffer_ + other.GetHeadOffset() + i));
130 }
131 87 size_ = other.size_;
132 87 }
133
134 Item *buffer_;
135 Item *head_;
136 size_t size_;
137 size_t capacity_;
138 };
139
140 #endif // CVMFS_BIGQUEUE_H_
141