GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/bigqueue.h
Date: 2026-06-14 02:36:34
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:
21 418 BigQueue() {
22 418 Alloc(kNumInit);
23 418 size_ = 0;
24 418 }
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 12 BigQueue(const BigQueue<Item> &other) { CopyFrom(other); }
33
34 150 BigQueue<Item> &operator=(const BigQueue<Item> &other) {
35
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 150 if (&other == this)
36 ✗ return *this;
37
38 150 Dealloc();
39 150 CopyFrom(other);
40 150 return *this;
41 }
42
43 427 ~BigQueue() { Dealloc(); }
44
45 240124368 void PushBack(const Item &item) {
46
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 240124368 if (GetAvailableSpace() == 0) {
47 1066 Migrate(1.9 * static_cast<float>(capacity_));
48
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 1066 assert(GetAvailableSpace() > 0);
49 }
50
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 240124368 new (head_ + size_) Item(item);
51 240124368 size_++;
52 240124368 }
53
54 240018013 void PopFront() {
55
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 240018013 assert(!IsEmpty());
56 240018013 head_++;
57 240018013 size_--;
58
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 240018013 if ((size_ > kCompactThreshold) && (size_ < (capacity_ / 2)))
59 612 Migrate(static_cast<int>(static_cast<float>(capacity_ * 0.6)));
60 240018013 }
61
62 240118757 bool Peek(Item **item) {
63
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 240118757 if (IsEmpty())
64 169 return false;
65 240118588 *item = head_;
66 240118588 return true;
67 }
68
69 480136770 bool IsEmpty() const { return size_ == 0; }
70
71 150 void Clear() {
72 150 Dealloc();
73 150 Alloc(kNumInit);
74 150 }
75
76 63216 size_t size() const { return size_; }
77 120 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 300228194 size_t GetHeadOffset() const { return head_ - buffer_; }
84 240125434 size_t GetAvailableSpace() const {
85 240125434 return capacity_ - (size_ + GetHeadOffset());
86 }
87
88 2408 void Alloc(const size_t num_elements) {
89 2408 size_t num_bytes = sizeof(Item) * num_elements;
90 2408 buffer_ = static_cast<Item *>(smmap(num_bytes));
91 2408 capacity_ = num_elements;
92 2408 head_ = buffer_;
93 2408 }
94
95 727 void Dealloc() {
96 727 FreeBuffer(buffer_, GetHeadOffset() + size_);
97 727 buffer_ = NULL;
98 727 head_ = NULL;
99 727 capacity_ = 0;
100 727 size_ = 0;
101 727 }
102
103 1678 void Migrate(size_t new_capacity) {
104
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 1678 assert(new_capacity > 0);
105
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 1678 assert(new_capacity >= size_);
106
107 1678 size_t head_offset = GetHeadOffset();
108 1678 Item *old_buffer = buffer_;
109
110 1678 Alloc(new_capacity);
111
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 672616464 for (size_t i = 0; i < size_; ++i)
112
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 672614786 new (buffer_ + i) Item(old_buffer[head_offset + i]);
113
114 1678 FreeBuffer(old_buffer, head_offset + size_);
115 1678 }
116
117 2405 void FreeBuffer(Item *buf, const size_t nitems) {
118
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 972841911 for (size_t i = 0; i < nitems; ++i)
119 972839506 buf[i].~Item();
120
121
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 2405 if (buf)
122 2405 smunmap(buf);
123 2405 }
124
125 162 void CopyFrom(const BigQueue<Item> &other) {
126 162 size_t min_items = kNumInit;
127 162 Alloc(std::max(other.size_, min_items));
128
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 60100517 for (size_t i = 0; i < other.size_; ++i) {
129
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 60100355 new (buffer_ + i) Item(*(other.buffer_ + other.GetHeadOffset() + i));
130 }
131 162 size_ = other.size_;
132 162 }
133
134 Item *buffer_;
135 Item *head_;
136 size_t size_;
137 size_t capacity_;
138 };
139
140 #endif // CVMFS_BIGQUEUE_H_
141