GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/bigqueue.h
Date: 2026-01-25 02:35:50
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:
21 784 BigQueue() {
22 784 Alloc(kNumInit);
23 784 size_ = 0;
24 784 }
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 70 BigQueue<Item> &operator=(const BigQueue<Item> &other) {
35
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 70 if (&other == this)
36 ✗ return *this;
37
38 70 Dealloc();
39 70 CopyFrom(other);
40 70 return *this;
41 }
42
43 762 ~BigQueue() { Dealloc(); }
44
45 240048712 void PushBack(const Item &item) {
46
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 240048712 if (GetAvailableSpace() == 0) {
47 696 Migrate(1.9 * static_cast<float>(capacity_));
48
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 696 assert(GetAvailableSpace() > 0);
49 }
50
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 240048712 new (head_ + size_) Item(item);
51 240048712 size_++;
52 240048712 }
53
54 240018102 void PopFront() {
55
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 240018102 assert(!IsEmpty());
56 240018102 head_++;
57 240018102 size_--;
58
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 240018102 if ((size_ > kCompactThreshold) && (size_ < (capacity_ / 2)))
59 612 Migrate(static_cast<int>(static_cast<float>(capacity_ * 0.6)));
60 240018102 }
61
62 240043330 bool Peek(Item **item) {
63
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 240043330 if (IsEmpty())
64 366 return false;
65 240042964 *item = head_;
66 240042964 return true;
67 }
68
69 480061432 bool IsEmpty() const { return size_ == 0; }
70
71 70 void Clear() {
72 70 Dealloc();
73 70 Alloc(kNumInit);
74 70 }
75
76 15888 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 300076228 size_t GetHeadOffset() const { return head_ - buffer_; }
84 240049408 size_t GetAvailableSpace() const {
85 240049408 return capacity_ - (size_ + GetHeadOffset());
86 }
87
88 2244 void Alloc(const size_t num_elements) {
89 2244 size_t num_bytes = sizeof(Item) * num_elements;
90 2244 buffer_ = static_cast<Item *>(smmap(num_bytes));
91 2244 capacity_ = num_elements;
92 2244 head_ = buffer_;
93 2244 }
94
95 902 void Dealloc() {
96 902 FreeBuffer(buffer_, GetHeadOffset() + size_);
97 902 buffer_ = NULL;
98 902 head_ = NULL;
99 902 capacity_ = 0;
100 902 size_ = 0;
101 902 }
102
103 1308 void Migrate(size_t new_capacity) {
104
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 1308 assert(new_capacity > 0);
105
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 1308 assert(new_capacity >= size_);
106
107 1308 size_t head_offset = GetHeadOffset();
108 1308 Item *old_buffer = buffer_;
109
110 1308 Alloc(new_capacity);
111
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 672492144 for (size_t i = 0; i < size_; ++i)
112
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 672490836 new (buffer_ + i) Item(old_buffer[head_offset + i]);
113
114 1308 FreeBuffer(old_buffer, head_offset + size_);
115 1308 }
116
117 2210 void FreeBuffer(Item *buf, const size_t nitems) {
118
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 972566334 for (size_t i = 0; i < nitems; ++i)
119 972564124 buf[i].~Item();
120
121
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 2210 if (buf)
122 2210 smunmap(buf);
123 2210 }
124
125 82 void CopyFrom(const BigQueue<Item> &other) {
126 82 size_t min_items = kNumInit;
127 82 Alloc(std::max(other.size_, min_items));
128
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 60024692 for (size_t i = 0; i < other.size_; ++i) {
129
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 60024610 new (buffer_ + i) Item(*(other.buffer_ + other.GetHeadOffset() + i));
130 }
131 82 size_ = other.size_;
132 82 }
133
134 Item *buffer_;
135 Item *head_;
136 size_t size_;
137 size_t capacity_;
138 };
139
140 #endif // CVMFS_BIGQUEUE_H_
141