GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/bigqueue.h
Date: 2025-06-29 02:35:41
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:
21 904 BigQueue() {
22 904 Alloc(kNumInit);
23 904 size_ = 0;
24 904 }
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 44 BigQueue(const BigQueue<Item> &other) { CopyFrom(other); }
33
34 182 BigQueue<Item> &operator=(const BigQueue<Item> &other) {
35
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 182 if (&other == this)
36 ✗ return *this;
37
38 182 Dealloc();
39 182 CopyFrom(other);
40 182 return *this;
41 }
42
43 904 ~BigQueue() { Dealloc(); }
44
45 880182384 void PushBack(const Item &item) {
46
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 880182384 if (GetAvailableSpace() == 0) {
47 2572 Migrate(1.9 * static_cast<float>(capacity_));
48
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 2572 assert(GetAvailableSpace() > 0);
49 }
50
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 880182384 new (head_ + size_) Item(item);
51 880182384 size_++;
52 880182384 }
53
54 880066132 void PopFront() {
55
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 880066132 assert(!IsEmpty());
56 880066132 head_++;
57 880066132 size_--;
58
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 880066132 if ((size_ > kCompactThreshold) && (size_ < (capacity_ / 2)))
59 2244 Migrate(static_cast<int>(static_cast<float>(capacity_ * 0.6)));
60 880066132 }
61
62 880161452 bool Peek(Item **item) {
63
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 880161452 if (IsEmpty())
64 620 return false;
65 880160832 *item = head_;
66 880160832 return true;
67 }
68
69 1760227584 bool IsEmpty() const { return size_ == 0; }
70
71 182 void Clear() {
72 182 Dealloc();
73 182 Alloc(kNumInit);
74 182 }
75
76 60340 size_t size() const { return size_; }
77 440 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 1100285292 size_t GetHeadOffset() const { return head_ - buffer_; }
84 880184956 size_t GetAvailableSpace() const {
85 880184956 return capacity_ - (size_ + GetHeadOffset());
86 }
87
88 6128 void Alloc(const size_t num_elements) {
89 6128 size_t num_bytes = sizeof(Item) * num_elements;
90 6128 buffer_ = static_cast<Item *>(smmap(num_bytes));
91 6128 capacity_ = num_elements;
92 6128 head_ = buffer_;
93 6128 }
94
95 1268 void Dealloc() {
96 1268 FreeBuffer(buffer_, GetHeadOffset() + size_);
97 1268 buffer_ = NULL;
98 1268 head_ = NULL;
99 1268 capacity_ = 0;
100 1268 size_ = 0;
101 1268 }
102
103 4816 void Migrate(size_t new_capacity) {
104
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 4816 assert(new_capacity > 0);
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 4816 assert(new_capacity >= size_);
106
107 4816 size_t head_offset = GetHeadOffset();
108 4816 Item *old_buffer = buffer_;
109
110 4816 Alloc(new_capacity);
111
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 2465811248 for (size_t i = 0; i < size_; ++i)
112
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 2465806432 new (buffer_ + i) Item(old_buffer[head_offset + i]);
113
114 4816 FreeBuffer(old_buffer, head_offset + size_);
115 4816 }
116
117 6084 void FreeBuffer(Item *buf, const size_t nitems) {
118
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 3566089108 for (size_t i = 0; i < nitems; ++i)
119 3566083024 buf[i].~Item();
120
121
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 6084 if (buf)
122 6084 smunmap(buf);
123 6084 }
124
125 226 void CopyFrom(const BigQueue<Item> &other) {
126 226 size_t min_items = kNumInit;
127 226 Alloc(std::max(other.size_, min_items));
128
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 220094478 for (size_t i = 0; i < other.size_; ++i) {
129
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 220094252 new (buffer_ + i) Item(*(other.buffer_ + other.GetHeadOffset() + i));
130 }
131 226 size_ = other.size_;
132 226 }
133
134 Item *buffer_;
135 Item *head_;
136 size_t size_;
137 size_t capacity_;
138 };
139
140 #endif // CVMFS_BIGQUEUE_H_
141