GCC Code Coverage Report

Directory: cvmfs/
File: cvmfs/bigqueue.h
Date: 2025-10-26 02:35:25
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:
21 939 BigQueue() {
22 939 Alloc(kNumInit);
23 939 size_ = 0;
24 939 }
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 47 BigQueue(const BigQueue<Item> &other) { CopyFrom(other); }
33
34 176 BigQueue<Item> &operator=(const BigQueue<Item> &other) {
35
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 176 if (&other == this)
36 ✗ return *this;
37
38 176 Dealloc();
39 176 CopyFrom(other);
40 176 return *this;
41 }
42
43 957 ~BigQueue() { Dealloc(); }
44
45 940194470 void PushBack(const Item &item) {
46
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 940194470 if (GetAvailableSpace() == 0) {
47 2746 Migrate(1.9 * static_cast<float>(capacity_));
48
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 2746 assert(GetAvailableSpace() > 0);
49 }
50
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 940194470 new (head_ + size_) Item(item);
51 940194470 size_++;
52 940194470 }
53
54 940070589 void PopFront() {
55
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 940070589 assert(!IsEmpty());
56 940070589 head_++;
57 940070589 size_--;
58
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 940070589 if ((size_ > kCompactThreshold) && (size_ < (capacity_ / 2)))
59 2397 Migrate(static_cast<int>(static_cast<float>(capacity_ * 0.6)));
60 940070589 }
61
62 940171852 bool Peek(Item **item) {
63
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 940171852 if (IsEmpty())
64 508 return false;
65 940171344 *item = head_;
66 940171344 return true;
67 }
68
69 1880242441 bool IsEmpty() const { return size_ == 0; }
70
71 176 void Clear() {
72 176 Dealloc();
73 176 Alloc(kNumInit);
74 176 }
75
76 64171 size_t size() const { return size_; }
77 470 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 1175304049 size_t GetHeadOffset() const { return head_ - buffer_; }
84 940197216 size_t GetAvailableSpace() const {
85 940197216 return capacity_ - (size_ + GetHeadOffset());
86 }
87
88 6481 void Alloc(const size_t num_elements) {
89 6481 size_t num_bytes = sizeof(Item) * num_elements;
90 6481 buffer_ = static_cast<Item *>(smmap(num_bytes));
91 6481 capacity_ = num_elements;
92 6481 head_ = buffer_;
93 6481 }
94
95 1309 void Dealloc() {
96 1309 FreeBuffer(buffer_, GetHeadOffset() + size_);
97 1309 buffer_ = NULL;
98 1309 head_ = NULL;
99 1309 capacity_ = 0;
100 1309 size_ = 0;
101 1309 }
102
103 5143 void Migrate(size_t new_capacity) {
104
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 5143 assert(new_capacity > 0);
105
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 5143 assert(new_capacity >= size_);
106
107 5143 size_t head_offset = GetHeadOffset();
108 5143 Item *old_buffer = buffer_;
109
110 5143 Alloc(new_capacity);
111
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 2633934284 for (size_t i = 0; i < size_; ++i)
112
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 2633929141 new (buffer_ + i) Item(old_buffer[head_offset + i]);
113
114 5143 FreeBuffer(old_buffer, head_offset + size_);
115 5143 }
116
117 6452 void FreeBuffer(Item *buf, const size_t nitems) {
118
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 3809230415 for (size_t i = 0; i < nitems; ++i)
119 3809223963 buf[i].~Item();
120
121
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 6452 if (buf)
122 6452 smunmap(buf);
123 6452 }
124
125 223 void CopyFrom(const BigQueue<Item> &other) {
126 223 size_t min_items = kNumInit;
127 223 Alloc(std::max(other.size_, min_items));
128
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 235100604 for (size_t i = 0; i < other.size_; ++i) {
129
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 235100381 new (buffer_ + i) Item(*(other.buffer_ + other.GetHeadOffset() + i));
130 }
131 223 size_ = other.size_;
132 223 }
133
134 Item *buffer_;
135 Item *head_;
136 size_t size_;
137 size_t capacity_;
138 };
139
140 #endif // CVMFS_BIGQUEUE_H_
141