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1 | /* | |
2 | * This file is part of the PulseView project. | |
3 | * | |
4 | * Copyright (C) 2017 Soeren Apel <soeren@apelpie.net> | |
5 | * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
19 | */ | |
20 | ||
21 | #include "segment.hpp" | |
22 | ||
23 | #include <cassert> | |
24 | #include <cstdlib> | |
25 | #include <cstring> | |
26 | #include <vector> | |
27 | ||
28 | using std::lock_guard; | |
29 | using std::recursive_mutex; | |
30 | using std::vector; | |
31 | ||
32 | namespace pv { | |
33 | namespace data { | |
34 | ||
35 | const uint64_t Segment::MaxChunkSize = 10*1024*1024; /* 10MiB */ | |
36 | ||
37 | Segment::Segment(uint64_t samplerate, unsigned int unit_size) : | |
38 | sample_count_(0), | |
39 | start_time_(0), | |
40 | samplerate_(samplerate), | |
41 | unit_size_(unit_size), | |
42 | iterator_count_(0), | |
43 | mem_optimization_requested_(false) | |
44 | { | |
45 | lock_guard<recursive_mutex> lock(mutex_); | |
46 | assert(unit_size_ > 0); | |
47 | ||
48 | // Determine the number of samples we can fit in one chunk | |
49 | // without exceeding MaxChunkSize | |
50 | chunk_size_ = std::min(MaxChunkSize, | |
51 | (MaxChunkSize / unit_size_) * unit_size_); | |
52 | ||
53 | // Create the initial chunk | |
54 | current_chunk_ = new uint8_t[chunk_size_]; | |
55 | data_chunks_.push_back(current_chunk_); | |
56 | used_samples_ = 0; | |
57 | unused_samples_ = chunk_size_ / unit_size_; | |
58 | } | |
59 | ||
60 | Segment::~Segment() | |
61 | { | |
62 | lock_guard<recursive_mutex> lock(mutex_); | |
63 | ||
64 | for (uint8_t* chunk : data_chunks_) | |
65 | delete[] chunk; | |
66 | } | |
67 | ||
68 | uint64_t Segment::get_sample_count() const | |
69 | { | |
70 | lock_guard<recursive_mutex> lock(mutex_); | |
71 | return sample_count_; | |
72 | } | |
73 | ||
74 | const pv::util::Timestamp& Segment::start_time() const | |
75 | { | |
76 | return start_time_; | |
77 | } | |
78 | ||
79 | double Segment::samplerate() const | |
80 | { | |
81 | return samplerate_; | |
82 | } | |
83 | ||
84 | void Segment::set_samplerate(double samplerate) | |
85 | { | |
86 | samplerate_ = samplerate; | |
87 | } | |
88 | ||
89 | unsigned int Segment::unit_size() const | |
90 | { | |
91 | return unit_size_; | |
92 | } | |
93 | ||
94 | void Segment::free_unused_memory() | |
95 | { | |
96 | lock_guard<recursive_mutex> lock(mutex_); | |
97 | ||
98 | // Do not mess with the data chunks if we have iterators pointing at them | |
99 | if (iterator_count_ > 0) { | |
100 | mem_optimization_requested_ = true; | |
101 | return; | |
102 | } | |
103 | ||
104 | // No more data will come in, so re-create the last chunk accordingly | |
105 | uint8_t* resized_chunk = new uint8_t[used_samples_ * unit_size_]; | |
106 | memcpy(resized_chunk, current_chunk_, used_samples_ * unit_size_); | |
107 | ||
108 | delete[] current_chunk_; | |
109 | current_chunk_ = resized_chunk; | |
110 | ||
111 | data_chunks_.pop_back(); | |
112 | data_chunks_.push_back(resized_chunk); | |
113 | } | |
114 | ||
115 | void Segment::append_single_sample(void *data) | |
116 | { | |
117 | lock_guard<recursive_mutex> lock(mutex_); | |
118 | ||
119 | // There will always be space for at least one sample in | |
120 | // the current chunk, so we do not need to test for space | |
121 | ||
122 | memcpy(current_chunk_ + (used_samples_ * unit_size_), | |
123 | data, unit_size_); | |
124 | used_samples_++; | |
125 | unused_samples_--; | |
126 | ||
127 | if (unused_samples_ == 0) { | |
128 | current_chunk_ = new uint8_t[chunk_size_]; | |
129 | data_chunks_.push_back(current_chunk_); | |
130 | used_samples_ = 0; | |
131 | unused_samples_ = chunk_size_ / unit_size_; | |
132 | } | |
133 | ||
134 | sample_count_++; | |
135 | } | |
136 | ||
137 | void Segment::append_samples(void* data, uint64_t samples) | |
138 | { | |
139 | lock_guard<recursive_mutex> lock(mutex_); | |
140 | ||
141 | if (unused_samples_ >= samples) { | |
142 | // All samples fit into the current chunk | |
143 | memcpy(current_chunk_ + (used_samples_ * unit_size_), | |
144 | data, (samples * unit_size_)); | |
145 | used_samples_ += samples; | |
146 | unused_samples_ -= samples; | |
147 | } else { | |
148 | // Only a part of the samples fit, split data up between chunks | |
149 | memcpy(current_chunk_ + (used_samples_ * unit_size_), | |
150 | data, (unused_samples_ * unit_size_)); | |
151 | const uint64_t remaining_samples = samples - unused_samples_; | |
152 | ||
153 | // If we're out of memory, this will throw std::bad_alloc | |
154 | current_chunk_ = new uint8_t[chunk_size_]; | |
155 | data_chunks_.push_back(current_chunk_); | |
156 | memcpy(current_chunk_, (uint8_t*)data + (unused_samples_ * unit_size_), | |
157 | (remaining_samples * unit_size_)); | |
158 | ||
159 | used_samples_ = remaining_samples; | |
160 | unused_samples_ = (chunk_size_ / unit_size_) - remaining_samples; | |
161 | } | |
162 | ||
163 | if (unused_samples_ == 0) { | |
164 | // If we're out of memory, this will throw std::bad_alloc | |
165 | current_chunk_ = new uint8_t[chunk_size_]; | |
166 | data_chunks_.push_back(current_chunk_); | |
167 | used_samples_ = 0; | |
168 | unused_samples_ = chunk_size_ / unit_size_; | |
169 | } | |
170 | ||
171 | sample_count_ += samples; | |
172 | } | |
173 | ||
174 | uint8_t* Segment::get_raw_samples(uint64_t start, uint64_t count) const | |
175 | { | |
176 | assert(start < sample_count_); | |
177 | assert(start + count <= sample_count_); | |
178 | assert(count > 0); | |
179 | ||
180 | lock_guard<recursive_mutex> lock(mutex_); | |
181 | ||
182 | uint8_t* dest = new uint8_t[count * unit_size_]; | |
183 | uint8_t* dest_ptr = dest; | |
184 | ||
185 | uint64_t chunk_num = (start * unit_size_) / chunk_size_; | |
186 | uint64_t chunk_offs = (start * unit_size_) % chunk_size_; | |
187 | ||
188 | while (count > 0) { | |
189 | const uint8_t* chunk = data_chunks_[chunk_num]; | |
190 | ||
191 | uint64_t copy_size = std::min(count * unit_size_, | |
192 | chunk_size_ - chunk_offs); | |
193 | ||
194 | memcpy(dest_ptr, chunk + chunk_offs, copy_size); | |
195 | ||
196 | dest_ptr += copy_size; | |
197 | count -= (copy_size / unit_size_); | |
198 | ||
199 | chunk_num++; | |
200 | chunk_offs = 0; | |
201 | } | |
202 | ||
203 | return dest; | |
204 | } | |
205 | ||
206 | SegmentRawDataIterator* Segment::begin_raw_sample_iteration(uint64_t start) | |
207 | { | |
208 | SegmentRawDataIterator* it = new SegmentRawDataIterator; | |
209 | ||
210 | assert(start < sample_count_); | |
211 | ||
212 | iterator_count_++; | |
213 | ||
214 | it->sample_index = start; | |
215 | it->chunk_num = (start * unit_size_) / chunk_size_; | |
216 | it->chunk_offs = (start * unit_size_) % chunk_size_; | |
217 | it->chunk = data_chunks_[it->chunk_num]; | |
218 | it->value = it->chunk + it->chunk_offs; | |
219 | ||
220 | return it; | |
221 | } | |
222 | ||
223 | void Segment::continue_raw_sample_iteration(SegmentRawDataIterator* it, uint64_t increase) | |
224 | { | |
225 | lock_guard<recursive_mutex> lock(mutex_); | |
226 | ||
227 | if (it->sample_index > sample_count_) | |
228 | { | |
229 | // Fail gracefully if we are asked to deliver data we don't have | |
230 | return; | |
231 | } else { | |
232 | it->sample_index += increase; | |
233 | it->chunk_offs += (increase * unit_size_); | |
234 | } | |
235 | ||
236 | if (it->chunk_offs > (chunk_size_ - 1)) { | |
237 | it->chunk_num++; | |
238 | it->chunk_offs -= chunk_size_; | |
239 | it->chunk = data_chunks_[it->chunk_num]; | |
240 | } | |
241 | ||
242 | it->value = it->chunk + it->chunk_offs; | |
243 | } | |
244 | ||
245 | void Segment::end_raw_sample_iteration(SegmentRawDataIterator* it) | |
246 | { | |
247 | delete it; | |
248 | ||
249 | iterator_count_--; | |
250 | ||
251 | if ((iterator_count_ == 0) && mem_optimization_requested_) { | |
252 | mem_optimization_requested_ = false; | |
253 | free_unused_memory(); | |
254 | } | |
255 | } | |
256 | ||
257 | ||
258 | } // namespace data | |
259 | } // namespace pv |