2 * This file is part of the PulseView project.
4 * Copyright (C) 2017 Soeren Apel <soeren@apelpie.net>
5 * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
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.
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.
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/>.
21 #include "segment.hpp"
27 using std::lock_guard;
29 using std::recursive_mutex;
34 const uint64_t Segment::MaxChunkSize = 10 * 1024 * 1024; /* 10MiB */
36 Segment::Segment(uint64_t samplerate, unsigned int unit_size) :
39 samplerate_(samplerate),
40 unit_size_(unit_size),
42 mem_optimization_requested_(false)
44 lock_guard<recursive_mutex> lock(mutex_);
45 assert(unit_size_ > 0);
47 // Determine the number of samples we can fit in one chunk
48 // without exceeding MaxChunkSize
49 chunk_size_ = min(MaxChunkSize, (MaxChunkSize / unit_size_) * unit_size_);
51 // Create the initial chunk
52 current_chunk_ = new uint8_t[chunk_size_];
53 data_chunks_.push_back(current_chunk_);
55 unused_samples_ = chunk_size_ / unit_size_;
60 lock_guard<recursive_mutex> lock(mutex_);
62 for (uint8_t* chunk : data_chunks_)
66 uint64_t Segment::get_sample_count() const
68 lock_guard<recursive_mutex> lock(mutex_);
72 const pv::util::Timestamp& Segment::start_time() const
77 double Segment::samplerate() const
82 void Segment::set_samplerate(double samplerate)
84 samplerate_ = samplerate;
87 unsigned int Segment::unit_size() const
92 void Segment::free_unused_memory()
94 lock_guard<recursive_mutex> lock(mutex_);
96 // Do not mess with the data chunks if we have iterators pointing at them
97 if (iterator_count_ > 0) {
98 mem_optimization_requested_ = true;
102 // No more data will come in, so re-create the last chunk accordingly
103 uint8_t* resized_chunk = new uint8_t[used_samples_ * unit_size_];
104 memcpy(resized_chunk, current_chunk_, used_samples_ * unit_size_);
106 delete[] current_chunk_;
107 current_chunk_ = resized_chunk;
109 data_chunks_.pop_back();
110 data_chunks_.push_back(resized_chunk);
113 void Segment::append_single_sample(void *data)
115 lock_guard<recursive_mutex> lock(mutex_);
117 // There will always be space for at least one sample in
118 // the current chunk, so we do not need to test for space
120 memcpy(current_chunk_ + (used_samples_ * unit_size_), data, unit_size_);
124 if (unused_samples_ == 0) {
125 current_chunk_ = new uint8_t[chunk_size_];
126 data_chunks_.push_back(current_chunk_);
128 unused_samples_ = chunk_size_ / unit_size_;
134 void Segment::append_samples(void* data, uint64_t samples)
136 lock_guard<recursive_mutex> lock(mutex_);
138 if (unused_samples_ >= samples) {
139 // All samples fit into the current chunk
140 memcpy(current_chunk_ + (used_samples_ * unit_size_),
141 data, (samples * unit_size_));
142 used_samples_ += samples;
143 unused_samples_ -= samples;
145 // Only a part of the samples fit, split data up between chunks
146 memcpy(current_chunk_ + (used_samples_ * unit_size_),
147 data, (unused_samples_ * unit_size_));
148 const uint64_t remaining_samples = samples - unused_samples_;
150 // If we're out of memory, this will throw std::bad_alloc
151 current_chunk_ = new uint8_t[chunk_size_];
152 data_chunks_.push_back(current_chunk_);
153 memcpy(current_chunk_, (uint8_t*)data + (unused_samples_ * unit_size_),
154 (remaining_samples * unit_size_));
156 used_samples_ = remaining_samples;
157 unused_samples_ = (chunk_size_ / unit_size_) - remaining_samples;
160 if (unused_samples_ == 0) {
161 // If we're out of memory, this will throw std::bad_alloc
162 current_chunk_ = new uint8_t[chunk_size_];
163 data_chunks_.push_back(current_chunk_);
165 unused_samples_ = chunk_size_ / unit_size_;
168 sample_count_ += samples;
171 uint8_t* Segment::get_raw_samples(uint64_t start, uint64_t count) const
173 assert(start < sample_count_);
174 assert(start + count <= sample_count_);
177 lock_guard<recursive_mutex> lock(mutex_);
179 uint8_t* dest = new uint8_t[count * unit_size_];
180 uint8_t* dest_ptr = dest;
182 uint64_t chunk_num = (start * unit_size_) / chunk_size_;
183 uint64_t chunk_offs = (start * unit_size_) % chunk_size_;
186 const uint8_t* chunk = data_chunks_[chunk_num];
188 uint64_t copy_size = min(count * unit_size_,
189 chunk_size_ - chunk_offs);
191 memcpy(dest_ptr, chunk + chunk_offs, copy_size);
193 dest_ptr += copy_size;
194 count -= (copy_size / unit_size_);
203 SegmentRawDataIterator* Segment::begin_raw_sample_iteration(uint64_t start)
205 SegmentRawDataIterator* it = new SegmentRawDataIterator;
207 assert(start < sample_count_);
211 it->sample_index = start;
212 it->chunk_num = (start * unit_size_) / chunk_size_;
213 it->chunk_offs = (start * unit_size_) % chunk_size_;
214 it->chunk = data_chunks_[it->chunk_num];
215 it->value = it->chunk + it->chunk_offs;
220 void Segment::continue_raw_sample_iteration(SegmentRawDataIterator* it, uint64_t increase)
222 // Fail gracefully if we are asked to deliver data we don't have
223 if (it->sample_index > sample_count_)
226 it->sample_index += increase;
227 it->chunk_offs += (increase * unit_size_);
229 if (it->chunk_offs > (chunk_size_ - 1)) {
231 it->chunk_offs -= chunk_size_;
232 it->chunk = data_chunks_[it->chunk_num];
235 it->value = it->chunk + it->chunk_offs;
238 void Segment::end_raw_sample_iteration(SegmentRawDataIterator* it)
244 if ((iterator_count_ == 0) && mem_optimization_requested_) {
245 mem_optimization_requested_ = false;
246 free_unused_memory();