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),
45 lock_guard<recursive_mutex> lock(mutex_);
46 assert(unit_size_ > 0);
48 // Determine the number of samples we can fit in one chunk
49 // without exceeding MaxChunkSize
50 chunk_size_ = min(MaxChunkSize, (MaxChunkSize / unit_size_) * unit_size_);
52 // Create the initial chunk
53 current_chunk_ = new uint8_t[chunk_size_];
54 data_chunks_.push_back(current_chunk_);
56 unused_samples_ = chunk_size_ / unit_size_;
61 lock_guard<recursive_mutex> lock(mutex_);
63 for (uint8_t* chunk : data_chunks_)
67 uint64_t Segment::get_sample_count() const
69 lock_guard<recursive_mutex> lock(mutex_);
73 const pv::util::Timestamp& Segment::start_time() const
78 double Segment::samplerate() const
83 void Segment::set_samplerate(double samplerate)
85 samplerate_ = samplerate;
88 unsigned int Segment::unit_size() const
93 void Segment::set_complete()
98 bool Segment::is_complete() const
103 void Segment::free_unused_memory()
105 lock_guard<recursive_mutex> lock(mutex_);
107 // Do not mess with the data chunks if we have iterators pointing at them
108 if (iterator_count_ > 0) {
109 mem_optimization_requested_ = true;
113 // No more data will come in, so re-create the last chunk accordingly
114 uint8_t* resized_chunk = new uint8_t[used_samples_ * unit_size_];
115 memcpy(resized_chunk, current_chunk_, used_samples_ * unit_size_);
117 delete[] current_chunk_;
118 current_chunk_ = resized_chunk;
120 data_chunks_.pop_back();
121 data_chunks_.push_back(resized_chunk);
124 void Segment::append_single_sample(void *data)
126 lock_guard<recursive_mutex> lock(mutex_);
128 // There will always be space for at least one sample in
129 // the current chunk, so we do not need to test for space
131 memcpy(current_chunk_ + (used_samples_ * unit_size_), data, unit_size_);
135 if (unused_samples_ == 0) {
136 current_chunk_ = new uint8_t[chunk_size_];
137 data_chunks_.push_back(current_chunk_);
139 unused_samples_ = chunk_size_ / unit_size_;
145 void Segment::append_samples(void* data, uint64_t samples)
147 lock_guard<recursive_mutex> lock(mutex_);
149 const uint8_t* data_byte_ptr = (uint8_t*)data;
150 uint64_t remaining_samples = samples;
151 uint64_t data_offset = 0;
154 uint64_t copy_count = 0;
156 if (remaining_samples <= unused_samples_) {
157 // All samples fit into the current chunk
158 copy_count = remaining_samples;
160 // Only a part of the samples fit, fill up current chunk
161 copy_count = unused_samples_;
164 const uint8_t* dest = &(current_chunk_[used_samples_ * unit_size_]);
165 const uint8_t* src = &(data_byte_ptr[data_offset]);
166 memcpy((void*)dest, (void*)src, (copy_count * unit_size_));
168 used_samples_ += copy_count;
169 unused_samples_ -= copy_count;
170 remaining_samples -= copy_count;
171 data_offset += (copy_count * unit_size_);
173 if (unused_samples_ == 0) {
174 // If we're out of memory, this will throw std::bad_alloc
175 current_chunk_ = new uint8_t[chunk_size_];
176 data_chunks_.push_back(current_chunk_);
178 unused_samples_ = chunk_size_ / unit_size_;
180 } while (remaining_samples > 0);
182 sample_count_ += samples;
185 void Segment::get_raw_samples(uint64_t start, uint64_t count,
188 assert(start < sample_count_);
189 assert(start + count <= sample_count_);
191 assert(dest != nullptr);
193 lock_guard<recursive_mutex> lock(mutex_);
195 uint8_t* dest_ptr = dest;
197 uint64_t chunk_num = (start * unit_size_) / chunk_size_;
198 uint64_t chunk_offs = (start * unit_size_) % chunk_size_;
201 const uint8_t* chunk = data_chunks_[chunk_num];
203 uint64_t copy_size = min(count * unit_size_,
204 chunk_size_ - chunk_offs);
206 memcpy(dest_ptr, chunk + chunk_offs, copy_size);
208 dest_ptr += copy_size;
209 count -= (copy_size / unit_size_);
216 SegmentRawDataIterator* Segment::begin_raw_sample_iteration(uint64_t start)
218 SegmentRawDataIterator* it = new SegmentRawDataIterator;
220 assert(start < sample_count_);
224 it->sample_index = start;
225 it->chunk_num = (start * unit_size_) / chunk_size_;
226 it->chunk_offs = (start * unit_size_) % chunk_size_;
227 it->chunk = data_chunks_[it->chunk_num];
228 it->value = it->chunk + it->chunk_offs;
233 void Segment::continue_raw_sample_iteration(SegmentRawDataIterator* it, uint64_t increase)
235 // Fail gracefully if we are asked to deliver data we don't have
236 if (it->sample_index > sample_count_)
239 it->sample_index += increase;
240 it->chunk_offs += (increase * unit_size_);
242 if (it->chunk_offs > (chunk_size_ - 1)) {
244 it->chunk_offs -= chunk_size_;
245 it->chunk = data_chunks_[it->chunk_num];
248 it->value = it->chunk + it->chunk_offs;
251 void Segment::end_raw_sample_iteration(SegmentRawDataIterator* it)
257 if ((iterator_count_ == 0) && mem_optimization_requested_) {
258 mem_optimization_requested_ = false;
259 free_unused_memory();