/*
* This file is part of the PulseView project.
*
+ * Copyright (C) 2017 Soeren Apel <soeren@apelpie.net>
* Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
*
* This program is free software; you can redistribute it and/or modify
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "segment.hpp"
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>
+#include <cassert>
+#include <cstdlib>
+#include <cstring>
using std::lock_guard;
+using std::min;
using std::recursive_mutex;
namespace pv {
namespace data {
+const uint64_t Segment::MaxChunkSize = 10*1024*1024; /* 10MiB */
+
Segment::Segment(uint64_t samplerate, unsigned int unit_size) :
sample_count_(0),
start_time_(0),
samplerate_(samplerate),
- capacity_(0),
- unit_size_(unit_size)
+ unit_size_(unit_size),
+ iterator_count_(0),
+ mem_optimization_requested_(false)
{
lock_guard<recursive_mutex> lock(mutex_);
assert(unit_size_ > 0);
+
+ // Determine the number of samples we can fit in one chunk
+ // without exceeding MaxChunkSize
+ chunk_size_ = min(MaxChunkSize, (MaxChunkSize / unit_size_) * unit_size_);
+
+ // Create the initial chunk
+ current_chunk_ = new uint8_t[chunk_size_];
+ data_chunks_.push_back(current_chunk_);
+ used_samples_ = 0;
+ unused_samples_ = chunk_size_ / unit_size_;
}
Segment::~Segment()
{
lock_guard<recursive_mutex> lock(mutex_);
+
+ for (uint8_t* chunk : data_chunks_)
+ delete[] chunk;
}
uint64_t Segment::get_sample_count() const
return unit_size_;
}
-void Segment::set_capacity(const uint64_t new_capacity)
+void Segment::free_unused_memory()
{
lock_guard<recursive_mutex> lock(mutex_);
- assert(capacity_ >= sample_count_);
- if (new_capacity > capacity_) {
- // If we're out of memory, this will throw std::bad_alloc
- data_.resize((new_capacity * unit_size_) + sizeof(uint64_t));
- capacity_ = new_capacity;
+ // Do not mess with the data chunks if we have iterators pointing at them
+ if (iterator_count_ > 0) {
+ mem_optimization_requested_ = true;
+ return;
}
+
+ // No more data will come in, so re-create the last chunk accordingly
+ uint8_t* resized_chunk = new uint8_t[used_samples_ * unit_size_];
+ memcpy(resized_chunk, current_chunk_, used_samples_ * unit_size_);
+
+ delete[] current_chunk_;
+ current_chunk_ = resized_chunk;
+
+ data_chunks_.pop_back();
+ data_chunks_.push_back(resized_chunk);
}
-uint64_t Segment::capacity() const
+void Segment::append_single_sample(void *data)
{
lock_guard<recursive_mutex> lock(mutex_);
- return data_.size();
+
+ // There will always be space for at least one sample in
+ // the current chunk, so we do not need to test for space
+
+ memcpy(current_chunk_ + (used_samples_ * unit_size_), data, unit_size_);
+ used_samples_++;
+ unused_samples_--;
+
+ if (unused_samples_ == 0) {
+ current_chunk_ = new uint8_t[chunk_size_];
+ data_chunks_.push_back(current_chunk_);
+ used_samples_ = 0;
+ unused_samples_ = chunk_size_ / unit_size_;
+ }
+
+ sample_count_++;
}
-void Segment::append_data(void *data, uint64_t samples)
+void Segment::append_samples(void* data, uint64_t samples)
{
lock_guard<recursive_mutex> lock(mutex_);
- assert(capacity_ >= sample_count_);
+ if (unused_samples_ >= samples) {
+ // All samples fit into the current chunk
+ memcpy(current_chunk_ + (used_samples_ * unit_size_),
+ data, (samples * unit_size_));
+ used_samples_ += samples;
+ unused_samples_ -= samples;
+ } else {
+ // Only a part of the samples fit, split data up between chunks
+ memcpy(current_chunk_ + (used_samples_ * unit_size_),
+ data, (unused_samples_ * unit_size_));
+ const uint64_t remaining_samples = samples - unused_samples_;
+
+ // If we're out of memory, this will throw std::bad_alloc
+ current_chunk_ = new uint8_t[chunk_size_];
+ data_chunks_.push_back(current_chunk_);
+ memcpy(current_chunk_, (uint8_t*)data + (unused_samples_ * unit_size_),
+ (remaining_samples * unit_size_));
- // Ensure there's enough capacity to copy.
- const uint64_t free_space = capacity_ - sample_count_;
- if (free_space < samples)
- set_capacity(sample_count_ + samples);
+ used_samples_ = remaining_samples;
+ unused_samples_ = (chunk_size_ / unit_size_) - remaining_samples;
+ }
+
+ if (unused_samples_ == 0) {
+ // If we're out of memory, this will throw std::bad_alloc
+ current_chunk_ = new uint8_t[chunk_size_];
+ data_chunks_.push_back(current_chunk_);
+ used_samples_ = 0;
+ unused_samples_ = chunk_size_ / unit_size_;
+ }
- memcpy((uint8_t*)data_.data() + sample_count_ * unit_size_,
- data, samples * unit_size_);
sample_count_ += samples;
}
+uint8_t* Segment::get_raw_samples(uint64_t start, uint64_t count) const
+{
+ assert(start < sample_count_);
+ assert(start + count <= sample_count_);
+ assert(count > 0);
+
+ lock_guard<recursive_mutex> lock(mutex_);
+
+ uint8_t* dest = new uint8_t[count * unit_size_];
+ uint8_t* dest_ptr = dest;
+
+ uint64_t chunk_num = (start * unit_size_) / chunk_size_;
+ uint64_t chunk_offs = (start * unit_size_) % chunk_size_;
+
+ while (count > 0) {
+ const uint8_t* chunk = data_chunks_[chunk_num];
+
+ uint64_t copy_size = min(count * unit_size_,
+ chunk_size_ - chunk_offs);
+
+ memcpy(dest_ptr, chunk + chunk_offs, copy_size);
+
+ dest_ptr += copy_size;
+ count -= (copy_size / unit_size_);
+
+ chunk_num++;
+ chunk_offs = 0;
+ }
+
+ return dest;
+}
+
+SegmentRawDataIterator* Segment::begin_raw_sample_iteration(uint64_t start)
+{
+ SegmentRawDataIterator* it = new SegmentRawDataIterator;
+
+ assert(start < sample_count_);
+
+ iterator_count_++;
+
+ it->sample_index = start;
+ it->chunk_num = (start * unit_size_) / chunk_size_;
+ it->chunk_offs = (start * unit_size_) % chunk_size_;
+ it->chunk = data_chunks_[it->chunk_num];
+ it->value = it->chunk + it->chunk_offs;
+
+ return it;
+}
+
+void Segment::continue_raw_sample_iteration(SegmentRawDataIterator* it, uint64_t increase)
+{
+ lock_guard<recursive_mutex> lock(mutex_);
+
+ // Fail gracefully if we are asked to deliver data we don't have
+ if (it->sample_index > sample_count_)
+ return;
+
+ it->sample_index += increase;
+ it->chunk_offs += (increase * unit_size_);
+
+ if (it->chunk_offs > (chunk_size_ - 1)) {
+ it->chunk_num++;
+ it->chunk_offs -= chunk_size_;
+ it->chunk = data_chunks_[it->chunk_num];
+ }
+
+ it->value = it->chunk + it->chunk_offs;
+}
+
+void Segment::end_raw_sample_iteration(SegmentRawDataIterator* it)
+{
+ delete it;
+
+ iterator_count_--;
+
+ if ((iterator_count_ == 0) && mem_optimization_requested_) {
+ mem_optimization_requested_ = false;
+ free_unused_memory();
+ }
+}
+
} // namespace data
} // namespace pv
projects / pulseview.git / blobdiff