#include "segment.hpp"
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <vector>
+#include <cassert>
+#include <cstdlib>
+#include <cstring>
using std::lock_guard;
+using std::min;
using std::recursive_mutex;
-using std::vector;
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),
- 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_ = std::min(MaxChunkSize,
- (MaxChunkSize / unit_size_) * unit_size_);
+ chunk_size_ = min(MaxChunkSize, (MaxChunkSize / unit_size_) * unit_size_);
// Create the initial chunk
current_chunk_ = new uint8_t[chunk_size_];
{
lock_guard<recursive_mutex> lock(mutex_);
+ // 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_);
// 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_);
+ memcpy(current_chunk_ + (used_samples_ * unit_size_), data, unit_size_);
used_samples_++;
unused_samples_--;
while (count > 0) {
const uint8_t* chunk = data_chunks_[chunk_num];
- uint64_t copy_size = std::min(count * unit_size_,
+ uint64_t copy_size = min(count * unit_size_,
chunk_size_ - chunk_offs);
memcpy(dest_ptr, chunk + chunk_offs, copy_size);
return dest;
}
-SegmentRawDataIterator* Segment::begin_raw_sample_iteration(uint64_t start) const
+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_;
return it;
}
-void Segment::continue_raw_sample_iteration(SegmentRawDataIterator* it, uint64_t increase) const
+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_)
- {
- // Fail gracefully if we are asked to deliver data we don't have
return;
- } else {
- it->sample_index += increase;
- it->chunk_offs += (increase * unit_size_);
- }
+
+ it->sample_index += increase;
+ it->chunk_offs += (increase * unit_size_);
if (it->chunk_offs > (chunk_size_ - 1)) {
it->chunk_num++;
it->value = it->chunk + it->chunk_offs;
}
-void Segment::end_raw_sample_iteration(SegmentRawDataIterator* it) const
+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