pv/data/segment.cpp

   1 /*
   2  * This file is part of the PulseView project.
   3  *
   4  * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "segment.hpp"
  21
  22 #include <assert.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 using std::lock_guard;
  27 using std::recursive_mutex;
  28
  29 namespace pv {
  30 namespace data {
  31
  32 Segment::Segment(uint64_t samplerate, unsigned int unit_size) :
  33         sample_count_(0),
  34         start_time_(0),
  35         samplerate_(samplerate),
  36         capacity_(0),
  37         unit_size_(unit_size)
  38 {
  39         lock_guard<recursive_mutex> lock(mutex_);
  40         assert(unit_size_ > 0);
  41 }
  42
  43 Segment::~Segment()
  44 {
  45         lock_guard<recursive_mutex> lock(mutex_);
  46 }
  47
  48 uint64_t Segment::get_sample_count() const
  49 {
  50         lock_guard<recursive_mutex> lock(mutex_);
  51         return sample_count_;
  52 }
  53
  54 const pv::util::Timestamp& Segment::start_time() const
  55 {
  56         return start_time_;
  57 }
  58
  59 double Segment::samplerate() const
  60 {
  61         return samplerate_;
  62 }
  63
  64 void Segment::set_samplerate(double samplerate)
  65 {
  66         samplerate_ = samplerate;
  67 }
  68
  69 unsigned int Segment::unit_size() const
  70 {
  71         return unit_size_;
  72 }
  73
  74 void Segment::set_capacity(const uint64_t new_capacity)
  75 {
  76         lock_guard<recursive_mutex> lock(mutex_);
  77
  78         assert(capacity_ >= sample_count_);
  79         if (new_capacity > capacity_) {
  80                 // If we're out of memory, this will throw std::bad_alloc
  81                 data_.resize((new_capacity * unit_size_) + sizeof(uint64_t));
  82                 capacity_ = new_capacity;
  83         }
  84 }
  85
  86 uint64_t Segment::capacity() const
  87 {
  88         lock_guard<recursive_mutex> lock(mutex_);
  89         return data_.size();
  90 }
  91
  92 void Segment::append_data(void *data, uint64_t samples)
  93 {
  94         lock_guard<recursive_mutex> lock(mutex_);
  95
  96         assert(capacity_ >= sample_count_);
  97
  98         // Ensure there's enough capacity to copy.
  99         const uint64_t free_space = capacity_ - sample_count_;
 100         if (free_space < samples)
 101                 set_capacity(sample_count_ + samples);
 102
 103         memcpy((uint8_t*)data_.data() + sample_count_ * unit_size_,
 104                 data, samples * unit_size_);
 105         sample_count_ += samples;
 106 }
 107
 108 } // namespace data
 109 } // namespace pv