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, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include "segment.hpp"
  22
  23 #include <assert.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 using std::lock_guard;
  28 using std::recursive_mutex;
  29
  30 namespace pv {
  31 namespace data {
  32
  33 Segment::Segment(uint64_t samplerate, unsigned int unit_size) :
  34         sample_count_(0),
  35         start_time_(0),
  36         samplerate_(samplerate),
  37         capacity_(0),
  38         unit_size_(unit_size)
  39 {
  40         lock_guard<recursive_mutex> lock(mutex_);
  41         assert(unit_size_ > 0);
  42 }
  43
  44 Segment::~Segment()
  45 {
  46         lock_guard<recursive_mutex> lock(mutex_);
  47 }
  48
  49 uint64_t Segment::get_sample_count() const
  50 {
  51         lock_guard<recursive_mutex> lock(mutex_);
  52         return sample_count_;
  53 }
  54
  55 double Segment::start_time() const
  56 {
  57         return start_time_;
  58 }
  59
  60 double Segment::samplerate() const
  61 {
  62         return samplerate_;
  63 }
  64
  65 void Segment::set_samplerate(double samplerate)
  66 {
  67         samplerate_ = samplerate;
  68 }
  69
  70 unsigned int Segment::unit_size() const
  71 {
  72         return unit_size_;
  73 }
  74
  75 void Segment::set_capacity(const uint64_t new_capacity)
  76 {
  77         lock_guard<recursive_mutex> lock(mutex_);
  78
  79         assert(capacity_ >= sample_count_);
  80         if (new_capacity > capacity_) {
  81                 // If we're out of memory, this will throw std::bad_alloc
  82                 data_.resize((new_capacity * unit_size_) + sizeof(uint64_t));
  83                 capacity_ = new_capacity;
  84         }
  85 }
  86
  87 uint64_t Segment::capacity() const
  88 {
  89         lock_guard<recursive_mutex> lock(mutex_);
  90         return data_.size();
  91 }
  92
  93 void Segment::append_data(void *data, uint64_t samples)
  94 {
  95         lock_guard<recursive_mutex> lock(mutex_);
  96
  97         assert(capacity_ >= sample_count_);
  98
  99         // Ensure there's enough capacity to copy.
 100         const uint64_t free_space = capacity_ - sample_count_;
 101         if (free_space < samples) {
 102                 set_capacity(sample_count_ + samples);
 103         }
 104
 105         memcpy((uint8_t*)data_.data() + sample_count_ * unit_size_,
 106                 data, samples * unit_size_);
 107         sample_count_ += samples;
 108 }
 109
 110 } // namespace data
 111 } // namespace pv