pv/data/snapshot.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 "snapshot.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 Snapshot::Snapshot(unsigned int unit_size) :
  34         sample_count_(0),
  35         start_time_(0),
  36         capacity_(0),
  37         unit_size_(unit_size)
  38 {
  39         lock_guard<recursive_mutex> lock(mutex_);
  40         assert(unit_size_ > 0);
  41 }
  42
  43 Snapshot::~Snapshot()
  44 {
  45         lock_guard<recursive_mutex> lock(mutex_);
  46 }
  47
  48 uint64_t Snapshot::get_sample_count() const
  49 {
  50         lock_guard<recursive_mutex> lock(mutex_);
  51         return sample_count_;
  52 }
  53
  54 double Snapshot::start_time() const
  55 {
  56         return start_time_;
  57 }
  58
  59 unsigned int Snapshot::unit_size() const
  60 {
  61         return unit_size_;
  62 }
  63
  64 void Snapshot::set_capacity(const uint64_t new_capacity)
  65 {
  66         lock_guard<recursive_mutex> lock(mutex_);
  67
  68         assert(capacity_ >= sample_count_);
  69         if (new_capacity > capacity_) {
  70                 capacity_ = new_capacity;
  71                 data_.resize((new_capacity * unit_size_) + sizeof(uint64_t));
  72         }
  73 }
  74
  75 uint64_t Snapshot::capacity() const
  76 {
  77         lock_guard<recursive_mutex> lock(mutex_);
  78         return data_.size();
  79 }
  80
  81 void Snapshot::append_data(void *data, uint64_t samples)
  82 {
  83         lock_guard<recursive_mutex> lock(mutex_);
  84
  85         assert(capacity_ >= sample_count_);
  86
  87         // Ensure there's enough capacity to copy.
  88         const uint64_t free_space = capacity_ - sample_count_;
  89         if (free_space < samples) {
  90                 set_capacity(sample_count_ + samples);
  91         }
  92
  93         memcpy((uint8_t*)data_.data() + sample_count_ * unit_size_,
  94                 data, samples * unit_size_);
  95         sample_count_ += samples;
  96 }
  97
  98 } // namespace data
  99 } // namespace pv