decoderstack.cpp

Go to the documentation of this file.

/*
 * This file is part of the PulseView project.
 *
 * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * 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
 */

#include <libsigrokdecode/libsigrokdecode.h>

#include <stdexcept>

#include <QDebug>

#include "decoderstack.hpp"

#include <pv/data/logic.hpp>
#include <pv/data/logicsegment.hpp>
#include <pv/data/decode/decoder.hpp>
#include <pv/data/decode/annotation.hpp>
#include <pv/session.hpp>
#include <pv/view/logicsignal.hpp>

using std::lock_guard;
using std::mutex;
using boost::optional;
using std::unique_lock;
using std::deque;
using std::make_pair;
using std::max;
using std::min;
using std::list;
using std::map;
using std::pair;
using std::shared_ptr;
using std::vector;

using namespace pv::data::decode;

namespace pv {
namespace data {

const double DecoderStack::DecodeMargin = 1.0;
const double DecoderStack::DecodeThreshold = 0.2;
const int64_t DecoderStack::DecodeChunkLength = 4096;
const unsigned int DecoderStack::DecodeNotifyPeriod = 65536;

mutex DecoderStack::global_decode_mutex_;

DecoderStack::DecoderStack(pv::Session &session,
    const srd_decoder *const dec) :
    session_(session),
    start_time_(0),
    samplerate_(0),
    sample_count_(0),
    frame_complete_(false),
    samples_decoded_(0)
{
    connect(&session_, SIGNAL(frame_began()),
        this, SLOT(on_new_frame()));
    connect(&session_, SIGNAL(data_received()),
        this, SLOT(on_data_received()));
    connect(&session_, SIGNAL(frame_ended()),
        this, SLOT(on_frame_ended()));

    stack_.push_back(shared_ptr<decode::Decoder>(
        new decode::Decoder(dec)));
}

DecoderStack::~DecoderStack()
{
    if (decode_thread_.joinable()) {
        interrupt_ = true;
        input_cond_.notify_one();
        decode_thread_.join();
    }
}

const std::list< std::shared_ptr<decode::Decoder> >&
DecoderStack::stack() const
{
    return stack_;
}

void DecoderStack::push(std::shared_ptr<decode::Decoder> decoder)
{
    assert(decoder);
    stack_.push_back(decoder);
}

void DecoderStack::remove(int index)
{
    assert(index >= 0);
    assert(index < (int)stack_.size());

    // Find the decoder in the stack
    auto iter = stack_.begin();
    for (int i = 0; i < index; i++, iter++)
        assert(iter != stack_.end());

    // Delete the element
    stack_.erase(iter);
}

double DecoderStack::samplerate() const
{
    return samplerate_;
}

const pv::util::Timestamp& DecoderStack::start_time() const
{
    return start_time_;
}

int64_t DecoderStack::samples_decoded() const
{
    lock_guard<mutex> decode_lock(output_mutex_);
    return samples_decoded_;
}

std::vector<Row> DecoderStack::get_visible_rows() const
{
    lock_guard<mutex> lock(output_mutex_);

    vector<Row> rows;

    for (const shared_ptr<decode::Decoder> &dec : stack_) {
        assert(dec);
        if (!dec->shown())
            continue;

        const srd_decoder *const decc = dec->decoder();
        assert(dec->decoder());

        // Add a row for the decoder if it doesn't have a row list
        if (!decc->annotation_rows)
            rows.push_back(Row(decc));

        // Add the decoder rows
        for (const GSList *l = decc->annotation_rows; l; l = l->next) {
            const srd_decoder_annotation_row *const ann_row =
                (srd_decoder_annotation_row *)l->data;
            assert(ann_row);
            rows.push_back(Row(decc, ann_row));
        }
    }

    return rows;
}

void DecoderStack::get_annotation_subset(
    std::vector<pv::data::decode::Annotation> &dest,
    const Row &row, uint64_t start_sample,
    uint64_t end_sample) const
{
    lock_guard<mutex> lock(output_mutex_);

    const auto iter = rows_.find(row);
    if (iter != rows_.end())
        (*iter).second.get_annotation_subset(dest,
            start_sample, end_sample);
}

QString DecoderStack::error_message()
{
    lock_guard<mutex> lock(output_mutex_);
    return error_message_;
}

void DecoderStack::clear()
{
    sample_count_ = 0;
    frame_complete_ = false;
    samples_decoded_ = 0;
    error_message_ = QString();
    rows_.clear();
    class_rows_.clear();
}

void DecoderStack::begin_decode()
{
    shared_ptr<pv::view::LogicSignal> logic_signal;
    shared_ptr<pv::data::Logic> data;

    if (decode_thread_.joinable()) {
        interrupt_ = true;
        input_cond_.notify_one();
        decode_thread_.join();
    }

    clear();

    // Check that all decoders have the required channels
    for (const shared_ptr<decode::Decoder> &dec : stack_)
        if (!dec->have_required_channels()) {
            error_message_ = tr("One or more required channels "
                "have not been specified");
            return;
        }

    // Add classes
    for (const shared_ptr<decode::Decoder> &dec : stack_) {
        assert(dec);
        const srd_decoder *const decc = dec->decoder();
        assert(dec->decoder());

        // Add a row for the decoder if it doesn't have a row list
        if (!decc->annotation_rows)
            rows_[Row(decc)] = decode::RowData();

        // Add the decoder rows
        for (const GSList *l = decc->annotation_rows; l; l = l->next) {
            const srd_decoder_annotation_row *const ann_row =
                (srd_decoder_annotation_row *)l->data;
            assert(ann_row);

            const Row row(decc, ann_row);

            // Add a new empty row data object
            rows_[row] = decode::RowData();

            // Map out all the classes
            for (const GSList *ll = ann_row->ann_classes;
                ll; ll = ll->next)
                class_rows_[make_pair(decc,
                    GPOINTER_TO_INT(ll->data))] = row;
        }
    }

    // We get the logic data of the first channel in the list.
    // This works because we are currently assuming all
    // LogicSignals have the same data/segment
    for (const shared_ptr<decode::Decoder> &dec : stack_)
        if (dec && !dec->channels().empty() &&
            ((logic_signal = (*dec->channels().begin()).second)) &&
            ((data = logic_signal->logic_data())))
            break;

    if (!data)
        return;

    // Check we have a segment of data
    const deque< shared_ptr<pv::data::LogicSegment> > &segments =
        data->logic_segments();
    if (segments.empty())
        return;
    segment_ = segments.front();

    // Get the samplerate and start time
    start_time_ = segment_->start_time();
    samplerate_ = segment_->samplerate();
    if (samplerate_ == 0.0)
        samplerate_ = 1.0;

    interrupt_ = false;
    decode_thread_ = std::thread(&DecoderStack::decode_proc, this);
}

uint64_t DecoderStack::max_sample_count() const
{
    uint64_t max_sample_count = 0;

    for (auto i = rows_.cbegin(); i != rows_.end(); i++)
        max_sample_count = max(max_sample_count,
            (*i).second.get_max_sample());

    return max_sample_count;
}

optional<int64_t> DecoderStack::wait_for_data() const
{
    unique_lock<mutex> input_lock(input_mutex_);
    while (!interrupt_ && !frame_complete_ &&
        samples_decoded_ >= sample_count_)
        input_cond_.wait(input_lock);
    return boost::make_optional(!interrupt_ &&
        (samples_decoded_ < sample_count_ || !frame_complete_),
        sample_count_);
}

void DecoderStack::decode_data(
    const int64_t sample_count, const unsigned int unit_size,
    srd_session *const session)
{
    uint8_t chunk[DecodeChunkLength];

    const unsigned int chunk_sample_count =
        DecodeChunkLength / segment_->unit_size();

    for (int64_t i = 0; !interrupt_ && i < sample_count;
            i += chunk_sample_count) {
        lock_guard<mutex> decode_lock(global_decode_mutex_);

        const int64_t chunk_end = min(
            i + chunk_sample_count, sample_count);
        segment_->get_samples(chunk, i, chunk_end);

        if (srd_session_send(session, i, chunk_end, chunk,
                (chunk_end - i) * unit_size, unit_size) != SRD_OK) {
            error_message_ = tr("Decoder reported an error");
            break;
        }

        {
            lock_guard<mutex> lock(output_mutex_);
            samples_decoded_ = chunk_end;
        }

        if (i % DecodeNotifyPeriod == 0)
            new_decode_data();
    }

    new_decode_data();
}

void DecoderStack::decode_proc()
{
    optional<int64_t> sample_count;
    srd_session *session;
    srd_decoder_inst *prev_di = nullptr;

    assert(segment_);

    // Create the session
    srd_session_new(&session);
    assert(session);

    // Create the decoders
    const unsigned int unit_size = segment_->unit_size();

    for (const shared_ptr<decode::Decoder> &dec : stack_) {
        srd_decoder_inst *const di = dec->create_decoder_inst(session);

        if (!di) {
            error_message_ = tr("Failed to create decoder instance");
            srd_session_destroy(session);
            return;
        }

        if (prev_di)
            srd_inst_stack (session, prev_di, di);

        prev_di = di;
    }

    // Get the intial sample count
    {
        unique_lock<mutex> input_lock(input_mutex_);
        sample_count = sample_count_ = segment_->get_sample_count();
    }

    // Start the session
    srd_session_metadata_set(session, SRD_CONF_SAMPLERATE,
        g_variant_new_uint64((uint64_t)samplerate_));

    srd_pd_output_callback_add(session, SRD_OUTPUT_ANN,
        DecoderStack::annotation_callback, this);

    srd_session_start(session);

    do {
        decode_data(*sample_count, unit_size, session);
    } while (error_message_.isEmpty() && (sample_count = wait_for_data()));

    // Destroy the session
    srd_session_destroy(session);
}

void DecoderStack::annotation_callback(srd_proto_data *pdata, void *decoder)
{
    assert(pdata);
    assert(decoder);

    DecoderStack *const d = (DecoderStack*)decoder;
    assert(d);

    lock_guard<mutex> lock(d->output_mutex_);

    const Annotation a(pdata);

    // Find the row
    assert(pdata->pdo);
    assert(pdata->pdo->di);
    const srd_decoder *const decc = pdata->pdo->di->decoder;
    assert(decc);

    auto row_iter = d->rows_.end();

    // Try looking up the sub-row of this class
    const auto r = d->class_rows_.find(make_pair(decc, a.format()));
    if (r != d->class_rows_.end())
        row_iter = d->rows_.find((*r).second);
    else {
        // Failing that, use the decoder as a key
        row_iter = d->rows_.find(Row(decc));    
    }

    assert(row_iter != d->rows_.end());
    if (row_iter == d->rows_.end()) {
        qDebug() << "Unexpected annotation: decoder = " << decc <<
            ", format = " << a.format();
        assert(0);
        return;
    }

    // Add the annotation
    (*row_iter).second.push_annotation(a);
}

void DecoderStack::on_new_frame()
{
    begin_decode();
}

void DecoderStack::on_data_received()
{
    {
        unique_lock<mutex> lock(input_mutex_);
        if (segment_)
            sample_count_ = segment_->get_sample_count();
    }
    input_cond_.notify_one();
}

void DecoderStack::on_frame_ended()
{
    {
        unique_lock<mutex> lock(input_mutex_);
        if (segment_)
            frame_complete_ = true;
    }
    input_cond_.notify_one();
}

} // namespace data
} // namespace pv