view data/fileio/RemoteFile.cpp @ 211:e2bbb58e6df6

Several changes related to referring to remote URLs for sessions and files:
* Pull file dialog wrapper functions out from MainWindow into FileFinder
* If a file referred to in a session is not found at its expected location,
  try a few other alternatives (same location as the session file or same
  location as the last audio file) before asking the user to locate it
* Allow user to give a URL when locating an audio file, not just locate on
  the filesystem
* Make wave file models remember the "original" location (e.g. URL) of
  the audio file, not just the actual location from which the data was
  loaded (e.g. local copy of that URL) -- when saving a session, use the
  original location so as not to refer to a temporary file
* Clean up incompletely-downloaded local copies of files

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2007 QMUL.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#include "RemoteFile.h"
#include "base/TempDirectory.h"
#include "base/Exceptions.h"

#include <QHttp>
#include <QFtp>
#include <QFileInfo>
#include <QDir>
#include <QApplication>
#include <QProgressDialog>
#include <QHttpResponseHeader>

#include <iostream>

int
RemoteFile::m_count = 0;

QMutex
RemoteFile::m_fileCreationMutex;

RemoteFile::RemoteFile(QUrl url) :
    m_ftp(0),
    m_http(0),
    m_localFile(0),
    m_ok(false),
    m_lastStatus(0),
    m_done(false),
    m_progressDialog(0),
    m_progressShowTimer(this)
{
    if (!canHandleScheme(url)) {
        std::cerr << "RemoteFile::RemoteFile: ERROR: Unsupported scheme in URL \"" << url.toString().toStdString() << "\"" << std::endl;
        return;
    }

    m_localFilename = createLocalFile(url);
    if (m_localFilename == "") return;
    m_localFile = new QFile(m_localFilename);
    m_localFile->open(QFile::WriteOnly);

    QString scheme = url.scheme().toLower();

    if (scheme == "http") {

        m_ok = true;
        m_http = new QHttp(url.host(), url.port(80));
        connect(m_http, SIGNAL(done(bool)), this, SLOT(done(bool)));
        connect(m_http, SIGNAL(dataReadProgress(int, int)),
                this, SLOT(dataReadProgress(int, int)));
        connect(m_http, SIGNAL(responseHeaderReceived(const QHttpResponseHeader &)),
                this, SLOT(responseHeaderReceived(const QHttpResponseHeader &)));
        m_http->get(url.path(), m_localFile);

    } else if (scheme == "ftp") {

        m_ok = true;
        m_ftp = new QFtp;
        connect(m_ftp, SIGNAL(done(bool)), this, SLOT(done(bool)));
        connect(m_ftp, SIGNAL(dataTransferProgress(qint64, qint64)),
                this, SLOT(dataTransferProgress(qint64, qint64)));
        m_ftp->connectToHost(url.host(), url.port(21));

        QString username = url.userName();
        if (username == "") {
            username = "anonymous";
        }

        QString password = url.password();
        if (password == "") {
            password = QString("%1@%2").arg(getenv("USER")).arg(getenv("HOST"));
        }

        QStringList path = url.path().split('/');
        for (QStringList::iterator i = path.begin(); i != path.end(); ) {
            QString bit = *i;
            ++i;
            if (i != path.end()) {
                m_ftp->cd(*i);
            } else {
                m_ftp->get(*i, m_localFile);
            }
        }
    }

    if (m_ok) {
        m_progressDialog = new QProgressDialog(tr("Downloading %1...").arg(url.toString()), tr("Cancel"), 0, 100);
        m_progressDialog->hide();
        connect(&m_progressShowTimer, SIGNAL(timeout()),
                this, SLOT(showProgressDialog()));
        connect(m_progressDialog, SIGNAL(canceled()), this, SLOT(cancelled()));
        m_progressShowTimer.setSingleShot(true);
        m_progressShowTimer.start(2000);
    }
}

RemoteFile::~RemoteFile()
{
    cleanup();
}

void
RemoteFile::cleanup()
{
//    std::cerr << "RemoteFile::cleanup" << std::endl;
    m_done = true;
    delete m_http;
    m_http = 0;
    delete m_ftp;
    m_ftp = 0;
    delete m_progressDialog;
    m_progressDialog = 0;
    delete m_localFile;
    m_localFile = 0;
}

bool
RemoteFile::canHandleScheme(QUrl url)
{
    QString scheme = url.scheme().toLower();
    return (scheme == "http" || scheme == "ftp");
}

bool
RemoteFile::isAvailable()
{
    while (m_ok && (!m_done && m_lastStatus == 0)) {
        QApplication::processEvents();
    }
    bool available = true;
    if (!m_ok) available = false;
    else available = (m_lastStatus / 100 == 2);
    std::cerr << "RemoteFile::isAvailable: " << (available ? "yes" : "no")
              << std::endl;
    return available;
}

void
RemoteFile::wait()
{
    while (m_ok && !m_done) {
        QApplication::processEvents();
    }
}

bool
RemoteFile::isOK() const
{
    return m_ok;
}

bool
RemoteFile::isDone() const
{
    return m_done;
}

QString
RemoteFile::getLocalFilename() const
{
    return m_localFilename;
}

QString
RemoteFile::getErrorString() const
{
    return m_errorString;
}

void
RemoteFile::dataReadProgress(int done, int total)
{
    dataTransferProgress(done, total);
}

void
RemoteFile::responseHeaderReceived(const QHttpResponseHeader &resp)
{
    m_lastStatus = resp.statusCode();
    if (m_lastStatus / 100 >= 4) {
        m_errorString = QString("%1 %2")
            .arg(resp.statusCode()).arg(resp.reasonPhrase());
        std::cerr << "RemoteFile::responseHeaderReceived: "
                  << m_errorString.toStdString() << std::endl;
    } else {
        std::cerr << "RemoteFile::responseHeaderReceived: "
                  << m_lastStatus << std::endl;
    }        
}

void
RemoteFile::dataTransferProgress(qint64 done, qint64 total)
{
    if (!m_progressDialog) return;

    int percent = int((double(done) / double(total)) * 100.0 - 0.1);
    emit progress(percent);

    if (percent > 0) {
        m_progressDialog->setValue(percent);
        m_progressDialog->show();
    }
}

void
RemoteFile::cancelled()
{
    deleteLocalFile();
    m_done = true;
    m_ok = false;
    m_errorString = tr("Download cancelled");
}

void
RemoteFile::done(bool error)
{
//    std::cerr << "RemoteFile::done(" << error << ")" << std::endl;

    if (m_done) return;

    emit progress(100);

    if (error) {
        if (m_http) {
            m_errorString = m_http->errorString();
        } else if (m_ftp) {
            m_errorString = m_ftp->errorString();
        }
    }

    if (m_lastStatus / 100 >= 4) {
        error = true;
    }

    cleanup();

    if (!error) {
        QFileInfo fi(m_localFilename);
        if (!fi.exists()) {
            m_errorString = tr("Failed to create local file %1").arg(m_localFilename);
            error = true;
        } else if (fi.size() == 0) {
            m_errorString = tr("File contains no data!");
            error = true;
        }
    }

    if (error) {
        deleteLocalFile();
    }

    m_ok = !error;
    m_done = true;
}

void
RemoteFile::deleteLocalFile()
{
//    std::cerr << "RemoteFile::deleteLocalFile" << std::endl;

    cleanup();

    if (m_localFilename == "") return;

    m_fileCreationMutex.lock();

    if (!QFile(m_localFilename).remove()) {
        std::cerr << "RemoteFile::deleteLocalFile: ERROR: Failed to delete file \"" << m_localFilename.toStdString() << "\"" << std::endl;
    } else {
        m_localFilename = "";
    }

    m_fileCreationMutex.unlock();

    m_done = true;
}

void
RemoteFile::showProgressDialog()
{
    if (m_progressDialog) m_progressDialog->show();
}

QString
RemoteFile::createLocalFile(QUrl url)
{
    QDir dir;
    try {
        dir = TempDirectory::getInstance()->getSubDirectoryPath("download");
    } catch (DirectoryCreationFailed f) {
        std::cerr << "RemoteFile::createLocalFile: ERROR: Failed to create temporary directory: " << f.what() << std::endl;
        return "";
    }

    QString filepart = url.path().section('/', -1, -1,
                                          QString::SectionSkipEmpty);

    QString extension = filepart.section('.', -1);
    QString base = filepart;
    if (extension != "") {
        base = base.left(base.length() - extension.length() - 1);
    }
    if (base == "") base = "remote";

    QString filename;

    if (extension == "") {
        filename = base;
    } else {
        filename = QString("%1.%2").arg(base).arg(extension);
    }

    QString filepath(dir.filePath(filename));

    std::cerr << "RemoteFile::createLocalFile: URL is \"" << url.toString().toStdString() << "\", dir is \"" << dir.path().toStdString() << "\", base \"" << base.toStdString() << "\", extension \"" << extension.toStdString() << "\", filebase \"" << filename.toStdString() << "\", filename \"" << filepath.toStdString() << "\"" << std::endl;

    m_fileCreationMutex.lock();
    ++m_count;

    if (QFileInfo(filepath).exists() ||
        !QFile(filepath).open(QFile::WriteOnly)) {

        std::cerr << "RemoteFile::createLocalFile: Failed to create local file \""
                  << filepath.toStdString() << "\" for URL \""
                  << url.toString().toStdString() << "\" (or file already exists): appending suffix instead" << std::endl;


        if (extension == "") {
            filename = QString("%1_%2").arg(base).arg(m_count);
        } else {
            filename = QString("%1_%2.%3").arg(base).arg(m_count).arg(extension);
        }
        filepath = dir.filePath(filename);

        if (QFileInfo(filepath).exists() ||
            !QFile(filepath).open(QFile::WriteOnly)) {

            std::cerr << "RemoteFile::createLocalFile: ERROR: Failed to create local file \""
                      << filepath.toStdString() << "\" for URL \""
                      << url.toString().toStdString() << "\" (or file already exists)" << std::endl;

            m_fileCreationMutex.unlock();
            return "";
        }
    }

    m_fileCreationMutex.unlock();

    std::cerr << "RemoteFile::createLocalFile: url "
              << url.toString().toStdString() << " -> local filename "
              << filepath.toStdString() << std::endl;

    return filepath;
}