comparison data/fileio/RemoteFile.cpp @ 208:8a3d68910b37

* Framework for retrieving files from remote locations

+/* -*- 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 <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_done(false),
+    m_progressDialog(0)
+{
+    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_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)));
+        m_http->get(url.path(), m_localFile);
+        m_ok = true;
+
+    } else if (scheme == "ftp") {
+
+        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);
+            }
+        }
+
+        m_ok = true;
+    }
+
+    if (m_ok) {
+        m_progressDialog = new QProgressDialog(tr("Downloading %1...").arg(url.toString()), tr("Cancel"), 0, 100);
+        m_progressDialog->show();
+    }
+}
+
+RemoteFile::~RemoteFile()
+{
+    delete m_ftp;
+    delete m_http;
+    delete m_localFile;
+    delete m_progressDialog;
+}
+
+bool
+RemoteFile::canHandleScheme(QUrl url)
+{
+    QString scheme = url.scheme().toLower();
+    return (scheme == "http" || scheme == "ftp");
+}
+
+void
+RemoteFile::wait()
+{
+    while (!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::dataTransferProgress(qint64 done, qint64 total)
+{
+    int percent = int((double(done) / double(total)) * 100.0 - 0.1);
+    emit progress(percent);
+
+    m_progressDialog->setValue(percent);
+}
+
+void
+RemoteFile::done(bool error)
+{
+    //!!! need to identify 404s etc in the return headers
+
+    emit progress(100);
+    m_ok = !error;
+    if (error) {
+        if (m_http) {
+            m_errorString = m_http->errorString();
+        } else if (m_ftp) {
+            m_errorString = m_ftp->errorString();
+        }
+    }
+
+    delete m_localFile;
+    m_localFile = 0;
+
+    delete m_progressDialog;
+    m_progressDialog = 0;
+
+    if (m_ok) {
+        QFileInfo fi(m_localFilename);
+        if (!fi.exists()) {
+            m_errorString = tr("Failed to create local file %1").arg(m_localFilename);
+            m_ok = false;
+        } else if (fi.size() == 0) {
+            m_errorString = tr("File contains no data!");
+            m_ok = false;
+        }
+    }
+    m_done = true;
+}
+
+QString
+RemoteFile::createLocalFile(QUrl url)
+{
+    //!!! should we actually put up dialogs for these errors? or propagate an exception?
+    
+    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;
+}