From 9f3a9830162f379d6f856c84668c3664df6d6477 Mon Sep 17 00:00:00 2001
From: Christian Kandeler <christian.kandeler@qt.io>
Date: Mon, 18 Mar 2019 15:02:53 +0100
Subject: Introduce the session command
MIME-Version: 1.0
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Offers a JSON-based API for interaction with other tools via stdin/
stdout.
This allows for proper qbs support in IDEs that do not use Qt or even
C++.

Change-Id: Ib051a40b7ebe1c6e0c3147cca9bd96e7daec1fde
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
---
 src/app/qbs/stdinreader.cpp | 146 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 src/app/qbs/stdinreader.cpp

(limited to 'src/app/qbs/stdinreader.cpp')

diff --git a/src/app/qbs/stdinreader.cpp b/src/app/qbs/stdinreader.cpp
new file mode 100644
index 000000000..4f784505d
--- /dev/null
+++ b/src/app/qbs/stdinreader.cpp
@@ -0,0 +1,146 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qbs.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "stdinreader.h"
+
+#include <tools/hostosinfo.h>
+
+#include <QtCore/qfile.h>
+#include <QtCore/qsocketnotifier.h>
+
+#include <cerrno>
+#include <cstring>
+
+#ifdef Q_OS_WIN32
+#include <qt_windows.h>
+#include <QtCore/qtimer.h>
+#else
+#include <fcntl.h>
+#endif
+
+namespace qbs {
+namespace Internal {
+
+class UnixStdinReader : public StdinReader
+{
+public:
+    UnixStdinReader(QObject *parent) : StdinReader(parent), m_notifier(0, QSocketNotifier::Read) {}
+
+private:
+    void start() override
+    {
+        if (!m_stdIn.open(stdin, QIODevice::ReadOnly)) {
+            emit errorOccurred(tr("Cannot read from standard input."));
+            return;
+        }
+        const auto emitError = [this] {
+            emit errorOccurred(tr("Failed to make standard input non-blocking: %1")
+                               .arg(QLatin1String(std::strerror(errno))));
+        };
+#ifdef Q_OS_UNIX
+        const int flags = fcntl(0, F_GETFL, 0);
+        if (flags == -1) {
+            emitError();
+            return;
+        }
+        if (fcntl(0, F_SETFL, flags | O_NONBLOCK)) {
+            emitError();
+            return;
+        }
+#endif
+        connect(&m_notifier, &QSocketNotifier::activated, this, [this] {
+            emit dataAvailable(m_stdIn.readAll());
+        });
+    }
+
+    QFile m_stdIn;
+    QSocketNotifier m_notifier;
+};
+
+class WindowsStdinReader : public StdinReader
+{
+public:
+    WindowsStdinReader(QObject *parent) : StdinReader(parent) {}
+
+private:
+    void start() override
+    {
+#ifdef Q_OS_WIN32
+        m_stdinHandle = GetStdHandle(STD_INPUT_HANDLE);
+        if (!m_stdinHandle) {
+            emit errorOccurred(tr("Failed to create handle for standard input."));
+            return;
+        }
+
+        // A timer seems slightly less awful than to block in a thread
+        // (how would we abort that one?), but ideally we'd like
+        // to have a signal-based approach like in the Unix variant.
+        const auto timer = new QTimer(this);
+        connect(timer, &QTimer::timeout, this, [this] {
+            char buf[1024];
+            DWORD bytesAvail;
+            PeekNamedPipe(m_stdinHandle, nullptr, 0, nullptr, &bytesAvail, nullptr);
+            while (bytesAvail > 0) {
+                DWORD bytesRead;
+                ReadFile(m_stdinHandle, buf, std::min<DWORD>(bytesAvail, sizeof buf), &bytesRead,
+                         nullptr);
+                emit dataAvailable(QByteArray(buf, bytesRead));
+                bytesAvail -= bytesRead;
+            }
+        });
+        timer->start(10);
+#endif
+    }
+
+#ifdef Q_OS_WIN32
+    HANDLE m_stdinHandle;
+#endif
+};
+
+StdinReader *StdinReader::create(QObject *parent)
+{
+    if (HostOsInfo::isWindowsHost())
+        return new WindowsStdinReader(parent);
+    return new UnixStdinReader(parent);
+}
+
+StdinReader::StdinReader(QObject *parent) : QObject(parent) { }
+
+} // namespace Internal
+} // namespace qbs
-- 
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