Import QMimeType / QMimeDatabase into QtCore.

History of the development before the import:
ssh://codereview.qt-project.org/playground/mimetypes.git

Mimetype definitions come from shared-mime-info where available (UNIX systems),
loaded using a mmap'ed binary cache generated by update-mime-database.
As a fallback if no cache is found, we parse the raw XML files otherwise.

This makes the MIME type support fast and with very low memory usage on UNIX,
and it makes it easy to use on Windows (no dependency on shared-mime-info,
Qt even includes a freedesktop.xml file to use if none are found on the system).

Change-Id: I27b05008216ff936dc463bd80d3893422bfb940e
Reviewed-by: Richard J. Moore <rich@kde.org>

1 files changed, 240 insertions, 0 deletions

diff --git a/src/corelib/mimetypes/qmimeglobpattern.cpp b/src/corelib/mimetypes/qmimeglobpattern.cpp
new file mode 100644
index 0000000000..de26dbaf15
--- /dev/null
+++ b/src/corelib/mimetypes/qmimeglobpattern.cpp
@@ -0,0 +1,240 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qmimeglobpattern_p.h"
+
+#include <QRegExp>
+#include <QStringList>
+#include <QDebug>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \internal
+    \class QMimeGlobMatchResult
+    \brief The QMimeGlobMatchResult class accumulates results from glob matching.
+
+    Handles glob weights, and preferring longer matches over shorter matches.
+*/
+
+void QMimeGlobMatchResult::addMatch(const QString &mimeType, int weight, const QString &pattern)
+{
+    // Is this a lower-weight pattern than the last match? Skip this match then.
+    if (weight < m_weight)
+        return;
+    bool replace = weight > m_weight;
+    if (!replace) {
+        // Compare the length of the match
+        if (pattern.length() < m_matchingPatternLength)
+            return; // too short, ignore
+        else if (pattern.length() > m_matchingPatternLength) {
+            // longer: clear any previous match (like *.bz2, when pattern is *.tar.bz2)
+            replace = true;
+        }
+    }
+    if (replace) {
+        m_matchingMimeTypes.clear();
+        // remember the new "longer" length
+        m_matchingPatternLength = pattern.length();
+        m_weight = weight;
+    }
+    m_matchingMimeTypes.append(mimeType);
+    if (pattern.startsWith(QLatin1String("*.")))
+        m_foundSuffix = pattern.mid(2);
+}
+
+/*!
+    \internal
+    \class QMimeGlobPattern
+    \brief The QMimeGlobPattern class contains the glob pattern for file names for MIME type matching.
+
+    \sa QMimeType, QMimeDatabase, QMimeMagicRuleMatcher, QMimeMagicRule
+*/
+
+bool QMimeGlobPattern::matchFileName(const QString &inputFilename) const
+{
+    // "Applications MUST match globs case-insensitively, except when the case-sensitive
+    // attribute is set to true."
+    // The constructor takes care of putting case-insensitive patterns in lowercase.
+    const QString filename = m_caseSensitivity == Qt::CaseInsensitive ? inputFilename.toLower() : inputFilename;
+
+    const int pattern_len = m_pattern.length();
+    if (!pattern_len)
+        return false;
+    const int len = filename.length();
+
+    const int starCount = m_pattern.count(QLatin1Char('*'));
+
+    // Patterns like "*~", "*.extension"
+    if (m_pattern[0] == QLatin1Char('*') && m_pattern.indexOf(QLatin1Char('[')) == -1 && starCount == 1)
+    {
+        if (len + 1 < pattern_len) return false;
+
+        const QChar *c1 = m_pattern.unicode() + pattern_len - 1;
+        const QChar *c2 = filename.unicode() + len - 1;
+        int cnt = 1;
+        while (cnt < pattern_len && *c1-- == *c2--)
+            ++cnt;
+        return cnt == pattern_len;
+    }
+
+    // Patterns like "README*" (well this is currently the only one like that...)
+    if (starCount == 1 && m_pattern.at(pattern_len - 1) == QLatin1Char('*')) {
+        if (len + 1 < pattern_len) return false;
+        if (m_pattern.at(0) == QLatin1Char('*'))
+            return filename.indexOf(m_pattern.mid(1, pattern_len - 2)) != -1;
+
+        const QChar *c1 = m_pattern.unicode();
+        const QChar *c2 = filename.unicode();
+        int cnt = 1;
+        while (cnt < pattern_len && *c1++ == *c2++)
+           ++cnt;
+        return cnt == pattern_len;
+    }
+
+    // Names without any wildcards like "README"
+    if (m_pattern.indexOf(QLatin1Char('[')) == -1 && starCount == 0 && m_pattern.indexOf(QLatin1Char('?')))
+        return (m_pattern == filename);
+
+    // Other (quite rare) patterns, like "*.anim[1-9j]": use slow but correct method
+    const QRegExp rx(m_pattern, Qt::CaseSensitive, QRegExp::WildcardUnix);
+    return rx.exactMatch(filename);
+}
+
+static bool isFastPattern(const QString &pattern)
+{
+   // starts with "*.", has no other '*' and no other '.'
+   return pattern.lastIndexOf(QLatin1Char('*')) == 0
+      && pattern.lastIndexOf(QLatin1Char('.')) == 1
+      // and contains no other special character
+      && !pattern.contains(QLatin1Char('?'))
+      && !pattern.contains(QLatin1Char('['))
+      ;
+}
+
+void QMimeAllGlobPatterns::addGlob(const QMimeGlobPattern &glob)
+{
+    const QString &pattern = glob.pattern();
+    Q_ASSERT(!pattern.isEmpty());
+
+    // Store each patterns into either m_fastPatternDict (*.txt, *.html etc. with default weight 50)
+    // or for the rest, like core.*, *.tar.bz2, *~, into highWeightPatternOffset (>50)
+    // or lowWeightPatternOffset (<=50)
+
+    if (glob.weight() == 50 && isFastPattern(pattern) && !glob.isCaseSensitive()) {
+        // The bulk of the patterns is *.foo with weight 50 --> those go into the fast patterns hash.
+        const QString extension = pattern.mid(2).toLower();
+        QStringList &patterns = m_fastPatterns[extension]; // find or create
+        // This would just slow things down: if (!patterns.contains(glob.mimeType()))
+        patterns.append(glob.mimeType());
+    } else {
+        if (glob.weight() > 50) {
+            // This would just slow things down: if (!m_highWeightGlobs.hasPattern(glob.mimeType(), glob.pattern()))
+            m_highWeightGlobs.append(glob);
+        } else {
+            //This would just slow things down: if (!m_lowWeightGlobs.hasPattern(glob.mimeType(), glob.pattern()))
+            m_lowWeightGlobs.append(glob);
+        }
+    }
+}
+
+void QMimeAllGlobPatterns::removeMimeType(const QString &mimeType)
+{
+    QMutableHashIterator<QString, QStringList> it(m_fastPatterns);
+    while (it.hasNext()) {
+        it.next().value().removeAll(mimeType);
+    }
+    m_highWeightGlobs.removeMimeType(mimeType);
+    m_lowWeightGlobs.removeMimeType(mimeType);
+}
+
+void QMimeGlobPatternList::match(QMimeGlobMatchResult &result,
+                                 const QString &fileName) const
+{
+
+    QMimeGlobPatternList::const_iterator it = this->constBegin();
+    const QMimeGlobPatternList::const_iterator endIt = this->constEnd();
+    for (; it != endIt; ++it) {
+        const QMimeGlobPattern &glob = *it;
+        if (glob.matchFileName(fileName))
+            result.addMatch(glob.mimeType(), glob.weight(), glob.pattern());
+    }
+}
+
+QStringList QMimeAllGlobPatterns::matchingGlobs(const QString &fileName, QString *foundSuffix) const
+{
+    // First try the high weight matches (>50), if any.
+    QMimeGlobMatchResult result;
+    m_highWeightGlobs.match(result, fileName);
+    if (result.m_matchingMimeTypes.isEmpty()) {
+
+        // Now use the "fast patterns" dict, for simple *.foo patterns with weight 50
+        // (which is most of them, so this optimization is definitely worth it)
+        const int lastDot = fileName.lastIndexOf(QLatin1Char('.'));
+        if (lastDot != -1) { // if no '.', skip the extension lookup
+            const int ext_len = fileName.length() - lastDot - 1;
+            const QString simpleExtension = fileName.right(ext_len).toLower();
+            // (toLower because fast patterns are always case-insensitive and saved as lowercase)
+
+            const QStringList matchingMimeTypes = m_fastPatterns.value(simpleExtension);
+            foreach (const QString &mime, matchingMimeTypes) {
+                result.addMatch(mime, 50, QLatin1String("*.") + simpleExtension);
+            }
+            // Can't return yet; *.tar.bz2 has to win over *.bz2, so we need the low-weight mimetypes anyway,
+            // at least those with weight 50.
+        }
+
+        // Finally, try the low weight matches (<=50)
+        m_lowWeightGlobs.match(result, fileName);
+    }
+    if (foundSuffix)
+        *foundSuffix = result.m_foundSuffix;
+    return result.m_matchingMimeTypes;
+}
+
+void QMimeAllGlobPatterns::clear()
+{
+    m_fastPatterns.clear();
+    m_highWeightGlobs.clear();
+    m_lowWeightGlobs.clear();
+}
+
+QT_END_NAMESPACE