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, 387 insertions, 0 deletions

diff --git a/src/corelib/mimetypes/qmimemagicrule.cpp b/src/corelib/mimetypes/qmimemagicrule.cpp
new file mode 100644
index 0000000000..1dee62f6d0
--- /dev/null
+++ b/src/corelib/mimetypes/qmimemagicrule.cpp
@@ -0,0 +1,387 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#define QT_NO_CAST_FROM_ASCII
+
+#include "qmimemagicrule_p.h"
+
+#include <QtCore/QList>
+#include <QtCore/QDebug>
+#include <qendian.h>
+
+QT_BEGIN_NAMESPACE
+
+// in the same order as Type!
+static const char magicRuleTypes_string[] =
+    "invalid\0"
+    "string\0"
+    "host16\0"
+    "host32\0"
+    "big16\0"
+    "big32\0"
+    "little16\0"
+    "little32\0"
+    "byte\0"
+    "\0";
+
+static const int magicRuleTypes_indices[] = {
+    0, 8, 15, 22, 29, 35, 41, 50, 59, 65, 0
+};
+
+QMimeMagicRule::Type QMimeMagicRule::type(const QByteArray &theTypeName)
+{
+    for (int i = String; i <= Byte; ++i) {
+        if (theTypeName == magicRuleTypes_string + magicRuleTypes_indices[i])
+            return Type(i);
+    }
+    return Invalid;
+}
+
+QByteArray QMimeMagicRule::typeName(QMimeMagicRule::Type theType)
+{
+    return magicRuleTypes_string + magicRuleTypes_indices[theType];
+}
+
+class QMimeMagicRulePrivate
+{
+public:
+    bool operator==(const QMimeMagicRulePrivate &other) const;
+
+    QMimeMagicRule::Type type;
+    QByteArray value;
+    int startPos;
+    int endPos;
+    QByteArray mask;
+
+    QByteArray pattern;
+    quint32 number;
+    quint32 numberMask;
+
+    typedef bool (*MatchFunction)(const QMimeMagicRulePrivate *d, const QByteArray &data);
+    MatchFunction matchFunction;
+};
+
+bool QMimeMagicRulePrivate::operator==(const QMimeMagicRulePrivate &other) const
+{
+    return type == other.type &&
+           value == other.value &&
+           startPos == other.startPos &&
+           endPos == other.endPos &&
+           mask == other.mask &&
+           pattern == other.pattern &&
+           number == other.number &&
+           numberMask == other.numberMask &&
+           matchFunction == other.matchFunction;
+}
+
+// Used by both providers
+bool QMimeMagicRule::matchSubstring(const char *dataPtr, int dataSize, int rangeStart, int rangeLength,
+                                    int valueLength, const char *valueData, const char *mask)
+{
+    // Size of searched data.
+    // Example: value="ABC", rangeLength=3 -> we need 3+3-1=5 bytes (ABCxx,xABCx,xxABC would match)
+    const int dataNeeded = qMin(rangeLength + valueLength - 1, dataSize - rangeStart);
+
+    if (!mask) {
+        // callgrind says QByteArray::indexOf is much slower, since our strings are typically too
+        // short for be worth Boyer-Moore matching (1 to 71 bytes, 11 bytes on average).
+        bool found = false;
+        for (int i = rangeStart; i < rangeStart + rangeLength; ++i) {
+            if (i + valueLength > dataSize)
+                break;
+
+            if (memcmp(valueData, dataPtr + i, valueLength) == 0) {
+                found = true;
+                break;
+            }
+        }
+        if (!found)
+            return false;
+    } else {
+        bool found = false;
+        const char *readDataBase = dataPtr + rangeStart;
+        // Example (continued from above):
+        // deviceSize is 4, so dataNeeded was max'ed to 4.
+        // maxStartPos = 4 - 3 + 1 = 2, and indeed
+        // we need to check for a match a positions 0 and 1 (ABCx and xABC).
+        const int maxStartPos = dataNeeded - valueLength + 1;
+        for (int i = 0; i < maxStartPos; ++i) {
+            const char *d = readDataBase + i;
+            bool valid = true;
+            for (int idx = 0; idx < valueLength; ++idx) {
+                if (((*d++) & mask[idx]) != (valueData[idx] & mask[idx])) {
+                    valid = false;
+                    break;
+                }
+            }
+            if (valid)
+                found = true;
+        }
+        if (!found)
+            return false;
+    }
+    //qDebug() << "Found" << value << "in" << searchedData;
+    return true;
+}
+
+static bool matchString(const QMimeMagicRulePrivate *d, const QByteArray &data)
+{
+    const int rangeLength = d->endPos - d->startPos + 1;
+    return QMimeMagicRule::matchSubstring(data.constData(), data.size(), d->startPos, rangeLength, d->pattern.size(), d->pattern.constData(), d->mask.constData());
+}
+
+template <typename T>
+static bool matchNumber(const QMimeMagicRulePrivate *d, const QByteArray &data)
+{
+    const T value(d->number);
+    const T mask(d->numberMask);
+
+    //qDebug() << "matchNumber" << "0x" << QString::number(d->number, 16) << "size" << sizeof(T);
+    //qDebug() << "mask" << QString::number(d->numberMask, 16);
+
+    const char *p = data.constData() + d->startPos;
+    const char *e = data.constData() + qMin(data.size() - int(sizeof(T)), d->endPos + 1);
+    for ( ; p <= e; ++p) {
+        if ((*reinterpret_cast<const T*>(p) & mask) == (value & mask))
+            return true;
+    }
+
+    return false;
+}
+
+static inline QByteArray makePattern(const QByteArray &value)
+{
+    QByteArray pattern(value.size(), Qt::Uninitialized);
+    char *data = pattern.data();
+
+    const char *p = value.constData();
+    const char *e = p + value.size();
+    for ( ; p < e; ++p) {
+        if (*p == '\\' && ++p < e) {
+            if (*p == 'x') { // hex (\\xff)
+                char c = 0;
+                for (int i = 0; i < 2 && p + 1 < e; ++i) {
+                    ++p;
+                    if (*p >= '0' && *p <= '9')
+                        c = (c << 4) + *p - '0';
+                    else if (*p >= 'a' && *p <= 'f')
+                        c = (c << 4) + *p - 'a' + 10;
+                    else if (*p >= 'A' && *p <= 'F')
+                        c = (c << 4) + *p - 'A' + 10;
+                    else
+                        continue;
+                }
+                *data++ = c;
+            } else if (*p >= '0' && *p <= '7') { // oct (\\7, or \\77, or \\377)
+                char c = *p - '0';
+                if (p + 1 < e && p[1] >= '0' && p[1] <= '7') {
+                    c = (c << 3) + *(++p) - '0';
+                    if (p + 1 < e && p[1] >= '0' && p[1] <= '7' && p[-1] <= '3')
+                        c = (c << 3) + *(++p) - '0';
+                }
+                *data++ = c;
+            } else if (*p == 'n') {
+                *data++ = '\n';
+            } else if (*p == 'r') {
+                *data++ = '\r';
+            } else { // escaped
+                *data++ = *p;
+            }
+        } else {
+            *data++ = *p;
+        }
+    }
+    pattern.truncate(data - pattern.data());
+
+    return pattern;
+}
+
+QMimeMagicRule::QMimeMagicRule(QMimeMagicRule::Type theType,
+                               const QByteArray &theValue,
+                               int theStartPos,
+                               int theEndPos,
+                               const QByteArray &theMask) :
+    d(new QMimeMagicRulePrivate)
+{
+    Q_ASSERT(!theValue.isEmpty());
+
+    d->type = theType;
+    d->value = theValue;
+    d->startPos = theStartPos;
+    d->endPos = theEndPos;
+    d->mask = theMask;
+    d->matchFunction = 0;
+
+    if (d->type >= Host16 && d->type <= Byte) {
+        bool ok;
+        d->number = d->value.toUInt(&ok, 0); // autodetect
+        Q_ASSERT(ok);
+        d->numberMask = !d->mask.isEmpty() ? d->mask.toUInt(&ok, 0) : 0; // autodetect
+    }
+
+    switch (d->type) {
+    case String:
+        d->pattern = makePattern(d->value);
+        d->pattern.squeeze();
+        if (!d->mask.isEmpty()) {
+            Q_ASSERT(d->mask.size() >= 4 && d->mask.startsWith("0x"));
+            d->mask = QByteArray::fromHex(QByteArray::fromRawData(d->mask.constData() + 2, d->mask.size() - 2));
+            Q_ASSERT(d->mask.size() == d->pattern.size());
+        } else {
+            d->mask.fill(static_cast<char>(0xff), d->pattern.size());
+        }
+        d->mask.squeeze();
+        d->matchFunction = matchString;
+        break;
+    case Byte:
+        if (d->number <= quint8(-1)) {
+            if (d->numberMask == 0)
+                d->numberMask = quint8(-1);
+            d->matchFunction = matchNumber<quint8>;
+        }
+        break;
+    case Big16:
+    case Host16:
+    case Little16:
+        if (d->number <= quint16(-1)) {
+            d->number = d->type == Little16 ? qFromLittleEndian<quint16>(d->number) : qFromBigEndian<quint16>(d->number);
+            if (d->numberMask == 0)
+                d->numberMask = quint16(-1);
+            d->matchFunction = matchNumber<quint16>;
+        }
+        break;
+    case Big32:
+    case Host32:
+    case Little32:
+        if (d->number <= quint32(-1)) {
+            d->number = d->type == Little32 ? qFromLittleEndian<quint32>(d->number) : qFromBigEndian<quint32>(d->number);
+            if (d->numberMask == 0)
+                d->numberMask = quint32(-1);
+            d->matchFunction = matchNumber<quint32>;
+        }
+        break;
+    default:
+        break;
+    }
+}
+
+QMimeMagicRule::QMimeMagicRule(const QMimeMagicRule &other) :
+    d(new QMimeMagicRulePrivate(*other.d))
+{
+}
+
+QMimeMagicRule::~QMimeMagicRule()
+{
+}
+
+QMimeMagicRule &QMimeMagicRule::operator=(const QMimeMagicRule &other)
+{
+    *d = *other.d;
+    return *this;
+}
+
+bool QMimeMagicRule::operator==(const QMimeMagicRule &other) const
+{
+    return d == other.d ||
+           *d == *other.d;
+}
+
+QMimeMagicRule::Type QMimeMagicRule::type() const
+{
+    return d->type;
+}
+
+QByteArray QMimeMagicRule::value() const
+{
+    return d->value;
+}
+
+int QMimeMagicRule::startPos() const
+{
+    return d->startPos;
+}
+
+int QMimeMagicRule::endPos() const
+{
+    return d->endPos;
+}
+
+QByteArray QMimeMagicRule::mask() const
+{
+    QByteArray result = d->mask;
+    if (d->type == String) {
+        // restore '0x'
+        result = "0x" + result.toHex();
+    }
+    return result;
+}
+
+bool QMimeMagicRule::isValid() const
+{
+    return d->matchFunction;
+}
+
+bool QMimeMagicRule::matches(const QByteArray &data) const
+{
+    const bool ok = d->matchFunction && d->matchFunction(d.data(), data);
+    if (!ok)
+        return false;
+
+    // No submatch? Then we are done.
+    if (m_subMatches.isEmpty())
+        return true;
+
+    //qDebug() << "Checking" << m_subMatches.count() << "sub-rules";
+    // Check that one of the submatches matches too
+    for ( QList<QMimeMagicRule>::const_iterator it = m_subMatches.begin(), end = m_subMatches.end() ;
+          it != end ; ++it ) {
+        if ((*it).matches(data)) {
+            // One of the hierarchies matched -> mimetype recognized.
+            return true;
+        }
+    }
+    return false;
+
+
+}
+
+QT_END_NAMESPACE