Long live Qt 4.5!

1 files changed, 323 insertions, 0 deletions

diff --git a/src/corelib/tools/qstringmatcher.cpp b/src/corelib/tools/qstringmatcher.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qstringmatcher.h"
+#include "qunicodetables_p.h"
+
+QT_BEGIN_NAMESPACE
+
+static void bm_init_skiptable(const ushort *uc, int len, uchar *skiptable, Qt::CaseSensitivity cs)
+{
+    int l = qMin(len, 255);
+    memset(skiptable, l, 256*sizeof(uchar));
+    uc += len - l;
+    if (cs == Qt::CaseSensitive) {
+        while (l--) {
+            skiptable[*uc & 0xff] = l;
+            uc++;
+        }
+    } else {
+        const ushort *start = uc;
+        while (l--) {
+            skiptable[foldCase(uc, start) & 0xff] = l;
+            uc++;
+        }
+    }
+}
+
+static inline int bm_find(const ushort *uc, uint l, int index, const ushort *puc, uint pl,
+                          const uchar *skiptable, Qt::CaseSensitivity cs)
+{
+    if (pl == 0)
+        return index > (int)l ? -1 : index;
+    const uint pl_minus_one = pl - 1;
+
+    register const ushort *current = uc + index + pl_minus_one;
+    const ushort *end = uc + l;
+    if (cs == Qt::CaseSensitive) {
+        while (current < end) {
+            uint skip = skiptable[*current & 0xff];
+            if (!skip) {
+                // possible match
+                while (skip < pl) {
+                    if (*(current - skip) != puc[pl_minus_one-skip])
+                        break;
+                    skip++;
+                }
+                if (skip > pl_minus_one) // we have a match
+                    return (current - uc) - pl_minus_one;
+
+                // in case we don't have a match we are a bit inefficient as we only skip by one
+                // when we have the non matching char in the string.
+                if (skiptable[*(current - skip) & 0xff] == pl)
+                    skip = pl - skip;
+                else
+                    skip = 1;
+            }
+            if (current > end - skip)
+                break;
+            current += skip;
+        }
+    } else {
+        while (current < end) {
+            uint skip = skiptable[foldCase(current, uc) & 0xff];
+            if (!skip) {
+                // possible match
+                while (skip < pl) {
+                    if (foldCase(current - skip, uc) != foldCase(puc + pl_minus_one - skip, puc))
+                        break;
+                    skip++;
+                }
+                if (skip > pl_minus_one) // we have a match
+                    return (current - uc) - pl_minus_one;
+                // in case we don't have a match we are a bit inefficient as we only skip by one
+                // when we have the non matching char in the string.
+                if (skiptable[foldCase(current - skip, uc) & 0xff] == pl)
+                    skip = pl - skip;
+                else
+                    skip = 1;
+            }
+            if (current > end - skip)
+                break;
+            current += skip;
+        }
+    }
+    return -1; // not found
+}
+
+/*!
+    \class QStringMatcher
+    \brief The QStringMatcher class holds a sequence of characters that
+    can be quickly matched in a Unicode string.
+
+    \ingroup tools
+    \ingroup text
+
+    This class is useful when you have a sequence of \l{QChar}s that
+    you want to repeatedly match against some strings (perhaps in a
+    loop), or when you want to search for the same sequence of
+    characters multiple times in the same string. Using a matcher
+    object and indexIn() is faster than matching a plain QString with
+    QString::indexOf() if repeated matching takes place. This class
+    offers no benefit if you are doing one-off string matches.
+
+    Create the QStringMatcher with the QString you want to search
+    for. Then call indexIn() on the QString that you want to search.
+
+    \sa QString, QByteArrayMatcher, QRegExp
+*/
+
+/*!
+    Constructs an empty string matcher that won't match anything.
+    Call setPattern() to give it a pattern to match.
+*/
+QStringMatcher::QStringMatcher()
+    : d_ptr(0), q_cs(Qt::CaseSensitive)
+{
+    qMemSet(q_data, 0, sizeof(q_data));
+}
+
+/*!
+    Constructs a string matcher that will search for \a pattern, with
+    case sensitivity \a cs.
+
+    Call indexIn() to perform a search.
+*/
+QStringMatcher::QStringMatcher(const QString &pattern, Qt::CaseSensitivity cs)
+    : d_ptr(0), q_pattern(pattern), q_cs(cs)
+{
+    p.uc = pattern.unicode();
+    p.len = pattern.size();
+    bm_init_skiptable((const ushort *)p.uc, p.len, p.q_skiptable, cs);
+}
+
+/*!
+    \fn QStringMatcher::QStringMatcher(const QChar *uc, int length, Qt::CaseSensitivity cs)
+    \since 4.5
+
+    Constructs a string matcher that will search for the pattern referred to
+    by \a uc with the given \a length and case sensitivity specified by \a cs.
+*/
+QStringMatcher::QStringMatcher(const QChar *uc, int len, Qt::CaseSensitivity cs)
+    : d_ptr(0), q_cs(cs)
+{
+    p.uc = uc;
+    p.len = len;
+    bm_init_skiptable((const ushort *)p.uc, len, p.q_skiptable, cs);
+}
+
+/*!
+    Copies the \a other string matcher to this string matcher.
+*/
+QStringMatcher::QStringMatcher(const QStringMatcher &other)
+    : d_ptr(0)
+{
+    operator=(other);
+}
+
+/*!
+    Destroys the string matcher.
+*/
+QStringMatcher::~QStringMatcher()
+{
+}
+
+/*!
+    Assigns the \a other string matcher to this string matcher.
+*/
+QStringMatcher &QStringMatcher::operator=(const QStringMatcher &other)
+{
+    if (this != &other) {
+        q_pattern = other.q_pattern;
+        q_cs = other.q_cs;
+        qMemCopy(q_data, other.q_data, sizeof(q_data));
+    }
+    return *this;
+}
+
+/*!
+    Sets the string that this string matcher will search for to \a
+    pattern.
+
+    \sa pattern(), setCaseSensitivity(), indexIn()
+*/
+void QStringMatcher::setPattern(const QString &pattern)
+{
+    q_pattern = pattern;
+    p.uc = pattern.unicode();
+    p.len = pattern.size();
+    bm_init_skiptable((const ushort *)pattern.unicode(), pattern.size(), p.q_skiptable, q_cs);
+}
+
+/*!
+    \fn QString QStringMatcher::pattern() const
+
+    Returns the string pattern that this string matcher will search
+    for.
+
+    \sa setPattern()
+*/
+
+QString QStringMatcher::pattern() const
+{
+    if (!q_pattern.isEmpty())
+        return q_pattern;
+    return QString(p.uc, p.len);
+}
+
+/*!
+    Sets the case sensitivity setting of this string matcher to \a
+    cs.
+
+    \sa caseSensitivity(), setPattern(), indexIn()
+*/
+void QStringMatcher::setCaseSensitivity(Qt::CaseSensitivity cs)
+{
+    if (cs == q_cs)
+        return;
+    bm_init_skiptable((const ushort *)q_pattern.unicode(), q_pattern.size(), p.q_skiptable, cs);
+    q_cs = cs;
+}
+
+/*!
+    Searches the string \a str from character position \a from
+    (default 0, i.e. from the first character), for the string
+    pattern() that was set in the constructor or in the most recent
+    call to setPattern(). Returns the position where the pattern()
+    matched in \a str, or -1 if no match was found.
+
+    \sa setPattern(), setCaseSensitivity()
+*/
+int QStringMatcher::indexIn(const QString &str, int from) const
+{
+    if (from < 0)
+        from = 0;
+    return bm_find((const ushort *)str.unicode(), str.size(), from,
+                   (const ushort *)p.uc, p.len,
+                   p.q_skiptable, q_cs);
+}
+
+/*!
+    \since 4.5
+
+    Searches the string starting at \a str (of length \a length) from
+    character position \a from (default 0, i.e. from the first
+    character), for the string pattern() that was set in the
+    constructor or in the most recent call to setPattern(). Returns
+    the position where the pattern() matched in \a str, or -1 if no
+    match was found.
+
+    \sa setPattern(), setCaseSensitivity()
+*/
+int QStringMatcher::indexIn(const QChar *str, int length, int from) const
+{
+    if (from < 0)
+        from = 0;
+    return bm_find((const ushort *)str, length, from,
+                   (const ushort *)p.uc, p.len,
+                   p.q_skiptable, q_cs);
+}
+
+/*!
+    \fn Qt::CaseSensitivity QStringMatcher::caseSensitivity() const
+
+    Returns the case sensitivity setting for this string matcher.
+
+    \sa setCaseSensitivity()
+*/
+
+/*!
+    \internal
+*/
+
+int qFindStringBoyerMoore(
+    const QChar *haystack, int haystackLen, int haystackOffset,
+    const QChar *needle, int needleLen, Qt::CaseSensitivity cs)
+{
+    uchar skiptable[256];
+    bm_init_skiptable((const ushort *)needle, needleLen, skiptable, cs);
+    if (haystackOffset < 0)
+        haystackOffset = 0;
+    return bm_find((const ushort *)haystack, haystackLen, haystackOffset,
+                   (const ushort *)needle, needleLen, skiptable, cs);
+}
+
+QT_END_NAMESPACE