Move text-related code out of corelib/tools/ to corelib/text/

This includes byte array, string, char, unicode, locale, collation and
regular expressions.

Change-Id: I8b125fa52c8c513eb57a0f1298b91910e5a0d786
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 348 insertions, 0 deletions

diff --git a/src/corelib/text/qstringmatcher.cpp b/src/corelib/text/qstringmatcher.cpp
new file mode 100644
index 0000000000..167a467480
--- /dev/null
+++ b/src/corelib/text/qstringmatcher.cpp
@@ -0,0 +1,348 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2019 Mail.ru Group.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 "qstringmatcher.h"
+
+QT_BEGIN_NAMESPACE
+
+static void bm_init_skiptable(const ushort *uc, qsizetype len, uchar *skiptable, Qt::CaseSensitivity cs)
+{
+    int l = int(qMin(len, qsizetype(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 qsizetype bm_find(const ushort *uc, qsizetype l, qsizetype index, const ushort *puc, qsizetype pl,
+                          const uchar *skiptable, Qt::CaseSensitivity cs)
+{
+    if (pl == 0)
+        return index > l ? -1 : index;
+    const qsizetype pl_minus_one = pl - 1;
+
+    const ushort *current = uc + index + pl_minus_one;
+    const ushort *end = uc + l;
+    if (cs == Qt::CaseSensitive) {
+        while (current < end) {
+            qsizetype 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) {
+            qsizetype 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
+    \inmodule QtCore
+    \brief The QStringMatcher class holds a sequence of characters that
+    can be quickly matched in a Unicode string.
+
+    \ingroup tools
+    \ingroup string-processing
+
+    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(nullptr), q_cs(Qt::CaseSensitive)
+{
+    memset(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(nullptr), 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)
+    : QStringMatcher(QStringView(uc, len), cs)
+{
+}
+
+/*!
+    \fn QStringMatcher::QStringMatcher(QStringView pattern, Qt::CaseSensitivity cs = Qt::CaseSensitive)
+    \since 5.14
+
+    Constructs a string matcher that will search for \a pattern, with
+    case sensitivity \a cs.
+
+    Call indexIn() to perform a search.
+*/
+QStringMatcher::QStringMatcher(QStringView str, Qt::CaseSensitivity cs)
+    : d_ptr(nullptr), q_cs(cs)
+{
+    p.uc = str.data();
+    p.len = int(str.size());
+    bm_init_skiptable((const ushort *)p.uc, p.len, p.q_skiptable, cs);
+}
+/*!
+    Copies the \a other string matcher to this string matcher.
+*/
+QStringMatcher::QStringMatcher(const QStringMatcher &other)
+    : d_ptr(nullptr)
+{
+    operator=(other);
+}
+
+/*!
+    Destroys the string matcher.
+*/
+QStringMatcher::~QStringMatcher()
+{
+    Q_UNUSED(d_ptr);
+}
+
+/*!
+    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;
+        memcpy(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 *)p.uc, p.len, 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
+{
+    return int(indexIn(QStringView(str), from));
+}
+
+/*!
+    \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
+{
+    return int(indexIn(QStringView(str, length), from));
+}
+
+/*!
+    \since 5.14
+
+    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()
+*/
+qsizetype QStringMatcher::indexIn(QStringView str, qsizetype from) const
+{
+    if (from < 0)
+        from = 0;
+    return bm_find((const ushort *)str.data(), str.size(), 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
+*/
+
+qsizetype qFindStringBoyerMoore(
+    QStringView haystack, qsizetype haystackOffset,
+    QStringView needle, Qt::CaseSensitivity cs)
+{
+    uchar skiptable[256];
+    bm_init_skiptable((const ushort *)needle.data(), needle.size(), skiptable, cs);
+    if (haystackOffset < 0)
+        haystackOffset = 0;
+    return bm_find((const ushort *)haystack.data(), haystack.size(), haystackOffset,
+                   (const ushort *)needle.data(), needle.size(), skiptable, cs);
+}
+
+QT_END_NAMESPACE