Rename Core to Base (Closes #3733).

src/base/utils/string.cpp

@@ -0,0 +1,211 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2015  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include <QByteArray>
+#include <QString>
+#include <QLocale>
+#include <cmath>
+#include "string.h"
+
+QString Utils::String::fromStdString(const std::string &str)
+{
+    return QString::fromUtf8(str.c_str());
+}
+
+std::string Utils::String::toStdString(const QString &str)
+{
+    QByteArray utf8 = str.toUtf8();
+    return std::string(utf8.constData(), utf8.length());
+}
+
+// uses lessThan comparison
+bool Utils::String::naturalSort(const QString &left, const QString &right, bool &result)
+{
+    // Return value indicates if functions was successful
+    // result argument will contain actual comparison result if function was successful
+    int posL = 0;
+    int posR = 0;
+    do {
+        forever {
+            if (posL == left.size() || posR == right.size())
+                return false; // No data
+
+            QChar leftChar = left.at(posL);
+            QChar rightChar = right.at(posR);
+            bool leftCharIsDigit = leftChar.isDigit();
+            bool rightCharIsDigit = rightChar.isDigit();
+            if (leftCharIsDigit != rightCharIsDigit)
+                return false; // Digit positions mismatch
+
+            if (leftCharIsDigit)
+                break; // Both are digit, break this loop and compare numbers
+
+            if (leftChar != rightChar)
+                return false; // Strings' subsets before digit do not match
+
+            ++posL;
+            ++posR;
+        }
+
+        QString temp;
+        while (posL < left.size()) {
+            if (left.at(posL).isDigit())
+                temp += left.at(posL);
+            else
+                break;
+            posL++;
+        }
+        int numL = temp.toInt();
+        temp.clear();
+
+        while (posR < right.size()) {
+            if (right.at(posR).isDigit())
+                temp += right.at(posR);
+            else
+                break;
+            posR++;
+        }
+        int numR = temp.toInt();
+
+        if (numL != numR) {
+            result = (numL < numR);
+            return true;
+        }
+
+        // Strings + digits do match and we haven't hit string end
+        // Do another round
+
+    } while (true);
+
+    return false;
+}
+
+Utils::String::NaturalCompare::NaturalCompare()
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 2, 0))
+#if defined(Q_OS_WIN)
+    // Without ICU library, QCollator doesn't support `setNumericMode(true)` on OS older than Win7
+    if(QSysInfo::windowsVersion() < QSysInfo::WV_WINDOWS7)
+        return;
+#endif
+    m_collator.setNumericMode(true);
+    m_collator.setCaseSensitivity(Qt::CaseInsensitive);
+#endif
+}
+
+bool Utils::String::NaturalCompare::operator()(const QString &l, const QString &r)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 2, 0))
+#if defined(Q_OS_WIN)
+    // Without ICU library, QCollator doesn't support `setNumericMode(true)` on OS older than Win7
+    if(QSysInfo::windowsVersion() < QSysInfo::WV_WINDOWS7)
+        return lessThan(l, r);
+#endif
+    return (m_collator.compare(l, r) < 0);
+#else
+    return lessThan(l, r);
+#endif
+}
+
+bool Utils::String::NaturalCompare::lessThan(const QString &left, const QString &right)
+{
+    // Return value `false` indicates `right` should go before `left`, otherwise, after
+    int posL = 0;
+    int posR = 0;
+    while (true) {
+        while (true) {
+            if (posL == left.size() || posR == right.size())
+                return (left.size() < right.size());  // when a shorter string is another string's prefix, shorter string place before longer string
+
+            QChar leftChar = left[posL].toLower();
+            QChar rightChar = right[posR].toLower();
+            if (leftChar == rightChar)
+                ;  // compare next character
+            else if (leftChar.isDigit() && rightChar.isDigit())
+                break; // Both are digits, break this loop and compare numbers
+            else
+                return leftChar < rightChar;
+
+            ++posL;
+            ++posR;
+        }
+
+        int startL = posL;
+        while ((posL < left.size()) && left[posL].isDigit())
+            ++posL;
+#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
+        int numL = left.midRef(startL, posL - startL).toInt();
+#else
+        int numL = left.mid(startL, posL - startL).toInt();
+#endif
+
+        int startR = posR;
+        while ((posR < right.size()) && right[posR].isDigit())
+            ++posR;
+#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
+        int numR = right.midRef(startR, posR - startR).toInt();
+#else
+        int numR = right.mid(startR, posR - startR).toInt();
+#endif
+
+        if (numL != numR)
+            return (numL < numR);
+
+        // Strings + digits do match and we haven't hit string end
+        // Do another round
+    }
+    return false;
+}
+
+// to send numbers instead of strings with suffixes
+QString Utils::String::fromDouble(double n, int precision)
+{
+    /* HACK because QString rounds up. Eg QString::number(0.999*100.0, 'f' ,1) == 99.9
+    ** but QString::number(0.9999*100.0, 'f' ,1) == 100.0 The problem manifests when
+    ** the number has more digits after the decimal than we want AND the digit after
+    ** our 'wanted' is >= 5. In this case our last digit gets rounded up. So for each
+    ** precision we add an extra 0 behind 1 in the below algorithm. */
+
+    double prec = std::pow(10.0, precision);
+    return QLocale::system().toString(std::floor(n * prec) / prec, 'f', precision);
+}
+
+// Implements constant-time comparison to protect against timing attacks
+// Taken from https://crackstation.net/hashing-security.htm
+bool Utils::String::slowEquals(const QByteArray &a, const QByteArray &b)
+{
+    int lengthA = a.length();
+    int lengthB = b.length();
+
+    int diff = lengthA ^ lengthB;
+    for (int i = 0; (i < lengthA) && (i < lengthB); i++)
+        diff |= a[i] ^ b[i];
+
+    return (diff == 0);
+}