FileSearch: Fixes for making FileIterator actual ForwardIterator

Give iterators 'a' and 'b', if a == b, either both are non-dereference
or *a and *b are references bound to the same object.
Also add missing default constructor, copy constructor and copy
assignment operator.

Change-Id: I53fd30a620155b9faa9850b2ffcf546376b14cff
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/libs/utils/filesearch.cpp

@@ -494,14 +494,8 @@ void FileIterator::advance(FileIterator::const_iterator *it) const
         return;
     ++it->m_index;
     const_cast<FileIterator *>(this)->update(it->m_index);
-    if (it->m_index < currentFileCount()) {
-        it->m_item.filePath = fileAt(it->m_index);
-        it->m_item.encoding = codecAt(it->m_index);
-    } else {
+    if (it->m_index >= currentFileCount())
         it->m_index = -1; // == end
-        it->m_item.filePath.clear();
-        it->m_item.encoding = 0;
-    }
 }
 
 FileIterator::const_iterator FileIterator::begin() const
@@ -509,25 +503,30 @@ FileIterator::const_iterator FileIterator::begin() const
     const_cast<FileIterator *>(this)->update(0);
     if (currentFileCount() == 0)
         return end();
-    return FileIterator::const_iterator(this,
-                                        FileIterator::Item(fileAt(0), codecAt(0)),
-                                        0/*index*/);
+    return FileIterator::const_iterator(this, 0/*index*/);
 }
 
 FileIterator::const_iterator FileIterator::end() const
 {
-    return FileIterator::const_iterator(this, FileIterator::Item(QString(), 0),
-                                        -1/*end*/);
+    return FileIterator::const_iterator(this, -1/*end*/);
 }
 
 // #pragma mark -- FileListIterator
 
+QTextCodec *encodingAt(const QList<QTextCodec *> encodings, int index)
+{
+    if (index >= 0 && index < encodings.size())
+        return encodings.at(index);
+    return QTextCodec::codecForLocale();
+}
+
 FileListIterator::FileListIterator(const QStringList &fileList,
                                    const QList<QTextCodec *> encodings)
-    : m_files(fileList),
-      m_encodings(encodings),
-      m_maxIndex(-1)
+    : m_maxIndex(-1)
 {
+    m_items.reserve(fileList.size());
+    for (int i = 0; i < fileList.size(); ++i)
+        m_items.append(Item(fileList.at(i), encodingAt(encodings, i)));
 }
 
 void FileListIterator::update(int requestedIndex)
@@ -538,22 +537,17 @@ void FileListIterator::update(int requestedIndex)
 
 int FileListIterator::currentFileCount() const
 {
-    return m_files.size();
+    return m_items.size();
 }
 
-QString FileListIterator::fileAt(int index) const
+const FileIterator::Item &FileListIterator::itemAt(int index) const
 {
-    return m_files.at(index);
-}
-
-QTextCodec *FileListIterator::codecAt(int index) const
-{
-    return m_encodings.at(index);
+    return m_items.at(index);
 }
 
 int FileListIterator::maxProgress() const
 {
-    return m_files.size();
+    return m_items.size();
 }
 
 int FileListIterator::currentProgress() const
@@ -561,13 +555,6 @@ int FileListIterator::currentProgress() const
     return m_maxIndex + 1;
 }
 
-QTextCodec *FileListIterator::encodingAt(int index) const
-{
-    if (index >= 0 && index < m_encodings.size())
-        return m_encodings.at(index);
-    return QTextCodec::codecForLocale();
-}
-
 // #pragma mark -- SubDirFileIterator
 
 namespace {
@@ -589,12 +576,17 @@ SubDirFileIterator::SubDirFileIterator(const QStringList &directories, const QSt
     }
 }
 
+SubDirFileIterator::~SubDirFileIterator()
+{
+    qDeleteAll(m_items);
+}
+
 void SubDirFileIterator::update(int index)
 {
-    if (index < m_files.size())
+    if (index < m_items.size())
         return;
     // collect files from the directories until we have enough for the given index
-    while (!m_dirs.isEmpty() && index >= m_files.size()) {
+    while (!m_dirs.isEmpty() && index >= m_items.size()) {
         QDir dir = m_dirs.pop();
         const qreal dirProgressMax = m_progressValues.pop();
         const bool processed = m_processedValues.pop();
@@ -607,9 +599,10 @@ void SubDirFileIterator::update(int index)
                     QDir::Files|QDir::Hidden);
                 QStringListIterator it(fileEntries);
                 it.toBack();
+                m_items.reserve(m_items.size() + fileEntries.size());
                 while (it.hasPrevious()) {
                     const QString &file = it.previous();
-                    m_files.append(dir.path()+ QLatin1Char('/') +file);
+                    m_items.append(new Item(dir.path()+ QLatin1Char('/') + file, m_encoding));
                 }
                 m_progress += dirProgressMax;
             } else {
@@ -630,24 +623,18 @@ void SubDirFileIterator::update(int index)
             m_progress += dirProgressMax;
         }
     }
-    if (index >= m_files.size())
+    if (index >= m_items.size())
         m_progress = MAX_PROGRESS;
 }
 
 int SubDirFileIterator::currentFileCount() const
 {
-    return m_files.size();
-}
-
-QString SubDirFileIterator::fileAt(int index) const
-{
-    return m_files.at(index);
+    return m_items.size();
 }
 
-QTextCodec *SubDirFileIterator::codecAt(int index) const
+const FileIterator::Item &SubDirFileIterator::itemAt(int index) const
 {
-    Q_UNUSED(index)
-    return m_encoding;
+    return *m_items.at(index);
 }
 
 int SubDirFileIterator::maxProgress() const

src/libs/utils/filesearch.h

@@ -28,10 +28,10 @@
 
 #include "utils_global.h"
 
+#include <QDir>
 #include <QFuture>
 #include <QMap>
 #include <QStack>
-#include <QDir>
 #include <QTextDocument>
 
 QT_FORWARD_DECLARE_CLASS(QTextCodec)
@@ -44,6 +44,7 @@ public:
     class Item
     {
     public:
+        Item() : encoding(nullptr) { }
         Item(const QString &path, QTextCodec *codec)
             : filePath(path), encoding(codec)
         {}
@@ -62,11 +63,15 @@ public:
         typedef const value_type *pointer;
         typedef const value_type &reference;
 
-        const_iterator(const FileIterator *parent, Item item, int id)
-            : m_parent(parent), m_item(item), m_index(id)
+        const_iterator() : m_parent(nullptr), m_index(-1) { }
+        const_iterator(const FileIterator *parent, int id)
+            : m_parent(parent), m_index(id)
         {}
-        const Item operator*() const { return m_item; }
-        const Item *operator->() const { return &m_item; }
+        const_iterator(const const_iterator &) = default;
+        const_iterator &operator=(const const_iterator &) = default;
+
+        reference operator*() const { return m_parent->itemAt(m_index); }
+        pointer operator->() const { return &m_parent->itemAt(m_index); }
         void operator++() { m_parent->advance(this); }
         bool operator==(const const_iterator &other) const
         {
@@ -75,23 +80,22 @@ public:
         bool operator!=(const const_iterator &other) const { return !operator==(other); }
 
         const FileIterator *m_parent;
-        Item m_item;
         int m_index; // -1 == end
     };
 
     virtual ~FileIterator() {}
-    void advance(const_iterator *it) const;
     const_iterator begin() const;
     const_iterator end() const;
 
     virtual int maxProgress() const = 0;
     virtual int currentProgress() const = 0;
 
+    void advance(const_iterator *it) const;
+    virtual const Item &itemAt(int index) const = 0;
+
 protected:
     virtual void update(int requestedIndex) = 0;
     virtual int currentFileCount() const = 0;
-    virtual QString fileAt(int index) const = 0;
-    virtual QTextCodec *codecAt(int index) const = 0;
 };
 
 class QTCREATOR_UTILS_EXPORT FileListIterator : public FileIterator
@@ -106,13 +110,10 @@ public:
 protected:
     void update(int requestedIndex) override;
     int currentFileCount() const override;
-    QString fileAt(int index) const override;
-    QTextCodec *codecAt(int index) const override;
+    const Item &itemAt(int index) const override;
 
 private:
-    QTextCodec *encodingAt(int index) const;
-    QStringList m_files;
-    QList<QTextCodec *> m_encodings;
+    QVector<Item> m_items;
     int m_maxIndex;
 };
 
@@ -121,6 +122,7 @@ class QTCREATOR_UTILS_EXPORT SubDirFileIterator : public FileIterator
 public:
     SubDirFileIterator(const QStringList &directories, const QStringList &filters,
                        QTextCodec *encoding = 0);
+    ~SubDirFileIterator();
 
     int maxProgress() const override;
     int currentProgress() const override;
@@ -128,8 +130,7 @@ public:
 protected:
     void update(int requestedIndex) override;
     int currentFileCount() const override;
-    QString fileAt(int index) const override;
-    QTextCodec *codecAt(int index) const override;
+    const Item &itemAt(int index) const override;
 
 private:
     QStringList m_filters;
@@ -138,7 +139,8 @@ private:
     QStack<qreal> m_progressValues;
     QStack<bool> m_processedValues;
     qreal m_progress;
-    QStringList m_files;
+    // Use heap allocated objects directly because we want references to stay valid even after resize
+    QList<Item *> m_items;
 };
 
 class QTCREATOR_UTILS_EXPORT FileSearchResult