#91 [Core][UI] functions profiler::writeTreesToFile(), profiler::writeTreesToStream() are now working. Snapshot feature is now working: select an area on Diagram (with right mouse button or double-click) and press Snapshot button to save it to separate file.

easy_profiler_core/include/easy/reader.h

@@ -283,86 +283,41 @@ namespace profiler {
 
     class PROFILER_API SerializedData EASY_FINAL
     {
-        char*  m_data;
+        uint64_t m_size;
-        size_t m_size;
+        char*    m_data;
 
     public:
 
         SerializedData(const SerializedData&) = delete;
         SerializedData& operator = (const SerializedData&) = delete;
 
-        SerializedData() : m_data(nullptr), m_size(0)
+        SerializedData();
-        {
-        }
 
-        SerializedData(SerializedData&& that) : m_data(that.m_data), m_size(that.m_size)
+        SerializedData(SerializedData&& that);
-        {
-            that.m_data = nullptr;
-            that.m_size = 0;
-        }
 
-        ~SerializedData()
+        ~SerializedData();
-        {
-            clear();
-        }
 
         void set(uint64_t _size);
+
         void extend(uint64_t _size);
 
-        SerializedData& operator = (SerializedData&& that)
+        SerializedData& operator = (SerializedData&& that);
-        {
-            set(that.m_data, that.m_size);
-            that.m_data = nullptr;
-            that.m_size = 0;
-            return *this;
-        }
 
-        char* operator [] (uint64_t i)
+        char* operator [] (uint64_t i);
-        {
-            return m_data + i;
-        }
 
-        const char* operator [] (uint64_t i) const
+        const char* operator [] (uint64_t i) const;
-        {
-            return m_data + i;
-        }
 
-        bool empty() const
+        bool empty() const;
-        {
-            return m_size == 0;
-        }
 
-        uint64_t size() const
+        uint64_t size() const;
-        {
-            return m_size;
-        }
 
-        char* data()
+        char* data();
-        {
-            return m_data;
-        }
 
-        const char* data() const
+        const char* data() const;
-        {
-            return m_data;
-        }
 
-        void clear()
+        void clear();
-        {
-            set(nullptr, 0);
-        }
 
-        void swap(SerializedData& other)
+        void swap(SerializedData& other);
-        {
-            char* d = other.m_data;
-            uint64_t sz = other.m_size;
-
-            other.m_data = m_data;
-            other.m_size = m_size;
-
-            m_data = d;
-            m_size = (size_t)sz;
-        }
 
     private:
 
@@ -409,6 +364,7 @@ extern "C" {
 
     PROFILER_API profiler::block_index_t writeTreesToFile(std::atomic<int>& progress, const char* filename,
                                                           const profiler::SerializedData& serialized_descriptors,
+                                                          const profiler::descriptors_list_t& descriptors,
                                                           profiler::block_id_t descriptors_count,
                                                           const profiler::thread_blocks_tree_t& trees,
                                                           profiler::block_getter_fn block_getter,
@@ -419,6 +375,7 @@ extern "C" {
 
     PROFILER_API profiler::block_index_t writeTreesToStream(std::atomic<int>& progress, std::ostream& str,
                                                             const profiler::SerializedData& serialized_descriptors,
+                                                            const profiler::descriptors_list_t& descriptors,
                                                             profiler::block_id_t descriptors_count,
                                                             const profiler::thread_blocks_tree_t& trees,
                                                             profiler::block_getter_fn block_getter,
@@ -445,6 +402,7 @@ inline profiler::block_index_t fillTreesFromFile(const char* filename, profiler:
 
 inline profiler::block_index_t writeTreesToFile(const char* filename,
                                                 const profiler::SerializedData& serialized_descriptors,
+                                                const profiler::descriptors_list_t& descriptors,
                                                 profiler::block_id_t descriptors_count,
                                                 const profiler::thread_blocks_tree_t& trees,
                                                 profiler::block_getter_fn block_getter,
@@ -454,12 +412,13 @@ inline profiler::block_index_t writeTreesToFile(const char* filename,
                                                 std::ostream& log)
 {
     std::atomic<int> progress = ATOMIC_VAR_INIT(0);
-    return writeTreesToFile(progress, filename, serialized_descriptors, descriptors_count, trees, std::move(block_getter),
+    return writeTreesToFile(progress, filename, serialized_descriptors, descriptors, descriptors_count, trees,
-                            begin_time, end_time, pid, log);
+                            std::move(block_getter), begin_time, end_time, pid, log);
 }
 
 inline profiler::block_index_t writeTreesToStream(std::ostream& str,
                                                   const profiler::SerializedData& serialized_descriptors,
+                                                  const profiler::descriptors_list_t& descriptors,
                                                   profiler::block_id_t descriptors_count,
                                                   const profiler::thread_blocks_tree_t& trees,
                                                   profiler::block_getter_fn block_getter,
@@ -469,8 +428,8 @@ inline profiler::block_index_t writeTreesToStream(std::ostream& str,
                                                   std::ostream& log)
 {
     std::atomic<int> progress = ATOMIC_VAR_INIT(0);
-    return writeTreesToStream(progress, str, serialized_descriptors, descriptors_count, trees, std::move(block_getter),
+    return writeTreesToStream(progress, str, serialized_descriptors, descriptors, descriptors_count, trees,
-                              begin_time, end_time, pid, log);
+                              std::move(block_getter), begin_time, end_time, pid, log);
 }
 
 inline bool readDescriptionsFromStream(std::istream& str,

easy_profiler_core/reader.cpp

@@ -129,11 +129,26 @@ inline bool isCompatibleVersion(uint32_t _version)
 
 namespace profiler {
 
+    SerializedData::SerializedData() : m_size(0), m_data(nullptr)
+    {
+    }
+
+    SerializedData::SerializedData(SerializedData&& that) : m_size(that.m_size), m_data(that.m_data)
+    {
+        that.m_size = 0;
+        that.m_data = nullptr;
+    }
+
+    SerializedData::~SerializedData()
+    {
+        clear();
+    }
+
     void SerializedData::set(char* _data, uint64_t _size)
     {
         delete [] m_data;
-        m_data = _data;
         m_size = _size;
+        m_data = _data;
     }
 
     void SerializedData::set(uint64_t _size)
@@ -146,8 +161,8 @@ namespace profiler {
 
     void SerializedData::extend(uint64_t _size)
     {
-        auto olddata = m_data;
         auto oldsize = m_size;
+        auto olddata = m_data;
 
         m_size = oldsize + _size;
         m_data = new char[m_size];
@@ -158,6 +173,61 @@ namespace profiler {
         }
     }
 
+    SerializedData& SerializedData::operator = (SerializedData&& that)
+    {
+        set(that.m_data, that.m_size);
+        that.m_size = 0;
+        that.m_data = nullptr;
+        return *this;
+    }
+
+    char* SerializedData::operator [] (uint64_t i)
+    {
+        return m_data + i;
+    }
+
+    const char* SerializedData::operator [] (uint64_t i) const
+    {
+        return m_data + i;
+    }
+
+    bool SerializedData::empty() const
+    {
+        return m_size == 0;
+    }
+
+    uint64_t SerializedData::size() const
+    {
+        return m_size;
+    }
+
+    char* SerializedData::data()
+    {
+        return m_data;
+    }
+
+    const char* SerializedData::data() const
+    {
+        return m_data;
+    }
+
+    void SerializedData::clear()
+    {
+        set(nullptr, 0);
+    }
+
+    void SerializedData::swap(SerializedData& other)
+    {
+        char* d = other.m_data;
+        const auto sz = other.m_size;
+
+        other.m_data = m_data;
+        other.m_size = m_size;
+
+        m_data = d;
+        m_size = sz;
+    }
+
     extern "C" PROFILER_API void release_stats(BlockStatistics*& _stats)
     {
         if (_stats == nullptr)
@@ -653,6 +723,12 @@ extern "C" PROFILER_API profiler::block_index_t fillTreesFromStream(std::atomic<
                 return 0;
             }
 
+            if (i + sz > memory_size)
+            {
+                _log << "File corrupted.\nActual context switches data size > size pointed in file.";
+                return 0;
+            }
+
             char* data = serialized_blocks[i];
             inFile.read(data, sz);
             i += sz;
@@ -714,6 +790,12 @@ extern "C" PROFILER_API profiler::block_index_t fillTreesFromStream(std::atomic<
                 return 0;
             }
 
+            if (i + sz > memory_size)
+            {
+                _log << "File corrupted.\nActual blocks data size > size pointed in file.";
+                return 0;
+            }
+
             char* data = serialized_blocks[i];
             inFile.read(data, sz);
             i += sz;
@@ -1146,7 +1228,9 @@ BlocksRange findRange(const profiler::BlocksTree::children_t& children, profiler
 
 BlocksMemoryAndCount calculateUsedMemoryAndBlocksCount(const profiler::BlocksTree::children_t& children,
                                                        const BlocksRange& range,
-                                                       const profiler::block_getter_fn& getter, bool contextSwitches)
+                                                       const profiler::block_getter_fn& getter,
+                                                       const profiler::descriptors_list_t& descriptors,
+                                                       bool contextSwitches)
 {
     BlocksMemoryAndCount memoryAndCount;
 
@@ -1157,12 +1241,18 @@ BlocksMemoryAndCount calculateUsedMemoryAndBlocksCount(const profiler::BlocksTre
             const auto& child = getter(children[i]);
 
             // Calculate self memory consumption
-            const uint64_t usedMemorySize = sizeof(profiler::SerializedBlock) + strlen(child.node->name()) + 1;
+            const auto& desc = *descriptors[child.node->id()];
+            uint64_t usedMemorySize = 0;
+
+            if (desc.type() == profiler::BlockType::Value)
+                usedMemorySize = sizeof(profiler::ArbitraryValue) + child.value->data_size();
+            else
+                usedMemorySize = sizeof(profiler::SerializedBlock) + strlen(child.node->name()) + 1;
 
             // Calculate children memory consumption
             const BlocksRange childRange(0, static_cast<profiler::block_index_t>(child.children.size()));
             const auto childrenMemoryAndCount = calculateUsedMemoryAndBlocksCount(child.children, childRange,
-                                                                                  getter,
+                                                                                  getter, descriptors,
                                                                                   false);
 
             // Accumulate memory and count
@@ -1185,37 +1275,53 @@ BlocksMemoryAndCount calculateUsedMemoryAndBlocksCount(const profiler::BlocksTre
     return memoryAndCount;
 }
 
-void serialize(profiler::SerializedData& output, uint64_t& position, const profiler::BlocksTree::children_t& children,
+void serializeBlocks(std::ostream& output, std::vector<char>& buffer, const profiler::BlocksTree::children_t& children,
-               const BlocksRange& range, const profiler::block_getter_fn& getter, bool contextSwitches)
+                     const BlocksRange& range, const profiler::block_getter_fn& getter,
+                     const profiler::descriptors_list_t& descriptors)
 {
-    if (!contextSwitches)
+    for (auto i = range.begin; i < range.end; ++i)
     {
-        // Serialize blocks
+        const auto& child = getter(children[i]);
 
-        for (auto i = range.begin; i < range.end; ++i)
+        // Serialize children
+        const BlocksRange childRange(0, static_cast<profiler::block_index_t>(child.children.size()));
+        serializeBlocks(output, buffer, child.children, childRange, getter, descriptors);
+
+        // Serialize self
+        const auto& desc = *descriptors[child.node->id()];
+        uint16_t usedMemorySize = 0;
+
+        if (desc.type() == profiler::BlockType::Value)
         {
-            const auto& child = getter(children[i]);
+            usedMemorySize = static_cast<uint16_t>(sizeof(profiler::ArbitraryValue)) + child.value->data_size();
+            buffer.resize(usedMemorySize + sizeof(uint16_t));
+            unaligned_store16(buffer.data(), usedMemorySize);
+            memcpy(buffer.data() + sizeof(uint16_t), child.value, static_cast<size_t>(usedMemorySize));
+        }
+        else
+        {
+            usedMemorySize = static_cast<uint16_t>(sizeof(profiler::SerializedBlock)
+                                                   + strlen(child.node->name()) + 1);
 
-            // Serialize children
+            buffer.resize(usedMemorySize + sizeof(uint16_t));
-            const BlocksRange childRange(0, static_cast<profiler::block_index_t>(child.children.size()));
+            unaligned_store16(buffer.data(), usedMemorySize);
-            serialize(output, position, child.children, childRange, getter, false);
+            memcpy(buffer.data() + sizeof(uint16_t), child.node, static_cast<size_t>(usedMemorySize));
 
-            // Serialize self
+            if (child.node->id() != desc.id())
-            const auto usedMemorySize = static_cast<uint16_t>(
+            {
-                sizeof(profiler::SerializedBlock) + strlen(child.node->name()) + 1);
+                // This block id is dynamic. Restore it's value like it was before in the input .prof file
-
+                auto block = reinterpret_cast<profiler::SerializedBlock*>(buffer.data() + sizeof(uint16_t));
-            unaligned_store16(output.data() + position, usedMemorySize);
+                block->setId(desc.id());
-            memcpy(output.data() + position + sizeof(uint16_t), child.node, static_cast<size_t>(usedMemorySize));
+            }
-
-            // TODO: write valid block id (it can be dynamic)
-
-            position += usedMemorySize + sizeof(uint16_t);
         }
 
-        return;
+        write(output, buffer.data(), buffer.size());
     }
+}
 
-    // Serialize context switches
+void serializeContextSwitches(std::ostream& output, std::vector<char>& buffer, const profiler::BlocksTree::children_t& children,
+                              const BlocksRange& range, const profiler::block_getter_fn& getter)
+{
     for (auto i = range.begin; i < range.end; ++i)
     {
         const auto& child = getter(children[i]);
@@ -1223,15 +1329,39 @@ void serialize(profiler::SerializedData& output, uint64_t& position, const profi
         const auto usedMemorySize = static_cast<uint16_t>(
             sizeof(profiler::SerializedCSwitch) + strlen(child.cs->name()) + 1);
 
-        unaligned_store16(output.data() + position, usedMemorySize);
+        buffer.resize(usedMemorySize + sizeof(uint16_t));
-        memcpy(output.data() + position + sizeof(uint16_t), child.cs, static_cast<size_t>(usedMemorySize));
+        unaligned_store16(buffer.data(), usedMemorySize);
+        memcpy(buffer.data() + sizeof(uint16_t), child.cs, static_cast<size_t>(usedMemorySize));
 
-        position += usedMemorySize + sizeof(uint16_t);
+        write(output, buffer.data(), buffer.size());
+    }
+}
+
+void serializeDescriptors(std::ostream& output, std::vector<char>& buffer,
+                          const profiler::descriptors_list_t& descriptors,
+                          profiler::block_id_t descriptors_count)
+{
+    const size_t size = std::min(descriptors.size(), static_cast<size_t>(descriptors_count));
+    for (size_t i = 0; i < size; ++i)
+    {
+        const auto& desc = *descriptors[i];
+        if (desc.id() != i)
+            break;
+
+        const auto usedMemorySize = static_cast<uint16_t>(sizeof(profiler::SerializedBlockDescriptor)
+                                                          + strlen(desc.name()) + strlen(desc.file()) + 2);
+
+        buffer.resize(usedMemorySize + sizeof(uint16_t));
+        unaligned_store16(buffer.data(), usedMemorySize);
+        memcpy(buffer.data() + sizeof(uint16_t), &desc, static_cast<size_t>(usedMemorySize));
+
+        write(output, buffer.data(), buffer.size());
     }
 }
 
 extern "C" PROFILER_API profiler::block_index_t writeTreesToFile(std::atomic<int>& progress, const char* filename,
                                                                  const profiler::SerializedData& serialized_descriptors,
+                                                                 const profiler::descriptors_list_t& descriptors,
                                                                  profiler::block_id_t descriptors_count,
                                                                  const profiler::thread_blocks_tree_t& trees,
                                                                  profiler::block_getter_fn block_getter,
@@ -1251,8 +1381,8 @@ extern "C" PROFILER_API profiler::block_index_t writeTreesToFile(std::atomic<int
     }
 
     // Write data to file
-    auto result = writeTreesToStream(progress, outFile, serialized_descriptors, descriptors_count, trees, std::move(block_getter),
+    auto result = writeTreesToStream(progress, outFile, serialized_descriptors, descriptors, descriptors_count, trees,
-                                        begin_time, end_time, pid, log);
+                                     std::move(block_getter), begin_time, end_time, pid, log);
 
     return result;
 }
@@ -1261,6 +1391,7 @@ extern "C" PROFILER_API profiler::block_index_t writeTreesToFile(std::atomic<int
 
 extern "C" PROFILER_API profiler::block_index_t writeTreesToStream(std::atomic<int>& progress, std::ostream& str,
                                                                    const profiler::SerializedData& serialized_descriptors,
+                                                                   const profiler::descriptors_list_t& descriptors,
                                                                    profiler::block_id_t descriptors_count,
                                                                    const profiler::thread_blocks_tree_t& trees,
                                                                    profiler::block_getter_fn block_getter,
@@ -1281,6 +1412,7 @@ extern "C" PROFILER_API profiler::block_index_t writeTreesToStream(std::atomic<i
     ranges_t block_ranges;
 
     // Calculate block ranges and used memory (for serialization)
+    profiler::timestamp_t beginTime = begin_time, endTime = end_time;
     size_t i = 0;
     for (const auto& kv : trees)
     {
@@ -1292,12 +1424,26 @@ extern "C" PROFILER_API profiler::block_index_t writeTreesToStream(std::atomic<i
         range.blocks = findRange(tree.children, begin_time, end_time, block_getter);
         range.cswitches = findRange(tree.sync, begin_time, end_time, block_getter);
 
-        range.blocksMemoryAndCount = calculateUsedMemoryAndBlocksCount(tree.children, range.blocks, block_getter, false);
+        range.blocksMemoryAndCount = calculateUsedMemoryAndBlocksCount(tree.children, range.blocks, block_getter,
+                                                                       descriptors, false);
         total += range.blocksMemoryAndCount;
 
-        range.cswitchesMemoryAndCount = calculateUsedMemoryAndBlocksCount(tree.sync, range.cswitches, block_getter, true);
+        if (range.blocksMemoryAndCount.blocksCount != 0)
+        {
+            beginTime = std::min(beginTime, block_getter(tree.children[range.blocks.begin]).node->begin());
+            endTime = std::max(endTime, block_getter(tree.children[range.blocks.end - 1]).node->end());
+        }
+
+        range.cswitchesMemoryAndCount = calculateUsedMemoryAndBlocksCount(tree.sync, range.cswitches, block_getter,
+                                                                          descriptors, true);
         total += range.cswitchesMemoryAndCount;
 
+        if (range.cswitchesMemoryAndCount.blocksCount != 0)
+        {
+            beginTime = std::min(beginTime, block_getter(tree.children[range.cswitches.begin]).cs->begin());
+            endTime = std::max(endTime, block_getter(tree.children[range.cswitches.end - 1]).cs->end());
+        }
+
         block_ranges[id] = range;
 
         if (!update_progress_write(progress, 15 / static_cast<int>(trees.size() - i), log))
@@ -1322,22 +1468,20 @@ extern "C" PROFILER_API profiler::block_index_t writeTreesToStream(std::atomic<i
     // write 0 because we do not need to convert time from ticks to nanoseconds (it's already converted)
     write<int64_t>(str, 0LL); // CPU frequency
 
-    write(str, begin_time);
+    write(str, beginTime);
-    write(str, end_time);
+    write(str, endTime);
 
     write(str, total.usedMemorySize);
     write(str, usedMemorySizeDescriptors);
     write(str, total.blocksCount);
     write(str, descriptors_count);
 
+    std::vector<char> buffer;
+
     // Serialize all descriptors
-    // TODO
+    serializeDescriptors(str, buffer, descriptors, descriptors_count);
 
     // Serialize all blocks
-    profiler::SerializedData serializedBlocks;
-    serializedBlocks.set(total.usedMemorySize + sizeof(uint16_t) * total.blocksCount);
-    uint64_t position = 0;
-
     i = 0;
     for (const auto& kv : trees)
     {
@@ -1349,25 +1493,16 @@ extern "C" PROFILER_API profiler::block_index_t writeTreesToStream(std::atomic<i
         write(str, id);
         write(str, nameSize);
         write(str, tree.name(), nameSize);
-        write(str, range.cswitchesMemoryAndCount.blocksCount);
 
         // Serialize context switches
         write(str, range.cswitchesMemoryAndCount.blocksCount);
         if (range.cswitchesMemoryAndCount.blocksCount != 0)
-        {
+            serializeContextSwitches(str, buffer, tree.sync, range.cswitches, block_getter);
-            const auto previousPosition = position;
-            serialize(serializedBlocks, position, tree.sync, range.cswitches, block_getter, true);
-            write(str, serializedBlocks.data() + previousPosition, position - previousPosition);
-        }
 
         // Serialize blocks
         write(str, range.blocksMemoryAndCount.blocksCount);
         if (range.blocksMemoryAndCount.blocksCount != 0)
-        {
+            serializeBlocks(str, buffer, tree.children, range.blocks, block_getter, descriptors);
-            const auto previousPosition = position;
-            serialize(serializedBlocks, position, tree.children, range.blocks, block_getter, false);
-            write(str, serializedBlocks.data() + previousPosition, position - previousPosition);
-        }
 
         if (!update_progress_write(progress, 40 + 60 / static_cast<int>(trees.size() - i), log))
             return 0;

profiler_gui/blocks_graphics_view.cpp

@@ -407,6 +407,8 @@ void BlocksGraphicsView::clear()
 
     EASY_GLOBALS.selected_thread = 0;
     emit EASY_GLOBALS.events.selectedThreadChanged(0);
+
+    emit EASY_GLOBALS.events.rulerVisible(false);
 }
 
 void BlocksGraphicsView::notifySceneSizeChange()
@@ -438,7 +440,10 @@ void BlocksGraphicsView::notifyVisibleRegionPosChange()
 
 void BlocksGraphicsView::notifyVisibleRegionPosChange(qreal _pos)
 {
-    m_offset = estd::clamp(0., _pos, m_sceneWidth - m_visibleRegionWidth);
+    if (m_sceneWidth < m_visibleRegionWidth)
+        m_offset = 0;
+    else
+        m_offset = estd::clamp(0., _pos, m_sceneWidth - m_visibleRegionWidth);
     notifyVisibleRegionPosChange();
 }
 
@@ -616,25 +621,15 @@ const BlocksGraphicsView::Items &BlocksGraphicsView::getItems() const
 
 bool BlocksGraphicsView::getSelectionRegionForSaving(profiler::timestamp_t& _beginTime, profiler::timestamp_t& _endTime) const
 {
-    if (m_selectedBlocks.empty())
+    if (m_bEmpty)
         return false;
 
-    _beginTime = ~0ULL;
+    if (!m_selectionItem->isVisible() && !m_rulerItem->isVisible())
-    _endTime = 0;
+        return false;
 
-    for (const auto& selection : m_selectedBlocks)
+    decltype(m_selectionItem) ruler = m_selectionItem->isVisible() ? m_selectionItem : m_rulerItem;
-    {
+    _beginTime = m_beginTime + position2time(ruler->left());
-        const auto& tree = easyBlocksTree(selection.tree);
+    _endTime = m_beginTime + position2time(ruler->right());
-        _beginTime = std::min(_beginTime, tree.node->begin());
-        _endTime = std::max(_endTime, tree.node->end());
-    }
-
-    if (_beginTime > 10)
-        _beginTime -= 10;
-    else
-        _beginTime = 0;
-
-    _endTime += 10;
 
     return true;
 }
@@ -923,7 +918,10 @@ void BlocksGraphicsView::onWheel(qreal _scenePos, int _wheelDelta)
     notifyVisibleRegionSizeChange();
 
     // Calculate new offset to simulate QGraphicsView::AnchorUnderMouse scaling behavior
-    m_offset = clamp(0., initialPosition - _scenePos / m_scale, m_sceneWidth - m_visibleRegionWidth);
+    if (m_sceneWidth < m_visibleRegionWidth)
+        m_offset = 0;
+    else
+        m_offset = clamp(0., initialPosition - _scenePos / m_scale, m_sceneWidth - m_visibleRegionWidth);
 
     // Update slider position
     profiler_gui::BoolFlagGuard guard(m_bUpdatingRect, true); // To be sure that updateVisibleSceneRect will not be called by scrollbar change
@@ -980,6 +978,7 @@ void BlocksGraphicsView::mousePressEvent(QMouseEvent* _event)
             m_selectionItem->setLeftRight(mouseX, mouseX);
             m_selectionItem->hide();
             m_pScrollbar->hideSelectionIndicator();
+            emit EASY_GLOBALS.events.rulerVisible(m_rulerItem->isVisible());
         }
     }
 
@@ -1009,6 +1008,7 @@ void BlocksGraphicsView::mouseDoubleClickEvent(QMouseEvent* _event)
         m_rulerItem->setLeftRight(mouseX, mouseX);
         m_rulerItem->hide();
         emit sceneUpdated();
+        emit EASY_GLOBALS.events.rulerVisible(m_selectionItem->isVisible());
     }
 
     _event->accept();
@@ -1035,6 +1035,7 @@ void BlocksGraphicsView::mouseReleaseEvent(QMouseEvent* _event)
         {
             m_selectionItem->hide();
             m_pScrollbar->hideSelectionIndicator();
+            emit EASY_GLOBALS.events.rulerVisible(m_rulerItem->isVisible());
         }
 
         if (!m_selectedBlocks.empty())
@@ -1071,6 +1072,7 @@ void BlocksGraphicsView::mouseReleaseEvent(QMouseEvent* _event)
         {
             chronoHidden = true;
             m_rulerItem->hide();
+            emit EASY_GLOBALS.events.rulerVisible(m_selectionItem->isVisible());
         }
         else if (m_selectionItem->isVisible() && m_selectionItem->hoverIndicator())
         {
@@ -1216,6 +1218,9 @@ void BlocksGraphicsView::addSelectionToHierarchy()
 
 void BlocksGraphicsView::onZoomSelection()
 {
+    if (m_selectionItem->width() < 1e-6)
+        return;
+
     auto deltaScale = m_visibleRegionWidth / m_selectionItem->width();
 
     if (fabs(deltaScale - 1) < 1e-6)
@@ -1254,6 +1259,9 @@ void BlocksGraphicsView::onInspectCurrentView(bool _strict)
         m_selectionItem->show();
         m_pScrollbar->setSelectionPos(m_selectionItem->left(), m_selectionItem->right());
         m_pScrollbar->showSelectionIndicator();
+
+        emit EASY_GLOBALS.events.rulerVisible(true);
+
         addSelectionToHierarchy();
     }
     else
@@ -1306,6 +1314,7 @@ bool BlocksGraphicsView::moveChrono(GraphicsRulerItem* _chronometerItem, qreal _
     if (!_chronometerItem->isVisible() && _chronometerItem->width() > 1e-6)
     {
         _chronometerItem->show();
+        emit EASY_GLOBALS.events.rulerVisible(true);
         return true;
     }
 

profiler_gui/globals_qobjects.h

@@ -93,6 +93,7 @@ namespace profiler_gui {
         void hexThreadIdChanged();
         void refreshRequired();
         void blocksTreeModeChanged();
+        void rulerVisible(bool);
 
         void sceneCleared();
         void sceneSizeChanged(qreal left, qreal right);

profiler_gui/main_window.cpp

@@ -379,8 +379,10 @@ MainWindow::MainWindow() : Parent(), m_theme("default"), m_lastAddress("localhos
     });
 
     action = toolbar->addAction(QIcon(imagePath("crop")), "Snapshot");
-    action->setToolTip("Save selected area\nas separate .prof file.");
+    action->setToolTip("Take a snapshot.\nSave selected area to\nseparate .prof file.");
+    action->setEnabled(false);
     connect(action, &QAction::triggered, this, &This::onSnapshotClicked);
+    connect(&EASY_GLOBALS.events, &profiler_gui::GlobalSignals::rulerVisible, action, &QAction::setEnabled);
 
     toolbar->addSeparator();
     auto menu = new QMenu("Settings", this);
@@ -1944,7 +1946,8 @@ void MainWindow::onLoadingFinish(profiler::block_index_t& _nblocks)
     }
     else
     {
-        QMessageBox::warning(this, "Warning", QString("Cannot read profiled blocks.\n\nReason:\n%1").arg(m_reader.getError()), QMessageBox::Close);
+        QMessageBox::warning(this, "Warning", QString("Cannot read profiled blocks.\n\nReason:\n%1")
+            .arg(m_reader.getError()), QMessageBox::Close);
 
         if (m_reader.isFile())
         {
@@ -1964,7 +1967,12 @@ void MainWindow::onLoadingFinish(profiler::block_index_t& _nblocks)
 
 void MainWindow::onSavingFinish()
 {
-
+    const auto errorMessage = m_reader.getError();
+    if (!errorMessage.isEmpty())
+    {
+        QMessageBox::warning(this, "Warning", QString("Cannot save profiled blocks.\n\nReason:\n%1")
+            .arg(errorMessage), QMessageBox::Close);
+    }
 }
 
 void MainWindow::onFileReaderTimeout()
@@ -2114,7 +2122,8 @@ void FileReader::load(std::stringstream& _stream)
 }
 
 void FileReader::save(const QString& _filename, profiler::timestamp_t _beginTime, profiler::timestamp_t _endTime,
-                      const profiler::SerializedData& _serializedDescriptors, profiler::block_id_t descriptors_count,
+                      const profiler::SerializedData& _serializedDescriptors,
+                      const profiler::descriptors_list_t& _descriptors, profiler::block_id_t descriptors_count,
                       const profiler::thread_blocks_tree_t& _trees, profiler::block_getter_fn block_getter,
                       profiler::processid_t _pid)
 {
@@ -2125,13 +2134,37 @@ void FileReader::save(const QString& _filename, profiler::timestamp_t _beginTime
     m_filename = _filename;
 
     auto serializedDescriptors = std::ref(_serializedDescriptors);
+    auto descriptors = std::ref(_descriptors);
     auto trees = std::ref(_trees);
 
-    m_thread = std::thread([=] (profiler::block_getter_fn getter) {
+    m_thread = std::thread([=] (profiler::block_getter_fn getter)
-        writeTreesToFile(m_progress, m_filename.toStdString().c_str(), serializedDescriptors, descriptors_count, trees,
+    {
-                         getter, _beginTime, _endTime, _pid, m_errorMessage);
+        const QString tmpFile = m_filename + ".tmp";
+
+        const auto result = writeTreesToFile(m_progress, tmpFile.toStdString().c_str(), serializedDescriptors,
+                                             descriptors, descriptors_count, trees, getter, _beginTime, _endTime,
+                                             _pid, m_errorMessage);
+
+        if (result == 0 || !m_errorMessage.str().empty())
+        {
+            // Remove temporary file in case of error
+            QFile::remove(tmpFile);
+        }
+        else
+        {
+            // Remove old file if exists
+            {
+                QFile out(m_filename);
+                if (out.exists())
+                    out.remove();
+            }
+
+            QFile::rename(tmpFile, m_filename);
+        }
+
         m_progress.store(100, std::memory_order_release);
         m_bDone.store(true, std::memory_order_release);
+
     }, std::move(block_getter));
 }
 
@@ -2254,8 +2287,9 @@ void MainWindow::onSnapshotClicked(bool)
 
     createProgressDialog(tr("Saving selected region..."));
     m_readerTimer.start();
-    m_reader.save(filename, beginTime, endTime, m_serializedDescriptors, m_descriptorsNumberInFile,
+
-                  EASY_GLOBALS.profiler_blocks, easyBlocksTree, EASY_GLOBALS.pid);
+    m_reader.save(filename, beginTime, endTime, m_serializedDescriptors, EASY_GLOBALS.descriptors,
+                  m_descriptorsNumberInFile, EASY_GLOBALS.profiler_blocks, easyBlocksTree, EASY_GLOBALS.pid);
 }
 
 //////////////////////////////////////////////////////////////////////////

profiler_gui/main_window.h

@@ -130,8 +130,9 @@ public:
     /** \brief Save data to file.
     */
     void save(const QString& _filename, profiler::timestamp_t _beginTime, profiler::timestamp_t _endTime,
-              const profiler::SerializedData& _serializedDescriptors, profiler::block_id_t descriptors_count,
+              const profiler::SerializedData& _serializedDescriptors, const profiler::descriptors_list_t& _descriptors,
-              const profiler::thread_blocks_tree_t& _trees, profiler::block_getter_fn block_getter, profiler::processid_t _pid);
+              profiler::block_id_t descriptors_count, const profiler::thread_blocks_tree_t& _trees,
+              profiler::block_getter_fn block_getter, profiler::processid_t _pid);
 
     void interrupt();
     void get(profiler::SerializedData& _serializedBlocks, profiler::SerializedData& _serializedDescriptors,