Fast TChunkedBuffer::Size()

commit_hash:6dd56a3c0d552a30b3e30a2b133d638716e1893d

Author: nepal

yql/essentials/utils/chunked_buffer.cpp

@@ -6,10 +6,14 @@ namespace NYql {
 
 TChunkedBuffer::TChunkedBuffer(TChunkedBuffer&& other) {
     Items_ = std::move(other.Items_);
+    Size_ = other.Size_;
+    other.Size_ = 0;
 }
 
 TChunkedBuffer& TChunkedBuffer::operator=(TChunkedBuffer&& other) {
     Items_ = std::move(other.Items_);
+    Size_ = other.Size_;
+    other.Size_ = 0;
     return *this;
 }
 
@@ -40,25 +44,10 @@ size_t TChunkedBuffer::CopyTo(IOutputStream& dst, size_t toCopy) const {
     return copied;
 }
 
-size_t TChunkedBuffer::ContigousSize() const {
-    return Items_.empty() ? 0 : Front().Buf.size();
-}
-
-size_t TChunkedBuffer::Size() const {
-    size_t result = 0;
-    for (auto& item : Items_) {
-        result += item.Buf.size();
-    }
-    return result;
-}
-
-bool TChunkedBuffer::Empty() const {
-    return Items_.empty();
-}
-
 TChunkedBuffer& TChunkedBuffer::Append(TStringBuf buf, const std::shared_ptr<const void>& owner) {
     if (!buf.empty()) {
         Items_.emplace_back(TChunk{buf, owner});
+        Size_ += buf.size();
     }
     return *this;
 }
@@ -67,20 +56,24 @@ TChunkedBuffer& TChunkedBuffer::Append(TString&& str) {
     if (!str.empty()) {
         auto owner = std::make_shared<TString>(std::move(str));
         Items_.emplace_back(TChunk{*owner, owner});
+        Size_ += owner->size();
     }
     return *this;
 }
 
 TChunkedBuffer& TChunkedBuffer::Append(TChunkedBuffer&& other) {
     while (!other.Items_.empty()) {
         Items_.emplace_back(std::move(other.Items_.front()));
+        Size_ += Items_.back().Buf.size();
         other.Items_.pop_front();
     }
+    other.Size_ = 0;
     return *this;
 }
 
 TChunkedBuffer& TChunkedBuffer::Clear() {
     Items_.clear();
+    Size_ = 0;
     return *this;
 }
 
@@ -90,6 +83,7 @@ TChunkedBuffer& TChunkedBuffer::Erase(size_t size) {
         size_t toErase = std::min(buf.size(), size);
         buf.Skip(toErase);
         size -= toErase;
+        Size_ -= toErase;
         if (buf.empty()) {
             Items_.pop_front();
         }

yql/essentials/utils/chunked_buffer.h

@@ -18,9 +18,17 @@ class TChunkedBuffer {
     explicit TChunkedBuffer(TStringBuf buf, const std::shared_ptr<const void>& owner);
     explicit TChunkedBuffer(TString&& str);
 
-    size_t ContigousSize() const;
-    size_t Size() const;
-    bool Empty() const;
+    inline size_t ContigousSize() const {
+        return Items_.empty() ? 0 : Front().Buf.size();
+    }
+
+    inline size_t Size() const {
+        return Size_;
+    }
+
+    inline bool Empty() const {
+        return Size_ == 0;
+    }
 
     struct TChunk {
         TStringBuf Buf;
@@ -39,6 +47,7 @@ class TChunkedBuffer {
 
 private:
     std::deque<TChunk> Items_;
+    size_t Size_ = 0;
 };
 
 class TChunkedBufferOutput : public IOutputStream {