From 4eb205ad183dcc00f9bd6c2530d797566f21a05b Mon Sep 17 00:00:00 2001
From: Bartosz Taudul <wolf.pld@gmail.com>
Date: Sat, 14 Apr 2018 17:12:41 +0200
Subject: [PATCH] Optimize FastVector for fast push_next() operation.

---
 client/TracyFastVector.hpp | 58 +++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 29 deletions(-)

diff --git a/client/TracyFastVector.hpp b/client/TracyFastVector.hpp
index 61087445..91273d9e 100644
--- a/client/TracyFastVector.hpp
+++ b/client/TracyFastVector.hpp
@@ -18,8 +18,8 @@ public:
 
     FastVector( size_t capacity )
         : m_ptr( (T*)tracy_malloc( sizeof( T ) * capacity ) )
-        , m_size( 0 )
-        , m_capacity( capacity )
+        , m_write( m_ptr )
+        , m_end( m_ptr + capacity )
     {
     }
 
@@ -34,70 +34,70 @@ public:
     FastVector& operator=( const FastVector& ) = delete;
     FastVector& operator=( FastVector&& ) = delete;
 
-    bool empty() const { return m_size == 0; }
-    size_t size() const { return m_size; }
+    bool empty() const { return m_ptr == m_write; }
+    size_t size() const { return m_write - m_ptr; }
 
     T* data() { return m_ptr; }
     const T* data() const { return m_ptr; };
 
     T* begin() { return m_ptr; }
     const T* begin() const { return m_ptr; }
-    T* end() { return m_ptr + m_size; }
-    const T* end() const { return m_ptr + m_size; }
+    T* end() { return m_write; }
+    const T* end() const { return m_write; }
 
-    T& front() { assert( m_size > 0 ); return m_ptr[0]; }
-    const T& front() const { assert( m_size > 0 ); return m_ptr[0]; }
+    T& front() { assert( !empty() ); return m_ptr[0]; }
+    const T& front() const { assert( !empty() ); return m_ptr[0]; }
 
-    T& back() { assert( m_size > 0 ); return m_ptr[m_size - 1]; }
-    const T& back() const { assert( m_size > 0 ); return m_ptr[m_size - 1]; }
+    T& back() { assert( !empty() ); return m_write[-1]; }
+    const T& back() const { assert( !empty() ); return m_write[-1]; }
 
     T& operator[]( size_t idx ) { return m_ptr[idx]; }
     const T& operator[]( size_t idx ) const { return m_ptr[idx]; }
 
     T* push_next()
     {
-        T* ret;
-        if( m_size == m_capacity ) AllocMore();
-        ret = m_ptr + m_size;
-        m_size++;
-        return ret;
+        if( m_write == m_end ) AllocMore();
+        return m_write++;
     }
 
     void clear()
     {
-        m_size = 0;
+        m_write = m_ptr;
     }
 
     void swap( FastVector& vec )
     {
         const auto ptr1 = m_ptr;
         const auto ptr2 = vec.m_ptr;
-        const auto size1 = m_size;
-        const auto size2 = vec.m_size;
-        const auto cap1 = m_capacity;
-        const auto cap2 = vec.m_capacity;
+        const auto write1 = m_write;
+        const auto write2 = vec.m_write;
+        const auto end1 = m_end;
+        const auto end2 = vec.m_end;
 
         m_ptr = ptr2;
         vec.m_ptr = ptr1;
-        m_size = size2;
-        vec.m_size = size1;
-        m_capacity = cap2;
-        vec.m_capacity = cap1;
+        m_write = write2;
+        vec.m_write = write1;
+        m_end = end2;
+        vec.m_end = end1;
     }
 
 private:
     tracy_no_inline void AllocMore()
     {
-        m_capacity *= 2;
-        T* ptr = (T*)tracy_malloc( sizeof( T ) * m_capacity );
-        memcpy( ptr, m_ptr, m_size * sizeof( T ) );
+        const auto cap = ( m_end - m_ptr ) * 2;
+        const auto size = m_write - m_ptr;
+        T* ptr = (T*)tracy_malloc( sizeof( T ) * cap );
+        memcpy( ptr, m_ptr, size * sizeof( T ) );
         tracy_free( m_ptr );
         m_ptr = ptr;
+        m_write = m_ptr + size;
+        m_end = m_ptr + cap;
     }
 
     T* m_ptr;
-    size_t m_size;
-    size_t m_capacity;
+    T* m_write;
+    T* m_end;
 };
 
 }