From 18f3af443ec13df374ec864e0a27a7d3a01050e0 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Mon, 7 Nov 2016 22:18:56 -0500
Subject: [PATCH] add GapBuffer::compact()

---
 src/core/GapBuffer.cc | 10 ++++++++++
 src/core/GapBuffer.h  |  4 +++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/core/GapBuffer.cc b/src/core/GapBuffer.cc
index f35cc12..d38d58f 100644
--- a/src/core/GapBuffer.cc
+++ b/src/core/GapBuffer.cc
@@ -1,5 +1,6 @@
 #include "GapBuffer.h"
 #include "System.h"
+#include <string.h>
 
 GapBuffer::GapBuffer(Encoding::Type encoding)
 {
@@ -33,6 +34,15 @@ std::shared_ptr<GapBuffer::Cursor> GapBuffer::add_cursor()
     return cursor;
 }
 
+void GapBuffer::compact()
+{
+    if (m_gap_position < m_size)
+    {
+        memmove(&m_buffer[m_gap_position], &m_buffer[m_gap_position + gap_size()], m_size - m_gap_position);
+        m_gap_position = m_size;
+    }
+}
+
 
 void GapBuffer::Iterator::go_forward()
 {
diff --git a/src/core/GapBuffer.h b/src/core/GapBuffer.h
index 0931e9e..e5f80a3 100644
--- a/src/core/GapBuffer.h
+++ b/src/core/GapBuffer.h
@@ -102,9 +102,11 @@ public:
         }
         else
         {
-            return &m_buffer[offset + (m_buffer_size - m_size)];
+            return &m_buffer[offset + gap_size()];
         }
     }
+    size_t gap_size() const { return m_buffer_size - m_size; }
+    void compact();
 
 protected:
     uint8_t * m_buffer;