From 0cbc36c5ffe40a5f461c8a50fc33da7498e9fb1e Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 1 Nov 2016 22:46:44 -0400
Subject: [PATCH] change Buffer to start using GapBuffer

---
 src/core/Buffer.cc | 47 +++++++++++++++++++++-------------------------
 src/core/Buffer.h  | 13 +++++--------
 src/jes.cc         |  5 +++--
 3 files changed, 29 insertions(+), 36 deletions(-)

diff --git a/src/core/Buffer.cc b/src/core/Buffer.cc
index 9ebd4ea..8d8a523 100644
--- a/src/core/Buffer.cc
+++ b/src/core/Buffer.cc
@@ -5,21 +5,25 @@
 #include "TextLoader.h"
 #include <cassert>
 
-Buffer::Buffer()
+Buffer::Buffer(const char * filename)
 {
-    m_file_buffer = nullptr;
-    m_file_buffer_size = 0u;
-    m_eol_at_eof = true;
-    m_line_endings = LineEndings::LF;
-    m_encoding = Encoding::UTF_8;
+    if (filename != nullptr)
+    {
+        if (!load_from_file(filename))
+        {
+            load_empty_buffer();
+        }
+    }
+    else
+    {
+        load_empty_buffer();
+    }
 }
 
-Buffer::~Buffer()
+void Buffer::load_empty_buffer()
 {
-    if (m_file_buffer != nullptr)
-    {
-        free_file_buffer();
-    }
+    m_gap_buffer = std::make_shared<GapBuffer>();
+    m_eol_at_eof = true;
 }
 
 bool Buffer::load_from_file(const char * filename)
@@ -36,26 +40,24 @@ bool Buffer::load_from_file(const char * filename)
         return false;
     }
 
-    m_file_buffer_size = ((unsigned long)file_size + 2u * System::page_size) & System::page_base_mask;
-    m_file_buffer = (uint8_t *)System::alloc_pages(m_file_buffer_size >> System::page_size_log);
-    if (m_file_buffer == NULL)
+    size_t buffer_size = ((unsigned long)file_size + 2u * System::page_size) & System::page_base_mask;
+    uint8_t * buffer = (uint8_t *)System::alloc_pages(buffer_size >> System::page_size_log);
+    if (buffer == NULL)
     {
         return false;
     }
 
-    if (!file.read(m_file_buffer, file_size))
+    if (!file.read(buffer, file_size))
     {
-        free_file_buffer();
+        System::free_pages(buffer, buffer_size >> System::page_size_log);
         return false;
     }
 
     TextLoader text_loader;
     size_t loaded_size;
-    text_loader.load_buffer(m_file_buffer, file_size, &loaded_size);
+    text_loader.load_buffer(buffer, file_size, &loaded_size);
 
     m_eol_at_eof = text_loader.get_eol_at_eof();
-    m_line_endings = text_loader.get_line_endings();
-    m_encoding = text_loader.get_encoding();
 
     return true;
 }
@@ -72,10 +74,3 @@ bool Buffer::write_to_file(const char * filename)
 
     return true;
 }
-
-void Buffer::free_file_buffer()
-{
-    System::free_pages(m_file_buffer, m_file_buffer_size >> System::page_size_log);
-    m_file_buffer = nullptr;
-    m_file_buffer_size = 0u;
-}
diff --git a/src/core/Buffer.h b/src/core/Buffer.h
index 042584d..1eab87e 100644
--- a/src/core/Buffer.h
+++ b/src/core/Buffer.h
@@ -5,23 +5,20 @@
 #include <memory>
 #include "LineEndings.h"
 #include "Encoding.h"
+#include "GapBuffer.h"
 
 class Buffer
 {
 public:
-    Buffer();
-    ~Buffer();
-    bool load_from_file(const char * filename);
+    Buffer(const char * filename = nullptr);
     bool write_to_file(const char * filename);
 
 protected:
-    uint8_t * m_file_buffer;
-    unsigned long m_file_buffer_size;
     bool m_eol_at_eof;
-    LineEndings::Type m_line_endings;
-    Encoding::Type m_encoding;
+    std::shared_ptr<GapBuffer> m_gap_buffer;
 
-    void free_file_buffer();
+    bool load_from_file(const char * filename);
+    void load_empty_buffer();
 };
 
 #endif
diff --git a/src/jes.cc b/src/jes.cc
index b8dd61f..e3d0899 100644
--- a/src/jes.cc
+++ b/src/jes.cc
@@ -13,11 +13,12 @@ int main(int argc, char * argv[])
 
     Runtime::init(argv[0], APPNAME);
 
-    std::shared_ptr<Buffer> b = std::make_shared<Buffer>();
+    const char * filename = nullptr;
     if (argc > 1)
     {
-        b->load_from_file(argv[1]);
+        filename = argv[1];
     }
+    std::shared_ptr<Buffer> b = std::make_shared<Buffer>(filename);
     Window w;
     if (!w.create(b))
     {