support crlf line ending when reading and writing buffers

src/file.cc

@@ -75,36 +75,91 @@ String read_file(const String& filename)
 
 Buffer* create_buffer_from_file(const String& filename)
 {
-    String content = read_file(filename);
-
     if (Buffer* buffer = BufferManager::instance().get_buffer(filename))
         delete buffer;
 
-    return new Buffer(filename, Buffer::Type::File, content);
+    Buffer* buffer = new Buffer(filename, Buffer::Type::File, "");
+
+    int fd = open(filename.c_str(), O_RDONLY);
+    if (fd == -1)
+    {
+        if (errno == ENOENT)
+            throw file_not_found(filename);
+
+        throw file_access_error(filename, strerror(errno));
+    }
+
+    String content;
+    char buf[256];
+    bool crlf = false;
+    while (true)
+    {
+        ssize_t size = read(fd, buf, 256);
+        if (size == -1 or size == 0)
+            break;
+
+        ssize_t start = 0;
+        for (ssize_t pos = 0; pos < size+1; ++pos)
+        {
+            if (buf[pos] == '\r' or pos == size)
+            {
+                if (buf[pos] == '\r')
+                    crlf = true;
+
+                buffer->modify(Modification::make_insert(buffer->end(), String(buf+start, buf+pos)));
+                start = pos+1;
+            }
+        }
+    }
+    close(fd);
+
+    if (crlf)
+        buffer->option_manager().set_option("eolformat", Option("crlf"));
+    else
+        buffer->option_manager().set_option("eolformat", Option("lf"));
+
+    // it never happened, buffer always was like that
+    buffer->reset_undo_data();
+
+    return buffer;
 }
 
-void write_buffer_to_file(const Buffer& buffer, const String& filename)
+static void write(int fd, const memoryview<char>& data, const String& filename)
 {
-    int fd = open(filename.c_str(), O_CREAT | O_WRONLY | O_TRUNC, 0644);
-    if (fd == -1)
-        throw file_access_error(filename, strerror(errno));
-
-    for (size_t i = 0; i < buffer.line_count(); ++i)
-    {
-        const String& content = buffer.line_content(i);
-        memoryview<char> data = content.data();
     const char* ptr = data.pointer();
     ssize_t count   = data.size();
 
     while (count)
     {
-            ssize_t written = write(fd, ptr, count);
+        ssize_t written = ::write(fd, ptr, count);
         ptr += written;
         count -= written;
 
         if (written == -1)
             throw file_access_error(filename, strerror(errno));
     }
+}
+
+void write_buffer_to_file(const Buffer& buffer, const String& filename)
+{
+    String eolformat = buffer.option_manager()["eolformat"].as_string();
+    if (eolformat == "crlf")
+        eolformat = "\r\n";
+    else
+        eolformat = "\n";
+    auto eoldata = eolformat.data();
+
+    int fd = open(filename.c_str(), O_CREAT | O_WRONLY | O_TRUNC, 0644);
+    if (fd == -1)
+        throw file_access_error(filename, strerror(errno));
+
+    for (size_t i = 0; i < buffer.line_count(); ++i)
+    {
+        // end of lines are written according to eolformat but always
+        // stored as \n
+        memoryview<char> linedata = buffer.line_content(i).data();
+        write(fd, linedata.subrange(0, linedata.size()-1), filename);
+        write(fd, eoldata, filename);
     }
     close(fd);
 }

src/option_manager.cc

@@ -94,6 +94,7 @@ GlobalOptionManager::GlobalOptionManager()
     : OptionManager()
 {
     set_option("tabstop", Option(8));
+    set_option("eolformat", Option("lf"));
 }
 
 }