util: add copy_file

1 files changed, 44 insertions, 0 deletions

diff --git a/lib/gitano/util.lua b/lib/gitano/util.lua
index c5ff673..2e25f91 100644
--- a/lib/gitano/util.lua
+++ b/lib/gitano/util.lua
@@ -186,6 +186,49 @@ local function rm_rf(path)
    return (ret == 0), luxio.strerror(err)
 end
 
+local function _write_all(file, data)
+   local towrite = #data
+   local written = 0
+   while written < towrite do
+      local write_count, emsg = file:write(data, written)
+      if not write_count then
+         return false, written, emsg
+      end
+      written = written + write_count
+   end
+   return true, written
+end
+
+local function copy_file(from, to, buffer_size)
+   -- Default buffer size is 4M, but can be changed
+   buffer_size = buffer_size or 4 * 1024 * 1024
+   local fromfile, emsg = sio.open(from, "r")
+   if not fromfile then
+      return false, emsg
+   end
+   local tofile, emsg = sio.open(to, "wce")
+   if not tofile then
+      return false, emsg
+   end
+   local write_count
+   repeat
+      local ok
+      local bytes, emsg = fromfile:read(buffer_size)
+      if not bytes then
+         fromfile:close()
+         tofile:close()
+         return false, emsg
+      end
+      ok, write_count, emsg = _write_all(tofile, bytes)
+      if not ok then
+         fromfile:close()
+         tofile:close()
+         return false, emsg
+      end
+   until write_count == 0
+   return true
+end
+
 local function html_escape(s)
    return (s:gsub("&", "&amp;"):
 	   gsub("<", "&lt;"):
@@ -329,6 +372,7 @@ return {
    dirname = dirname,
    basename = basename,
 
+   copy_file = copy_file,
    mkdir_p = mkdir_p,
    rm_rf = rm_rf,