Merge remote-tracking branch 'refs/remotes/map/fsync4' into origin-master

Conflicts:
	src/db.erl
	src/plop.erl

1 files changed, 24 insertions, 0 deletions

diff --git a/src/atomic.erl b/src/atomic.erl
new file mode 100644
index 0000000..5bf5670
--- /dev/null
+++ b/src/atomic.erl
@@ -0,0 +1,24 @@
+%%
+%% Copyright (c) 2014 Kungliga Tekniska Högskolan
+%% (KTH Royal Institute of Technology, Stockholm, Sweden).
+%%
+
+-module(atomic).
+-export([replacefile/2, readfile/1]).
+
+-spec replacefile(string(), binary()) -> ok.
+replacefile(Path, Content) ->
+    TempName = util:tempfilename(Path),
+    util:write_tempfile_and_rename(Path, TempName, Content),
+    util:fsync([Path, filename:dirname(Path)]).
+
+-spec readfile(string()) -> binary().
+readfile(Path) ->
+    case file:read_file(Path) of
+        {ok, Contents} ->
+            Contents;
+	{error, enoent} ->
+            noentry;
+        {error, Error} ->
+            util:exit_with_error(readfile, Error, "Error reading file")
+    end.