basic file system KVS backend

src/store_fs.erl

@@ -0,0 +1,47 @@
+-module(store_fs).
+-copyright('Synrc Research Center s.r.o.').
+-include("config.hrl").
+-include("metainfo.hrl").
+-include_lib("stdlib/include/qlc.hrl").
+-compile(export_all).
+
+start()    -> ok.
+stop()     -> ok.
+destroy()  -> ok.
+version()  -> {version,"KVS FS"}.
+dir()      -> [ {table,F} || F <- filelib:wildcard("data/*"), filelib:is_dir(F) ].
+join()     -> filelib:ensure_dir("data/").
+join(Node) -> ok. % should be rsync or smth
+change_storage(Table,Type) -> ok.
+
+initialize() ->
+    kvs:info(?MODULE,"[store_mnesia] mnesia init.~n",[]),
+    mnesia:create_schema([node()]),
+    [ kvs:init(store_fs,Module) || Module <- kvs:modules() ],
+    mnesia:wait_for_tables([ T#table.name || T <- kvs:tables()],infinity).
+
+index(Tab,Key,Value) -> ok.
+get(TableName, Key) ->
+    HashKey = wf:url_encode(base64:encode(crypto:sha(term_to_binary(Key)))),
+    Dir = lists:concat(["data/",TableName,"/"]),
+    case file:read_file(lists:concat([Dir,HashKey])) of
+         {ok,Binary} -> {ok,binary_to_term(Binary,[safe])};
+         {error,Reason} -> {error,Reason} end.
+
+put(Records) when is_list(Records) -> lists:map(fun(Record) -> put(Record) end, Records);
+put(Record) ->
+    TableName = element(1,Record),
+    HashKey = wf:url_encode(base64:encode(crypto:sha(term_to_binary(element(2,Record))))),
+    BinaryValue = term_to_binary(Record),
+    Dir = lists:concat(["data/",TableName,"/"]),
+    filelib:ensure_dir(Dir),
+    File = lists:concat([Dir,HashKey]),
+    io:format("File: ~p~n",[File]),
+    file:write_file(File,BinaryValue,[write,raw,binary,exclusive,sync]).
+
+delete(Tab, Key) -> ok.
+count(RecordName) -> length(filelib:fold_files(lists:concat(["data/",RecordName]), "",true, fun(A,Acc)-> [A|Acc] end, [])).
+all(R) -> filelib:fold_files(lists:concat(["data/",R]), "",true, fun(A,Acc)-> [A|Acc] end, []).
+next_id(RecordName, Incr) -> mnesia:dirty_update_counter({id_seq, RecordName}, Incr).
+create_table(Name,Options) -> filelib:ensure_dir(lists:concat(["data/",Name,"/"])).
+add_table_index(Record, Field) -> ok.