dump of work-in-progress. Hideous code.

TODO

@@ -3,3 +3,4 @@
 * round-robin writing
 * LastModified instead of Version
 * monic_file:new and monic_file:delete
+* keep monic_file servers alive.

include/monic.hrl

@@ -1,3 +1,4 @@
+-define(BUFFER_SIZE, 64*1024).
 -define(INDEX_SIZE, 28).
 -define(HEADER_SIZE, 28).
 -define(FOOTER_SIZE, 24).

src/monic_file.erl

@@ -24,10 +24,8 @@
     tid=nil
 }).
 
--define(BUFFER_SIZE, 16384).
-
 %% public API
--export([open/1, add/3, read/4, close/1]).
+-export([open/1, add/3, lookup/3, close/1]).
 
 %% gen_server API
 -export([init/1, terminate/2, code_change/3,handle_call/3, handle_cast/2, handle_info/2]).
@@ -40,8 +38,8 @@ open(Path) ->
 add(Pid, Size, StreamBody) ->
     gen_server:call(Pid, {add, Size, StreamBody}, infinity).
 
-read(Pid, Key, Cookie, Fun) ->
-    gen_server:call(Pid, {read, Key, Cookie, Fun}, infinity).
+lookup(Pid, Key, Cookie) ->
+    gen_server:call(Pid, {lookup, Key, Cookie}, infinity).
 
 close(Pid) ->
     gen_server:call(Pid, close, infinity).
@@ -68,6 +66,14 @@ init(Path) ->
             {stop, Else}
     end.
 
+handle_call({lookup, Key, _Cookie}, _From, #state{tid=Tid}=State) ->
+    Reply = case ets:lookup(Tid, Key) of
+        [] ->
+            {error, not_found};
+        [{Key, Location, Size, _}] ->
+            {ok, Location, Size}
+    end,
+    {reply, Reply, State};
 handle_call({read, Key, Cookie, Fun}, _From, #state{tid=Tid, main_fd=Fd}=State) ->
     case ets:lookup(Tid, Key) of
         [{Key, Location, Size, _}] ->
@@ -223,7 +229,8 @@ copy_in(Fd, {Bin, Next}, Location, Remaining, Sha) ->
             end
     end.
 
-copy_out(_Fd, _Fun, _Location, 0) ->
+copy_out(_Fd, Fun, _Location, 0) ->
+    Fun(eof),
     ok;
 copy_out(Fd, Fun, Location, Remaining) ->
     case file:pread(Fd, Location, min(Remaining, ?BUFFER_SIZE)) of

src/monic_file_resource.erl

@@ -26,7 +26,7 @@
 -export([show_file/2, create_file/2, add_item/2]).
 
 -include_lib("webmachine/include/webmachine.hrl").
--define(BUFFER_SIZE, 64*1024).
+-include("monic.hrl").
 
 allowed_methods(ReqData, Context) ->
     {['DELETE', 'GET', 'PUT', 'POST'], ReqData, Context}.
@@ -89,7 +89,6 @@ create_file(ReqData, Context) ->
     end.
 
 add_item(ReqData, Context) ->
-    erlang:display({disp, wrq:disp_path(ReqData)}),
     case monic_file:open(monic_utils:path(ReqData, Context)) of
         {ok, Pid} ->
             try

src/monic_item_resource.erl

@@ -16,20 +16,73 @@
 -export([init/1,
     allowed_methods/2,
     content_types_provided/2,
-    delete_resource/2,
     resource_exists/2]).
+-export([fetch/2]).
+
+-include_lib("webmachine/include/webmachine.hrl").
+-include("monic.hrl").
 
 allowed_methods(ReqData, Context) ->
-    {['DELETE', 'GET', 'POST'], ReqData, Context}.
+    {['GET'], ReqData, Context}.
 
 content_types_provided(ReqData, Context) ->
-    {[{"application/octet-stream", to_binary}], ReqData, Context}.
-
-delete_resource(ReqData, Context) ->
-    {false, ReqData, Context}.
+    {[{"application/octet-stream", fetch}], ReqData, Context}.
 
 init(ConfigProps) ->
     {ok, ConfigProps}.
 
 resource_exists(ReqData, Context) ->
-    {true, ReqData, Context}.
+    Key = list_to_integer(wrq:path_info(key, ReqData)),
+    Cookie = list_to_integer(wrq:path_info(cookie, ReqData)),
+    Exists = case monic_file:open(monic_utils:path(ReqData, Context)) of
+        {ok, Pid} ->
+            try
+                case monic_file:lookup(Pid, Key, Cookie) of
+                    {ok, _, _} ->
+                        true;
+                    {error, not_found} ->
+                        false
+                end
+            after
+                monic_file:close(Pid)
+            end;
+        _ ->
+            false
+    end,
+    {Exists, ReqData, Context}.
+
+fetch(ReqData, Context) ->
+    Path = monic_utils:path(ReqData, Context),
+    Key = list_to_integer(wrq:path_info(key, ReqData)),
+    Cookie = list_to_integer(wrq:path_info(cookie, ReqData)),
+    case monic_file:open(Path) of
+        {ok, Pid} ->
+            try
+                StreamBody = case monic_file:lookup(Pid, Key, Cookie) of
+                    {ok, Location, Size} ->
+                        case file:open(Path, [read]) of
+                            {ok, Fd} ->
+                                {stream, pump(Fd, Location, Size)};
+                            _ ->
+                                <<>>
+                        end;
+                    {error, not_found} ->
+                        <<>>
+                end,
+                {StreamBody, ReqData, Context}
+            after
+                monic_file:close(Pid)
+            end;
+        _ ->
+            {<<>>, ReqData, Context}
+    end.
+
+pump(Fd, Location, Remaining) ->
+    {ok, Bin} = file:pread(Fd, Location, min(Remaining, ?BUFFER_SIZE)),
+    Size = iolist_size(Bin),
+    case Size == Remaining of
+        true ->
+            {Bin, done};
+        false ->
+            {Bin, fun() -> pump(Fd, Location + Size, Remaining - Size) end}
+    end.

test/monic_file_test.erl

@@ -38,7 +38,8 @@ cleanup(Pid) ->
     monic_file:close(Pid).
 
 add(Pid) ->
-    ?_assertMatch({ok, 0, _}, monic_file:add(Pid, 3, {<<"123">>, done})).
+    [?_assertMatch({ok, 0, _}, monic_file:add(Pid, 3, {<<"123">>, done})),
+    ?_assertMatch(true, monic_file:exists(Pid, 0, 0))].
 
 add_long(Pid) ->
     ?_assertMatch({ok, 0, _}, monic_file:add(Pid, 6,