remove backend-handler construct, simplify

api.lua

@@ -1,50 +1,13 @@
 
--- type => handler_def
-local backend_handlers = {}
-
-function mapsync.register_backend_handler(name, handler)
-    -- default to no-op functions
-    handler.validate_config = handler.validate_config or function() end
-    handler.init = handler.init or function() end
-
-    backend_handlers[name] = handler
-end
-
-function mapsync.select_handler(backend_def)
-    return backend_handlers[backend_def.type]
-end
-
--- type => handler_def
-local data_backend_handlers = {}
-
-function mapsync.register_data_backend_handler(name, handler)
-    data_backend_handlers[name] = handler
-end
-
-function mapsync.select_data_handler(data_backend_def)
-    return data_backend_handlers[data_backend_def.type]
-end
-
 -- name => backend_def
 local backends = {}
 
 -- register a map backend
 function mapsync.register_backend(name, backend_def)
-    local handler = mapsync.select_handler(backend_def)
-    if not handler then
-        error("unknown backend type: '" .. backend_def.type .. "' for backend '" .. name .. "'")
-    end
-
     backend_def.name = name
     -- default to always-on backend if no selector specified
     backend_def.select = backend_def.select or function() return true end
 
-    -- validate config
-    handler.validate_config(backend_def)
-
-    -- init backend def
-    handler.init(backend_def)
-
     -- register
     backends[name] = backend_def
 end

api.spec.lua

@@ -11,11 +11,9 @@ mtt.register("backend selection", function(callback)
     })
 
     local backend_def = mapsync.select_backend({x=0, y=0, z=0})
-    local handler = mapsync.select_handler(backend_def)
-
-    assert(handler)
     assert(backend_def.name == "my-backend")
-    assert(handler.save_chunk(backend_def, {x=0, y=0, z=0}))
+
+    assert(mapsync.save({x=0, y=0, z=0}))
 
     backend_def = mapsync.select_backend({x=0, y=10, z=0})
     assert(not backend_def)

data.lua

@@ -1,3 +1,4 @@
+local global_env = ...
 
 function mapsync.save_data(key, value)
     local data_backend_def = mapsync.get_data_backend()
@@ -6,10 +7,9 @@ function mapsync.save_data(key, value)
         return
     end
 
-    local data_handler = mapsync.select_data_handler(data_backend_def)
-    if data_handler then
-        data_handler.save_data(data_backend_def, key, value)
-    end
+    local f = assert(global_env.io.open(data_backend_def.path .. "/" .. key .. ".lua", "w"))
+    f:write(minetest.serialize(value))
+    f:close()
 end
 
 function mapsync.load_data(key)
@@ -19,8 +19,11 @@ function mapsync.load_data(key)
         return
     end
 
-    local data_handler = mapsync.select_data_handler(data_backend_def)
-    if data_handler then
-        return data_handler.load_data(data_backend_def, key)
+    local f = global_env.io.open(data_backend_def.path .. "/" .. key .. ".lua", "r")
+    if not f then
+        return
     end
+    local value = minetest.deserialize(f:read("*all"))
+    f:close()
+    return value
 end

functions.lua

@@ -70,10 +70,8 @@ function mapsync.get_backend_chunk_mtime(chunk_pos)
         return
     end
 
-	local handler = mapsync.select_handler(backend_def)
-
     -- get manifest
-    local manifest = handler.get_manifest(backend_def, chunk_pos)
+    local manifest = mapsync.get_manifest(mapsync.get_chunk_zip_path(backend_def.path, chunk_pos))
     if not manifest then
         return
     end
@@ -151,6 +149,14 @@ function mapsync.deep_compare(tbl1, tbl2)
 	return false
 end
 
+function mapsync.get_chunk_json_path(prefix, chunk_pos)
+    return prefix .. "/chunk_" .. minetest.pos_to_string(chunk_pos) .. ".json"
+end
+
+function mapsync.get_chunk_zip_path(prefix, chunk_pos)
+    return prefix .. "/chunk_" .. minetest.pos_to_string(chunk_pos) .. ".zip"
+end
+
 -- https://gist.github.com/SafeteeWoW/080e784e5ebfda42cad486c58e6d26e4
 -- license: zlib
 

init.lua

@@ -26,33 +26,31 @@ end
 dofile(MP.."/api.lua")
 dofile(MP.."/privs.lua")
 
--- backends
-loadfile(MP.."/backend_fs.lua")(global_env)
-loadfile(MP.."/backend_patch.lua")(global_env)
-
 -- utilities / helpers
 dofile(MP.."/pos_iterator.lua")
 dofile(MP.."/encoding.lua")
 dofile(MP.."/serialize_mapblock.lua")
 dofile(MP.."/deserialize_mapblock.lua")
 dofile(MP.."/localize_nodeids.lua")
+dofile(MP.."/functions.lua")
 
 -- diff / patch
 dofile(MP.."/create_diff.lua")
 dofile(MP.."/apply_diff.lua")
+loadfile(MP.."/patch.lua")(global_env)
 
 -- save/load
 dofile(MP.."/auto_save.lua")
 dofile(MP.."/auto_update.lua")
-dofile(MP.."/save.lua")
+loadfile(MP.."/save.lua")(global_env)
+loadfile(MP.."/data.lua")(global_env)
+dofile(MP.."/load.lua")
 dofile(MP.."/mapgen.lua")
-dofile(MP.."/data.lua")
 
 -- hud stuff
 dofile(MP.."/hud.lua")
 
 -- pass on global env (secure/insecure)
-loadfile(MP.."/functions.lua")(global_env)
 loadfile(MP.."/serialize_chunk.lua")(global_env)
 loadfile(MP.."/parse_chunk.lua")(global_env)
 loadfile(MP.."/deserialize_chunk.lua")(global_env)
@@ -72,7 +70,7 @@ if minetest.get_modpath("mtt") and mtt.enabled then
 	dofile(MP.."/crypto.spec.lua")
 	dofile(MP.."/data.spec.lua")
 	dofile(MP.."/diff.spec.lua")
-	dofile(MP.."/backend_patch.spec.lua")
+	dofile(MP.."/patch.spec.lua")
 	dofile(MP.."/api.spec.lua")
 	dofile(MP.."/serialize_chunk.spec.lua")
 end