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-rw-r--r--util/datamanager.lua47
1 files changed, 33 insertions, 14 deletions
diff --git a/util/datamanager.lua b/util/datamanager.lua
index 29a5b994..5d3074a3 100644
--- a/util/datamanager.lua
+++ b/util/datamanager.lua
@@ -15,11 +15,12 @@ local pcall = pcall;
local log = require "util.logger".init("datamanager");
local io_open = io.open;
local os_remove = os.remove;
+local os_rename = os.rename;
local tostring, tonumber = tostring, tonumber;
local error = error;
local next = next;
local t_insert = table.insert;
-local append = require "util.serialization".append;
+local t_concat = table.concat;
local envloadfile = require"util.envload".envloadfile;
local serialize = require "util.serialization".serialize;
local path_separator = assert ( package.config:match ( "^([^\n]+)" ) , "package.config not in standard form" ) -- Extract directory seperator from package.config (an undocumented string that comes with lua)
@@ -149,6 +150,28 @@ function load(username, host, datastore)
return ret;
end
+local function atomic_store(filename, data)
+ local scratch = filename.."~";
+ local f, ok, msg;
+ repeat
+ f, msg = io_open(scratch, "w");
+ if not f then break end
+
+ ok, msg = f:write(data);
+ if not ok then break end
+
+ ok, msg = f:close();
+ if not ok then break end
+
+ return os_rename(scratch, filename);
+ until false;
+
+ -- Cleanup
+ if f then f:close(); end
+ os_remove(scratch);
+ return nil, msg;
+end
+
function store(username, host, datastore, data)
if not data then
data = {};
@@ -160,14 +183,12 @@ function store(username, host, datastore, data)
end
-- save the datastore
- local f, msg = io_open(getpath(username, host, datastore, nil, true), "w+");
- if not f then
+ local d = "return " .. serialize(data) .. ";\n";
+ local ok, msg = atomic_store(getpath(username, host, datastore, nil, true), d);
+ if not ok then
log("error", "Unable to write to %s storage ('%s') for user: %s@%s", datastore, msg, username or "nil", host or "nil");
return nil, "Error saving to storage";
end
- f:write("return ");
- append(f, data);
- f:close();
if next(data) == nil then -- try to delete empty datastore
log("debug", "Removing empty %s datastore for user %s@%s", datastore, username or "nil", host or "nil");
os_remove(getpath(username, host, datastore));
@@ -206,17 +227,15 @@ function list_store(username, host, datastore, data)
end
if callback(username, host, datastore) == false then return true; end
-- save the datastore
- local f, msg = io_open(getpath(username, host, datastore, "list", true), "w+");
- if not f then
+ local d = {};
+ for _, item in ipairs(data) do
+ d[#d+1] = "item(" .. serialize(item) .. ");\n";
+ end
+ local ok, msg = atomic_store(getpath(username, host, datastore, "list", true), t_concat(d));
+ if not ok then
log("error", "Unable to write to %s storage ('%s') for user: %s@%s", datastore, msg, username or "nil", host or "nil");
return;
end
- for _, d in ipairs(data) do
- f:write("item(");
- append(f, d);
- f:write(");\n");
- end
- f:close();
if next(data) == nil then -- try to delete empty datastore
log("debug", "Removing empty %s datastore for user %s@%s", datastore, username or "nil", host or "nil");
os_remove(getpath(username, host, datastore, "list"));