6.7 KiB
Basic usage
local bitser = require 'bitser'
-- some_thing can be almost any lua value
local binary_data = bitser.dumps(some_thing)
-- binary_data is a string containing some serialized value
local copy_of_some_thing = bitser.loads(binary_data)
Bitser can't dump values of type function
, userdata
or thread
, or anything that
contains one of those. If you need to, look into bitser.register
.
Serializing class instances
All you need to make bitser correctly serialize your class instances is register that class:
-- this is usually enough
bitser.registerClass(MyClass)
-- if you use Slither, you can add it to __attributes__
class 'MyClass' {
__attributes__ = {bitser.registerClass},
-- insert rest of class here
}
local data = bitser.dumps(MyClass(42))
local instance = bitser.loads(data)
Note that classnames need to be unique to avoid confusion, so if you have two different classes named Foo
you'll need to do
something like:
-- in module_a.lua
bitser.registerClass('module_a.Foo', Foo)
-- in module_b.lua
bitser.registerClass('module_b.Foo', Foo)
See the reference sections on bitser.registerClass
and
bitser.unregisterClass
for more information.
Supported class libraries
- MiddleClass
- SECL
- hump.class
- Slither
- Moonscript classes
Advanced usage
If you use LÖVE, you'll want to use bitser.dumpLoveFile
and bitser.loadLoveFile
if you want to serialize to the save directory. You also might have images and other resources that you'll need to register, like follows:
function love.load()
bad_guy_img = bitser.register('bad_guy_img', love.graphics.newImage('img/bad_guy.png'))
if love.filesystem.exists('save_point.dat') then
level_data = bitser.loadLoveFile('save_point.dat')
else
level_data = create_level_data()
end
end
function save_point_reached()
bitser.dumpLoveFile('save_point.dat', level_data)
end
Reference
dumps
string = bitser.dumps(value)
Basic serialization of value
into a Lua string.
See also: bitser.loads
.
dumpLoveFile
bitser.dumpLoveFile(file_name, value)
Serializes value
and writes the result to file_name
more efficiently than serializing to a string and writing
that string to a file. Only useful if you're running LÖVE.
See also: bitser.loadLoveFile
.
loads
value = bitser.loads(string)
Deserializes value
from string
.
See also: bitser.dumps
.
loadData
value = bitser.loadData(light_userdata, size)
Deserializes value
from raw data. You probably won't need to use this function ever.
When running LÖVE, you would use it like this:
value = bitser.loadData(data:getPointer(), data:getSize())
Where data
is an instance of a subclass of Data.
loadLoveFile
value = bitser.loadLoveFile(file_name)
Reads from file_name
and deserializes value
more efficiently than reading the file and then deserializing that string.
Only useful if you're running LÖVE.
See also: bitser.dumpLoveFile
.
register
resource = bitser.register(name, resource)
Registers the value resource
with the name name
, which has to be a unique string. Registering static resources like images,
functions, classes, huge strings and LuaJIT ctypes, makes sure bitser doesn't attempt to serialize them, but only stores a named
reference to them.
Returns the registered resource as a convenience.
See also: bitser.unregister
.
registerClass
class = bitser.registerClass(class)
class = bitser.registerClass(name, class)
class = bitser.registerClass(name, class, classkey, deserializer)
Registers the class class
, so that bitser can correctly serialize and deserialize instances of class
.
Note that if you want to serialize the class itself, you'll need to register the class as a resource.
Most of the time the first variant is enough, but some class libraries don't store the class name on the class object itself, in which case you'll need to use the second variant.
Class names also have to be unique, so if you use multiple classes with the same name, you'll need to use the second variant as well to give them different names.
The arguments classkey
and deserializer
exist so you can hook in unsupported class libraries without needing
to patch bitser. See the list of supported class libraries.
If not nil, the argument classkey
should be a string such that
rawget(obj, classkey) == class
for any obj
whose type is class
. This is done so that key is skipped for serialization.
If not nil, the argument deserializer
should be a function such that deserializer(obj, class)
returns a valid
instance of class
with the properties of obj
. deserializer
is allowed to mutate obj
.
Returns the registered class as a convenience.
See also: bitser.unregisterClass
.
unregister
bitser.unregister(name)
Deregisters the previously registered value with the name name
.
See also: bitser.register
.
unregisterClass
bitser.unregisterClass(name)
Deregisters the previously registered class with the name name
. Note that this works by name and not value,
which is useful in a context where you don't have a reference to the class you want to unregister.
See also: bitser.registerClass
.
reserveBuffer
bitser.reserveBuffer(num_bytes)
Makes sure the buffer used for reading and writing serialized data is at least num_bytes
large.
You probably don't need to ever use this function.
clearBuffer
bitser.clearBuffer()
Frees up the buffer used for reading and writing serialized data for garbage collection. You'll rarely need to use this function, except if you needed a huge buffer before and now only need a small buffer (or are done (de)serializing altogether). Most of the time, using this function will decrease performance needlessly.