README.md

fb-thrift: Thrift serialization for Lua objects

This module implements Thrift serialization for arbitrary Lua objects with optional compression. Scalars, tables, functions with upvalues (serializing bytecode), and torch Tensors are supported. The module supports serializing arbitrary object graphs (with cycles), and the graph is restored properly on deserialization.

Lua interface

local thrift = require('fb.thrift')

local obj = { foo = 2 }  -- arbitrary Lua object

-- Serialization

-- to Lua string
local str = thrift.to_string(obj)

-- to open io.file object
local f = io.open('/tmp/foo', 'wb')
thrift.to_file(obj, f)

-- Deserialization

-- from Lua string
local obj = thrift.from_string(str)

-- from open io.file object
local f = io.open('/tmp/foo')
local obj = thrift.from_file(obj)

to_file writes to the file at the current position of the file pointer, and advances the file pointer past the serialized data. from_file reads from the current file pointer and advances the file pointer past the serialized data (that is, the format is self-delimiting, and you can serialize multiple objects to the same file without any special framing).

Serialization functions (to_file' and to_string') accept an additional argument that indicates the codec to use when compressing the data, if any. Valid values are in the thrift.codec table: NONE (no compression), LZ4, SNAPPY, ZLIB, LZMA2 (but some might not be available if the corresponding library wasn't installed on your system when folly was built).

C++ interface

There is limited support for writing and reading Lua-serialized objects from C++, without calling into Lua. Currently, only scalars and tensors are supported. See LuaObject.h for details (you should be able to include it as <fblua/thrift/LuaObject.h>)