diff --git a/docs/source/LuaUsage.md b/docs/source/LuaUsage.md index 75b1f3b8a..43c370f5d 100644 --- a/docs/source/LuaUsage.md +++ b/docs/source/LuaUsage.md @@ -29,8 +29,8 @@ flatbuffers/blob/master/tests/luatest.lua). To run the tests, use the [LuaTest.sh](https://github.com/google/flatbuffers/ blob/master/tests/LuaTest.sh) shell script. -*Note: This script requires [Lua 5.3](https://www.lua.org/) to be -installed.* +*Note: This script requires [Lua 5.3](https://www.lua.org/) and +[LuaJIT](http://luajit.org/) to be installed.* ## Using the FlatBuffers Lua library diff --git a/lua/flatbuffers/binaryarray.lua b/lua/flatbuffers/binaryarray.lua index bf728cddd..3d16c36e1 100644 --- a/lua/flatbuffers/binaryarray.lua +++ b/lua/flatbuffers/binaryarray.lua @@ -1,3 +1,9 @@ +local compat = require("flatbuffers.compat") +-- locals for slightly faster access +local string_pack = compat.string_pack +local string_unpack = compat.string_unpack + + local m = {} -- the module table local mt = {} -- the module metatable @@ -104,19 +110,15 @@ function mt:Set(value, position) self.data[position] = value end --- locals for slightly faster access -local sunpack = string.unpack -local spack = string.pack - -- Pack the data into a binary representation function m.Pack(fmt, ...) - return spack(fmt, ...) + return string_pack(fmt, ...) end -- Unpack the data from a binary representation in -- a Lua value function m.Unpack(fmt, s, pos) - return sunpack(fmt, s.str, pos + 1) + return string_unpack(fmt, s.str, pos + 1) end -- Return the binary array module diff --git a/lua/flatbuffers/builder.lua b/lua/flatbuffers/builder.lua index 4a0c4f6a2..bb8072327 100644 --- a/lua/flatbuffers/builder.lua +++ b/lua/flatbuffers/builder.lua @@ -1,6 +1,7 @@ local N = require("flatbuffers.numTypes") local ba = require("flatbuffers.binaryarray") local compat = require("flatbuffers.compat") +local string_unpack = compat.string_unpack local m = {} @@ -34,7 +35,7 @@ local function vtableEqual(a, objectStart, b) end for i, elem in ipairs(a) do - local x = string.unpack(VOffsetT.packFmt, b, 1 + (i - 1) * 2) + local x = string_unpack(VOffsetT.packFmt, b, 1 + (i - 1) * 2) if x ~= 0 or elem ~= 0 then local y = objectStart - elem if x ~= y then @@ -119,7 +120,7 @@ function mt:WriteVtable() local vt2Offset = self.vtables[i] local vt2Start = #self.bytes - vt2Offset local vt2lenstr = self.bytes:Slice(vt2Start, vt2Start+1) - local vt2Len = string.unpack(VOffsetT.packFmt, vt2lenstr, 1) + local vt2Len = string_unpack(VOffsetT.packFmt, vt2lenstr, 1) local metadata = VtableMetadataFields * 2 local vt2End = vt2Start + vt2Len @@ -210,7 +211,7 @@ function mt:Prep(size, additionalBytes) local h = self.head local k = #self.bytes - h + additionalBytes - local alignsize = ((~k) + 1) & (size - 1) -- getAlignSize(k, size) + local alignsize = getAlignSize(k, size) local desiredSize = alignsize + size + additionalBytes diff --git a/lua/flatbuffers/compat.lua b/lua/flatbuffers/compat.lua index 89c992beb..fbce45785 100644 --- a/lua/flatbuffers/compat.lua +++ b/lua/flatbuffers/compat.lua @@ -1,17 +1,12 @@ -local m = {} - -local getAlignSize +local m if _VERSION == "Lua 5.3" then - getAlignSize = function(k, size) - return ((~k) + 1) & (size - 1) - end + m = require("flatbuffers.compat_5_3") else - getAlignSize = function(self, size, additionalBytes) - local alignsize = bit32.bnot(#self.bytes-self:Head() + additionalBytes) + 1 - return bit32.band(alignsize,(size - 1)) + local ok = pcall(require, "jit") + if not ok then + error("Only Lua 5.3 or LuaJIT is supported") + else + m = require("flatbuffers.compat_luajit") end end - -m.GetAlignSize = getAlignSize - return m \ No newline at end of file diff --git a/lua/flatbuffers/compat_5_3.lua b/lua/flatbuffers/compat_5_3.lua new file mode 100644 index 000000000..762bf073c --- /dev/null +++ b/lua/flatbuffers/compat_5_3.lua @@ -0,0 +1,14 @@ +-- We need to put it into a separate file to avoid syntax error like `unexpected symbol near '~'` +local m = {} + + +m.GetAlignSize = function(k, size) + return ((~k) + 1) & (size - 1) +end + + +m.string_pack = string.pack +m.string_unpack = string.unpack + + +return m diff --git a/lua/flatbuffers/compat_luajit.lua b/lua/flatbuffers/compat_luajit.lua new file mode 100644 index 000000000..cb8be71e5 --- /dev/null +++ b/lua/flatbuffers/compat_luajit.lua @@ -0,0 +1,206 @@ +local bit = require("bit") +local ffi = require("ffi") +local band = bit.band +local bnot = bit.bnot + + +local m = {} +local Uint8Bound = 256 -- bound is the max uintN + 1 +local Uint16Bound = 65536 +local Uint32Bound = 4294967296 + + +m.GetAlignSize = function(k, size) + return band((bnot(k) + 1), (size - 1)) +end + + +local function pack_I1(n) + return string.char(n) +end +local function pack_i1(n) + if n < 0 then + n = Uint8Bound + n + end + return pack_I1(n) +end + +local function unpack_I1(n, pos) + return string.byte(n, pos) +end +local function unpack_i1(n, pos) + local res = unpack_I1(n, pos) + if res >= Uint8Bound / 2 then + return res - Uint8Bound + end + return res +end + +local b2 = ffi.new("unsigned char[2]") +local function pack_I2(n) + for i = 0, 1 do + b2[i] = bit.band(n, 255) + n = bit.rshift(n, 8) + end + return ffi.string(b2, 2) +end +local function pack_i2(n) + if n < 0 then + n = Uint16Bound + n + end + return pack_I2(n) +end + +local function unpack_I2(n, pos) + local a, b = string.byte(n, pos, pos + 1) + return b * Uint8Bound + a +end +local function unpack_i2(n, pos) + local res = unpack_I2(n, pos) + if res >= Uint16Bound / 2 then + return res - Uint16Bound + end + return res +end + +local b4 = ffi.new("unsigned char[4]") +local function pack_I4(n) + for i = 0, 3 do + b4[i] = bit.band(n, 255) + n = bit.rshift(n, 8) + end + return ffi.string(b4, 4) +end +local function pack_i4(n) + if n < 0 then + n = Uint32Bound + n + end + return pack_I4(n) +end + +local function unpack_I4(n, pos) + local a, b, c, d = string.byte(n, pos, pos + 3) + return Uint8Bound * (Uint8Bound * ((Uint8Bound * d) + c) + b) + a +end +local function unpack_i4(n, pos) + local res = unpack_I4(n, pos) + if res >= Uint32Bound / 2 then + return res - Uint32Bound + end + return res +end + +local b8 = ffi.new("unsigned char[8]") +local function pack_I8(n) + n = ffi.cast("unsigned long long", n) + local hi = math.floor(tonumber(n / Uint32Bound)) + local li = n % Uint32Bound + for i = 0, 3 do + b8[i] = bit.band(li, 255) + li = bit.rshift(li, 8) + end + for i = 4, 7 do + b8[i] = bit.band(hi, 255) + hi = bit.rshift(hi, 8) + end + return ffi.string(b8, 8) +end +local function pack_i8(n) + n = ffi.cast("signed long long", n) + return pack_I8(n) +end + +local function unpack_I8(n, pos) + local a, b, c, d = string.byte(n, pos, pos + 3) + local li = Uint8Bound * (Uint8Bound * ((Uint8Bound * d) + c) + b) + a + local a, b, c, d = string.byte(n, pos + 4, pos + 7) + local hi = Uint8Bound * (Uint8Bound * ((Uint8Bound * d) + c) + b) + a + return ffi.cast("unsigned long long", hi) * Uint32Bound + li +end +local function unpack_i8(n, pos) + local res = unpack_I8(n, pos) + return ffi.cast("signed long long", res) +end + +local bf = ffi.new("float[1]") +local function pack_f(n) + bf[0] = n + return ffi.string(bf, 4) +end + +local function unpack_f(n, pos) + ffi.copy(bf, ffi.cast("char *", n) + pos - 1, 4) + return tonumber(bf[0]) +end + +local bd = ffi.new("double[1]") +local function pack_d(n) + bd[0] = n + return ffi.string(bd, 8) +end + +local function unpack_d(n, pos) + ffi.copy(bd, ffi.cast("char *", n) + pos - 1, 8) + return tonumber(bd[0]) +end + + +m.string_pack = function(fmt, i, ...) + if fmt == "