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pretty/cdata.lua

128 lines
3.6 KiB
Lua

-- Import
local ffi = require 'ffi'
local bit = require 'bit'
-- Constants
--------------------------------------------------------------------------------
-- Util
local HEX_TO_BIN = {
['0'] = '0000', ['1'] = '0001', ['2'] = '0010', ['3'] = '0011',
['4'] = '0100', ['5'] = '0101', ['6'] = '0110', ['7'] = '0111',
['8'] = '1000', ['9'] = '1001', ['A'] = '1010', ['B'] = '1011',
['C'] = '1100', ['D'] = '1101', ['E'] = '1110', ['F'] = '1111',
}
local function to_hex (val, nr_elements, element_size)
local l = {}
for i = 0, nr_elements - 1 do
local v = val[i]
l[#l+1] = bit.tohex(v, -2*element_size)
l[#l+1] = ' '
end
l[#l] = nil
return table.concat(l, '')
end
local function to_bin (val, nr_elements, element_size)
return to_hex(val, nr_elements, element_size):gsub('[0-9A-F]', HEX_TO_BIN)
end
local function is_nice_unicode_string (str)
-- TODO... Maybe also look into a purely binary oriented representation.
return false
end
local function is_nice_ascii_string (str)
for i = 1, #str do
local byte = str:byte(i)
if not (32 <= byte and byte <= 126) then return false end
end
return true
end
local function get_type_and_size_of_singular ( ctype )
local nr_elements, layers = 1, 0
while true do
local etype, elements = ctype:match('(.+)%[(%d*)%]$')
if not elements then break end
ctype, nr_elements = etype, nr_elements * elements
layers = layers + 1
end
return ctype, nr_elements, layers
end
--------------------------------------------------------------------------------
local CDATA_REPR_MATCHER = 'cdata<(.+)>: (0x%w+)'
local function format_cdata (value, display, l, format_value)
-- Error check
assert(type(value) == 'cdata' )
assert(type(display) == 'number' )
assert(type(l) == 'table' )
assert(type(format_value) == 'function')
-- Do stuff
local native_repr = tostring(value)
local data_length = ffi.sizeof(value)
local ctype, addr = native_repr:match(CDATA_REPR_MATCHER)
-- Is void pointer?
if ctype == 'void *' then
local address_pointing_at = tonumber(ffi.cast('int', value))
l[#l+1] = 'void pointer to ' .. addr
return ;
end
-- Is normal pointer?
if ctype:match('%*$') then
if type(value[0]) ~= 'cdata' then
-- Data presentable in Lua, refered to by pointers?
l[#l+1] = 'pointer to '
return format_value(value[0], display, l.options, l)
else
l[#l+1] = '* '
return format_cdata(value[0], display, l.options, l, format_value)
end
end
l[#l+1] = 'cdata {'
--l[#l+1] = '\n\tnative = \'' .. native_repr .. '\','
l[#l+1] = '\n\ttype = ' .. ctype .. ','
l[#l+1] = '\n\taddr = ' .. addr .. ','
if data_length then
-- Size
local str = ffi.string(value, data_length)
l[#l+1] = '\n\tsize = ' .. data_length .. ','
-- Element size and type
local element_type, nr_elements, nr_layers = get_type_and_size_of_singular(ctype)
local element_size = data_length / nr_elements
l[#l+1] = '\n\tnr_e = ' .. nr_elements .. ','
l[#l+1] = '\n\ttype_e = ' .. element_type .. ','
l[#l+1] = '\n\tsize_e = ' .. element_size .. ','
-- If can be expressed as string, express it as string.
if is_nice_ascii_string(str) or is_nice_unicode_string(str) then
local string_or_unicode = is_nice_ascii_string(str) and 'ascii' or 'utf8 '
l[#l+1] = '\n\t'..string_or_unicode..' = ' .. str .. ','
end
--
if nr_layers == 1 then
-- Only a single level of arrays
l[#l+1] = '\n\thex = ' .. to_hex(value, nr_elements, element_size) .. ','
l[#l+1] = '\n\tbin = ' .. to_bin(value, nr_elements, element_size) .. ','
end
end
l[#l+1] = '\n}'
end
return format_cdata