From 267d04d2bd2a7681c8bbcfbb655612101440b765 Mon Sep 17 00:00:00 2001 From: William Wilgus Date: Fri, 6 Sep 2019 19:24:26 -0500 Subject: Lua add metadata and settings reading helper module Adds example scripts for reading track metadata + dumping albumart and rockbox settings settings are now stored as a table of strings rather than a table of tables as it saves ~15 kb of ram without adding much complexity Change-Id: I611c312b2a60ab96e595e4710b17aedbd6c0689b --- apps/plugins/lua/include_lua/rbsettings.lua | 164 ++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+) create mode 100644 apps/plugins/lua/include_lua/rbsettings.lua (limited to 'apps/plugins/lua/include_lua') diff --git a/apps/plugins/lua/include_lua/rbsettings.lua b/apps/plugins/lua/include_lua/rbsettings.lua new file mode 100644 index 0000000000..defdb11b77 --- /dev/null +++ b/apps/plugins/lua/include_lua/rbsettings.lua @@ -0,0 +1,164 @@ +--[[ Lua rb settings reader +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2019 William Wilgus + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ +]] + +rb.settings = rb.settings or {} + +local var = {offset = 1, size = 2, type = 3, fields = 3} + +local function bytesLE_n(str) + str = str or "" + local tbyte={str:byte(1, -1)} + local bpos, num = 1, 0 + for k = 1,#tbyte do -- (k = #t, 1, -1 for BE) + num = num + tbyte[k] * bpos + bpos = bpos * 256 --1<<8 + end + return num +end + +local function get_var_fields(s_var) + -- converts member string into table + -- var = {offset, size, "type"} + s_var = s_var or "" + local o, s, t = string.match(s_var, "(0x%x+),%s*(%d+),%s*(.+)") + local tvar = {o, s, t} + + return #tvar == var.fields and tvar or nil +end + +local function format_val(val, var_type) + local ret, num + if var_type == nil then + return nil + elseif var_type == "str" then + -- stop at first null byte, return nil if str doesn't exist + return val and string.match(val, "^%Z+") or nil + end + + num = bytesLE_n(val) + if string.find(var_type, "^b") then + if(num <= 0) then + ret = false + else + ret = true + end + elseif string.find(var_type, "^u_[cil]") then + -- Lua integers are signed so we need to do a bit of extra processing + ret = (string.format("%u", num)) + else + ret = num + end + + return ret +end + +local function dump_struct(t_settings, t_struct, n_elems, t_var) + --Internal function dumps structs + local tdata = {} + + local function struct_get_elem(v, elem_offset) + local val, offset, tvar1 + tvar1 = get_var_fields(v) + offset = t_var[var.offset] + tvar1[var.offset] + elem_offset + val = t_settings(offset, tvar1[var.size]) + return format_val(val, tvar1[var.type]) + end + + if n_elems > 0 then + -- Array of structs, struct[elems]; + local elemsize = (t_var[var.size] / n_elems) + for i = 0, n_elems - 1 do + tdata[i] = tdata[i] or {} + for k1, v1 in pairs(t_struct) do + tdata[i][k1] = struct_get_elem(v1, (elemsize * i)) + end + end + else + -- single struct, struct; + for k1, v1 in pairs(t_struct) do + tdata[k1] = struct_get_elem(v1, 0) + end + end + return tdata +end + +local function get_array_elems(var_type) + --extract the number of elements, returns 0 if not found + local elems = string.match(var_type,".*%[(%d+)%]") + return tonumber(elems) or 0 +end + +local function get_struct_name(var_type) + --extract the name of a struct, returns nil if not found + return string.match(var_type,"^s_([^%[%]%s]+)") +end + +function rb.settings.read(s_settings, s_var, s_groupname) + local data, val + local tvar = get_var_fields(s_var) + if tvar == nil then return nil end + + local elems = get_array_elems(tvar[var.type]) + local structname = get_struct_name(tvar[var.type]) + + local tsettings = rb[s_settings] + if not tsettings then error(s_settings .. " does not exist") end + + if structname and rb[s_groupname] then + return dump_struct(tsettings, rb[s_groupname][structname], elems, tvar) + end + + local voffset, vsize, vtype = tvar[var.offset], tvar[var.size], tvar[var.type] + if elems > 0 then + -- Arrays of values, val[elems]; + data = {} + local elemsize = (vsize / elems) + + for i = 0, elems - 1 do + val = tsettings(voffset + (elemsize * i), elemsize) + data[i] = format_val(val, vtype) + end + else + -- Single value, val; + if vtype == "ptr_char" then -- (**char) + vtype = "str" + val = tsettings(voffset, vsize, nil, true) + else + val = tsettings(voffset, vsize) + end + data = format_val(val, vtype) + end + return data +end + +function rb.settings.dump(s_settings, s_groupname, s_structname, t_output) + t_output = t_output or {} + local tgroup = rb[s_groupname] + s_structname = s_structname or s_settings + for k, v in pairs(tgroup[s_structname]) do + t_output[k] = rb.settings.read(s_settings, v, s_groupname) + end + return t_output +end + +return true -- cgit v1.2.3