local tz_info_mt = require "luatz.tzinfo".tz_info_mt
+local tt_info_mt = require "luatz.tzinfo".tt_info_mt
-local function read_int32be ( fd )
- local data , err = fd:read ( 4 )
- if data == nil then return nil , err end
- local o1 , o2 , o3 , o4 = data:byte ( 1 , 4 )
+local read_int32be, read_int64be
- local unsigned = o4 + o3*2^8 + o2*2^16 + o1*2^24
- if unsigned >= 2^31 then
- return unsigned - 2^32
- else
- return unsigned
+-- luacheck: push std max
+if string.unpack then
+ -- Only available in Lua 5.3+
+ function read_int32be(fd)
+ local data, err = fd:read(4)
+ if data == nil then return nil, err end
+ return string.unpack(">i4", data)
+ end
+
+ function read_int64be(fd)
+ local data, err = fd:read(8)
+ if data == nil then return nil, err end
+ return string.unpack(">i8", data)
+ end
+else -- luacheck: pop
+ function read_int32be(fd)
+ local data, err = fd:read(4)
+ if data == nil then return nil, err end
+ local o1, o2, o3, o4 = data:byte(1, 4)
+
+ local unsigned = o4 + o3*2^8 + o2*2^16 + o1*2^24
+ if unsigned >= 2^31 then
+ return unsigned - 2^32
+ else
+ return unsigned
+ end
end
-end
-local function read_int64be ( fd )
- local data , err = fd:read ( 8 )
- if data == nil then return nil , err end
- local o1 , o2 , o3 , o4 , o5 , o6 , o7 , o8 = data:byte ( 1 , 8 )
+ function read_int64be(fd)
+ local data, err = fd:read(8)
+ if data == nil then return nil, err end
+ local o1, o2, o3, o4, o5, o6, o7, o8 = data:byte(1, 8)
- local unsigned = o8 + o7*2^8 + o6*2^16 + o5*2^24 + o4*2^32 + o3*2^40 + o2*2^48 + o1*2^56
- if unsigned >= 2^63 then
- return unsigned - 2^64
- else
- return unsigned
+ local unsigned = o8 + o7*2^8 + o6*2^16 + o5*2^24 + o4*2^32 + o3*2^40 + o2*2^48 + o1*2^56
+ if unsigned >= 2^63 then
+ return unsigned - 2^64
+ else
+ return unsigned
+ end
end
end
-local function read_flags ( fd , n )
- local data , err = fd:read ( n )
- if data == nil then return nil , err end
+local function read_flags(fd, n)
+ local data, err = fd:read(n)
+ if data == nil then return nil, err end
- local res = { }
+ local res = {}
for i=1, n do
res[i] = data:byte(i,i) ~= 0
end
end
local fifteen_nulls = ("\0"):rep(15)
-local function read_tz ( fd )
- assert ( fd:read(4) == "TZif" )
- local version = assert ( fd:read(1) )
- if version == "\0" or version == "2" then
+local function read_tz(fd)
+ assert(fd:read(4) == "TZif", "Invalid TZ file")
+ local version = assert(fd:read(1))
+ if version == "\0" or version == "2" or version == "3" then
local MIN_TIME = -2^32+1
- assert ( assert ( fd:read(15) ) == fifteen_nulls , "Expected 15 nulls" )
+ assert(assert(fd:read(15)) == fifteen_nulls, "Expected 15 nulls")
-- The number of UTC/local indicators stored in the file.
- local tzh_ttisgmtcnt = assert ( read_int32be ( fd ) )
+ local tzh_ttisgmtcnt = assert(read_int32be(fd))
-- The number of standard/wall indicators stored in the file.
- local tzh_ttisstdcnt = assert ( read_int32be ( fd ) )
+ local tzh_ttisstdcnt = assert(read_int32be(fd))
-- The number of leap seconds for which data is stored in the file.
- local tzh_leapcnt = assert ( read_int32be ( fd ) )
+ local tzh_leapcnt = assert(read_int32be(fd))
-- The number of "transition times" for which data is stored in the file.
- local tzh_timecnt = assert ( read_int32be ( fd ) )
+ local tzh_timecnt = assert(read_int32be(fd))
-- The number of "local time types" for which data is stored in the file (must not be zero).
- local tzh_typecnt = assert ( read_int32be ( fd ) )
+ local tzh_typecnt = assert(read_int32be(fd))
-- The number of characters of "timezone abbreviation strings" stored in the file.
- local tzh_charcnt = assert ( read_int32be ( fd ) )
+ local tzh_charcnt = assert(read_int32be(fd))
- local transition_times = { }
+ local transition_times = {}
for i=1, tzh_timecnt do
- transition_times [ i ] = assert ( read_int32be ( fd ) )
+ transition_times[i] = assert(read_int32be(fd))
end
- local transition_time_ind = { assert ( fd:read ( tzh_timecnt ) ):byte ( 1 , -1 ) }
+ local transition_time_ind = {assert(fd:read(tzh_timecnt)):byte(1, -1)}
- local ttinfos = { }
+ local ttinfos = {}
for i=1, tzh_typecnt do
- ttinfos [ i ] = {
- gmtoff = assert ( read_int32be ( fd ) ) ;
- isdst = assert ( fd:read ( 1 ) ) ~= "\0" ;
- abbrind = assert ( fd:read ( 1 ) ):byte ( ) ;
+ ttinfos[i] = {
+ gmtoff = assert(read_int32be(fd));
+ isdst = assert(fd:read(1)) ~= "\0";
+ abbrind = assert(fd:read(1)):byte();
}
end
- local abbreviations = assert ( fd:read ( tzh_charcnt ) )
+ local abbreviations = assert(fd:read(tzh_charcnt))
- local leap_seconds = { }
+ local leap_seconds = {} -- luacheck: ignore 241
for i=1, tzh_leapcnt do
- leap_seconds [ i ] = {
- offset = assert ( read_int32be ( fd ) ) ;
- n = assert ( read_int32be ( fd ) ) ;
+ leap_seconds[i] = {
+ offset = assert(read_int32be(fd));
+ n = assert(read_int32be(fd));
}
end
- local isstd = assert ( read_flags ( fd , tzh_ttisstdcnt ) )
+ local isstd = assert(read_flags(fd, tzh_ttisstdcnt))
- local isgmt = assert ( read_flags ( fd , tzh_ttisgmtcnt ) )
+ local isgmt = assert(read_flags(fd, tzh_ttisgmtcnt))
- if version == "2" then
+ local TZ
+
+ if version == "2" or version == "3" then
--[[
For version-2-format timezone files, the above header and data is followed by a second header and data,
identical in format except that eight bytes are used for each transition time or leap-second time.
]]
- assert ( fd:read(5) == "TZif2" )
- assert ( assert ( fd:read(15) ) == fifteen_nulls , "Expected 15 nulls" )
+ assert(fd:read(4) == "TZif")
+ assert(fd:read(1) == version)
+ assert(assert(fd:read(15)) == fifteen_nulls, "Expected 15 nulls")
MIN_TIME = -2^64+1
-- The number of UTC/local indicators stored in the file.
- tzh_ttisgmtcnt = assert ( read_int32be ( fd ) )
+ tzh_ttisgmtcnt = assert(read_int32be(fd))
-- The number of standard/wall indicators stored in the file.
- tzh_ttisstdcnt = assert ( read_int32be ( fd ) )
+ tzh_ttisstdcnt = assert(read_int32be(fd))
-- The number of leap seconds for which data is stored in the file.
- tzh_leapcnt = assert ( read_int32be ( fd ) )
+ tzh_leapcnt = assert(read_int32be(fd))
-- The number of "transition times" for which data is stored in the file.
- tzh_timecnt = assert ( read_int32be ( fd ) )
+ tzh_timecnt = assert(read_int32be(fd))
-- The number of "local time types" for which data is stored in the file (must not be zero).
- tzh_typecnt = assert ( read_int32be ( fd ) )
+ tzh_typecnt = assert(read_int32be(fd))
-- The number of characters of "timezone abbreviation strings" stored in the file.
- tzh_charcnt = assert ( read_int32be ( fd ) )
+ tzh_charcnt = assert(read_int32be(fd))
- transition_times = { }
+ transition_times = {}
for i=1, tzh_timecnt do
- transition_times [ i ] = assert ( read_int64be ( fd ) )
+ transition_times[i] = assert(read_int64be(fd))
end
- transition_time_ind = { assert ( fd:read ( tzh_timecnt ) ):byte ( 1 , -1 ) }
+ transition_time_ind = {assert(fd:read(tzh_timecnt)):byte(1, -1)}
- ttinfos = { }
+ ttinfos = {}
for i=1, tzh_typecnt do
- ttinfos [ i ] = {
- gmtoff = assert ( read_int32be ( fd ) ) ;
- isdst = assert ( fd:read ( 1 ) ) ~= "\0" ;
- abbrind = assert ( fd:read ( 1 ) ):byte ( ) ;
+ ttinfos[i] = {
+ gmtoff = assert(read_int32be(fd));
+ isdst = assert(fd:read(1)) ~= "\0";
+ abbrind = assert(fd:read(1)):byte();
}
end
- abbreviations = assert ( fd:read ( tzh_charcnt ) )
+ abbreviations = assert(fd:read(tzh_charcnt))
- leap_seconds = { }
+ leap_seconds = {}
for i=1, tzh_leapcnt do
- leap_seconds [ i ] = {
- offset = assert ( read_int64be ( fd ) ) ;
- n = assert ( read_int32be ( fd ) ) ;
+ leap_seconds[i] = {
+ offset = assert(read_int64be(fd));
+ n = assert(read_int32be(fd));
}
end
- isstd = assert ( read_flags ( fd , tzh_ttisstdcnt ) )
+ isstd = assert(read_flags(fd, tzh_ttisstdcnt))
- isgmt = assert ( read_flags ( fd , tzh_ttisgmtcnt ) )
+ isgmt = assert(read_flags(fd, tzh_ttisgmtcnt))
--[[
After the second header and data comes a newline-enclosed, POSIX-TZ-environment-variable-style string
for use in handling instants after the last transition time stored in the file
(with nothing between the newlines if there is no POSIX representation for such instants).
]]
+
+ --[[
+ For version-3-format time zone files, the POSIX-TZ-style string may
+ use two minor extensions to the POSIX TZ format, as described in newtzset (3).
+ First, the hours part of its transition times may be signed and range from
+ -167 through 167 instead of the POSIX-required unsigned values
+ from 0 through 24. Second, DST is in effect all year if it starts
+ January 1 at 00:00 and ends December 31 at 24:00 plus the difference
+ between daylight saving and standard time.
+ ]]
+
+ assert(assert(fd:read(1)) == "\n", "Expected newline at end of version 2 header")
+
+ TZ = assert(fd:read("*l"))
+ if #TZ == 0 then
+ TZ = nil
+ end
end
for i=1, tzh_typecnt do
- local v = ttinfos [ i ]
- v.abbr = abbreviations:sub ( v.abbrind+1 , v.abbrind+3 )
- v.isstd = isstd [ i ] or false
- v.isgmt = isgmt [ i ] or false
+ local v = ttinfos[i]
+ v.abbr = abbreviations:sub(v.abbrind+1, v.abbrind+3)
+ v.isstd = isstd[i] or false
+ v.isgmt = isgmt[i] or false
+ setmetatable(v, tt_info_mt)
end
--[[
end
local res = {
+ future = TZ;
[0] = {
- transition_time = MIN_TIME ;
- info = ttinfos [ first ] ;
+ transition_time = MIN_TIME;
+ info = ttinfos[first];
}
}
for i=1, tzh_timecnt do
- res [ i ] = {
- transition_time = transition_times [ i ] ;
- info = ttinfos [ transition_time_ind [ i ]+1 ] ;
+ res[i] = {
+ transition_time = transition_times[i];
+ info = ttinfos[transition_time_ind[i]+1];
}
end
- return setmetatable ( res , tz_info_mt )
+ return setmetatable(res, tz_info_mt)
else
- error ( "Unsupported version" )
+ error("Unsupported version")
end
end
-local function read_tzfile ( path )
- local fd = assert ( io.open ( path ) )
- local tzinfo = read_tz ( fd )
- fd:close ( )
+local function read_tzfile(path)
+ local fd = assert(io.open(path, "rb"))
+ local tzinfo = read_tz(fd)
+ fd:close()
return tzinfo
end
return {
- read_tz = read_tz ;
- read_tzfile = read_tzfile ;
+ read_tz = read_tz;
+ read_tzfile = read_tzfile;
}