--- /dev/null
+local tz_info_mt = require "luatz.tzinfo".tz_info_mt
+local tt_info_mt = require "luatz.tzinfo".tt_info_mt
+
+local read_int32be, read_int64be
+
+-- 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
+
+ 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
+ end
+ end
+end
+
+local function read_flags(fd, n)
+ local data, err = fd:read(n)
+ if data == nil then return nil, err end
+
+ local res = {}
+ for i=1, n do
+ res[i] = data:byte(i,i) ~= 0
+ end
+ return res
+end
+
+local fifteen_nulls = ("\0"):rep(15)
+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")
+
+ -- The number of UTC/local indicators stored in the file.
+ local tzh_ttisgmtcnt = assert(read_int32be(fd))
+
+ -- The number of standard/wall indicators stored in the file.
+ 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))
+
+ -- The number of "transition times" for which data is stored in the file.
+ 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))
+
+ -- The number of characters of "timezone abbreviation strings" stored in the file.
+ local tzh_charcnt = assert(read_int32be(fd))
+
+ local transition_times = {}
+ for i=1, tzh_timecnt do
+ transition_times[i] = assert(read_int32be(fd))
+ end
+ local transition_time_ind = {assert(fd:read(tzh_timecnt)):byte(1, -1)}
+
+ 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();
+ }
+ end
+
+ local abbreviations = assert(fd:read(tzh_charcnt))
+
+ 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));
+ }
+ end
+
+ local isstd = assert(read_flags(fd, tzh_ttisstdcnt))
+
+ local isgmt = assert(read_flags(fd, tzh_ttisgmtcnt))
+
+ 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(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))
+
+ -- The number of standard/wall indicators stored in the file.
+ 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))
+
+ -- The number of "transition times" for which data is stored in the file.
+ 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))
+
+ -- The number of characters of "timezone abbreviation strings" stored in the file.
+ tzh_charcnt = assert(read_int32be(fd))
+
+ transition_times = {}
+ for i=1, tzh_timecnt do
+ transition_times[i] = assert(read_int64be(fd))
+ end
+ transition_time_ind = {assert(fd:read(tzh_timecnt)):byte(1, -1)}
+
+ 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();
+ }
+ end
+
+ abbreviations = assert(fd:read(tzh_charcnt))
+
+ leap_seconds = {}
+ for i=1, tzh_leapcnt do
+ leap_seconds[i] = {
+ offset = assert(read_int64be(fd));
+ n = assert(read_int32be(fd));
+ }
+ end
+
+ isstd = assert(read_flags(fd, tzh_ttisstdcnt))
+
+ 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
+ setmetatable(v, tt_info_mt)
+ end
+
+ --[[
+ Use the first standard-time ttinfo structure in the file
+ (or simply the first ttinfo structure in the absence of a standard-time structure)
+ if either tzh_timecnt is zero or the time argument is less than the first transition time recorded in the file.
+ ]]
+ local first = 1
+ do
+ for i=1, tzh_ttisstdcnt do
+ if isstd[i] then
+ first = i
+ break
+ end
+ end
+ end
+
+ local res = {
+ future = TZ;
+ [0] = {
+ 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];
+ }
+ end
+ return setmetatable(res, tz_info_mt)
+ else
+ error("Unsupported version")
+ end
+end
+
+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;
+}
projects / etc / awesome.git / blobdiff