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DateTime-Lite-v0.1.0

Changes for version v0.1.0 - 2026-04-10

  • Initial release.
  • Full port of DateTime 1.66 API.
  • Dependencies reduced from ~10 non-core to 3 (DateTime::TimeZone, DateTime::Locale::FromCLDR, Locale::Unicode).
  • Specio, Params::ValidationCompiler, Try::Tiny, namespace::autoclean all eliminated.
  • XS layer ported from DateTime.xs with 4 new functions: _rd_to_epoch, _epoch_to_rd, _normalize_nanoseconds, _compare_rd.
  • Pure-Perl fallback (DateTime::Lite::PP) for environments without a C compiler.
  • No die() in normal error paths: DateTime::Lite::Exception used throughout, errors returned as undef in scalar context.
  • DateTime::Lite::Infinite provides singleton Future/Past objects.
  • Locale data via DateTime::Locale::FromCLDR + Locale::Unicode::Data (SQLite backend, no generated Perl locale files).
  • Includes DateTime::Lite::TimeZone based thoroughly on the IANA Olson data accessible with a SQLite database.
  • Replaced the shallow Perl clone() with an XS deep copy (DateTime-Lite.xs):
    • Root object scalar fields are copied with newSVsv().
    • Nested blessed hashrefs (tz, locale) are copied with a new static helper dtl_clone_flat_hv(), then re-blessed into the original stash. The RV is created first with newRV_noinc() before calling sv_bless(), which requires an RV not a raw HV pointer.
    • The local_c cache (plain hashref) is also deep-copied, eliminating any shared state between original and clone.
    • Non-HV references (formatter objects, etc.) are shallow-copied with newSVsv(), acceptable since formatters are effectively immutable.
  • Implemented a TZif footer POSIX parser in XS, based on IANA code (public domain).
  • New file dtl_posix.h: self-contained C header containing eight functions derived from tzcode localtime.c (is_digit, getzname, getqzname, getnum, getsecs, getoffset, getrule, transtime) plus dtl_year_to_jan1() and the public entry point dtl_posix_tz_lookup(). All symbols prefixed dtl_; no dynamic allocation, no system calls, no global state.
  • New XS function DateTime::Lite::posix_tz_lookup(class_or_self, unix_secs, tz_string): parses any POSIX TZ footer and returns { offset, is_dst, short_name } or undef. Handles Jn, n, Mm.w.d rules; quoted <name> abbreviations; fractional offsets; negative and >24 h transition times (RFC 9636 s3.3.2 v3+ extensions); southern- hemisphere DST (start > end).
  • DateTime::Lite::TimeZone::_posix_tz_lookup() is now a thin Perl wrapper that delegates to the XS function.
  • Implemented process-level memory cache to DateTime::Lite::TimeZone. The cache is opt-in and activated either per-call or class-wide: use_cache_mem => 1 argument to new() enables it for that call; DateTime::Lite::TimeZone->enable_mem_cache enables it globally. Three new class methods: enable_mem_cache(), disable_mem_cache(), clear_mem_cache(). Cache is keyed by both input name and canonical name after alias resolution, so "US/Eastern" and "America/New_York" share the same cached object.
  • Implemented three-layer span cache to DateTime::Lite::TimeZone, active when use_cache_mem => 1 or enable_mem_cache() is set: Layer 1 - object cache: TimeZone->new() returns the cached object keyed by zone name and canonical name, bypassing SQLite entirely. Layer 2 - span cache: _lookup_span() and _lookup_span_local() store the last matched span boundaries per cached TZ object. Subsequent calls within the same span return the cached result in ~0.5 us instead of ~45 us (SQL query). SQL extended with utc_start/utc_end and local_start/local_end columns for range checks. Layer 3 - POSIX footer cache: For zones with a footer TZ string (e.g. America/New_York), the DST rule calculation result is cached by calendar day. Pre-check added BEFORE the SQL query so future dates skip the database entirely on subsequent calls.

Documentation

CONTRIBUTING.md
README.md
benchmark.pl
Compare DateTime and DateTime::Lite performance
build_tz_database.pl
Build the DateTime::Lite::TimeZone SQLite database
leap_seconds_header.pl
Generate leap_seconds.h for DateTime::Lite XS

Modules

DateTime::Lite
Lightweight, low-dependency drop-in replacement for DateTime
DateTime::Lite::Duration
Duration objects for use with DateTime::Lite
DateTime::Lite::Exception
Exception object for DateTime::Lite
DateTime::Lite::Infinite
Infinite past and future DateTime::Lite objects
DateTime::Lite::PP
Pure-Perl fallback for the DateTime::Lite XS layer
DateTime::Lite::TimeZone
Lightweight timezone support for DateTime::Lite

Provides

DateTime::Lite::Infinite::Future
in lib/DateTime/Lite/Infinite.pm
DateTime::Lite::Infinite::Past
in lib/DateTime/Lite/Infinite.pm
DateTime::Lite::_FakeLocale
in lib/DateTime/Lite/Infinite.pm
DateTime::Lite::_Thawed
in lib/DateTime/Lite.pm

Other files