0.72.0

Release notes

Enhancements

• Reduced the memory usage of TsSymbolMap for requests spanning many days
• Added TsSymbolMap::get_for_ts() for looking up a mapping by UNIX timestamp
• Added TsSymbolMap::on_record() and TsSymbolMap::on_symbol_mapping() for building a
  TsSymbolMap from live SymbolMappingMsg records
• Added interval() methods to Schema and RType in the Python bindings, which return
  the subsampling interval as a datetime.timedelta or None
• Added support for Python 3.15 to databento_dbn
• Added a preliminary v4 module for the in-development DBN version 4
• Added RecordHeaderKind trait to abstract over different RecordHeaders
• Added HasRType and Record traits and RecordRef, RecordRefMut, and RecordBuf
  aliases to the v1, v2, and v3 modules, bound to the v1-v3 RecordHeader
• Added a preliminary layout module for describing the fields of DBN version 4
  records
• Added DynFieldAccess and LayoutIndex for reading DBN version 4 record fields
  through a stream's layout
• Added Tbbo variant to RType for TBBO records in DBN version 4. Existing versions
  will continue to use the Mbp1 rtype
• Added RecordLayoutDesc and StructLayoutDesc traits and derive macros,
  StreamLayoutBuilder, RecordLayoutBuilder, StructLayoutBuilder,
  v4::types::Symbol, and v4::layouts::default_layout() for building DBN version 4
  layouts from record structs
• Upgraded pyo3 to 0.29.3
• Upgraded async-compression to 0.4.50

Breaking changes

• Changed TsSymbolMap::insert() to take the start and end of the mapping as UNIX
  timestamps instead of dates
• RecordRef, RecordRefMut, and RecordBuf are generic over the record header
  layout, which defaults to the v1-v3 RecordHeader. Record has a new Header
  associated type naming the layout a record begins with. Generic code bounded on T: HasRType that downcasts a RecordRef or builds a RecordBuf needs T: v3::HasRType
• RecordRef::new(), RecordRefMut::new(), and their unchecked_from_header()
  constructors need the header specified
• HasRType::has_rtype() takes a u16, and HasRType no longer requires RecordMut
• The RecordMut trait now requires Record and RecordMut::header_mut() returns
  &mut Self::Header. Generic code for version 1-3 that uses header_mut() will need a
  v3::HasRType bound
• DecodeRecord, DecodeStream, and AsyncDecodeRecord decode v1-v3 records, so their
  generic methods require T: v3::HasRType
• WithTsOut, transmute_record(), transmute_record_bytes(), and
  transmute_record_mut() accept only v1-v3 records, and InstrumentDefRec,
  StatRec, and SymbolMappingRec extend v3::HasRType
• dyn Record requires naming the header, e.g. dyn v3::Record, which can also hold v1
  and v2 records since they share the same header
• Removed From<&RecordEnum> and From<&RecordBuf> for RecordRef, and From<&mut RecordBuf> for RecordRefMut. The blanket From<&R> for RecordRef covers every
  Record, including these
• Added layout field to Metadata for the record layouts of a DBN version 4 stream

Deprecations

• Deprecated TsSymbolMap::get() in favor of get_for_ts()