Add `concatenate()` option to `{Zstd,Lz4}Reader`, to support decompressing
several concatenated frames.
For all decompressors suppporting concatenation (Zstd, Lz4, Zlib, Bzip2, and Xz
in certain header mores), reject empty data as the compressed stream even in the
concatenation mode.
PiperOrigin-RevId: 769991782
Riegeli/records is a file format for storing a sequence of string records, typically serialized protocol buffers. It supports dense compression, fast decoding, seeking, detection and optional skipping of data corruption, filtering of proto message fields for even faster decoding, and parallel encoding.
See documentation.
Riegeli file format will only change in a backward compatible way (i.e. future readers will understand current files, but current readers might not understand files using future features).
Riegeli C++ API might change in incompatible ways.