Codec overview (src/sydra/codec/*)

This directory contains encoding/compression helpers used by on-disk formats (notably segments).

Current usage:

• src/sydra/storage/segment.zig v1 (SYSEG2) uses:
  • timestamp codec 1 → src/sydra/codec/gorilla.zig.encodeTsDoD
  • value codec 1 → src/sydra/codec/gorilla.zig.encodeF64

Important: several codec modules are currently placeholders/stubs.

Modules

• src/sydra/codec/gorilla.zig – delta-of-delta timestamps + Gorilla-like float XOR encoding
• src/sydra/codec/bitpack.zig – bit-packing stub
• src/sydra/codec/rle.zig – run-length encoding stubs
• src/sydra/codec/zstd.zig – placeholder zstd wrapper (currently returns empty slices)

Code excerpt (integration point)

Segments currently hard-code codec IDs 1 and dispatch directly to Gorilla helpers:

src/sydra/storage/segment.zig (codec bytes + encoder calls)

try writer.writeByte(1); // ts codec: 1=dod-zzvar
try writer.writeByte(1); // val codec: 1=gorilla-xor

try @import("../codec/gorilla.zig").encodeTsDoD(writer, points[0].ts, points);

var vals = try alloc.alloc(f64, points.len);
defer alloc.free(vals);
for (points, 0..) |p, i| vals[i] = p.value;
try @import("../codec/gorilla.zig").encodeF64(writer, vals);