Module delta 

Delta codec for monotonic counter columns.

Monotonic counters (bytes_sent, request_count) have small positive deltas that compress well with simple delta encoding + varint packing.

Wire format:

[4 bytes] sample count (LE u32)
[8 bytes] first value (LE i64)
[N bytes] varint-encoded deltas (ZigZag + LEB128)

Varint encoding uses ZigZag to handle negative deltas (counter resets) efficiently: small absolute values → 1-2 bytes regardless of sign.

Compression: monotonic counters with small increments → ~1-2 bytes/sample. Non-monotonic data → ~2-4 bytes/sample (still better than raw 8 bytes).

Structs

DeltaDecoder

Streaming Delta decoder.

DeltaEncoder

Streaming Delta encoder. Accumulates values and produces compressed bytes on finish().

Functions

decode

Decode Delta-compressed bytes back to i64 values.

encode

Encode a slice of i64 values using Delta + ZigZag-varint compression.