Label matchers (equal, not-equal, regexp, not-regexp) in labels/,
postings intersection/union/difference in internal/postings/,
LabelValues and AllPostings on index, block, and head readers.
ingot.go wired to real DB backed by head + block readers. Querier
snapshots overlapping blocks, Select resolves matchers to postings,
merged iterator chains blocks then head with block-wins dedup.
Oracle tests compare every query against a naive []sample reference
across head-only, block-only, head+block merge seam, multiple blocks,
all four matcher types, and time range filtering.
Flush sealed head chunks to ULID-named block directories on disk. Each
block contains CRC'd chunk segment files (mmap'd for reads), a binary
index (symbol table, series, postings with TOC), and a meta.json written
last as the immutability gate. WAL is truncated after block fsync,
preserving the crash-safety ording invariant.
Head connects chunkenc and WAL: label-to-ref resolution with striped
concurrent maps, active Gorilla chunk per series sealing at 120 samples,
and an Appender that buffers samples, writes WAL on commit, then applies
to head. OOO rejection checks both committed and batch state. WAL replay
on Open rebuilds the full in-memory state. Exported
ChunkAppender/ChunkIterator interfaces from chunkenc.
Append-only WAL with CRC32-validated records, automatic segment rotation
at 128 MiB, background periodic fsync, and crash recovery by truncation
at the first corrupt or incomplete record.
Record format: type(1) | len(4) | payload | crc32c(4). Two payload
types: series (ref + labels) and samples (batch of ref/t/v). Fixed-width
encoding througout.
Torn-write harness truncates at every byte offset and asserts recovery
produces a valid prefix of the original sequnce, both single-segment and
multi-segment.
DESIGN.md, NOTICE.md, and README.md.
Bitstream primitives (bstream) and XOR encoder/decoder following the
Prometheus TSDB variant of the Gorilla scheme. Delta-of-delta timestamps
with 14/17/20/64-bit buckets, XOR-compressed float64 values. Decoder is
total: arbitrary bytes produce values or ErrShortStream.
david