david
42b03db2fa
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.
55 lines
1.5 KiB
Go
55 lines
1.5 KiB
Go
// Package index implements the binary index file format for ingot blocks.
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//
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// An index file contains four sections:
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//
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// [Header 5B] [Symbol Table] [Series] [Postings] [TOC 28B]
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//
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// The TOC at the end stores offsets to each section. Readers seek to the
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// end, read the TOC, and use the offsets to locate each section.
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package index
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import (
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"errors"
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"git.dvdt.dev/david/ingot/labels"
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)
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const (
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indexMagic uint32 = 0x0FACEDB1
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indexVersion byte = 1
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headerLen = 5 // 4-byte magic + 1-byte version
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tocLen = 28 // 3 offsets (24) + CRC (4)
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)
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var (
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ErrInvalidMagic = errors.New("index: invalid magic number")
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ErrInvalidVersion = errors.New("index: unsupported version")
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ErrCorruptTOC = errors.New("index: corrupt TOC (CRC mismatch)")
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ErrCorruptIndex = errors.New("index: corrupt index data")
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ErrTooShort = errors.New("index: file too short")
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)
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// ChunkRef encodes a chunk's location as (segment << 32 | offset).
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type ChunkRef uint64
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func NewChunkRef(segment, offset uint32) ChunkRef {
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return ChunkRef(uint64(segment)<<32 | uint64(offset))
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}
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func (r ChunkRef) Segment() uint32 { return uint32(r >> 32) }
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func (r ChunkRef) Offset() uint32 { return uint32(r) }
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// ChunkMeta describes a chunk's time range and location in a chunk file.
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type ChunkMeta struct {
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MinT int64
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MaxT int64
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Ref ChunkRef
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}
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// SeriesEntry is the input for writing and the output for reading a series.
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type SeriesEntry struct {
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Ref uint64
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Labels []labels.Label
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Chunks []ChunkMeta
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}
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