chunkenc

package
v3.7.4 Latest Latest
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 Go to latest Published: Jul 22, 2026 License: AGPL-3.0 Imports: 31 Imported by: 1

README

Chunk v4 format

// Header
+-----------------------------------+
| Magic Number (uint32, 4 bytes)    |
+-----------------------------------+
| Version (1 byte)                  |
+-----------------------------------+
| Encoding (1 byte)                 |
+-----------------------------------+

// Blocks
+--------------------+----------------------------+
| block 1 (n bytes)  | checksum (uint32, 4 bytes) |
+--------------------+----------------------------+
| block 1 (n bytes)  | checksum (uint32, 4 bytes) |
+--------------------+----------------------------+
| ...                                             |
+--------------------+----------------------------+
| block N (n bytes)  | checksum (uint32, 4 bytes) |
+--------------------+----------------------------+

// Metas
+------------------------------------------------------------------------------------------------------------------------+
| #blocks (uvarint)                                                                                                      |
+--------------------+-----------------+-----------------+------------------+---------------+----------------------------+
| #entries (uvarint) | minTs (uvarint) | maxTs (uvarint) | offset (uvarint) | len (uvarint) | uncompressedSize (uvarint) |
+--------------------+-----------------+-----------------+------------------+---------------+----------------------------+
| #entries (uvarint) | minTs (uvarint) | maxTs (uvarint) | offset (uvarint) | len (uvarint) | uncompressedSize (uvarint) |
+--------------------+-----------------+-----------------+------------------+---------------+----------------------------+
| ...                                                                                                                    |
+--------------------+-----------------+-----------------+------------------+---------------+----------------------------+
| #entries (uvarint) | minTs (uvarint) | maxTs (uvarint) | offset (uvarint) | len (uvarint) | uncompressedSize (uvarint) |
+--------------------+-----------------+-----------------+------------------+---------------+----------------------------+
| checksum (uint32, 4 bytes)                                                                                             | 
+------------------------------------------------------------------------------------------------------------------------+

// Structured Metadata
+---------------------------------+
| #labels (uvarint)               |
+---------------+-----------------+
| len (uvarint) | value (n bytes) |
+---------------+-----------------+
| ...                             |
+---------------+-----------------+
| checksum (uint32, 4 bytes)      |
+---------------------------------+

// Footer
+-----------------------+--------------------------+
| len (uint64, 8 bytes) | offset (uint64, 8 bytes) |   // offset to Structured Metadata
+-----------------------+--------------------------+
| len (uint64, 8 bytes) | offset (uint64, 8 bytes) |   // offset to Metas
+-----------------------+--------------------------+

Documentation

Index

Constants

View Source 
const (
	ChunkFormatV1 byte
	ChunkFormatV2
	ChunkFormatV3
	ChunkFormatV4
)
View Source 
const GzipLogChunk = chunk.Encoding(128)

GzipLogChunk is a cortex encoding type for our chunks. Deprecated: the chunk encoding/compression format is inside the chunk data.

View Source 
const LogChunk = chunk.Encoding(129)

LogChunk is a cortex encoding type for our chunks.

Variables

View Source 
var (
	ErrChunkFull       = errors.New("chunk full")
	ErrOutOfOrder      = errors.New("entry out of order")
	ErrInvalidSize     = errors.New("invalid size")
	ErrInvalidFlag     = errors.New("invalid flag")
	ErrInvalidChecksum = errors.New("invalid chunk checksum")
)

Errors returned by the chunk interface.

View Source 
var (
	// BytesBufferPool is a bytes buffer used for lines decompressed.
	// Buckets [0.5KB,1KB,2KB,4KB,8KB]
	BytesBufferPool = pool.New(1<<9, 1<<13, 2, func(size int) interface{} { return make([]byte, 0, size) })

	// LabelsPool is a matrix of bytes buffers used to store label names and values.
	// Buckets [8, 16, 32, 64, 128, 256].
	// Since we store label names and values, the number of labels we can store is the half the bucket size.
	// So we will be able to store from 0 to 128 labels.
	LabelsPool = pool.New(1<<3, 1<<8, 2, func(size int) interface{} { return make([][]byte, 0, size) })

	SymbolsPool = pool.New(1<<3, 1<<8, 2, func(size int) interface{} { return make([]symbol, 0, size) })

	// SamplesPool pooling array of samples [512,1024,...,16k]
	SamplesPool = pool.New(1<<9, 1<<14, 2, func(size int) interface{} { return make([]logproto.Sample, 0, size) })

	// EncodeBufferPool is a pool used to binary encode.
	EncodeBufferPool = sync.Pool{
		New: func() interface{} {
			return &encbuf{
				b: make([]byte, 0, 256),
			}
		},
	}
)
View Source 
var HeadBlockFmts = []HeadBlockFmt{OrderedHeadBlockFmt, UnorderedHeadBlockFmt, UnorderedWithStructuredMetadataHeadBlockFmt}

Functions

func ErrTooFarBehind 

func ErrTooFarBehind(entryTs, cutoff time.Time) error

func IsErrTooFarBehind 

func IsErrTooFarBehind(err error) bool

func IsOutOfOrderErr 

func IsOutOfOrderErr(err error) bool

func NewFacade 

func NewFacade(c Chunk, blockSize, targetSize int) chunk.Data

NewFacade makes a new Facade.

func UncompressedSize 

func UncompressedSize(c chunk.Data) (int, bool)

UncompressedSize is a helper function to hide the type assertion kludge when wanting the uncompressed size of the Cortex interface encoding.Chunk.

Types

type Block 

type Block interface {
	// MinTime is the minimum time of entries in the block
	MinTime() int64
	// MaxTime is the maximum time of entries in the block
	MaxTime() int64
	// Offset is the offset/position of the block in the chunk. Offset is unique for a given block per chunk.
	Offset() int
	// Entries is the amount of entries in the block.
	Entries() int
	// Iterator returns an entry iterator for the block.
	Iterator(ctx context.Context, pipeline log.StreamPipeline) iter.EntryIterator
	// SampleIterator returns a sample iterator for the block.
	SampleIterator(ctx context.Context, extractor ...log.StreamSampleExtractor) iter.SampleIterator
}

Block is a chunk block.

type Chunk 

type Chunk interface {
	Bounds() (time.Time, time.Time)
	SpaceFor(*logproto.Entry) bool
	// Append returns true if the entry appended was a duplicate
	Append(*logproto.Entry) (bool, error)
	Iterator(ctx context.Context, mintT, maxtT time.Time, direction logproto.Direction, pipeline log.StreamPipeline) (iter.EntryIterator, error)
	SampleIterator(ctx context.Context, from, through time.Time, extractor ...log.StreamSampleExtractor) iter.SampleIterator
	// Returns the list of blocks in the chunks.
	Blocks(mintT, maxtT time.Time) []Block
	// Size returns the number of entries in a chunk
	Size() int
	Bytes() ([]byte, error)
	BytesWith([]byte) ([]byte, error) // uses provided []byte for buffer instantiation
	io.WriterTo
	BlockCount() int
	Utilization() float64
	UncompressedSize() int
	CompressedSize() int
	Close() error
	Encoding() compression.Codec
	Rewrite(filter filter.Func) (Chunk, error)
}

Chunk is the interface for the compressed logs chunk format.

func NewDumbChunk 

func NewDumbChunk() Chunk

NewDumbChunk returns a new chunk that isn't very good.

type Facade 

type Facade struct {
	chunk.Data
	// contains filtered or unexported fields
}

Facade for compatibility with cortex chunk type, so we can use its chunk store.

func (Facade) Bounds 

func (f Facade) Bounds() (time.Time, time.Time)

func (Facade) Encoding 

func (Facade) Encoding() chunk.Encoding

Encoding implements chunk.Chunk.

func (Facade) Entries 

func (f Facade) Entries() int

func (Facade) LokiChunk 

func (f Facade) LokiChunk() Chunk

LokiChunk returns the chunkenc.Chunk.

func (Facade) Marshal 

func (f Facade) Marshal(w io.Writer) error

Marshal implements chunk.Chunk.

func (Facade) Rewrite added in v3.6.0 

func (f Facade) Rewrite(filter filter.Func) (chunk.Data, error)

func (Facade) Size 

func (f Facade) Size() int

Size implements encoding.Chunk, which unfortunately uses the Size method to refer to the byte size and not the entry count like chunkenc.Chunk does.

func (Facade) UncompressedSize 

func (f Facade) UncompressedSize() int

func (*Facade) UnmarshalFromBuf 

func (f *Facade) UnmarshalFromBuf(buf []byte) error

UnmarshalFromBuf implements chunk.Chunk.

func (Facade) Utilization 

func (f Facade) Utilization() float64

Utilization implements encoding.Chunk.

type HeadBlock 

type HeadBlock interface {
	IsEmpty() bool
	CheckpointTo(w io.Writer) error
	CheckpointBytes(b []byte) ([]byte, error)
	CheckpointSize() int
	LoadBytes(b []byte) error
	Serialise(pool compression.WriterPool) ([]byte, error)
	Reset()
	Bounds() (mint, maxt int64)
	Entries() int
	UncompressedSize() int
	Convert(HeadBlockFmt, *symbolizer) (HeadBlock, error)
	Append(int64, string, labels.Labels) (bool, error)
	Iterator(
		ctx context.Context,
		direction logproto.Direction,
		mint,
		maxt int64,
		pipeline log.StreamPipeline,
	) iter.EntryIterator
	SampleIterator(
		ctx context.Context,
		mint,
		maxt int64,
		extractor ...log.StreamSampleExtractor,
	) iter.SampleIterator
	Format() HeadBlockFmt
}

func HeadFromCheckpoint 

func HeadFromCheckpoint(b []byte, desiredIfNotUnordered HeadBlockFmt, symbolizer *symbolizer) (HeadBlock, error)

HeadFromCheckpoint handles reading any head block format and returning the desired form. This is particularly helpful replaying WALs from different configurations such as after enabling unordered writes.

type HeadBlockFmt 

type HeadBlockFmt byte
const (
	OrderedHeadBlockFmt HeadBlockFmt
	UnorderedHeadBlockFmt
	UnorderedWithStructuredMetadataHeadBlockFmt
)

func ChunkHeadFormatFor 

func ChunkHeadFormatFor(chunkfmt byte) HeadBlockFmt

ChunkHeadFormatFor returns corresponding head block format for the given `chunkfmt`.

func (HeadBlockFmt) Byte 

func (f HeadBlockFmt) Byte() byte

func (HeadBlockFmt) NewBlock 

func (f HeadBlockFmt) NewBlock(symbolizer *symbolizer) HeadBlock

func (HeadBlockFmt) String 

func (f HeadBlockFmt) String() string

type MemChunk 

type MemChunk struct {
	// contains filtered or unexported fields
}

MemChunk implements compressed log chunks.

func MemchunkFromCheckpoint 

func MemchunkFromCheckpoint(chk, head []byte, desiredIfNotUnordered HeadBlockFmt, blockSize int, targetSize int) (*MemChunk, error)

func NewByteChunk 

func NewByteChunk(b []byte, blockSize, targetSize int) (*MemChunk, error)

NewByteChunk returns a MemChunk on the passed bytes.

func NewMemChunk 

func NewMemChunk(chunkFormat byte, enc compression.Codec, head HeadBlockFmt, blockSize, targetSize int) *MemChunk

NewMemChunk returns a new in-mem chunk.

func (*MemChunk) Append 

func (c *MemChunk) Append(entry *logproto.Entry) (bool, error)

Append implements Chunk. The MemChunk may return true or false, depending on what the head block returns.

func (*MemChunk) BlockCount 

func (c *MemChunk) BlockCount() int

BlockCount implements Chunk.

func (*MemChunk) Blocks 

func (c *MemChunk) Blocks(mintT, maxtT time.Time) []Block

Blocks implements Chunk

func (*MemChunk) Bounds 

func (c *MemChunk) Bounds() (fromT, toT time.Time)

Bounds implements Chunk.

func (*MemChunk) Bytes 

func (c *MemChunk) Bytes() ([]byte, error)

Bytes implements Chunk. NOTE: Does not cut head block or include any head block data.

func (*MemChunk) BytesSize 

func (c *MemChunk) BytesSize() int

BytesSize returns the raw size of the chunk. NOTE: This does not account for the head block nor include any head block data.

func (*MemChunk) BytesWith 

func (c *MemChunk) BytesWith(b []byte) ([]byte, error)

BytesWith uses a provided []byte for buffer instantiation NOTE: This does not cut the head block nor include any head block data.

func (*MemChunk) CheckpointSize 

func (c *MemChunk) CheckpointSize() (chunk, head int)

func (*MemChunk) Close 

func (c *MemChunk) Close() error

Close implements Chunk. TODO: Fix this to check edge cases.

func (*MemChunk) CompressedSize 

func (c *MemChunk) CompressedSize() int

CompressedSize implements Chunk.

func (*MemChunk) ConvertHead 

func (c *MemChunk) ConvertHead(desired HeadBlockFmt) error

func (*MemChunk) Encoding 

func (c *MemChunk) Encoding() compression.Codec

Encoding implements Chunk.

func (*MemChunk) Iterator 

func (c *MemChunk) Iterator(ctx context.Context, mintT, maxtT time.Time, direction logproto.Direction, pipeline log.StreamPipeline) (iter.EntryIterator, error)

Iterator implements Chunk.

func (*MemChunk) Rebound 

func (c *MemChunk) Rebound(start, end time.Time, filter filter.Func) (Chunk, error)

Rebound builds a smaller chunk with logs having timestamp from start and end(both inclusive)

func (*MemChunk) Rewrite added in v3.6.0 

func (c *MemChunk) Rewrite(filter filter.Func) (Chunk, error)

Rewrite rewrites the chunk after filtering out lines based on response from filter.Func. Filter.Func would be called for each log entry, and the ones for which it returns true would be removed. The new chunk would have data in the same order as the original chunk.

func (*MemChunk) SampleIterator 

func (c *MemChunk) SampleIterator(
	ctx context.Context,
	from, through time.Time,
	extractors ...log.StreamSampleExtractor,
) iter.SampleIterator

Iterator implements Chunk.

func (*MemChunk) SerializeForCheckpointTo 

func (c *MemChunk) SerializeForCheckpointTo(chk, head io.Writer) error

SerializeForCheckpointTo serialize the chunk & head into different `io.Writer` for checkpointing use. This is to ensure eventually flushed chunks don't have different substructures depending on when they were checkpointed. In turn this allows us to maintain a more effective dedupe ratio in storage.

func (*MemChunk) Size 

func (c *MemChunk) Size() int

Size implements Chunk.

func (*MemChunk) SpaceFor 

func (c *MemChunk) SpaceFor(e *logproto.Entry) bool

SpaceFor implements Chunk.

func (*MemChunk) UncompressedSize 

func (c *MemChunk) UncompressedSize() int

UncompressedSize implements Chunk.

func (*MemChunk) Utilization 

func (c *MemChunk) Utilization() float64

Utilization implements Chunk.

func (*MemChunk) WriteTo 

func (c *MemChunk) WriteTo(w io.Writer) (int64, error)

Source Files

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