dailz
cf913b1d52
- go.mod with github.com/dailz/go-kv, Go 1.26.3, testify - config/config.go with WalConfig, Validate() with checked arithmetic - errors.go with sentinel errors (ErrCommitUnknown, ErrWriteStopped, etc.) - wal/constants.go with all WAL format constants and enums - wal/header.go with WAL File Header encode/decode (CRC32 IEEE) - wal/record.go with Physical Record codec, block boundary, SplitIntoRecords - wal/entry.go with WAL Entry codec (varint keys/values, OpType, ValueKind) - wal/sequence.go with SequenceManager (atomic, CAS, overflow-safe) - manifest/manifest.go with MANIFEST stub (Load/Save atomic) - manifest/current.go with CURRENT file (WriteCurrent/ReadCurrent) - Comprehensive tests for all modules - .golangci.yml configuration
81 lines
2.8 KiB
Go
81 lines
2.8 KiB
Go
package wal
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// WAL file format constants.
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const (
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// WalMagic is the file type identifier for WAL segment files ("WALK").
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WalMagic uint32 = 0x57414C4B
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// WalFormatVersion is the WAL file format version. First version is 1.
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WalFormatVersion uint16 = 1
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// WalFileHeaderSize is the size of the WAL file header in bytes.
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// Fields: magic(4) + formatVersion(2) + headerSize(2) + blockSize(4) +
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// segmentID(8) + startSequence(8) + headerCRC(4) = 32.
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WalFileHeaderSize = 32
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// WalBlockSize is the fixed size of each WAL block in bytes (32 KB).
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WalBlockSize = 32 * 1024
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// PhysicalRecordHeaderSize is the size of a physical record header in bytes.
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// Fields: crc32c(4) + length(2) + type(1) = 7.
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PhysicalRecordHeaderSize = 7
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// WalBatchHeaderSize is the size of a WAL batch header in bytes.
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// Fields: flags(2) + baseSequence(8) + entryCount(4) + entriesSize(4) = 18.
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WalBatchHeaderSize = 18
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// MaxWalBatchEntryCount limits the number of entries in a single batch.
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MaxWalBatchEntryCount uint32 = 10000
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// MaxWalBatchEntriesSize limits the total size of the entries region in bytes (4 MB).
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MaxWalBatchEntriesSize uint32 = 4 * 1024 * 1024
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// MaxWalKeyBytes limits the size of a single key in bytes (4 KB).
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MaxWalKeyBytes uint32 = 4 * 1024
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// MaxWalInlineValueBytes limits the size of an inline value in bytes (4 KB).
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// Values exceeding this must use ValueLogPointer.
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MaxWalInlineValueBytes uint32 = 4 * 1024
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// MaxWalVarintBytes is the maximum encoded length of a varint field.
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MaxWalVarintBytes = 5
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// DefaultMaxWalSegmentSize is the default maximum size of a WAL segment file (64 MB).
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DefaultMaxWalSegmentSize uint64 = 64 * 1024 * 1024
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)
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// Fragment types for physical records.
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const (
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// RecInvalid is an illegal fragment type used for corruption detection.
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RecInvalid uint8 = 0
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// RecFull indicates a complete WAL batch in a single physical record.
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RecFull uint8 = 1
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// RecFirst is the first fragment of a multi-record WAL batch.
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RecFirst uint8 = 2
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// RecMiddle is a middle fragment (may appear zero or more times).
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RecMiddle uint8 = 3
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// RecLast is the last fragment of a multi-record WAL batch.
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RecLast uint8 = 4
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)
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// OpType represents the operation type of a WAL entry.
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const (
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// OpInvalid is an illegal operation type used for corruption detection.
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OpInvalid uint8 = 0
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// OpPut represents a key-value put operation.
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OpPut uint8 = 1
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// OpDelete represents a key deletion operation.
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OpDelete uint8 = 2
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)
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// ValueKind represents how the value field is encoded in a WAL entry.
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const (
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// VKNone indicates no value (used with Delete operations).
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VKNone uint8 = 0
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// VKInline indicates the value field contains inline user bytes.
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VKInline uint8 = 1
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// VKValueLogPointer indicates the value field contains an encoded Value Log pointer.
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VKValueLogPointer uint8 = 2
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)
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