package table

import "github.com/dgraph-io/badger/v2/table"

Index

Functions

func IDToFilename 

func IDToFilename(id uint64) string

IDToFilename does the inverse of ParseFileID

func NewFilename 

func NewFilename(id uint64, dir string) string

NewFilename should be named TableFilepath -- it combines the dir with the ID to make a table filepath.

func NewMergeIterator 

func NewMergeIterator(iters []y.Iterator, reverse bool) y.Iterator

NewMergeIterator creates a merge iterator.

func ParseFileID 

func ParseFileID(name string) (uint64, bool)

ParseFileID reads the file id out of a filename.

Types

type Builder 

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

Builder is used in building a table.

func NewTableBuilder 

func NewTableBuilder(opts Options) *Builder

NewTableBuilder makes a new TableBuilder.

func (*Builder) Add 

func (b *Builder) Add(key []byte, value y.ValueStruct, valueLen uint32)

Add adds a key-value pair to the block.

func (*Builder) Close 

func (b *Builder) Close()

Close closes the TableBuilder.

func (*Builder) DataKey 

func (b *Builder) DataKey() *pb.DataKey

DataKey returns datakey of the builder.

func (*Builder) Empty 

func (b *Builder) Empty() bool

Empty returns whether it's empty.

func (*Builder) Finish 

func (b *Builder) Finish() []byte

Finish finishes the table by appending the index.

The table structure looks like +---------+------------+-----------+---------------+ | Block 1 | Block 2 | Block 3 | Block 4 | +---------+------------+-----------+---------------+ | Block 5 | Block 6 | Block ... | Block N | +---------+------------+-----------+---------------+ | Index | Index Size | Checksum | Checksum Size | +---------+------------+-----------+---------------+

In case the data is encrypted, the "IV" is added to the end of the index.

func (*Builder) ReachedCapacity 

func (b *Builder) ReachedCapacity(cap int64) bool

ReachedCapacity returns true if we... roughly (?) reached capacity?

type ConcatIterator 

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

ConcatIterator concatenates the sequences defined by several iterators. (It only works with TableIterators, probably just because it's faster to not be so generic.)

func NewConcatIterator 

func NewConcatIterator(tbls []*Table, reversed bool) *ConcatIterator

NewConcatIterator creates a new concatenated iterator

func (*ConcatIterator) Close 

func (s *ConcatIterator) Close() error

Close implements y.Interface.

func (*ConcatIterator) Key 

func (s *ConcatIterator) Key() []byte

Key implements y.Interface

func (*ConcatIterator) Next 

func (s *ConcatIterator) Next()

Next advances our concat iterator.

func (*ConcatIterator) Rewind 

func (s *ConcatIterator) Rewind()

Rewind implements y.Interface

func (*ConcatIterator) Seek 

func (s *ConcatIterator) Seek(key []byte)

Seek brings us to element >= key if reversed is false. Otherwise, <= key.

func (*ConcatIterator) Valid 

func (s *ConcatIterator) Valid() bool

Valid implements y.Interface

func (*ConcatIterator) Value 

func (s *ConcatIterator) Value() y.ValueStruct

Value implements y.Interface

type Iterator 

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

Iterator is an iterator for a Table.

func (*Iterator) Close 

func (itr *Iterator) Close() error

Close closes the iterator (and it must be called).

func (*Iterator) Key 

func (itr *Iterator) Key() []byte

Key follows the y.Iterator interface. Returns the key with timestamp.

func (*Iterator) Next 

func (itr *Iterator) Next()

Next follows the y.Iterator interface

func (*Iterator) Rewind 

func (itr *Iterator) Rewind()

Rewind follows the y.Iterator interface

func (*Iterator) Seek 

func (itr *Iterator) Seek(key []byte)

Seek follows the y.Iterator interface

func (*Iterator) Valid 

func (itr *Iterator) Valid() bool

Valid follows the y.Iterator interface

func (*Iterator) Value 

func (itr *Iterator) Value() (ret y.ValueStruct)

Value follows the y.Iterator interface

func (*Iterator) ValueCopy 

func (itr *Iterator) ValueCopy() (ret y.ValueStruct)

ValueCopy copies the current value and returns it as decoded ValueStruct.

type MergeIterator 

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

MergeIterator merges multiple iterators. NOTE: MergeIterator owns the array of iterators and is responsible for closing them.

func (*MergeIterator) Close 

func (mi *MergeIterator) Close() error

Close implements y.Iterator.

func (*MergeIterator) Key 

func (mi *MergeIterator) Key() []byte

Key returns the key associated with the current iterator.

func (*MergeIterator) Next 

func (mi *MergeIterator) Next()

Next returns the next element. If it is the same as the current key, ignore it.

func (*MergeIterator) Rewind 

func (mi *MergeIterator) Rewind()

Rewind seeks to first element (or last element for reverse iterator).

func (*MergeIterator) Seek 

func (mi *MergeIterator) Seek(key []byte)

Seek brings us to element with key >= given key.

func (*MergeIterator) Valid 

func (mi *MergeIterator) Valid() bool

Valid returns whether the MergeIterator is at a valid element.

func (*MergeIterator) Value 

func (mi *MergeIterator) Value() y.ValueStruct

Value returns the value associated with the iterator.

type Options 

type Options struct {

	// ChkMode is the checksum verification mode for Table.
	ChkMode options.ChecksumVerificationMode

	// LoadingMode is the mode to be used for loading Table.
	LoadingMode options.FileLoadingMode

	// BloomFalsePositive is the false positive probabiltiy of bloom filter.
	BloomFalsePositive float64

	// BlockSize is the size of each block inside SSTable in bytes.
	BlockSize int

	// DataKey is the key used to decrypt the encrypted text.
	DataKey *pb.DataKey

	// Compression indicates the compression algorithm used for block compression.
	Compression options.CompressionType

	BlockCache *ristretto.Cache
	IndexCache *ristretto.Cache

	// ZSTDCompressionLevel is the ZSTD compression level used for compressing blocks.
	ZSTDCompressionLevel int

	// When LoadBloomsOnOpen is set, bloom filters will be loaded while opening
	// the table. Otherwise, they will be loaded lazily when they're accessed.
	LoadBloomsOnOpen bool
}

Options contains configurable options for Table/Builder.

type Table 

type Table struct {
	sync.Mutex

	Checksum []byte

	IsInmemory bool // Set to true if the table is on level 0 and opened in memory.
	// contains filtered or unexported fields
}

Table represents a loaded table file with the info we have about it.

func OpenInMemoryTable 

func OpenInMemoryTable(data []byte, id uint64, opt *Options) (*Table, error)

OpenInMemoryTable is similar to OpenTable but it opens a new table from the provided data. OpenInMemoryTable is used for L0 tables.

func OpenTable 

func OpenTable(fd *os.File, opts Options) (*Table, error)

OpenTable assumes file has only one table and opens it. Takes ownership of fd upon function entry. Returns a table with one reference count on it (decrementing which may delete the file! -- consider t.Close() instead). The fd has to writeable because we call Truncate on it before deleting. Checksum for all blocks of table is verified based on value of chkMode.

func (*Table) Biggest 

func (t *Table) Biggest() []byte

Biggest is its biggest key, or nil if there are none

func (*Table) Close 

func (t *Table) Close() error

Close closes the open table. (Releases resources back to the OS.)

func (*Table) CompressionType 

func (t *Table) CompressionType() options.CompressionType

CompressionType returns the compression algorithm used for block compression.

func (*Table) DecrRef 

func (t *Table) DecrRef() error

DecrRef decrements the refcount and possibly deletes the table

func (*Table) DoesNotHave 

func (t *Table) DoesNotHave(hash uint64) bool

DoesNotHave returns true if (but not "only if") the table does not have the key hash. It does a bloom filter lookup.

func (*Table) EstimatedSize 

func (t *Table) EstimatedSize() uint64

EstimatedSize returns the total size of key-values stored in this table (including the disk space occupied on the value log).

func (*Table) Filename 

func (t *Table) Filename() string

Filename is NOT the file name. Just kidding, it is.

func (*Table) ID 

func (t *Table) ID() uint64

ID is the table's ID number (used to make the file name).

func (*Table) IncrRef 

func (t *Table) IncrRef()

IncrRef increments the refcount (having to do with whether the file should be deleted)

func (*Table) KeyID 

func (t *Table) KeyID() uint64

KeyID returns data key id.

func (*Table) NewIterator 

func (t *Table) NewIterator(reversed bool) *Iterator

NewIterator returns a new iterator of the Table

func (*Table) Size 

func (t *Table) Size() int64

Size is its file size in bytes

func (*Table) Smallest 

func (t *Table) Smallest() []byte

Smallest is its smallest key, or nil if there are none

func (*Table) VerifyChecksum 

func (t *Table) VerifyChecksum() error

VerifyChecksum verifies checksum for all blocks of table. This function is called by OpenTable() function. This function is also called inside levelsController.VerifyChecksum().

type TableInterface 

type TableInterface interface {
	Smallest() []byte
	Biggest() []byte
	DoesNotHave(hash uint64) bool
}

TableInterface is useful for testing.

Source Files

builder.go iterator.go merge_iterator.go table.go

Version
v2.2007.4 (latest)
Published
Aug 25, 2021
Platform
linux/amd64
Imports
24 packages
Last checked
1 week ago –

Tools for package owners.