Documentation
¶
Index ¶
- Constants
- func PersistDictrionary(fileName string, db *DictionaryBuilder) error
- func ReadSimpleFile(fileName string, walker func(v []byte) error) error
- func SetDecompressionTableCondensity(fromBitSize int)
- type CompressionQueue
- type CompressionRatio
- type CompressionWord
- type Compressor
- type DecompressedFile
- type Decompressor
- func (d *Decompressor) Close()
- func (d *Decompressor) Count() int
- func (d *Decompressor) DisableReadAhead()
- func (d *Decompressor) EmptyWordsCount() int
- func (d *Decompressor) EnableMadvNormal() *Decompressor
- func (d *Decompressor) EnableReadAhead() *Decompressor
- func (d *Decompressor) EnableWillNeed() *Decompressor
- func (d *Decompressor) FileName() string
- func (d *Decompressor) FilePath() string
- func (d *Decompressor) MakeGetter() *Getter
- func (d *Decompressor) ModTime() time.Time
- func (d *Decompressor) Size() int64
- func (d *Decompressor) WithReadAhead(f func() error) error
- type DictAggregator
- type DictionaryBuilder
- func (db *DictionaryBuilder) Close()
- func (db *DictionaryBuilder) ForEach(f func(score uint64, word []byte))
- func (db *DictionaryBuilder) Len() int
- func (db *DictionaryBuilder) Less(i, j int) bool
- func (db *DictionaryBuilder) Pop() interface{}
- func (db *DictionaryBuilder) Push(x interface{})
- func (db *DictionaryBuilder) Reset(limit int)
- func (db *DictionaryBuilder) Sort()
- func (db *DictionaryBuilder) Swap(i, j int)
- type DynamicCell
- type Getter
- func (g *Getter) FastNext(buf []byte) ([]byte, uint64)
- func (g *Getter) FileName() string
- func (g *Getter) HasNext() bool
- func (g *Getter) Match(buf []byte) (bool, uint64)
- func (g *Getter) MatchCmp(buf []byte) int
- func (g *Getter) MatchPrefix(prefix []byte) bool
- func (g *Getter) MatchPrefixCmp(prefix []byte) int
- func (g *Getter) MatchPrefixUncompressed(prefix []byte) int
- func (g *Getter) Next(buf []byte) ([]byte, uint64)
- func (g *Getter) NextUncompressed() ([]byte, uint64)
- func (g *Getter) Reset(offset uint64)
- func (g *Getter) Size() int
- func (g *Getter) Skip() (uint64, int)
- func (g *Getter) SkipUncompressed() (uint64, int)
- func (g *Getter) Trace(t bool)
- type HuffmanCoder
- type Pattern
- type PatternHeap
- type PatternHuff
- type PatternList
- type Position
- type PositionHeap
- type PositionHuff
- type PositionList
- type Ring
Constants ¶
const MinPatternScore = 1024
MinPatternScore is minimum score (per superstring) required to consider including pattern into the dictionary
Variables ¶
This section is empty.
Functions ¶
func PersistDictrionary ¶
func PersistDictrionary(fileName string, db *DictionaryBuilder) error
func SetDecompressionTableCondensity ¶
func SetDecompressionTableCondensity(fromBitSize int)
Types ¶
type CompressionQueue ¶
type CompressionQueue []*CompressionWord
func (CompressionQueue) Len ¶
func (cq CompressionQueue) Len() int
func (CompressionQueue) Less ¶
func (cq CompressionQueue) Less(i, j int) bool
func (*CompressionQueue) Pop ¶
func (cq *CompressionQueue) Pop() interface{}
func (*CompressionQueue) Push ¶
func (cq *CompressionQueue) Push(x interface{})
func (*CompressionQueue) Swap ¶
func (cq *CompressionQueue) Swap(i, j int)
type CompressionRatio ¶
type CompressionRatio float64
func Ratio ¶
func Ratio(f1, f2 string) (CompressionRatio, error)
func (CompressionRatio) String ¶
func (r CompressionRatio) String() string
type CompressionWord ¶
type CompressionWord struct {
// contains filtered or unexported fields
}
CompressionWord hold a word to be compressed (if flag is set), and the result of compression To allow multiple words to be processed concurrently, order field is used to collect all the words after processing without disrupting their order
type Compressor ¶
type Compressor struct {
Ratio CompressionRatio
// contains filtered or unexported fields
}
Compressor is the main operating type for performing per-word compression After creating a compression, one needs to add superstrings to it, using `AddWord` function In order to add word without compression, function `AddUncompressedWord` needs to be used Compressor only tracks which words are compressed and which are not until the compressed file is created. After that, the user of the file needs to know when to call `Next` or `NextUncompressed` function on the decompressor. After that, `Compress` function needs to be called to perform the compression and eventually create output file
func NewCompressor ¶
func (*Compressor) AddUncompressedWord ¶
func (c *Compressor) AddUncompressedWord(word []byte) error
func (*Compressor) AddWord ¶
func (c *Compressor) AddWord(word []byte) error
func (*Compressor) Close ¶
func (c *Compressor) Close()
func (*Compressor) Compress ¶
func (c *Compressor) Compress() error
func (*Compressor) Count ¶
func (c *Compressor) Count() int
func (*Compressor) DisableFsync ¶
func (c *Compressor) DisableFsync()
func (*Compressor) SetTrace ¶
func (c *Compressor) SetTrace(trace bool)
type DecompressedFile ¶
type DecompressedFile struct {
// contains filtered or unexported fields
}
DecompressedFile - .dat file format - simple format for temporary data store
func NewUncompressedFile ¶
func NewUncompressedFile(filePath string) (*DecompressedFile, error)
func (*DecompressedFile) Append ¶
func (f *DecompressedFile) Append(v []byte) error
func (*DecompressedFile) AppendUncompressed ¶
func (f *DecompressedFile) AppendUncompressed(v []byte) error
func (*DecompressedFile) Close ¶
func (f *DecompressedFile) Close()
func (*DecompressedFile) ForEach ¶
func (f *DecompressedFile) ForEach(walker func(v []byte, compressed bool) error) error
ForEach - Read keys from the file and generate superstring (with extra byte 0x1 prepended to each character, and with 0x0 0x0 pair inserted between keys and values) We only consider values with length > 2, because smaller values are not compressible without going into bits
type Decompressor ¶
type Decompressor struct {
// contains filtered or unexported fields
}
Decompressor provides access to the superstrings in a file produced by a compressor
func NewDecompressor ¶
func NewDecompressor(compressedFilePath string) (d *Decompressor, err error)
func (*Decompressor) Close ¶
func (d *Decompressor) Close()
func (*Decompressor) Count ¶
func (d *Decompressor) Count() int
func (*Decompressor) DisableReadAhead ¶
func (d *Decompressor) DisableReadAhead()
DisableReadAhead - usage: `defer d.EnableReadAhead().DisableReadAhead()`. Please don't use this funcs without `defer` to avoid leak.
func (*Decompressor) EmptyWordsCount ¶
func (d *Decompressor) EmptyWordsCount() int
func (*Decompressor) EnableMadvNormal ¶
func (d *Decompressor) EnableMadvNormal() *Decompressor
func (*Decompressor) EnableReadAhead ¶
func (d *Decompressor) EnableReadAhead() *Decompressor
func (*Decompressor) EnableWillNeed ¶
func (d *Decompressor) EnableWillNeed() *Decompressor
func (*Decompressor) FileName ¶
func (d *Decompressor) FileName() string
func (*Decompressor) FilePath ¶
func (d *Decompressor) FilePath() string
func (*Decompressor) MakeGetter ¶
func (d *Decompressor) MakeGetter() *Getter
MakeGetter creates an object that can be used to access superstrings in the decompressor's file Getter is not thread-safe, but there can be multiple getters used simultaneously and concurrently for the same decompressor
func (*Decompressor) ModTime ¶
func (d *Decompressor) ModTime() time.Time
func (*Decompressor) Size ¶
func (d *Decompressor) Size() int64
func (*Decompressor) WithReadAhead ¶
func (d *Decompressor) WithReadAhead(f func() error) error
WithReadAhead - Expect read in sequential order. (Hence, pages in the given range can be aggressively read ahead, and may be freed soon after they are accessed.)
type DictAggregator ¶
type DictAggregator struct {
// contains filtered or unexported fields
}
func (*DictAggregator) Load ¶
func (da *DictAggregator) Load(loadFunc etl.LoadFunc, args etl.TransformArgs) error
type DictionaryBuilder ¶
type DictionaryBuilder struct {
// contains filtered or unexported fields
}
func (*DictionaryBuilder) Close ¶
func (db *DictionaryBuilder) Close()
func (*DictionaryBuilder) ForEach ¶
func (db *DictionaryBuilder) ForEach(f func(score uint64, word []byte))
func (*DictionaryBuilder) Len ¶
func (db *DictionaryBuilder) Len() int
func (*DictionaryBuilder) Less ¶
func (db *DictionaryBuilder) Less(i, j int) bool
func (*DictionaryBuilder) Pop ¶
func (db *DictionaryBuilder) Pop() interface{}
func (*DictionaryBuilder) Push ¶
func (db *DictionaryBuilder) Push(x interface{})
func (*DictionaryBuilder) Reset ¶
func (db *DictionaryBuilder) Reset(limit int)
func (*DictionaryBuilder) Sort ¶
func (db *DictionaryBuilder) Sort()
func (*DictionaryBuilder) Swap ¶
func (db *DictionaryBuilder) Swap(i, j int)
type DynamicCell ¶
type DynamicCell struct {
// contains filtered or unexported fields
}
DynamicCell represents result of dynamic programming for certain starting position
type Getter ¶
type Getter struct {
// contains filtered or unexported fields
}
Getter represent "reader" or "interator" that can move accross the data of the decompressor The full state of the getter can be captured by saving dataP, and dataBit
func (*Getter) FastNext ¶
FastNext extracts a compressed word from current offset in the file into the given buf, returning a new byte slice which contains extracted word. It is important to allocate enough buf size. Could throw an error if word in file is larger then the buf size. After extracting next word, it moves to the beginning of the next one
func (*Getter) Match ¶
Match returns true and next offset if the word at current offset fully matches the buf returns false and current offset otherwise.
func (*Getter) MatchCmp ¶
MatchCmp lexicographically compares given buf with the word at the current offset in the file. returns 0 if buf == word, -1 if buf < word, 1 if buf > word
func (*Getter) MatchPrefix ¶
MatchPrefix only checks if the word at the current offset has a buf prefix. Does not move offset to the next word.
func (*Getter) MatchPrefixCmp ¶
MatchPrefixCmp lexicographically compares given prefix with the word at the current offset in the file. returns 0 if buf == word, -1 if buf < word, 1 if buf > word
func (*Getter) MatchPrefixUncompressed ¶
func (*Getter) Next ¶
Next extracts a compressed word from current offset in the file and appends it to the given buf, returning the result of appending After extracting next word, it moves to the beginning of the next one
func (*Getter) NextUncompressed ¶
func (*Getter) Skip ¶
Skip moves offset to the next word and returns the new offset and the length of the word.
func (*Getter) SkipUncompressed ¶
type HuffmanCoder ¶
type HuffmanCoder struct {
// contains filtered or unexported fields
}
type Pattern ¶
type Pattern struct {
// contains filtered or unexported fields
}
Pattern is representation of a pattern that is searched in the superstrings to compress them patterns are stored in a patricia tree and contain pattern score (calculated during the initial dictionary building), frequency of usage, and code
type PatternHeap ¶
type PatternHeap []*PatternHuff
PatternHeap is priority queue of pattern for the purpose of building Huffman tree to determine efficient coding. Patterns with least usage have highest priority. We use a tie-breaker to make sure the resulting Huffman code is canonical
func (PatternHeap) Len ¶
func (ph PatternHeap) Len() int
func (PatternHeap) Less ¶
func (ph PatternHeap) Less(i, j int) bool
func (*PatternHeap) Pop ¶
func (ph *PatternHeap) Pop() interface{}
func (*PatternHeap) Push ¶
func (ph *PatternHeap) Push(x interface{})
func (*PatternHeap) Swap ¶
func (ph *PatternHeap) Swap(i, j int)
type PatternHuff ¶
type PatternHuff struct {
// contains filtered or unexported fields
}
PatternHuff is an intermediate node in a huffman tree of patterns It has two children, each of which may either be another intermediate node (h0 or h1) or leaf node, which is Pattern (p0 or p1).
func (*PatternHuff) AddOne ¶
func (h *PatternHuff) AddOne()
func (*PatternHuff) AddZero ¶
func (h *PatternHuff) AddZero()
func (*PatternHuff) SetDepth ¶
func (h *PatternHuff) SetDepth(depth int)
type PatternList ¶
type PatternList []*Pattern
PatternList is a sorted list of pattern for the purpose of building Huffman tree to determine efficient coding. Patterns with least usage come first, we use numerical code as a tie breaker to make sure the resulting Huffman code is canonical
func (PatternList) Len ¶
func (pl PatternList) Len() int
type PositionHeap ¶
type PositionHeap []*PositionHuff
func (PositionHeap) Len ¶
func (ph PositionHeap) Len() int
func (PositionHeap) Less ¶
func (ph PositionHeap) Less(i, j int) bool
func (*PositionHeap) Pop ¶
func (ph *PositionHeap) Pop() interface{}
func (*PositionHeap) Push ¶
func (ph *PositionHeap) Push(x interface{})
func (*PositionHeap) Swap ¶
func (ph *PositionHeap) Swap(i, j int)
type PositionHuff ¶
type PositionHuff struct {
// contains filtered or unexported fields
}
func (*PositionHuff) AddOne ¶
func (h *PositionHuff) AddOne()
func (*PositionHuff) AddZero ¶
func (h *PositionHuff) AddZero()
func (*PositionHuff) SetDepth ¶
func (h *PositionHuff) SetDepth(depth int)
type PositionList ¶
type PositionList []*Position
func (PositionList) Len ¶
func (pl PositionList) Len() int
type Ring ¶
type Ring struct {
// contains filtered or unexported fields
}
func (*Ring) Get ¶
func (r *Ring) Get(i int) *DynamicCell
func (*Ring) PushBack ¶
func (r *Ring) PushBack() *DynamicCell
func (*Ring) PushFront ¶
func (r *Ring) PushFront() *DynamicCell
Source Files