Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func NewWriter ¶
NewWriter returns a new pack.Writer that compresses data at the given level. Levels 0–9 are currently implemented. Levels outside this range will be replaced with the closest level available.
func Score ¶
func Score(m pack.AbsoluteMatch) int
Types ¶
type CompositeHasher ¶
type CompositeHasher struct {
A, B Hasher
}
A CompositeHasher wraps two Hashers and combines their output.
func (CompositeHasher) Candidates ¶
func (h CompositeHasher) Candidates(dst []int, data []byte, index int) []int
func (CompositeHasher) Init ¶
func (h CompositeHasher) Init()
func (CompositeHasher) Store ¶
func (h CompositeHasher) Store(data []byte, index int)
type Encoder ¶
type Encoder struct {
// contains filtered or unexported fields
}
An Encoder implements the pack.Encoder interface, writing in Brotli format.
type H2 ¶
type H2 struct {
// contains filtered or unexported fields
}
H2 is a Hasher similar to what the reference implementation of brotli uses for compression level 2.
type H3 ¶
type H3 struct {
// contains filtered or unexported fields
}
H3 is a Hasher similar to what the reference implementation of brotli uses for compression level 3.
type H4 ¶
type H4 struct {
// contains filtered or unexported fields
}
H4 is a Hasher similar to what the reference implementation of brotli uses for compression level 4.
type H5 ¶
type H5 struct {
// BlockBits is the base-2 logarithm of the number of entries per hash
// bucket. The reference implementation sets it to one less than the
// compression level.
BlockBits int
// BucketBits is the base-2 logarithm of the number of hash buckets.
// The reference implementation sets it to 14 or 15.
BucketBits int
// contains filtered or unexported fields
}
H5 is a Hasher similar to what the reference implementation of brotli uses for compression levels 5–9.
type H6 ¶
type H6 struct {
// BlockBits is the base-2 logarithm of the number of entries per hash
// bucket. The reference implementation sets it to one less than the
// compression level.
BlockBits int
// BucketBits is the base-2 logarithm of the number of hash buckets.
// The reference implementation sets it to 14 or 15.
BucketBits int
// HashLen is the number of bytes to hash. The reference implementation
// normally sets it to 5.
HashLen int
// contains filtered or unexported fields
}
H6 is a Hasher similar to what the reference implementation of brotli uses for compression levels 5–9.
It is basically the same as H5, but with a configurable hash length.
type Hasher ¶
type Hasher interface {
// Init allocates the Hasher's internal storage, or clears it if
// it is already allocated. Init must be called before any of the other
// methods.
Init()
// Store puts an entry in the hash table for the data at index.
Store(data []byte, index int)
// Candidates hashes the data at index, fetches a list of possible matches
// from the hash table, and appends the list to dst.
Candidates(dst []int, data []byte, index int) []int
}
A Hasher maintains a hash table for finding backreferences in data.
type M0 ¶
type M0 struct {
// Lazy turns on "lazy matching," for higher compression but less speed.
Lazy bool
MaxDistance int
MaxLength int
}
M0 is an implementation of the pack.MatchFinder interface based on the algorithm used by snappy, but modified to be more like the algorithm used by compression level 0 of the brotli reference implementation.
func (M0) FindMatches ¶
FindMatches looks for matches in src, appends them to dst, and returns dst. src must not be longer than 65536 bytes.
type MatchFinder ¶
type MatchFinder struct {
Hasher Hasher
// MaxLength is the limit on the length of matches to find;
// 0 means unlimited.
MaxLength int
// MaxDistance is the limit on the distance to look back for matches;
// 0 means unlimited.
MaxDistance int
// MaxHistory is the limit on how much data from previous blocks is
// kept around to look for matches in; 0 means that no matches from previous
// blocks will be found.
MaxHistory int
// MinHistory is the amount of data that is used to start a new history
// buffer after the size exceeds MaxHistory.
MinHistory int
// contains filtered or unexported fields
}
MatchFinder is an implementation of pack.MatchFinder that uses a Hasher to find matches.
func (*MatchFinder) FindMatches ¶
FindMatches looks for matches in src, appends them to dst, and returns dst.
func (*MatchFinder) Reset ¶
func (q *MatchFinder) Reset()
Source Files