mirror of
https://github.com/go-gitea/gitea.git
synced 2024-12-04 14:46:57 -05:00
684b7a999f
* Dump: Use mholt/archive/v3 to support tar including many compressions Signed-off-by: Philipp Homann <homann.philipp@googlemail.com> * Dump: Allow dump output to stdout Signed-off-by: Philipp Homann <homann.philipp@googlemail.com> * Dump: Fixed bug present since #6677 where SessionConfig.Provider is never "file" Signed-off-by: Philipp Homann <homann.philipp@googlemail.com> * Dump: never pack RepoRootPath, LFS.ContentPath and LogRootPath when they are below AppDataPath Signed-off-by: Philipp Homann <homann.philipp@googlemail.com> * Dump: also dump LFS (fixes #10058) Signed-off-by: Philipp Homann <homann.philipp@googlemail.com> * Dump: never dump CustomPath if CustomPath is a subdir of or equal to AppDataPath (fixes #10365) Signed-off-by: Philipp Homann <homann.philipp@googlemail.com> * Use log.Info instead of fmt.Fprintf Signed-off-by: Philipp Homann <homann.philipp@googlemail.com> * import ordering * make fmt Co-authored-by: zeripath <art27@cantab.net> Co-authored-by: techknowlogick <techknowlogick@gitea.io> Co-authored-by: Matti R <matti@mdranta.net>
254 lines
7.6 KiB
Go
Vendored
254 lines
7.6 KiB
Go
Vendored
package brotli
|
|
|
|
import "encoding/binary"
|
|
|
|
/* Copyright 2016 Google Inc. All Rights Reserved.
|
|
|
|
Distributed under MIT license.
|
|
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
|
|
*/
|
|
|
|
func (*hashForgetfulChain) HashTypeLength() uint {
|
|
return 4
|
|
}
|
|
|
|
func (*hashForgetfulChain) StoreLookahead() uint {
|
|
return 4
|
|
}
|
|
|
|
/* HashBytes is the function that chooses the bucket to place the address in.*/
|
|
func (h *hashForgetfulChain) HashBytes(data []byte) uint {
|
|
var hash uint32 = binary.LittleEndian.Uint32(data) * kHashMul32
|
|
|
|
/* The higher bits contain more mixture from the multiplication,
|
|
so we take our results from there. */
|
|
return uint(hash >> (32 - h.bucketBits))
|
|
}
|
|
|
|
type slot struct {
|
|
delta uint16
|
|
next uint16
|
|
}
|
|
|
|
/* A (forgetful) hash table to the data seen by the compressor, to
|
|
help create backward references to previous data.
|
|
|
|
Hashes are stored in chains which are bucketed to groups. Group of chains
|
|
share a storage "bank". When more than "bank size" chain nodes are added,
|
|
oldest nodes are replaced; this way several chains may share a tail. */
|
|
type hashForgetfulChain struct {
|
|
hasherCommon
|
|
|
|
bucketBits uint
|
|
numBanks uint
|
|
bankBits uint
|
|
numLastDistancesToCheck int
|
|
|
|
addr []uint32
|
|
head []uint16
|
|
tiny_hash [65536]byte
|
|
banks [][]slot
|
|
free_slot_idx []uint16
|
|
max_hops uint
|
|
}
|
|
|
|
func (h *hashForgetfulChain) Initialize(params *encoderParams) {
|
|
var q uint
|
|
if params.quality > 6 {
|
|
q = 7
|
|
} else {
|
|
q = 8
|
|
}
|
|
h.max_hops = q << uint(params.quality-4)
|
|
|
|
bankSize := 1 << h.bankBits
|
|
bucketSize := 1 << h.bucketBits
|
|
|
|
h.addr = make([]uint32, bucketSize)
|
|
h.head = make([]uint16, bucketSize)
|
|
h.banks = make([][]slot, h.numBanks)
|
|
for i := range h.banks {
|
|
h.banks[i] = make([]slot, bankSize)
|
|
}
|
|
h.free_slot_idx = make([]uint16, h.numBanks)
|
|
}
|
|
|
|
func (h *hashForgetfulChain) Prepare(one_shot bool, input_size uint, data []byte) {
|
|
var partial_prepare_threshold uint = (1 << h.bucketBits) >> 6
|
|
/* Partial preparation is 100 times slower (per socket). */
|
|
if one_shot && input_size <= partial_prepare_threshold {
|
|
var i uint
|
|
for i = 0; i < input_size; i++ {
|
|
var bucket uint = h.HashBytes(data[i:])
|
|
|
|
/* See InitEmpty comment. */
|
|
h.addr[bucket] = 0xCCCCCCCC
|
|
|
|
h.head[bucket] = 0xCCCC
|
|
}
|
|
} else {
|
|
/* Fill |addr| array with 0xCCCCCCCC value. Because of wrapping, position
|
|
processed by hasher never reaches 3GB + 64M; this makes all new chains
|
|
to be terminated after the first node. */
|
|
for i := range h.addr {
|
|
h.addr[i] = 0xCCCCCCCC
|
|
}
|
|
|
|
for i := range h.head {
|
|
h.head[i] = 0
|
|
}
|
|
}
|
|
|
|
h.tiny_hash = [65536]byte{}
|
|
for i := range h.free_slot_idx {
|
|
h.free_slot_idx[i] = 0
|
|
}
|
|
}
|
|
|
|
/* Look at 4 bytes at &data[ix & mask]. Compute a hash from these, and prepend
|
|
node to corresponding chain; also update tiny_hash for current position. */
|
|
func (h *hashForgetfulChain) Store(data []byte, mask uint, ix uint) {
|
|
var key uint = h.HashBytes(data[ix&mask:])
|
|
var bank uint = key & (h.numBanks - 1)
|
|
var idx uint
|
|
idx = uint(h.free_slot_idx[bank]) & ((1 << h.bankBits) - 1)
|
|
h.free_slot_idx[bank]++
|
|
var delta uint = ix - uint(h.addr[key])
|
|
h.tiny_hash[uint16(ix)] = byte(key)
|
|
if delta > 0xFFFF {
|
|
delta = 0xFFFF
|
|
}
|
|
h.banks[bank][idx].delta = uint16(delta)
|
|
h.banks[bank][idx].next = h.head[key]
|
|
h.addr[key] = uint32(ix)
|
|
h.head[key] = uint16(idx)
|
|
}
|
|
|
|
func (h *hashForgetfulChain) StoreRange(data []byte, mask uint, ix_start uint, ix_end uint) {
|
|
var i uint
|
|
for i = ix_start; i < ix_end; i++ {
|
|
h.Store(data, mask, i)
|
|
}
|
|
}
|
|
|
|
func (h *hashForgetfulChain) StitchToPreviousBlock(num_bytes uint, position uint, ringbuffer []byte, ring_buffer_mask uint) {
|
|
if num_bytes >= h.HashTypeLength()-1 && position >= 3 {
|
|
/* Prepare the hashes for three last bytes of the last write.
|
|
These could not be calculated before, since they require knowledge
|
|
of both the previous and the current block. */
|
|
h.Store(ringbuffer, ring_buffer_mask, position-3)
|
|
h.Store(ringbuffer, ring_buffer_mask, position-2)
|
|
h.Store(ringbuffer, ring_buffer_mask, position-1)
|
|
}
|
|
}
|
|
|
|
func (h *hashForgetfulChain) PrepareDistanceCache(distance_cache []int) {
|
|
prepareDistanceCache(distance_cache, h.numLastDistancesToCheck)
|
|
}
|
|
|
|
/* Find a longest backward match of &data[cur_ix] up to the length of
|
|
max_length and stores the position cur_ix in the hash table.
|
|
|
|
REQUIRES: PrepareDistanceCachehashForgetfulChain must be invoked for current distance cache
|
|
values; if this method is invoked repeatedly with the same distance
|
|
cache values, it is enough to invoke PrepareDistanceCachehashForgetfulChain once.
|
|
|
|
Does not look for matches longer than max_length.
|
|
Does not look for matches further away than max_backward.
|
|
Writes the best match into |out|.
|
|
|out|->score is updated only if a better match is found. */
|
|
func (h *hashForgetfulChain) FindLongestMatch(dictionary *encoderDictionary, data []byte, ring_buffer_mask uint, distance_cache []int, cur_ix uint, max_length uint, max_backward uint, gap uint, max_distance uint, out *hasherSearchResult) {
|
|
var cur_ix_masked uint = cur_ix & ring_buffer_mask
|
|
var min_score uint = out.score
|
|
var best_score uint = out.score
|
|
var best_len uint = out.len
|
|
var key uint = h.HashBytes(data[cur_ix_masked:])
|
|
var tiny_hash byte = byte(key)
|
|
/* Don't accept a short copy from far away. */
|
|
out.len = 0
|
|
|
|
out.len_code_delta = 0
|
|
|
|
/* Try last distance first. */
|
|
for i := 0; i < h.numLastDistancesToCheck; i++ {
|
|
var backward uint = uint(distance_cache[i])
|
|
var prev_ix uint = (cur_ix - backward)
|
|
|
|
/* For distance code 0 we want to consider 2-byte matches. */
|
|
if i > 0 && h.tiny_hash[uint16(prev_ix)] != tiny_hash {
|
|
continue
|
|
}
|
|
if prev_ix >= cur_ix || backward > max_backward {
|
|
continue
|
|
}
|
|
|
|
prev_ix &= ring_buffer_mask
|
|
{
|
|
var len uint = findMatchLengthWithLimit(data[prev_ix:], data[cur_ix_masked:], max_length)
|
|
if len >= 2 {
|
|
var score uint = backwardReferenceScoreUsingLastDistance(uint(len))
|
|
if best_score < score {
|
|
if i != 0 {
|
|
score -= backwardReferencePenaltyUsingLastDistance(uint(i))
|
|
}
|
|
if best_score < score {
|
|
best_score = score
|
|
best_len = uint(len)
|
|
out.len = best_len
|
|
out.distance = backward
|
|
out.score = best_score
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
{
|
|
var bank uint = key & (h.numBanks - 1)
|
|
var backward uint = 0
|
|
var hops uint = h.max_hops
|
|
var delta uint = cur_ix - uint(h.addr[key])
|
|
var slot uint = uint(h.head[key])
|
|
for {
|
|
tmp6 := hops
|
|
hops--
|
|
if tmp6 == 0 {
|
|
break
|
|
}
|
|
var prev_ix uint
|
|
var last uint = slot
|
|
backward += delta
|
|
if backward > max_backward {
|
|
break
|
|
}
|
|
prev_ix = (cur_ix - backward) & ring_buffer_mask
|
|
slot = uint(h.banks[bank][last].next)
|
|
delta = uint(h.banks[bank][last].delta)
|
|
if cur_ix_masked+best_len > ring_buffer_mask || prev_ix+best_len > ring_buffer_mask || data[cur_ix_masked+best_len] != data[prev_ix+best_len] {
|
|
continue
|
|
}
|
|
{
|
|
var len uint = findMatchLengthWithLimit(data[prev_ix:], data[cur_ix_masked:], max_length)
|
|
if len >= 4 {
|
|
/* Comparing for >= 3 does not change the semantics, but just saves
|
|
for a few unnecessary binary logarithms in backward reference
|
|
score, since we are not interested in such short matches. */
|
|
var score uint = backwardReferenceScore(uint(len), backward)
|
|
if best_score < score {
|
|
best_score = score
|
|
best_len = uint(len)
|
|
out.len = best_len
|
|
out.distance = backward
|
|
out.score = best_score
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
h.Store(data, ring_buffer_mask, cur_ix)
|
|
}
|
|
|
|
if out.score == min_score {
|
|
searchInStaticDictionary(dictionary, h, data[cur_ix_masked:], max_length, max_backward+gap, max_distance, out, false)
|
|
}
|
|
}
|