brotli/h55.go

107 lines
3.3 KiB
Go

package brotli
/* NOLINT(build/header_guard) */
/* Copyright 2018 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
/* Composite hasher: This hasher allows to combine two other hashers, HASHER_A
and HASHER_B. */
func HashTypeLengthH55() uint {
var a uint = HashTypeLengthH54()
var b uint = HashTypeLengthHROLLING_FAST()
if a > b {
return a
} else {
return b
}
}
func StoreLookaheadH55() uint {
var a uint = StoreLookaheadH54()
var b uint = StoreLookaheadHROLLING_FAST()
if a > b {
return a
} else {
return b
}
}
type H55 struct {
HasherCommon
ha HasherHandle
hb HasherHandle
params *BrotliEncoderParams
}
func SelfH55(handle HasherHandle) *H55 {
return handle.(*H55)
}
func (h *H55) Initialize(params *BrotliEncoderParams) {
h.ha = nil
h.hb = nil
h.params = params
}
/* TODO: Initialize of the hashers is defered to Prepare (and params
remembered here) because we don't get the one_shot and input_size params
here that are needed to know the memory size of them. Instead provide
those params to all hashers InitializeH55 */
func (h *H55) Prepare(one_shot bool, input_size uint, data []byte) {
if h.ha == nil {
var common_a *HasherCommon
var common_b *HasherCommon
h.ha = new(H54)
common_a = h.ha.Common()
common_a.params = h.params.hasher
common_a.is_prepared_ = false
common_a.dict_num_lookups = 0
common_a.dict_num_matches = 0
h.ha.Initialize(h.params)
h.hb = new(HROLLING_FAST)
common_b = h.hb.Common()
common_b.params = h.params.hasher
common_b.is_prepared_ = false
common_b.dict_num_lookups = 0
common_b.dict_num_matches = 0
h.hb.Initialize(h.params)
}
h.ha.Prepare(one_shot, input_size, data)
h.hb.Prepare(one_shot, input_size, data)
}
func StoreH55(handle HasherHandle, data []byte, mask uint, ix uint) {
var self *H55 = SelfH55(handle)
StoreH54(self.ha, data, mask, ix)
StoreHROLLING_FAST(self.hb, data, mask, ix)
}
func StoreRangeH55(handle HasherHandle, data []byte, mask uint, ix_start uint, ix_end uint) {
var self *H55 = SelfH55(handle)
StoreRangeH54(self.ha, data, mask, ix_start, ix_end)
StoreRangeHROLLING_FAST(self.hb, data, mask, ix_start, ix_end)
}
func (h *H55) StitchToPreviousBlock(num_bytes uint, position uint, ringbuffer []byte, ring_buffer_mask uint) {
h.ha.StitchToPreviousBlock(num_bytes, position, ringbuffer, ring_buffer_mask)
h.hb.StitchToPreviousBlock(num_bytes, position, ringbuffer, ring_buffer_mask)
}
func PrepareDistanceCacheH55(handle HasherHandle, distance_cache []int) {
var self *H55 = SelfH55(handle)
PrepareDistanceCacheH54(self.ha, distance_cache)
PrepareDistanceCacheHROLLING_FAST(self.hb, &distance_cache[0])
}
func FindLongestMatchH55(handle HasherHandle, dictionary *BrotliEncoderDictionary, 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 self *H55 = SelfH55(handle)
FindLongestMatchH54(self.ha, dictionary, data, ring_buffer_mask, distance_cache, cur_ix, max_length, max_backward, gap, max_distance, out)
FindLongestMatchHROLLING_FAST(self.hb, dictionary, data, ring_buffer_mask, &distance_cache[0], cur_ix, max_length, max_backward, gap, max_distance, out)
}