🐛 Fixed Scopes domain parsing

This commit is contained in:
Maxim Lebedev 2023-08-06 05:58:57 +06:00
parent ba25e69680
commit 0b69823912
Signed by: toby3d
GPG Key ID: 1F14E25B7C119FC5
156 changed files with 190 additions and 285707 deletions

7
go.mod
View File

@ -4,7 +4,7 @@ go 1.20
require (
github.com/DATA-DOG/go-sqlmock v1.5.0
github.com/brianvoe/gofakeit/v6 v6.22.0
github.com/brianvoe/gofakeit/v6 v6.23.1
github.com/caarlos0/env/v9 v9.0.0
github.com/goccy/go-json v0.10.2
github.com/google/go-cmp v0.5.9
@ -19,17 +19,15 @@ require (
golang.org/x/xerrors v0.0.0-20220907171357-04be3eba64a2
inet.af/netaddr v0.0.0-20230525184311-b8eac61e914a
modernc.org/sqlite v1.25.0
source.toby3d.me/toby3d/form v0.3.0
source.toby3d.me/toby3d/form v0.4.0
willnorris.com/go/microformats v1.2.0
)
require (
github.com/andybalholm/brotli v1.0.5 // indirect
github.com/decred/dcrd/dcrec/secp256k1/v4 v4.2.0 // indirect
github.com/dustin/go-humanize v1.0.1 // indirect
github.com/google/uuid v1.3.0 // indirect
github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 // indirect
github.com/klauspost/compress v1.16.7 // indirect
github.com/lestrrat-go/blackmagic v1.0.1 // indirect
github.com/lestrrat-go/httpcc v1.0.1 // indirect
github.com/lestrrat-go/httprc v1.0.4 // indirect
@ -40,7 +38,6 @@ require (
github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
github.com/segmentio/asm v1.2.0 // indirect
github.com/valyala/bytebufferpool v1.0.0 // indirect
github.com/valyala/fasthttp v1.48.0 // indirect
go4.org/intern v0.0.0-20230525184215-6c62f75575cb // indirect
go4.org/unsafe/assume-no-moving-gc v0.0.0-20230525183740-e7c30c78aeb2 // indirect
golang.org/x/crypto v0.12.0 // indirect

14
go.sum
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@ -2,10 +2,8 @@ github.com/DATA-DOG/go-sqlmock v1.5.0 h1:Shsta01QNfFxHCfpW6YH2STWB0MudeXXEWMr20O
github.com/DATA-DOG/go-sqlmock v1.5.0/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
github.com/andybalholm/brotli v1.0.2/go.mod h1:loMXtMfwqflxFJPmdbJO0a3KNoPuLBgiu3qAvBg8x/Y=
github.com/andybalholm/brotli v1.0.3/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
github.com/andybalholm/brotli v1.0.5 h1:8uQZIdzKmjc/iuPu7O2ioW48L81FgatrcpfFmiq/cCs=
github.com/andybalholm/brotli v1.0.5/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
github.com/brianvoe/gofakeit/v6 v6.22.0 h1:BzOsDot1o3cufTfOk+fWKE9nFYojyDV+XHdCWL2+uyE=
github.com/brianvoe/gofakeit/v6 v6.22.0/go.mod h1:Ow6qC71xtwm79anlwKRlWZW6zVq9D2XHE4QSSMP/rU8=
github.com/brianvoe/gofakeit/v6 v6.23.1 h1:k2gX0hQpJStvixDbbw8oJOvPBg0XmHJWbSOF5JkiUHw=
github.com/brianvoe/gofakeit/v6 v6.23.1/go.mod h1:Ow6qC71xtwm79anlwKRlWZW6zVq9D2XHE4QSSMP/rU8=
github.com/caarlos0/env/v9 v9.0.0 h1:SI6JNsOA+y5gj9njpgybykATIylrRMklbs5ch6wO6pc=
github.com/caarlos0/env/v9 v9.0.0/go.mod h1:ye5mlCVMYh6tZ+vCgrs/B95sj88cg5Tlnc0XIzgZ020=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@ -33,8 +31,6 @@ github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNU
github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
github.com/klauspost/compress v1.13.4/go.mod h1:8dP1Hq4DHOhN9w426knH3Rhby4rFm6D8eO+e+Dq5Gzg=
github.com/klauspost/compress v1.13.5/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
github.com/klauspost/compress v1.16.7 h1:2mk3MPGNzKyxErAw8YaohYh69+pa4sIQSC0fPGCFR9I=
github.com/klauspost/compress v1.16.7/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQskQzEyD//IeE=
github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
github.com/lestrrat-go/blackmagic v1.0.1 h1:lS5Zts+5HIC/8og6cGHb0uCcNCa3OUt1ygh3Qz2Fe80=
github.com/lestrrat-go/blackmagic v1.0.1/go.mod h1:UrEqBzIR2U6CnzVyUtfM6oZNMt/7O7Vohk2J0OGSAtU=
@ -75,8 +71,6 @@ github.com/tomnomnom/linkheader v0.0.0-20180905144013-02ca5825eb80/go.mod h1:iFy
github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
github.com/valyala/fasthttp v1.30.0/go.mod h1:2rsYD01CKFrjjsvFxx75KlEUNpWNBY9JWD3K/7o2Cus=
github.com/valyala/fasthttp v1.48.0 h1:oJWvHb9BIZToTQS3MuQ2R3bJZiNSa2KiNdeI8A+79Tc=
github.com/valyala/fasthttp v1.48.0/go.mod h1:k2zXd82h/7UZc3VOdJ2WaUqt1uZ/XpXAfE9i+HBC3lA=
github.com/valyala/fasttemplate v1.2.2 h1:lxLXG0uE3Qnshl9QyaK6XJxMXlQZELvChBOCmQD0Loo=
github.com/valyala/fasttemplate v1.2.2/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
github.com/valyala/quicktemplate v1.7.0 h1:LUPTJmlVcb46OOUY3IeD9DojFpAVbsG+5WFTcjMJzCM=
@ -192,7 +186,7 @@ modernc.org/tcl v1.15.2 h1:C4ybAYCGJw968e+Me18oW55kD/FexcHbqH2xak1ROSY=
modernc.org/token v1.1.0 h1:Xl7Ap9dKaEs5kLoOQeQmPWevfnk/DM5qcLcYlA8ys6Y=
modernc.org/token v1.1.0/go.mod h1:UGzOrNV1mAFSEB63lOFHIpNRUVMvYTc6yu1SMY/XTDM=
modernc.org/z v1.7.3 h1:zDJf6iHjrnB+WRD88stbXokugjyc0/pB91ri1gO6LZY=
source.toby3d.me/toby3d/form v0.3.0 h1:kI8apdFeVr+koqTTGVoIRiR5NMqjrhCJlajYlu+1bVw=
source.toby3d.me/toby3d/form v0.3.0/go.mod h1:drlHMC+j/gb5zsttCSwx8qcYsbaRW+wFfE8bK6y+oeY=
source.toby3d.me/toby3d/form v0.4.0 h1:p4erlFQZpWi64oHQVYsNe8FKT75ZwnExELk69ZDoQO8=
source.toby3d.me/toby3d/form v0.4.0/go.mod h1:drlHMC+j/gb5zsttCSwx8qcYsbaRW+wFfE8bK6y+oeY=
willnorris.com/go/microformats v1.2.0 h1:73pzJCLJM69kYE5qsLI9OOC/7sImNVOzya9EQ0+1wmM=
willnorris.com/go/microformats v1.2.0/go.mod h1:RrlwCSvib4qz+JICKiN7rON4phzQ3HAT7j6s4O2cZj4=

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@ -122,6 +122,7 @@ func (r *AuthAuthorizationRequest) bind(req *http.Request) error {
r.ResponseType = domain.ResponseTypeCode
}
// NOTE(toby3d): fallback for multiple same-key form values
if req.URL.Query().Has("scope[]") {
for _, k := range req.URL.Query()["scope[]"] {
scope, err := domain.ParseScope(k)

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@ -98,7 +98,7 @@ func TestAuthorize(t *testing.T) {
t.Errorf("%s %s = %d, want %d", req.Method, u.String(), resp.StatusCode, http.StatusOK)
}
const expResult = `Authorize application`
expResult := `Authorize ` + client.GetName()
if result := string(body); !strings.Contains(result, expResult) {
t.Errorf("%s %s = %s, want %s", req.Method, u.String(), result, expResult)
}

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@ -2,7 +2,6 @@ package domain_test
import (
"fmt"
"reflect"
"testing"
"source.toby3d.me/toby3d/auth/internal/domain"
@ -45,53 +44,6 @@ func TestParseScope(t *testing.T) {
}
}
func TestScopes_UnmarshalForm(t *testing.T) {
t.Parallel()
input := []byte("profile email")
results := make(domain.Scopes, 0)
if err := results.UnmarshalForm(input); err != nil {
t.Fatalf("%+v", err)
}
expResults := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if !reflect.DeepEqual(results, expResults) {
t.Errorf("UnmarshalForm(%s) = %s, want %s", input, results, expResults)
}
}
func TestScopes_UnmarshalJSON(t *testing.T) {
t.Parallel()
input := []byte(`"profile email"`)
results := make(domain.Scopes, 0)
if err := results.UnmarshalJSON(input); err != nil {
t.Fatalf("%+v", err)
}
expResults := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if !reflect.DeepEqual(results, expResults) {
t.Errorf("UnmarshalJSON(%s) = %s, want %s", input, results, expResults)
}
}
func TestScopes_MarshalJSON(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeEmail, domain.ScopeProfile}
result, err := scopes.MarshalJSON()
if err != nil {
t.Fatalf("%+v", err)
}
if string(result) != fmt.Sprintf(`"%s"`, scopes) {
t.Errorf("MarshalJSON() = %s, want %s", result, fmt.Sprintf(`"%s"`, scopes))
}
}
func TestScope_String(t *testing.T) {
t.Parallel()
@ -123,30 +75,3 @@ func TestScope_String(t *testing.T) {
})
}
}
func TestScopes_String(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if result := scopes.String(); result != fmt.Sprint(scopes) {
t.Errorf("String() = %s, want %s", result, scopes)
}
}
func TestScopes_IsEmpty(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeUnd}
if result := scopes.IsEmpty(); !result {
t.Errorf("IsEmpty() = %t, want %t", result, true)
}
}
func TestScopes_Has(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if result := scopes.Has(domain.ScopeEmail); !result {
t.Errorf("Has(%s) = %t, want %t", domain.ScopeEmail, result, true)
}
}

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@ -11,23 +11,19 @@ type Scopes []Scope
// UnmarshalForm implements custom unmarshler for form values.
func (s *Scopes) UnmarshalForm(v []byte) error {
scopes := make(Scopes, 0)
for _, rawScope := range strings.Fields(string(v)) {
scope, err := ParseScope(rawScope)
if err != nil {
return fmt.Errorf("Scopes: UnmarshalForm: %w", err)
}
if scopes.Has(scope) {
if s.Has(scope) {
continue
}
scopes = append(scopes, scope)
*s = append(*s, scope)
}
*s = scopes
return nil
}
@ -38,23 +34,19 @@ func (s *Scopes) UnmarshalJSON(v []byte) error {
return fmt.Errorf("Scopes: UnmarshalJSON: %w", err)
}
result := make(Scopes, 0)
for _, rawScope := range strings.Fields(src) {
scope, err := ParseScope(rawScope)
if err != nil {
return fmt.Errorf("Scopes: UnmarshalJSON: %w", err)
}
if result.Has(scope) {
if s.Has(scope) {
continue
}
result = append(result, scope)
*s = append(*s, scope)
}
*s = result
return nil
}

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@ -0,0 +1,83 @@
package domain_test
import (
"fmt"
"reflect"
"testing"
"source.toby3d.me/toby3d/auth/internal/domain"
)
func TestScopes_UnmarshalForm(t *testing.T) {
t.Parallel()
input := []byte("profile email")
results := make(domain.Scopes, 0)
if err := results.UnmarshalForm(input); err != nil {
t.Fatalf("%+v", err)
}
expResults := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if !reflect.DeepEqual(results, expResults) {
t.Errorf("UnmarshalForm(%s) = %s, want %s", input, results, expResults)
}
}
func TestScopes_UnmarshalJSON(t *testing.T) {
t.Parallel()
input := []byte(`"profile email"`)
results := make(domain.Scopes, 0)
if err := results.UnmarshalJSON(input); err != nil {
t.Fatalf("%+v", err)
}
expResults := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if !reflect.DeepEqual(results, expResults) {
t.Errorf("UnmarshalJSON(%s) = %s, want %s", input, results, expResults)
}
}
func TestScopes_MarshalJSON(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeEmail, domain.ScopeProfile}
result, err := scopes.MarshalJSON()
if err != nil {
t.Fatalf("%+v", err)
}
if string(result) != fmt.Sprintf(`"%s"`, scopes) {
t.Errorf("MarshalJSON() = %s, want %s", result, fmt.Sprintf(`"%s"`, scopes))
}
}
func TestScopes_String(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if result := scopes.String(); result != fmt.Sprint(scopes) {
t.Errorf("String() = %s, want %s", result, scopes)
}
}
func TestScopes_IsEmpty(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeUnd}
if result := scopes.IsEmpty(); !result {
t.Errorf("IsEmpty() = %t, want %t", result, true)
}
}
func TestScopes_Has(t *testing.T) {
t.Parallel()
scopes := domain.Scopes{domain.ScopeProfile, domain.ScopeEmail}
if result := scopes.Has(domain.ScopeEmail); !result {
t.Errorf("Has(%s) = %t, want %t", domain.ScopeEmail, result, true)
}
}

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@ -1,19 +0,0 @@
Copyright (c) 2009, 2010, 2013-2016 by the Brotli Authors.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

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@ -1,7 +0,0 @@
This package is a brotli compressor and decompressor implemented in Go.
It was translated from the reference implementation (https://github.com/google/brotli)
with the `c2go` tool at https://github.com/andybalholm/c2go.
I am using it in production with https://github.com/andybalholm/redwood.
API documentation is found at https://pkg.go.dev/github.com/andybalholm/brotli?tab=doc.

View File

@ -1,185 +0,0 @@
package brotli
import (
"sync"
)
/* Copyright 2013 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
/* Function to find backward reference copies. */
func computeDistanceCode(distance uint, max_distance uint, dist_cache []int) uint {
if distance <= max_distance {
var distance_plus_3 uint = distance + 3
var offset0 uint = distance_plus_3 - uint(dist_cache[0])
var offset1 uint = distance_plus_3 - uint(dist_cache[1])
if distance == uint(dist_cache[0]) {
return 0
} else if distance == uint(dist_cache[1]) {
return 1
} else if offset0 < 7 {
return (0x9750468 >> (4 * offset0)) & 0xF
} else if offset1 < 7 {
return (0xFDB1ACE >> (4 * offset1)) & 0xF
} else if distance == uint(dist_cache[2]) {
return 2
} else if distance == uint(dist_cache[3]) {
return 3
}
}
return distance + numDistanceShortCodes - 1
}
var hasherSearchResultPool sync.Pool
func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher hasherHandle, dist_cache []int, last_insert_len *uint, commands *[]command, num_literals *uint) {
var max_backward_limit uint = maxBackwardLimit(params.lgwin)
var insert_length uint = *last_insert_len
var pos_end uint = position + num_bytes
var store_end uint
if num_bytes >= hasher.StoreLookahead() {
store_end = position + num_bytes - hasher.StoreLookahead() + 1
} else {
store_end = position
}
var random_heuristics_window_size uint = literalSpreeLengthForSparseSearch(params)
var apply_random_heuristics uint = position + random_heuristics_window_size
var gap uint = 0
/* Set maximum distance, see section 9.1. of the spec. */
const kMinScore uint = scoreBase + 100
/* For speed up heuristics for random data. */
/* Minimum score to accept a backward reference. */
hasher.PrepareDistanceCache(dist_cache)
sr2, _ := hasherSearchResultPool.Get().(*hasherSearchResult)
if sr2 == nil {
sr2 = &hasherSearchResult{}
}
sr, _ := hasherSearchResultPool.Get().(*hasherSearchResult)
if sr == nil {
sr = &hasherSearchResult{}
}
for position+hasher.HashTypeLength() < pos_end {
var max_length uint = pos_end - position
var max_distance uint = brotli_min_size_t(position, max_backward_limit)
sr.len = 0
sr.len_code_delta = 0
sr.distance = 0
sr.score = kMinScore
hasher.FindLongestMatch(&params.dictionary, ringbuffer, ringbuffer_mask, dist_cache, position, max_length, max_distance, gap, params.dist.max_distance, sr)
if sr.score > kMinScore {
/* Found a match. Let's look for something even better ahead. */
var delayed_backward_references_in_row int = 0
max_length--
for ; ; max_length-- {
var cost_diff_lazy uint = 175
if params.quality < minQualityForExtensiveReferenceSearch {
sr2.len = brotli_min_size_t(sr.len-1, max_length)
} else {
sr2.len = 0
}
sr2.len_code_delta = 0
sr2.distance = 0
sr2.score = kMinScore
max_distance = brotli_min_size_t(position+1, max_backward_limit)
hasher.FindLongestMatch(&params.dictionary, ringbuffer, ringbuffer_mask, dist_cache, position+1, max_length, max_distance, gap, params.dist.max_distance, sr2)
if sr2.score >= sr.score+cost_diff_lazy {
/* Ok, let's just write one byte for now and start a match from the
next byte. */
position++
insert_length++
*sr = *sr2
delayed_backward_references_in_row++
if delayed_backward_references_in_row < 4 && position+hasher.HashTypeLength() < pos_end {
continue
}
}
break
}
apply_random_heuristics = position + 2*sr.len + random_heuristics_window_size
max_distance = brotli_min_size_t(position, max_backward_limit)
{
/* The first 16 codes are special short-codes,
and the minimum offset is 1. */
var distance_code uint = computeDistanceCode(sr.distance, max_distance+gap, dist_cache)
if (sr.distance <= (max_distance + gap)) && distance_code > 0 {
dist_cache[3] = dist_cache[2]
dist_cache[2] = dist_cache[1]
dist_cache[1] = dist_cache[0]
dist_cache[0] = int(sr.distance)
hasher.PrepareDistanceCache(dist_cache)
}
*commands = append(*commands, makeCommand(&params.dist, insert_length, sr.len, sr.len_code_delta, distance_code))
}
*num_literals += insert_length
insert_length = 0
/* Put the hash keys into the table, if there are enough bytes left.
Depending on the hasher implementation, it can push all positions
in the given range or only a subset of them.
Avoid hash poisoning with RLE data. */
{
var range_start uint = position + 2
var range_end uint = brotli_min_size_t(position+sr.len, store_end)
if sr.distance < sr.len>>2 {
range_start = brotli_min_size_t(range_end, brotli_max_size_t(range_start, position+sr.len-(sr.distance<<2)))
}
hasher.StoreRange(ringbuffer, ringbuffer_mask, range_start, range_end)
}
position += sr.len
} else {
insert_length++
position++
/* If we have not seen matches for a long time, we can skip some
match lookups. Unsuccessful match lookups are very very expensive
and this kind of a heuristic speeds up compression quite
a lot. */
if position > apply_random_heuristics {
/* Going through uncompressible data, jump. */
if position > apply_random_heuristics+4*random_heuristics_window_size {
var kMargin uint = brotli_max_size_t(hasher.StoreLookahead()-1, 4)
/* It is quite a long time since we saw a copy, so we assume
that this data is not compressible, and store hashes less
often. Hashes of non compressible data are less likely to
turn out to be useful in the future, too, so we store less of
them to not to flood out the hash table of good compressible
data. */
var pos_jump uint = brotli_min_size_t(position+16, pos_end-kMargin)
for ; position < pos_jump; position += 4 {
hasher.Store(ringbuffer, ringbuffer_mask, position)
insert_length += 4
}
} else {
var kMargin uint = brotli_max_size_t(hasher.StoreLookahead()-1, 2)
var pos_jump uint = brotli_min_size_t(position+8, pos_end-kMargin)
for ; position < pos_jump; position += 2 {
hasher.Store(ringbuffer, ringbuffer_mask, position)
insert_length += 2
}
}
}
}
}
insert_length += pos_end - position
*last_insert_len = insert_length
hasherSearchResultPool.Put(sr)
hasherSearchResultPool.Put(sr2)
}

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@ -1,796 +0,0 @@
package brotli
import "math"
type zopfliNode struct {
length uint32
distance uint32
dcode_insert_length uint32
u struct {
cost float32
next uint32
shortcut uint32
}
}
const maxEffectiveDistanceAlphabetSize = 544
const kInfinity float32 = 1.7e38 /* ~= 2 ^ 127 */
var kDistanceCacheIndex = []uint32{0, 1, 2, 3, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1}
var kDistanceCacheOffset = []int{0, 0, 0, 0, -1, 1, -2, 2, -3, 3, -1, 1, -2, 2, -3, 3}
func initZopfliNodes(array []zopfliNode, length uint) {
var stub zopfliNode
var i uint
stub.length = 1
stub.distance = 0
stub.dcode_insert_length = 0
stub.u.cost = kInfinity
for i = 0; i < length; i++ {
array[i] = stub
}
}
func zopfliNodeCopyLength(self *zopfliNode) uint32 {
return self.length & 0x1FFFFFF
}
func zopfliNodeLengthCode(self *zopfliNode) uint32 {
var modifier uint32 = self.length >> 25
return zopfliNodeCopyLength(self) + 9 - modifier
}
func zopfliNodeCopyDistance(self *zopfliNode) uint32 {
return self.distance
}
func zopfliNodeDistanceCode(self *zopfliNode) uint32 {
var short_code uint32 = self.dcode_insert_length >> 27
if short_code == 0 {
return zopfliNodeCopyDistance(self) + numDistanceShortCodes - 1
} else {
return short_code - 1
}
}
func zopfliNodeCommandLength(self *zopfliNode) uint32 {
return zopfliNodeCopyLength(self) + (self.dcode_insert_length & 0x7FFFFFF)
}
/* Histogram based cost model for zopflification. */
type zopfliCostModel struct {
cost_cmd_ [numCommandSymbols]float32
cost_dist_ []float32
distance_histogram_size uint32
literal_costs_ []float32
min_cost_cmd_ float32
num_bytes_ uint
}
func initZopfliCostModel(self *zopfliCostModel, dist *distanceParams, num_bytes uint) {
var distance_histogram_size uint32 = dist.alphabet_size
if distance_histogram_size > maxEffectiveDistanceAlphabetSize {
distance_histogram_size = maxEffectiveDistanceAlphabetSize
}
self.num_bytes_ = num_bytes
self.literal_costs_ = make([]float32, (num_bytes + 2))
self.cost_dist_ = make([]float32, (dist.alphabet_size))
self.distance_histogram_size = distance_histogram_size
}
func cleanupZopfliCostModel(self *zopfliCostModel) {
self.literal_costs_ = nil
self.cost_dist_ = nil
}
func setCost(histogram []uint32, histogram_size uint, literal_histogram bool, cost []float32) {
var sum uint = 0
var missing_symbol_sum uint
var log2sum float32
var missing_symbol_cost float32
var i uint
for i = 0; i < histogram_size; i++ {
sum += uint(histogram[i])
}
log2sum = float32(fastLog2(sum))
missing_symbol_sum = sum
if !literal_histogram {
for i = 0; i < histogram_size; i++ {
if histogram[i] == 0 {
missing_symbol_sum++
}
}
}
missing_symbol_cost = float32(fastLog2(missing_symbol_sum)) + 2
for i = 0; i < histogram_size; i++ {
if histogram[i] == 0 {
cost[i] = missing_symbol_cost
continue
}
/* Shannon bits for this symbol. */
cost[i] = log2sum - float32(fastLog2(uint(histogram[i])))
/* Cannot be coded with less than 1 bit */
if cost[i] < 1 {
cost[i] = 1
}
}
}
func zopfliCostModelSetFromCommands(self *zopfliCostModel, position uint, ringbuffer []byte, ringbuffer_mask uint, commands []command, last_insert_len uint) {
var histogram_literal [numLiteralSymbols]uint32
var histogram_cmd [numCommandSymbols]uint32
var histogram_dist [maxEffectiveDistanceAlphabetSize]uint32
var cost_literal [numLiteralSymbols]float32
var pos uint = position - last_insert_len
var min_cost_cmd float32 = kInfinity
var cost_cmd []float32 = self.cost_cmd_[:]
var literal_costs []float32
histogram_literal = [numLiteralSymbols]uint32{}
histogram_cmd = [numCommandSymbols]uint32{}
histogram_dist = [maxEffectiveDistanceAlphabetSize]uint32{}
for i := range commands {
var inslength uint = uint(commands[i].insert_len_)
var copylength uint = uint(commandCopyLen(&commands[i]))
var distcode uint = uint(commands[i].dist_prefix_) & 0x3FF
var cmdcode uint = uint(commands[i].cmd_prefix_)
var j uint
histogram_cmd[cmdcode]++
if cmdcode >= 128 {
histogram_dist[distcode]++
}
for j = 0; j < inslength; j++ {
histogram_literal[ringbuffer[(pos+j)&ringbuffer_mask]]++
}
pos += inslength + copylength
}
setCost(histogram_literal[:], numLiteralSymbols, true, cost_literal[:])
setCost(histogram_cmd[:], numCommandSymbols, false, cost_cmd)
setCost(histogram_dist[:], uint(self.distance_histogram_size), false, self.cost_dist_)
for i := 0; i < numCommandSymbols; i++ {
min_cost_cmd = brotli_min_float(min_cost_cmd, cost_cmd[i])
}
self.min_cost_cmd_ = min_cost_cmd
{
literal_costs = self.literal_costs_
var literal_carry float32 = 0.0
num_bytes := int(self.num_bytes_)
literal_costs[0] = 0.0
for i := 0; i < num_bytes; i++ {
literal_carry += cost_literal[ringbuffer[(position+uint(i))&ringbuffer_mask]]
literal_costs[i+1] = literal_costs[i] + literal_carry
literal_carry -= literal_costs[i+1] - literal_costs[i]
}
}
}
func zopfliCostModelSetFromLiteralCosts(self *zopfliCostModel, position uint, ringbuffer []byte, ringbuffer_mask uint) {
var literal_costs []float32 = self.literal_costs_
var literal_carry float32 = 0.0
var cost_dist []float32 = self.cost_dist_
var cost_cmd []float32 = self.cost_cmd_[:]
var num_bytes uint = self.num_bytes_
var i uint
estimateBitCostsForLiterals(position, num_bytes, ringbuffer_mask, ringbuffer, literal_costs[1:])
literal_costs[0] = 0.0
for i = 0; i < num_bytes; i++ {
literal_carry += literal_costs[i+1]
literal_costs[i+1] = literal_costs[i] + literal_carry
literal_carry -= literal_costs[i+1] - literal_costs[i]
}
for i = 0; i < numCommandSymbols; i++ {
cost_cmd[i] = float32(fastLog2(uint(11 + uint32(i))))
}
for i = 0; uint32(i) < self.distance_histogram_size; i++ {
cost_dist[i] = float32(fastLog2(uint(20 + uint32(i))))
}
self.min_cost_cmd_ = float32(fastLog2(11))
}
func zopfliCostModelGetCommandCost(self *zopfliCostModel, cmdcode uint16) float32 {
return self.cost_cmd_[cmdcode]
}
func zopfliCostModelGetDistanceCost(self *zopfliCostModel, distcode uint) float32 {
return self.cost_dist_[distcode]
}
func zopfliCostModelGetLiteralCosts(self *zopfliCostModel, from uint, to uint) float32 {
return self.literal_costs_[to] - self.literal_costs_[from]
}
func zopfliCostModelGetMinCostCmd(self *zopfliCostModel) float32 {
return self.min_cost_cmd_
}
/* REQUIRES: len >= 2, start_pos <= pos */
/* REQUIRES: cost < kInfinity, nodes[start_pos].cost < kInfinity */
/* Maintains the "ZopfliNode array invariant". */
func updateZopfliNode(nodes []zopfliNode, pos uint, start_pos uint, len uint, len_code uint, dist uint, short_code uint, cost float32) {
var next *zopfliNode = &nodes[pos+len]
next.length = uint32(len | (len+9-len_code)<<25)
next.distance = uint32(dist)
next.dcode_insert_length = uint32(short_code<<27 | (pos - start_pos))
next.u.cost = cost
}
type posData struct {
pos uint
distance_cache [4]int
costdiff float32
cost float32
}
/* Maintains the smallest 8 cost difference together with their positions */
type startPosQueue struct {
q_ [8]posData
idx_ uint
}
func initStartPosQueue(self *startPosQueue) {
self.idx_ = 0
}
func startPosQueueSize(self *startPosQueue) uint {
return brotli_min_size_t(self.idx_, 8)
}
func startPosQueuePush(self *startPosQueue, posdata *posData) {
var offset uint = ^(self.idx_) & 7
self.idx_++
var len uint = startPosQueueSize(self)
var i uint
var q []posData = self.q_[:]
q[offset] = *posdata
/* Restore the sorted order. In the list of |len| items at most |len - 1|
adjacent element comparisons / swaps are required. */
for i = 1; i < len; i++ {
if q[offset&7].costdiff > q[(offset+1)&7].costdiff {
var tmp posData = q[offset&7]
q[offset&7] = q[(offset+1)&7]
q[(offset+1)&7] = tmp
}
offset++
}
}
func startPosQueueAt(self *startPosQueue, k uint) *posData {
return &self.q_[(k-self.idx_)&7]
}
/* Returns the minimum possible copy length that can improve the cost of any */
/* future position. */
func computeMinimumCopyLength(start_cost float32, nodes []zopfliNode, num_bytes uint, pos uint) uint {
var min_cost float32 = start_cost
var len uint = 2
var next_len_bucket uint = 4
/* Compute the minimum possible cost of reaching any future position. */
var next_len_offset uint = 10
for pos+len <= num_bytes && nodes[pos+len].u.cost <= min_cost {
/* We already reached (pos + len) with no more cost than the minimum
possible cost of reaching anything from this pos, so there is no point in
looking for lengths <= len. */
len++
if len == next_len_offset {
/* We reached the next copy length code bucket, so we add one more
extra bit to the minimum cost. */
min_cost += 1.0
next_len_offset += next_len_bucket
next_len_bucket *= 2
}
}
return uint(len)
}
/* REQUIRES: nodes[pos].cost < kInfinity
REQUIRES: nodes[0..pos] satisfies that "ZopfliNode array invariant". */
func computeDistanceShortcut(block_start uint, pos uint, max_backward_limit uint, gap uint, nodes []zopfliNode) uint32 {
var clen uint = uint(zopfliNodeCopyLength(&nodes[pos]))
var ilen uint = uint(nodes[pos].dcode_insert_length & 0x7FFFFFF)
var dist uint = uint(zopfliNodeCopyDistance(&nodes[pos]))
/* Since |block_start + pos| is the end position of the command, the copy part
starts from |block_start + pos - clen|. Distances that are greater than
this or greater than |max_backward_limit| + |gap| are static dictionary
references, and do not update the last distances.
Also distance code 0 (last distance) does not update the last distances. */
if pos == 0 {
return 0
} else if dist+clen <= block_start+pos+gap && dist <= max_backward_limit+gap && zopfliNodeDistanceCode(&nodes[pos]) > 0 {
return uint32(pos)
} else {
return nodes[pos-clen-ilen].u.shortcut
}
}
/* Fills in dist_cache[0..3] with the last four distances (as defined by
Section 4. of the Spec) that would be used at (block_start + pos) if we
used the shortest path of commands from block_start, computed from
nodes[0..pos]. The last four distances at block_start are in
starting_dist_cache[0..3].
REQUIRES: nodes[pos].cost < kInfinity
REQUIRES: nodes[0..pos] satisfies that "ZopfliNode array invariant". */
func computeDistanceCache(pos uint, starting_dist_cache []int, nodes []zopfliNode, dist_cache []int) {
var idx int = 0
var p uint = uint(nodes[pos].u.shortcut)
for idx < 4 && p > 0 {
var ilen uint = uint(nodes[p].dcode_insert_length & 0x7FFFFFF)
var clen uint = uint(zopfliNodeCopyLength(&nodes[p]))
var dist uint = uint(zopfliNodeCopyDistance(&nodes[p]))
dist_cache[idx] = int(dist)
idx++
/* Because of prerequisite, p >= clen + ilen >= 2. */
p = uint(nodes[p-clen-ilen].u.shortcut)
}
for ; idx < 4; idx++ {
dist_cache[idx] = starting_dist_cache[0]
starting_dist_cache = starting_dist_cache[1:]
}
}
/* Maintains "ZopfliNode array invariant" and pushes node to the queue, if it
is eligible. */
func evaluateNode(block_start uint, pos uint, max_backward_limit uint, gap uint, starting_dist_cache []int, model *zopfliCostModel, queue *startPosQueue, nodes []zopfliNode) {
/* Save cost, because ComputeDistanceCache invalidates it. */
var node_cost float32 = nodes[pos].u.cost
nodes[pos].u.shortcut = computeDistanceShortcut(block_start, pos, max_backward_limit, gap, nodes)
if node_cost <= zopfliCostModelGetLiteralCosts(model, 0, pos) {
var posdata posData
posdata.pos = pos
posdata.cost = node_cost
posdata.costdiff = node_cost - zopfliCostModelGetLiteralCosts(model, 0, pos)
computeDistanceCache(pos, starting_dist_cache, nodes, posdata.distance_cache[:])
startPosQueuePush(queue, &posdata)
}
}
/* Returns longest copy length. */
func updateNodes(num_bytes uint, block_start uint, pos uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, max_backward_limit uint, starting_dist_cache []int, num_matches uint, matches []backwardMatch, model *zopfliCostModel, queue *startPosQueue, nodes []zopfliNode) uint {
var cur_ix uint = block_start + pos
var cur_ix_masked uint = cur_ix & ringbuffer_mask
var max_distance uint = brotli_min_size_t(cur_ix, max_backward_limit)
var max_len uint = num_bytes - pos
var max_zopfli_len uint = maxZopfliLen(params)
var max_iters uint = maxZopfliCandidates(params)
var min_len uint
var result uint = 0
var k uint
var gap uint = 0
evaluateNode(block_start, pos, max_backward_limit, gap, starting_dist_cache, model, queue, nodes)
{
var posdata *posData = startPosQueueAt(queue, 0)
var min_cost float32 = (posdata.cost + zopfliCostModelGetMinCostCmd(model) + zopfliCostModelGetLiteralCosts(model, posdata.pos, pos))
min_len = computeMinimumCopyLength(min_cost, nodes, num_bytes, pos)
}
/* Go over the command starting positions in order of increasing cost
difference. */
for k = 0; k < max_iters && k < startPosQueueSize(queue); k++ {
var posdata *posData = startPosQueueAt(queue, k)
var start uint = posdata.pos
var inscode uint16 = getInsertLengthCode(pos - start)
var start_costdiff float32 = posdata.costdiff
var base_cost float32 = start_costdiff + float32(getInsertExtra(inscode)) + zopfliCostModelGetLiteralCosts(model, 0, pos)
var best_len uint = min_len - 1
var j uint = 0
/* Look for last distance matches using the distance cache from this
starting position. */
for ; j < numDistanceShortCodes && best_len < max_len; j++ {
var idx uint = uint(kDistanceCacheIndex[j])
var backward uint = uint(posdata.distance_cache[idx] + kDistanceCacheOffset[j])
var prev_ix uint = cur_ix - backward
var len uint = 0
var continuation byte = ringbuffer[cur_ix_masked+best_len]
if cur_ix_masked+best_len > ringbuffer_mask {
break
}
if backward > max_distance+gap {
/* Word dictionary -> ignore. */
continue
}
if backward <= max_distance {
/* Regular backward reference. */
if prev_ix >= cur_ix {
continue
}
prev_ix &= ringbuffer_mask
if prev_ix+best_len > ringbuffer_mask || continuation != ringbuffer[prev_ix+best_len] {
continue
}
len = findMatchLengthWithLimit(ringbuffer[prev_ix:], ringbuffer[cur_ix_masked:], max_len)
} else {
continue
}
{
var dist_cost float32 = base_cost + zopfliCostModelGetDistanceCost(model, j)
var l uint
for l = best_len + 1; l <= len; l++ {
var copycode uint16 = getCopyLengthCode(l)
var cmdcode uint16 = combineLengthCodes(inscode, copycode, j == 0)
var tmp float32
if cmdcode < 128 {
tmp = base_cost
} else {
tmp = dist_cost
}
var cost float32 = tmp + float32(getCopyExtra(copycode)) + zopfliCostModelGetCommandCost(model, cmdcode)
if cost < nodes[pos+l].u.cost {
updateZopfliNode(nodes, pos, start, l, l, backward, j+1, cost)
result = brotli_max_size_t(result, l)
}
best_len = l
}
}
}
/* At higher iterations look only for new last distance matches, since
looking only for new command start positions with the same distances
does not help much. */
if k >= 2 {
continue
}
{
/* Loop through all possible copy lengths at this position. */
var len uint = min_len
for j = 0; j < num_matches; j++ {
var match backwardMatch = matches[j]
var dist uint = uint(match.distance)
var is_dictionary_match bool = (dist > max_distance+gap)
var dist_code uint = dist + numDistanceShortCodes - 1
var dist_symbol uint16
var distextra uint32
var distnumextra uint32
var dist_cost float32
var max_match_len uint
/* We already tried all possible last distance matches, so we can use
normal distance code here. */
prefixEncodeCopyDistance(dist_code, uint(params.dist.num_direct_distance_codes), uint(params.dist.distance_postfix_bits), &dist_symbol, &distextra)
distnumextra = uint32(dist_symbol) >> 10
dist_cost = base_cost + float32(distnumextra) + zopfliCostModelGetDistanceCost(model, uint(dist_symbol)&0x3FF)
/* Try all copy lengths up until the maximum copy length corresponding
to this distance. If the distance refers to the static dictionary, or
the maximum length is long enough, try only one maximum length. */
max_match_len = backwardMatchLength(&match)
if len < max_match_len && (is_dictionary_match || max_match_len > max_zopfli_len) {
len = max_match_len
}
for ; len <= max_match_len; len++ {
var len_code uint
if is_dictionary_match {
len_code = backwardMatchLengthCode(&match)
} else {
len_code = len
}
var copycode uint16 = getCopyLengthCode(len_code)
var cmdcode uint16 = combineLengthCodes(inscode, copycode, false)
var cost float32 = dist_cost + float32(getCopyExtra(copycode)) + zopfliCostModelGetCommandCost(model, cmdcode)
if cost < nodes[pos+len].u.cost {
updateZopfliNode(nodes, pos, start, uint(len), len_code, dist, 0, cost)
if len > result {
result = len
}
}
}
}
}
}
return result
}
func computeShortestPathFromNodes(num_bytes uint, nodes []zopfliNode) uint {
var index uint = num_bytes
var num_commands uint = 0
for nodes[index].dcode_insert_length&0x7FFFFFF == 0 && nodes[index].length == 1 {
index--
}
nodes[index].u.next = math.MaxUint32
for index != 0 {
var len uint = uint(zopfliNodeCommandLength(&nodes[index]))
index -= uint(len)
nodes[index].u.next = uint32(len)
num_commands++
}
return num_commands
}
/* REQUIRES: nodes != NULL and len(nodes) >= num_bytes + 1 */
func zopfliCreateCommands(num_bytes uint, block_start uint, nodes []zopfliNode, dist_cache []int, last_insert_len *uint, params *encoderParams, commands *[]command, num_literals *uint) {
var max_backward_limit uint = maxBackwardLimit(params.lgwin)
var pos uint = 0
var offset uint32 = nodes[0].u.next
var i uint
var gap uint = 0
for i = 0; offset != math.MaxUint32; i++ {
var next *zopfliNode = &nodes[uint32(pos)+offset]
var copy_length uint = uint(zopfliNodeCopyLength(next))
var insert_length uint = uint(next.dcode_insert_length & 0x7FFFFFF)
pos += insert_length
offset = next.u.next
if i == 0 {
insert_length += *last_insert_len
*last_insert_len = 0
}
{
var distance uint = uint(zopfliNodeCopyDistance(next))
var len_code uint = uint(zopfliNodeLengthCode(next))
var max_distance uint = brotli_min_size_t(block_start+pos, max_backward_limit)
var is_dictionary bool = (distance > max_distance+gap)
var dist_code uint = uint(zopfliNodeDistanceCode(next))
*commands = append(*commands, makeCommand(&params.dist, insert_length, copy_length, int(len_code)-int(copy_length), dist_code))
if !is_dictionary && dist_code > 0 {
dist_cache[3] = dist_cache[2]
dist_cache[2] = dist_cache[1]
dist_cache[1] = dist_cache[0]
dist_cache[0] = int(distance)
}
}
*num_literals += insert_length
pos += copy_length
}
*last_insert_len += num_bytes - pos
}
func zopfliIterate(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, gap uint, dist_cache []int, model *zopfliCostModel, num_matches []uint32, matches []backwardMatch, nodes []zopfliNode) uint {
var max_backward_limit uint = maxBackwardLimit(params.lgwin)
var max_zopfli_len uint = maxZopfliLen(params)
var queue startPosQueue
var cur_match_pos uint = 0
var i uint
nodes[0].length = 0
nodes[0].u.cost = 0
initStartPosQueue(&queue)
for i = 0; i+3 < num_bytes; i++ {
var skip uint = updateNodes(num_bytes, position, i, ringbuffer, ringbuffer_mask, params, max_backward_limit, dist_cache, uint(num_matches[i]), matches[cur_match_pos:], model, &queue, nodes)
if skip < longCopyQuickStep {
skip = 0
}
cur_match_pos += uint(num_matches[i])
if num_matches[i] == 1 && backwardMatchLength(&matches[cur_match_pos-1]) > max_zopfli_len {
skip = brotli_max_size_t(backwardMatchLength(&matches[cur_match_pos-1]), skip)
}
if skip > 1 {
skip--
for skip != 0 {
i++
if i+3 >= num_bytes {
break
}
evaluateNode(position, i, max_backward_limit, gap, dist_cache, model, &queue, nodes)
cur_match_pos += uint(num_matches[i])
skip--
}
}
}
return computeShortestPathFromNodes(num_bytes, nodes)
}
/* Computes the shortest path of commands from position to at most
position + num_bytes.
On return, path->size() is the number of commands found and path[i] is the
length of the i-th command (copy length plus insert length).
Note that the sum of the lengths of all commands can be less than num_bytes.
On return, the nodes[0..num_bytes] array will have the following
"ZopfliNode array invariant":
For each i in [1..num_bytes], if nodes[i].cost < kInfinity, then
(1) nodes[i].copy_length() >= 2
(2) nodes[i].command_length() <= i and
(3) nodes[i - nodes[i].command_length()].cost < kInfinity
REQUIRES: nodes != nil and len(nodes) >= num_bytes + 1 */
func zopfliComputeShortestPath(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, dist_cache []int, hasher *h10, nodes []zopfliNode) uint {
var max_backward_limit uint = maxBackwardLimit(params.lgwin)
var max_zopfli_len uint = maxZopfliLen(params)
var model zopfliCostModel
var queue startPosQueue
var matches [2 * (maxNumMatchesH10 + 64)]backwardMatch
var store_end uint
if num_bytes >= hasher.StoreLookahead() {
store_end = position + num_bytes - hasher.StoreLookahead() + 1
} else {
store_end = position
}
var i uint
var gap uint = 0
var lz_matches_offset uint = 0
nodes[0].length = 0
nodes[0].u.cost = 0
initZopfliCostModel(&model, &params.dist, num_bytes)
zopfliCostModelSetFromLiteralCosts(&model, position, ringbuffer, ringbuffer_mask)
initStartPosQueue(&queue)
for i = 0; i+hasher.HashTypeLength()-1 < num_bytes; i++ {
var pos uint = position + i
var max_distance uint = brotli_min_size_t(pos, max_backward_limit)
var skip uint
var num_matches uint
num_matches = findAllMatchesH10(hasher, &params.dictionary, ringbuffer, ringbuffer_mask, pos, num_bytes-i, max_distance, gap, params, matches[lz_matches_offset:])
if num_matches > 0 && backwardMatchLength(&matches[num_matches-1]) > max_zopfli_len {
matches[0] = matches[num_matches-1]
num_matches = 1
}
skip = updateNodes(num_bytes, position, i, ringbuffer, ringbuffer_mask, params, max_backward_limit, dist_cache, num_matches, matches[:], &model, &queue, nodes)
if skip < longCopyQuickStep {
skip = 0
}
if num_matches == 1 && backwardMatchLength(&matches[0]) > max_zopfli_len {
skip = brotli_max_size_t(backwardMatchLength(&matches[0]), skip)
}
if skip > 1 {
/* Add the tail of the copy to the hasher. */
hasher.StoreRange(ringbuffer, ringbuffer_mask, pos+1, brotli_min_size_t(pos+skip, store_end))
skip--
for skip != 0 {
i++
if i+hasher.HashTypeLength()-1 >= num_bytes {
break
}
evaluateNode(position, i, max_backward_limit, gap, dist_cache, &model, &queue, nodes)
skip--
}
}
}
cleanupZopfliCostModel(&model)
return computeShortestPathFromNodes(num_bytes, nodes)
}
func createZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher *h10, dist_cache []int, last_insert_len *uint, commands *[]command, num_literals *uint) {
var nodes []zopfliNode
nodes = make([]zopfliNode, (num_bytes + 1))
initZopfliNodes(nodes, num_bytes+1)
zopfliComputeShortestPath(num_bytes, position, ringbuffer, ringbuffer_mask, params, dist_cache, hasher, nodes)
zopfliCreateCommands(num_bytes, position, nodes, dist_cache, last_insert_len, params, commands, num_literals)
nodes = nil
}
func createHqZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher hasherHandle, dist_cache []int, last_insert_len *uint, commands *[]command, num_literals *uint) {
var max_backward_limit uint = maxBackwardLimit(params.lgwin)
var num_matches []uint32 = make([]uint32, num_bytes)
var matches_size uint = 4 * num_bytes
var store_end uint
if num_bytes >= hasher.StoreLookahead() {
store_end = position + num_bytes - hasher.StoreLookahead() + 1
} else {
store_end = position
}
var cur_match_pos uint = 0
var i uint
var orig_num_literals uint
var orig_last_insert_len uint
var orig_dist_cache [4]int
var orig_num_commands int
var model zopfliCostModel
var nodes []zopfliNode
var matches []backwardMatch = make([]backwardMatch, matches_size)
var gap uint = 0
var shadow_matches uint = 0
var new_array []backwardMatch
for i = 0; i+hasher.HashTypeLength()-1 < num_bytes; i++ {
var pos uint = position + i
var max_distance uint = brotli_min_size_t(pos, max_backward_limit)
var max_length uint = num_bytes - i
var num_found_matches uint
var cur_match_end uint
var j uint
/* Ensure that we have enough free slots. */
if matches_size < cur_match_pos+maxNumMatchesH10+shadow_matches {
var new_size uint = matches_size
if new_size == 0 {
new_size = cur_match_pos + maxNumMatchesH10 + shadow_matches
}
for new_size < cur_match_pos+maxNumMatchesH10+shadow_matches {
new_size *= 2
}
new_array = make([]backwardMatch, new_size)
if matches_size != 0 {
copy(new_array, matches[:matches_size])
}
matches = new_array
matches_size = new_size
}
num_found_matches = findAllMatchesH10(hasher.(*h10), &params.dictionary, ringbuffer, ringbuffer_mask, pos, max_length, max_distance, gap, params, matches[cur_match_pos+shadow_matches:])
cur_match_end = cur_match_pos + num_found_matches
for j = cur_match_pos; j+1 < cur_match_end; j++ {
assert(backwardMatchLength(&matches[j]) <= backwardMatchLength(&matches[j+1]))
}
num_matches[i] = uint32(num_found_matches)
if num_found_matches > 0 {
var match_len uint = backwardMatchLength(&matches[cur_match_end-1])
if match_len > maxZopfliLenQuality11 {
var skip uint = match_len - 1
matches[cur_match_pos] = matches[cur_match_end-1]
cur_match_pos++
num_matches[i] = 1
/* Add the tail of the copy to the hasher. */
hasher.StoreRange(ringbuffer, ringbuffer_mask, pos+1, brotli_min_size_t(pos+match_len, store_end))
var pos uint = i
for i := 0; i < int(skip); i++ {
num_matches[pos+1:][i] = 0
}
i += skip
} else {
cur_match_pos = cur_match_end
}
}
}
orig_num_literals = *num_literals
orig_last_insert_len = *last_insert_len
copy(orig_dist_cache[:], dist_cache[:4])
orig_num_commands = len(*commands)
nodes = make([]zopfliNode, (num_bytes + 1))
initZopfliCostModel(&model, &params.dist, num_bytes)
for i = 0; i < 2; i++ {
initZopfliNodes(nodes, num_bytes+1)
if i == 0 {
zopfliCostModelSetFromLiteralCosts(&model, position, ringbuffer, ringbuffer_mask)
} else {
zopfliCostModelSetFromCommands(&model, position, ringbuffer, ringbuffer_mask, (*commands)[orig_num_commands:], orig_last_insert_len)
}
*commands = (*commands)[:orig_num_commands]
*num_literals = orig_num_literals
*last_insert_len = orig_last_insert_len
copy(dist_cache, orig_dist_cache[:4])
zopfliIterate(num_bytes, position, ringbuffer, ringbuffer_mask, params, gap, dist_cache, &model, num_matches, matches, nodes)
zopfliCreateCommands(num_bytes, position, nodes, dist_cache, last_insert_len, params, commands, num_literals)
}
cleanupZopfliCostModel(&model)
nodes = nil
matches = nil
num_matches = nil
}

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@ -1,436 +0,0 @@
package brotli
/* Copyright 2013 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
/* Functions to estimate the bit cost of Huffman trees. */
func shannonEntropy(population []uint32, size uint, total *uint) float64 {
var sum uint = 0
var retval float64 = 0