mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2025-10-30 22:52:25 -05:00
c00cad2ceb
- github.com/KimMachineGun/automemlimit v0.7.4 - github.com/miekg/dns v1.1.67 - github.com/minio/minio-go/v7 v7.0.95 - github.com/spf13/pflag v1.0.7 - github.com/tdewolff/minify/v2 v2.23.9 - github.com/uptrace/bun v1.2.15 - github.com/uptrace/bun/dialect/pgdialect v1.2.15 - github.com/uptrace/bun/dialect/sqlitedialect v1.2.15 - github.com/uptrace/bun/extra/bunotel v1.2.15 - golang.org/x/image v0.29.0 - golang.org/x/net v0.42.0 Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4339 Co-authored-by: kim <grufwub@gmail.com> Co-committed-by: kim <grufwub@gmail.com>
500 lines
14 KiB
Go
500 lines
14 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package regexp
|
|
|
|
import (
|
|
"regexp/syntax"
|
|
"slices"
|
|
"strings"
|
|
"unicode"
|
|
"unicode/utf8"
|
|
)
|
|
|
|
// "One-pass" regexp execution.
|
|
// Some regexps can be analyzed to determine that they never need
|
|
// backtracking: they are guaranteed to run in one pass over the string
|
|
// without bothering to save all the usual NFA state.
|
|
// Detect those and execute them more quickly.
|
|
|
|
// A onePassProg is a compiled one-pass regular expression program.
|
|
// It is the same as syntax.Prog except for the use of onePassInst.
|
|
type onePassProg struct {
|
|
Inst []onePassInst
|
|
Start int // index of start instruction
|
|
NumCap int // number of InstCapture insts in re
|
|
}
|
|
|
|
// A onePassInst is a single instruction in a one-pass regular expression program.
|
|
// It is the same as syntax.Inst except for the new 'Next' field.
|
|
type onePassInst struct {
|
|
syntax.Inst
|
|
Next []uint32
|
|
}
|
|
|
|
// onePassPrefix returns a literal string that all matches for the
|
|
// regexp must start with. Complete is true if the prefix
|
|
// is the entire match. Pc is the index of the last rune instruction
|
|
// in the string. The onePassPrefix skips over the mandatory
|
|
// EmptyBeginText.
|
|
func onePassPrefix(p *syntax.Prog) (prefix string, complete bool, pc uint32) {
|
|
i := &p.Inst[p.Start]
|
|
if i.Op != syntax.InstEmptyWidth || (syntax.EmptyOp(i.Arg))&syntax.EmptyBeginText == 0 {
|
|
return "", i.Op == syntax.InstMatch, uint32(p.Start)
|
|
}
|
|
pc = i.Out
|
|
i = &p.Inst[pc]
|
|
for i.Op == syntax.InstNop {
|
|
pc = i.Out
|
|
i = &p.Inst[pc]
|
|
}
|
|
// Avoid allocation of buffer if prefix is empty.
|
|
if iop(i) != syntax.InstRune || len(i.Rune) != 1 {
|
|
return "", i.Op == syntax.InstMatch, uint32(p.Start)
|
|
}
|
|
|
|
// Have prefix; gather characters.
|
|
var buf strings.Builder
|
|
for iop(i) == syntax.InstRune && len(i.Rune) == 1 && syntax.Flags(i.Arg)&syntax.FoldCase == 0 && i.Rune[0] != utf8.RuneError {
|
|
buf.WriteRune(i.Rune[0])
|
|
pc, i = i.Out, &p.Inst[i.Out]
|
|
}
|
|
if i.Op == syntax.InstEmptyWidth &&
|
|
syntax.EmptyOp(i.Arg)&syntax.EmptyEndText != 0 &&
|
|
p.Inst[i.Out].Op == syntax.InstMatch {
|
|
complete = true
|
|
}
|
|
return buf.String(), complete, pc
|
|
}
|
|
|
|
// onePassNext selects the next actionable state of the prog, based on the input character.
|
|
// It should only be called when i.Op == InstAlt or InstAltMatch, and from the one-pass machine.
|
|
// One of the alternates may ultimately lead without input to end of line. If the instruction
|
|
// is InstAltMatch the path to the InstMatch is in i.Out, the normal node in i.Next.
|
|
func onePassNext(i *onePassInst, r rune) uint32 {
|
|
next := i.MatchRunePos(r)
|
|
if next >= 0 {
|
|
return i.Next[next]
|
|
}
|
|
if i.Op == syntax.InstAltMatch {
|
|
return i.Out
|
|
}
|
|
return 0
|
|
}
|
|
|
|
func iop(i *syntax.Inst) syntax.InstOp {
|
|
op := i.Op
|
|
switch op {
|
|
case syntax.InstRune1, syntax.InstRuneAny, syntax.InstRuneAnyNotNL:
|
|
op = syntax.InstRune
|
|
}
|
|
return op
|
|
}
|
|
|
|
// Sparse Array implementation is used as a queueOnePass.
|
|
type queueOnePass struct {
|
|
sparse []uint32
|
|
dense []uint32
|
|
size, nextIndex uint32
|
|
}
|
|
|
|
func (q *queueOnePass) empty() bool {
|
|
return q.nextIndex >= q.size
|
|
}
|
|
|
|
func (q *queueOnePass) next() (n uint32) {
|
|
n = q.dense[q.nextIndex]
|
|
q.nextIndex++
|
|
return
|
|
}
|
|
|
|
func (q *queueOnePass) clear() {
|
|
q.size = 0
|
|
q.nextIndex = 0
|
|
}
|
|
|
|
func (q *queueOnePass) contains(u uint32) bool {
|
|
if u >= uint32(len(q.sparse)) {
|
|
return false
|
|
}
|
|
return q.sparse[u] < q.size && q.dense[q.sparse[u]] == u
|
|
}
|
|
|
|
func (q *queueOnePass) insert(u uint32) {
|
|
if !q.contains(u) {
|
|
q.insertNew(u)
|
|
}
|
|
}
|
|
|
|
func (q *queueOnePass) insertNew(u uint32) {
|
|
if u >= uint32(len(q.sparse)) {
|
|
return
|
|
}
|
|
q.sparse[u] = q.size
|
|
q.dense[q.size] = u
|
|
q.size++
|
|
}
|
|
|
|
func newQueue(size int) (q *queueOnePass) {
|
|
return &queueOnePass{
|
|
sparse: make([]uint32, size),
|
|
dense: make([]uint32, size),
|
|
}
|
|
}
|
|
|
|
// mergeRuneSets merges two non-intersecting runesets, and returns the merged result,
|
|
// and a NextIp array. The idea is that if a rune matches the OnePassRunes at index
|
|
// i, NextIp[i/2] is the target. If the input sets intersect, an empty runeset and a
|
|
// NextIp array with the single element mergeFailed is returned.
|
|
// The code assumes that both inputs contain ordered and non-intersecting rune pairs.
|
|
const mergeFailed = uint32(0xffffffff)
|
|
|
|
var (
|
|
noRune = []rune{}
|
|
noNext = []uint32{mergeFailed}
|
|
)
|
|
|
|
func mergeRuneSets(leftRunes, rightRunes *[]rune, leftPC, rightPC uint32) ([]rune, []uint32) {
|
|
leftLen := len(*leftRunes)
|
|
rightLen := len(*rightRunes)
|
|
if leftLen&0x1 != 0 || rightLen&0x1 != 0 {
|
|
panic("mergeRuneSets odd length []rune")
|
|
}
|
|
var (
|
|
lx, rx int
|
|
)
|
|
merged := make([]rune, 0)
|
|
next := make([]uint32, 0)
|
|
ok := true
|
|
defer func() {
|
|
if !ok {
|
|
merged = nil
|
|
next = nil
|
|
}
|
|
}()
|
|
|
|
ix := -1
|
|
extend := func(newLow *int, newArray *[]rune, pc uint32) bool {
|
|
if ix > 0 && (*newArray)[*newLow] <= merged[ix] {
|
|
return false
|
|
}
|
|
merged = append(merged, (*newArray)[*newLow], (*newArray)[*newLow+1])
|
|
*newLow += 2
|
|
ix += 2
|
|
next = append(next, pc)
|
|
return true
|
|
}
|
|
|
|
for lx < leftLen || rx < rightLen {
|
|
switch {
|
|
case rx >= rightLen:
|
|
ok = extend(&lx, leftRunes, leftPC)
|
|
case lx >= leftLen:
|
|
ok = extend(&rx, rightRunes, rightPC)
|
|
case (*rightRunes)[rx] < (*leftRunes)[lx]:
|
|
ok = extend(&rx, rightRunes, rightPC)
|
|
default:
|
|
ok = extend(&lx, leftRunes, leftPC)
|
|
}
|
|
if !ok {
|
|
return noRune, noNext
|
|
}
|
|
}
|
|
return merged, next
|
|
}
|
|
|
|
// cleanupOnePass drops working memory, and restores certain shortcut instructions.
|
|
func cleanupOnePass(prog *onePassProg, original *syntax.Prog) {
|
|
for ix, instOriginal := range original.Inst {
|
|
switch instOriginal.Op {
|
|
case syntax.InstAlt, syntax.InstAltMatch, syntax.InstRune:
|
|
case syntax.InstCapture, syntax.InstEmptyWidth, syntax.InstNop, syntax.InstMatch, syntax.InstFail:
|
|
prog.Inst[ix].Next = nil
|
|
case syntax.InstRune1, syntax.InstRuneAny, syntax.InstRuneAnyNotNL:
|
|
prog.Inst[ix].Next = nil
|
|
prog.Inst[ix] = onePassInst{Inst: instOriginal}
|
|
}
|
|
}
|
|
}
|
|
|
|
// onePassCopy creates a copy of the original Prog, as we'll be modifying it.
|
|
func onePassCopy(prog *syntax.Prog) *onePassProg {
|
|
p := &onePassProg{
|
|
Start: prog.Start,
|
|
NumCap: prog.NumCap,
|
|
Inst: make([]onePassInst, len(prog.Inst)),
|
|
}
|
|
for i, inst := range prog.Inst {
|
|
p.Inst[i] = onePassInst{Inst: inst}
|
|
}
|
|
|
|
// rewrites one or more common Prog constructs that enable some otherwise
|
|
// non-onepass Progs to be onepass. A:BD (for example) means an InstAlt at
|
|
// ip A, that points to ips B & C.
|
|
// A:BC + B:DA => A:BC + B:CD
|
|
// A:BC + B:DC => A:DC + B:DC
|
|
for pc := range p.Inst {
|
|
switch p.Inst[pc].Op {
|
|
default:
|
|
continue
|
|
case syntax.InstAlt, syntax.InstAltMatch:
|
|
// A:Bx + B:Ay
|
|
p_A_Other := &p.Inst[pc].Out
|
|
p_A_Alt := &p.Inst[pc].Arg
|
|
// make sure a target is another Alt
|
|
instAlt := p.Inst[*p_A_Alt]
|
|
if !(instAlt.Op == syntax.InstAlt || instAlt.Op == syntax.InstAltMatch) {
|
|
p_A_Alt, p_A_Other = p_A_Other, p_A_Alt
|
|
instAlt = p.Inst[*p_A_Alt]
|
|
if !(instAlt.Op == syntax.InstAlt || instAlt.Op == syntax.InstAltMatch) {
|
|
continue
|
|
}
|
|
}
|
|
instOther := p.Inst[*p_A_Other]
|
|
// Analyzing both legs pointing to Alts is for another day
|
|
if instOther.Op == syntax.InstAlt || instOther.Op == syntax.InstAltMatch {
|
|
// too complicated
|
|
continue
|
|
}
|
|
// simple empty transition loop
|
|
// A:BC + B:DA => A:BC + B:DC
|
|
p_B_Alt := &p.Inst[*p_A_Alt].Out
|
|
p_B_Other := &p.Inst[*p_A_Alt].Arg
|
|
patch := false
|
|
if instAlt.Out == uint32(pc) {
|
|
patch = true
|
|
} else if instAlt.Arg == uint32(pc) {
|
|
patch = true
|
|
p_B_Alt, p_B_Other = p_B_Other, p_B_Alt
|
|
}
|
|
if patch {
|
|
*p_B_Alt = *p_A_Other
|
|
}
|
|
|
|
// empty transition to common target
|
|
// A:BC + B:DC => A:DC + B:DC
|
|
if *p_A_Other == *p_B_Alt {
|
|
*p_A_Alt = *p_B_Other
|
|
}
|
|
}
|
|
}
|
|
return p
|
|
}
|
|
|
|
var anyRuneNotNL = []rune{0, '\n' - 1, '\n' + 1, unicode.MaxRune}
|
|
var anyRune = []rune{0, unicode.MaxRune}
|
|
|
|
// makeOnePass creates a onepass Prog, if possible. It is possible if at any alt,
|
|
// the match engine can always tell which branch to take. The routine may modify
|
|
// p if it is turned into a onepass Prog. If it isn't possible for this to be a
|
|
// onepass Prog, the Prog nil is returned. makeOnePass is recursive
|
|
// to the size of the Prog.
|
|
func makeOnePass(p *onePassProg) *onePassProg {
|
|
// If the machine is very long, it's not worth the time to check if we can use one pass.
|
|
if len(p.Inst) >= 1000 {
|
|
return nil
|
|
}
|
|
|
|
var (
|
|
instQueue = newQueue(len(p.Inst))
|
|
visitQueue = newQueue(len(p.Inst))
|
|
check func(uint32, []bool) bool
|
|
onePassRunes = make([][]rune, len(p.Inst))
|
|
)
|
|
|
|
// check that paths from Alt instructions are unambiguous, and rebuild the new
|
|
// program as a onepass program
|
|
check = func(pc uint32, m []bool) (ok bool) {
|
|
ok = true
|
|
inst := &p.Inst[pc]
|
|
if visitQueue.contains(pc) {
|
|
return
|
|
}
|
|
visitQueue.insert(pc)
|
|
switch inst.Op {
|
|
case syntax.InstAlt, syntax.InstAltMatch:
|
|
ok = check(inst.Out, m) && check(inst.Arg, m)
|
|
// check no-input paths to InstMatch
|
|
matchOut := m[inst.Out]
|
|
matchArg := m[inst.Arg]
|
|
if matchOut && matchArg {
|
|
ok = false
|
|
break
|
|
}
|
|
// Match on empty goes in inst.Out
|
|
if matchArg {
|
|
inst.Out, inst.Arg = inst.Arg, inst.Out
|
|
matchOut, matchArg = matchArg, matchOut
|
|
}
|
|
if matchOut {
|
|
m[pc] = true
|
|
inst.Op = syntax.InstAltMatch
|
|
}
|
|
|
|
// build a dispatch operator from the two legs of the alt.
|
|
onePassRunes[pc], inst.Next = mergeRuneSets(
|
|
&onePassRunes[inst.Out], &onePassRunes[inst.Arg], inst.Out, inst.Arg)
|
|
if len(inst.Next) > 0 && inst.Next[0] == mergeFailed {
|
|
ok = false
|
|
break
|
|
}
|
|
case syntax.InstCapture, syntax.InstNop:
|
|
ok = check(inst.Out, m)
|
|
m[pc] = m[inst.Out]
|
|
// pass matching runes back through these no-ops.
|
|
onePassRunes[pc] = append([]rune{}, onePassRunes[inst.Out]...)
|
|
inst.Next = make([]uint32, len(onePassRunes[pc])/2+1)
|
|
for i := range inst.Next {
|
|
inst.Next[i] = inst.Out
|
|
}
|
|
case syntax.InstEmptyWidth:
|
|
ok = check(inst.Out, m)
|
|
m[pc] = m[inst.Out]
|
|
onePassRunes[pc] = append([]rune{}, onePassRunes[inst.Out]...)
|
|
inst.Next = make([]uint32, len(onePassRunes[pc])/2+1)
|
|
for i := range inst.Next {
|
|
inst.Next[i] = inst.Out
|
|
}
|
|
case syntax.InstMatch, syntax.InstFail:
|
|
m[pc] = inst.Op == syntax.InstMatch
|
|
case syntax.InstRune:
|
|
m[pc] = false
|
|
if len(inst.Next) > 0 {
|
|
break
|
|
}
|
|
instQueue.insert(inst.Out)
|
|
if len(inst.Rune) == 0 {
|
|
onePassRunes[pc] = []rune{}
|
|
inst.Next = []uint32{inst.Out}
|
|
break
|
|
}
|
|
runes := make([]rune, 0)
|
|
if len(inst.Rune) == 1 && syntax.Flags(inst.Arg)&syntax.FoldCase != 0 {
|
|
r0 := inst.Rune[0]
|
|
runes = append(runes, r0, r0)
|
|
for r1 := unicode.SimpleFold(r0); r1 != r0; r1 = unicode.SimpleFold(r1) {
|
|
runes = append(runes, r1, r1)
|
|
}
|
|
slices.Sort(runes)
|
|
} else {
|
|
runes = append(runes, inst.Rune...)
|
|
}
|
|
onePassRunes[pc] = runes
|
|
inst.Next = make([]uint32, len(onePassRunes[pc])/2+1)
|
|
for i := range inst.Next {
|
|
inst.Next[i] = inst.Out
|
|
}
|
|
inst.Op = syntax.InstRune
|
|
case syntax.InstRune1:
|
|
m[pc] = false
|
|
if len(inst.Next) > 0 {
|
|
break
|
|
}
|
|
instQueue.insert(inst.Out)
|
|
runes := []rune{}
|
|
// expand case-folded runes
|
|
if syntax.Flags(inst.Arg)&syntax.FoldCase != 0 {
|
|
r0 := inst.Rune[0]
|
|
runes = append(runes, r0, r0)
|
|
for r1 := unicode.SimpleFold(r0); r1 != r0; r1 = unicode.SimpleFold(r1) {
|
|
runes = append(runes, r1, r1)
|
|
}
|
|
slices.Sort(runes)
|
|
} else {
|
|
runes = append(runes, inst.Rune[0], inst.Rune[0])
|
|
}
|
|
onePassRunes[pc] = runes
|
|
inst.Next = make([]uint32, len(onePassRunes[pc])/2+1)
|
|
for i := range inst.Next {
|
|
inst.Next[i] = inst.Out
|
|
}
|
|
inst.Op = syntax.InstRune
|
|
case syntax.InstRuneAny:
|
|
m[pc] = false
|
|
if len(inst.Next) > 0 {
|
|
break
|
|
}
|
|
instQueue.insert(inst.Out)
|
|
onePassRunes[pc] = append([]rune{}, anyRune...)
|
|
inst.Next = []uint32{inst.Out}
|
|
case syntax.InstRuneAnyNotNL:
|
|
m[pc] = false
|
|
if len(inst.Next) > 0 {
|
|
break
|
|
}
|
|
instQueue.insert(inst.Out)
|
|
onePassRunes[pc] = append([]rune{}, anyRuneNotNL...)
|
|
inst.Next = make([]uint32, len(onePassRunes[pc])/2+1)
|
|
for i := range inst.Next {
|
|
inst.Next[i] = inst.Out
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
instQueue.clear()
|
|
instQueue.insert(uint32(p.Start))
|
|
m := make([]bool, len(p.Inst))
|
|
for !instQueue.empty() {
|
|
visitQueue.clear()
|
|
pc := instQueue.next()
|
|
if !check(pc, m) {
|
|
p = nil
|
|
break
|
|
}
|
|
}
|
|
if p != nil {
|
|
for i := range p.Inst {
|
|
p.Inst[i].Rune = onePassRunes[i]
|
|
}
|
|
}
|
|
return p
|
|
}
|
|
|
|
// compileOnePass returns a new *syntax.Prog suitable for onePass execution if the original Prog
|
|
// can be recharacterized as a one-pass regexp program, or syntax.nil if the
|
|
// Prog cannot be converted. For a one pass prog, the fundamental condition that must
|
|
// be true is: at any InstAlt, there must be no ambiguity about what branch to take.
|
|
func compileOnePass(prog *syntax.Prog) (p *onePassProg) {
|
|
if prog.Start == 0 {
|
|
return nil
|
|
}
|
|
// onepass regexp is anchored
|
|
if prog.Inst[prog.Start].Op != syntax.InstEmptyWidth ||
|
|
syntax.EmptyOp(prog.Inst[prog.Start].Arg)&syntax.EmptyBeginText != syntax.EmptyBeginText {
|
|
return nil
|
|
}
|
|
// every instruction leading to InstMatch must be EmptyEndText
|
|
for _, inst := range prog.Inst {
|
|
opOut := prog.Inst[inst.Out].Op
|
|
switch inst.Op {
|
|
default:
|
|
if opOut == syntax.InstMatch {
|
|
return nil
|
|
}
|
|
case syntax.InstAlt, syntax.InstAltMatch:
|
|
if opOut == syntax.InstMatch || prog.Inst[inst.Arg].Op == syntax.InstMatch {
|
|
return nil
|
|
}
|
|
case syntax.InstEmptyWidth:
|
|
if opOut == syntax.InstMatch {
|
|
if syntax.EmptyOp(inst.Arg)&syntax.EmptyEndText == syntax.EmptyEndText {
|
|
continue
|
|
}
|
|
return nil
|
|
}
|
|
}
|
|
}
|
|
// Creates a slightly optimized copy of the original Prog
|
|
// that cleans up some Prog idioms that block valid onepass programs
|
|
p = onePassCopy(prog)
|
|
|
|
// checkAmbiguity on InstAlts, build onepass Prog if possible
|
|
p = makeOnePass(p)
|
|
|
|
if p != nil {
|
|
cleanupOnePass(p, prog)
|
|
}
|
|
return p
|
|
}
|