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authormsglm <msglm@techchud.xyz>2023-10-27 07:08:25 -0500
committermsglm <msglm@techchud.xyz>2023-10-27 07:08:25 -0500
commit032a7e0c1188d3507b8d9a9571f2446a43cf775b (patch)
tree2bd38c01bc7761a6195e426082ce7191ebc765a1 /vendor/github.com/tidwall/match/match.go
parent56e7bd01ca09ad52b0c4f48f146a20a4f1b78696 (diff)
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apply https://github.com/42wim/matterbridge/pull/1864v1.26.0+0.1.0
Diffstat (limited to 'vendor/github.com/tidwall/match/match.go')
-rw-r--r--vendor/github.com/tidwall/match/match.go237
1 files changed, 237 insertions, 0 deletions
diff --git a/vendor/github.com/tidwall/match/match.go b/vendor/github.com/tidwall/match/match.go
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index 00000000..11da28f1
--- /dev/null
+++ b/vendor/github.com/tidwall/match/match.go
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+// Package match provides a simple pattern matcher with unicode support.
+package match
+
+import (
+ "unicode/utf8"
+)
+
+// Match returns true if str matches pattern. This is a very
+// simple wildcard match where '*' matches on any number characters
+// and '?' matches on any one character.
+//
+// pattern:
+// { term }
+// term:
+// '*' matches any sequence of non-Separator characters
+// '?' matches any single non-Separator character
+// c matches character c (c != '*', '?', '\\')
+// '\\' c matches character c
+//
+func Match(str, pattern string) bool {
+ if pattern == "*" {
+ return true
+ }
+ return match(str, pattern, 0, nil, -1) == rMatch
+}
+
+// MatchLimit is the same as Match but will limit the complexity of the match
+// operation. This is to avoid long running matches, specifically to avoid ReDos
+// attacks from arbritary inputs.
+//
+// How it works:
+// The underlying match routine is recursive and may call itself when it
+// encounters a sandwiched wildcard pattern, such as: `user:*:name`.
+// Everytime it calls itself a counter is incremented.
+// The operation is stopped when counter > maxcomp*len(str).
+func MatchLimit(str, pattern string, maxcomp int) (matched, stopped bool) {
+ if pattern == "*" {
+ return true, false
+ }
+ counter := 0
+ r := match(str, pattern, len(str), &counter, maxcomp)
+ if r == rStop {
+ return false, true
+ }
+ return r == rMatch, false
+}
+
+type result int
+
+const (
+ rNoMatch result = iota
+ rMatch
+ rStop
+)
+
+func match(str, pat string, slen int, counter *int, maxcomp int) result {
+ // check complexity limit
+ if maxcomp > -1 {
+ if *counter > slen*maxcomp {
+ return rStop
+ }
+ *counter++
+ }
+
+ for len(pat) > 0 {
+ var wild bool
+ pc, ps := rune(pat[0]), 1
+ if pc > 0x7f {
+ pc, ps = utf8.DecodeRuneInString(pat)
+ }
+ var sc rune
+ var ss int
+ if len(str) > 0 {
+ sc, ss = rune(str[0]), 1
+ if sc > 0x7f {
+ sc, ss = utf8.DecodeRuneInString(str)
+ }
+ }
+ switch pc {
+ case '?':
+ if ss == 0 {
+ return rNoMatch
+ }
+ case '*':
+ // Ignore repeating stars.
+ for len(pat) > 1 && pat[1] == '*' {
+ pat = pat[1:]
+ }
+
+ // If this star is the last character then it must be a match.
+ if len(pat) == 1 {
+ return rMatch
+ }
+
+ // Match and trim any non-wildcard suffix characters.
+ var ok bool
+ str, pat, ok = matchTrimSuffix(str, pat)
+ if !ok {
+ return rNoMatch
+ }
+
+ // Check for single star again.
+ if len(pat) == 1 {
+ return rMatch
+ }
+
+ // Perform recursive wildcard search.
+ r := match(str, pat[1:], slen, counter, maxcomp)
+ if r != rNoMatch {
+ return r
+ }
+ if len(str) == 0 {
+ return rNoMatch
+ }
+ wild = true
+ default:
+ if ss == 0 {
+ return rNoMatch
+ }
+ if pc == '\\' {
+ pat = pat[ps:]
+ pc, ps = utf8.DecodeRuneInString(pat)
+ if ps == 0 {
+ return rNoMatch
+ }
+ }
+ if sc != pc {
+ return rNoMatch
+ }
+ }
+ str = str[ss:]
+ if !wild {
+ pat = pat[ps:]
+ }
+ }
+ if len(str) == 0 {
+ return rMatch
+ }
+ return rNoMatch
+}
+
+// matchTrimSuffix matches and trims any non-wildcard suffix characters.
+// Returns the trimed string and pattern.
+//
+// This is called because the pattern contains extra data after the wildcard
+// star. Here we compare any suffix characters in the pattern to the suffix of
+// the target string. Basically a reverse match that stops when a wildcard
+// character is reached. This is a little trickier than a forward match because
+// we need to evaluate an escaped character in reverse.
+//
+// Any matched characters will be trimmed from both the target
+// string and the pattern.
+func matchTrimSuffix(str, pat string) (string, string, bool) {
+ // It's expected that the pattern has at least two bytes and the first byte
+ // is a wildcard star '*'
+ match := true
+ for len(str) > 0 && len(pat) > 1 {
+ pc, ps := utf8.DecodeLastRuneInString(pat)
+ var esc bool
+ for i := 0; ; i++ {
+ if pat[len(pat)-ps-i-1] != '\\' {
+ if i&1 == 1 {
+ esc = true
+ ps++
+ }
+ break
+ }
+ }
+ if pc == '*' && !esc {
+ match = true
+ break
+ }
+ sc, ss := utf8.DecodeLastRuneInString(str)
+ if !((pc == '?' && !esc) || pc == sc) {
+ match = false
+ break
+ }
+ str = str[:len(str)-ss]
+ pat = pat[:len(pat)-ps]
+ }
+ return str, pat, match
+}
+
+var maxRuneBytes = [...]byte{244, 143, 191, 191}
+
+// Allowable parses the pattern and determines the minimum and maximum allowable
+// values that the pattern can represent.
+// When the max cannot be determined, 'true' will be returned
+// for infinite.
+func Allowable(pattern string) (min, max string) {
+ if pattern == "" || pattern[0] == '*' {
+ return "", ""
+ }
+
+ minb := make([]byte, 0, len(pattern))
+ maxb := make([]byte, 0, len(pattern))
+ var wild bool
+ for i := 0; i < len(pattern); i++ {
+ if pattern[i] == '*' {
+ wild = true
+ break
+ }
+ if pattern[i] == '?' {
+ minb = append(minb, 0)
+ maxb = append(maxb, maxRuneBytes[:]...)
+ } else {
+ minb = append(minb, pattern[i])
+ maxb = append(maxb, pattern[i])
+ }
+ }
+ if wild {
+ r, n := utf8.DecodeLastRune(maxb)
+ if r != utf8.RuneError {
+ if r < utf8.MaxRune {
+ r++
+ if r > 0x7f {
+ b := make([]byte, 4)
+ nn := utf8.EncodeRune(b, r)
+ maxb = append(maxb[:len(maxb)-n], b[:nn]...)
+ } else {
+ maxb = append(maxb[:len(maxb)-n], byte(r))
+ }
+ }
+ }
+ }
+ return string(minb), string(maxb)
+}
+
+// IsPattern returns true if the string is a pattern.
+func IsPattern(str string) bool {
+ for i := 0; i < len(str); i++ {
+ if str[i] == '*' || str[i] == '?' {
+ return true
+ }
+ }
+ return false
+}