diff options
Diffstat (limited to 'vendor/github.com/moby/patternmatcher/patternmatcher.go')
| -rw-r--r-- | vendor/github.com/moby/patternmatcher/patternmatcher.go | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/vendor/github.com/moby/patternmatcher/patternmatcher.go b/vendor/github.com/moby/patternmatcher/patternmatcher.go new file mode 100644 index 0000000..37a1a59 --- /dev/null +++ b/vendor/github.com/moby/patternmatcher/patternmatcher.go @@ -0,0 +1,474 @@ +package patternmatcher + +import ( + "errors" + "os" + "path/filepath" + "regexp" + "strings" + "text/scanner" + "unicode/utf8" +) + +// escapeBytes is a bitmap used to check whether a character should be escaped when creating the regex. +var escapeBytes [8]byte + +// shouldEscape reports whether a rune should be escaped as part of the regex. +// +// This only includes characters that require escaping in regex but are also NOT valid filepath pattern characters. +// Additionally, '\' is not excluded because there is specific logic to properly handle this, as it's a path separator +// on Windows. +// +// Adapted from regexp::QuoteMeta in go stdlib. +// See https://cs.opensource.google/go/go/+/refs/tags/go1.17.2:src/regexp/regexp.go;l=703-715;drc=refs%2Ftags%2Fgo1.17.2 +func shouldEscape(b rune) bool { + return b < utf8.RuneSelf && escapeBytes[b%8]&(1<<(b/8)) != 0 +} + +func init() { + for _, b := range []byte(`.+()|{}$`) { + escapeBytes[b%8] |= 1 << (b / 8) + } +} + +// PatternMatcher allows checking paths against a list of patterns +type PatternMatcher struct { + patterns []*Pattern + exclusions bool +} + +// New creates a new matcher object for specific patterns that can +// be used later to match against patterns against paths +func New(patterns []string) (*PatternMatcher, error) { + pm := &PatternMatcher{ + patterns: make([]*Pattern, 0, len(patterns)), + } + for _, p := range patterns { + // Eliminate leading and trailing whitespace. + p = strings.TrimSpace(p) + if p == "" { + continue + } + p = filepath.Clean(p) + newp := &Pattern{} + if p[0] == '!' { + if len(p) == 1 { + return nil, errors.New("illegal exclusion pattern: \"!\"") + } + newp.exclusion = true + p = p[1:] + pm.exclusions = true + } + // Do some syntax checking on the pattern. + // filepath's Match() has some really weird rules that are inconsistent + // so instead of trying to dup their logic, just call Match() for its + // error state and if there is an error in the pattern return it. + // If this becomes an issue we can remove this since its really only + // needed in the error (syntax) case - which isn't really critical. + if _, err := filepath.Match(p, "."); err != nil { + return nil, err + } + newp.cleanedPattern = p + newp.dirs = strings.Split(p, string(os.PathSeparator)) + pm.patterns = append(pm.patterns, newp) + } + return pm, nil +} + +// Matches returns true if "file" matches any of the patterns +// and isn't excluded by any of the subsequent patterns. +// +// The "file" argument should be a slash-delimited path. +// +// Matches is not safe to call concurrently. +// +// Deprecated: This implementation is buggy (it only checks a single parent dir +// against the pattern) and will be removed soon. Use either +// MatchesOrParentMatches or MatchesUsingParentResults instead. +func (pm *PatternMatcher) Matches(file string) (bool, error) { + matched := false + file = filepath.FromSlash(file) + parentPath := filepath.Dir(file) + parentPathDirs := strings.Split(parentPath, string(os.PathSeparator)) + + for _, pattern := range pm.patterns { + // Skip evaluation if this is an inclusion and the filename + // already matched the pattern, or it's an exclusion and it has + // not matched the pattern yet. + if pattern.exclusion != matched { + continue + } + + match, err := pattern.match(file) + if err != nil { + return false, err + } + + if !match && parentPath != "." { + // Check to see if the pattern matches one of our parent dirs. + if len(pattern.dirs) <= len(parentPathDirs) { + match, _ = pattern.match(strings.Join(parentPathDirs[:len(pattern.dirs)], string(os.PathSeparator))) + } + } + + if match { + matched = !pattern.exclusion + } + } + + return matched, nil +} + +// MatchesOrParentMatches returns true if "file" matches any of the patterns +// and isn't excluded by any of the subsequent patterns. +// +// The "file" argument should be a slash-delimited path. +// +// Matches is not safe to call concurrently. +func (pm *PatternMatcher) MatchesOrParentMatches(file string) (bool, error) { + matched := false + file = filepath.FromSlash(file) + parentPath := filepath.Dir(file) + parentPathDirs := strings.Split(parentPath, string(os.PathSeparator)) + + for _, pattern := range pm.patterns { + // Skip evaluation if this is an inclusion and the filename + // already matched the pattern, or it's an exclusion and it has + // not matched the pattern yet. + if pattern.exclusion != matched { + continue + } + + match, err := pattern.match(file) + if err != nil { + return false, err + } + + if !match && parentPath != "." { + // Check to see if the pattern matches one of our parent dirs. + for i := range parentPathDirs { + match, _ = pattern.match(strings.Join(parentPathDirs[:i+1], string(os.PathSeparator))) + if match { + break + } + } + } + + if match { + matched = !pattern.exclusion + } + } + + return matched, nil +} + +// MatchesUsingParentResult returns true if "file" matches any of the patterns +// and isn't excluded by any of the subsequent patterns. The functionality is +// the same as Matches, but as an optimization, the caller keeps track of +// whether the parent directory matched. +// +// The "file" argument should be a slash-delimited path. +// +// MatchesUsingParentResult is not safe to call concurrently. +// +// Deprecated: this function does behave correctly in some cases (see +// https://github.com/docker/buildx/issues/850). +// +// Use MatchesUsingParentResults instead. +func (pm *PatternMatcher) MatchesUsingParentResult(file string, parentMatched bool) (bool, error) { + matched := parentMatched + file = filepath.FromSlash(file) + + for _, pattern := range pm.patterns { + // Skip evaluation if this is an inclusion and the filename + // already matched the pattern, or it's an exclusion and it has + // not matched the pattern yet. + if pattern.exclusion != matched { + continue + } + + match, err := pattern.match(file) + if err != nil { + return false, err + } + + if match { + matched = !pattern.exclusion + } + } + return matched, nil +} + +// MatchInfo tracks information about parent dir matches while traversing a +// filesystem. +type MatchInfo struct { + parentMatched []bool +} + +// MatchesUsingParentResults returns true if "file" matches any of the patterns +// and isn't excluded by any of the subsequent patterns. The functionality is +// the same as Matches, but as an optimization, the caller passes in +// intermediate results from matching the parent directory. +// +// The "file" argument should be a slash-delimited path. +// +// MatchesUsingParentResults is not safe to call concurrently. +func (pm *PatternMatcher) MatchesUsingParentResults(file string, parentMatchInfo MatchInfo) (bool, MatchInfo, error) { + parentMatched := parentMatchInfo.parentMatched + if len(parentMatched) != 0 && len(parentMatched) != len(pm.patterns) { + return false, MatchInfo{}, errors.New("wrong number of values in parentMatched") + } + + file = filepath.FromSlash(file) + matched := false + + matchInfo := MatchInfo{ + parentMatched: make([]bool, len(pm.patterns)), + } + for i, pattern := range pm.patterns { + match := false + // If the parent matched this pattern, we don't need to recheck. + if len(parentMatched) != 0 { + match = parentMatched[i] + } + + if !match { + // Skip evaluation if this is an inclusion and the filename + // already matched the pattern, or it's an exclusion and it has + // not matched the pattern yet. + if pattern.exclusion != matched { + continue + } + + var err error + match, err = pattern.match(file) + if err != nil { + return false, matchInfo, err + } + + // If the zero value of MatchInfo was passed in, we don't have + // any information about the parent dir's match results, and we + // apply the same logic as MatchesOrParentMatches. + if !match && len(parentMatched) == 0 { + if parentPath := filepath.Dir(file); parentPath != "." { + parentPathDirs := strings.Split(parentPath, string(os.PathSeparator)) + // Check to see if the pattern matches one of our parent dirs. + for i := range parentPathDirs { + match, _ = pattern.match(strings.Join(parentPathDirs[:i+1], string(os.PathSeparator))) + if match { + break + } + } + } + } + } + matchInfo.parentMatched[i] = match + + if match { + matched = !pattern.exclusion + } + } + return matched, matchInfo, nil +} + +// Exclusions returns true if any of the patterns define exclusions +func (pm *PatternMatcher) Exclusions() bool { + return pm.exclusions +} + +// Patterns returns array of active patterns +func (pm *PatternMatcher) Patterns() []*Pattern { + return pm.patterns +} + +// Pattern defines a single regexp used to filter file paths. +type Pattern struct { + matchType matchType + cleanedPattern string + dirs []string + regexp *regexp.Regexp + exclusion bool +} + +type matchType int + +const ( + unknownMatch matchType = iota + exactMatch + prefixMatch + suffixMatch + regexpMatch +) + +func (p *Pattern) String() string { + return p.cleanedPattern +} + +// Exclusion returns true if this pattern defines exclusion +func (p *Pattern) Exclusion() bool { + return p.exclusion +} + +func (p *Pattern) match(path string) (bool, error) { + if p.matchType == unknownMatch { + if err := p.compile(string(os.PathSeparator)); err != nil { + return false, filepath.ErrBadPattern + } + } + + switch p.matchType { + case exactMatch: + return path == p.cleanedPattern, nil + case prefixMatch: + // strip trailing ** + return strings.HasPrefix(path, p.cleanedPattern[:len(p.cleanedPattern)-2]), nil + case suffixMatch: + // strip leading ** + suffix := p.cleanedPattern[2:] + if strings.HasSuffix(path, suffix) { + return true, nil + } + // **/foo matches "foo" + return suffix[0] == os.PathSeparator && path == suffix[1:], nil + case regexpMatch: + return p.regexp.MatchString(path), nil + } + + return false, nil +} + +func (p *Pattern) compile(sl string) error { + regStr := "^" + pattern := p.cleanedPattern + // Go through the pattern and convert it to a regexp. + // We use a scanner so we can support utf-8 chars. + var scan scanner.Scanner + scan.Init(strings.NewReader(pattern)) + + escSL := sl + if sl == `\` { + escSL += `\` + } + + p.matchType = exactMatch + for i := 0; scan.Peek() != scanner.EOF; i++ { + ch := scan.Next() + + if ch == '*' { + if scan.Peek() == '*' { + // is some flavor of "**" + scan.Next() + + // Treat **/ as ** so eat the "/" + if string(scan.Peek()) == sl { + scan.Next() + } + + if scan.Peek() == scanner.EOF { + // is "**EOF" - to align with .gitignore just accept all + if p.matchType == exactMatch { + p.matchType = prefixMatch + } else { + regStr += ".*" + p.matchType = regexpMatch + } + } else { + // is "**" + // Note that this allows for any # of /'s (even 0) because + // the .* will eat everything, even /'s + regStr += "(.*" + escSL + ")?" + p.matchType = regexpMatch + } + + if i == 0 { + p.matchType = suffixMatch + } + } else { + // is "*" so map it to anything but "/" + regStr += "[^" + escSL + "]*" + p.matchType = regexpMatch + } + } else if ch == '?' { + // "?" is any char except "/" + regStr += "[^" + escSL + "]" + p.matchType = regexpMatch + } else if shouldEscape(ch) { + // Escape some regexp special chars that have no meaning + // in golang's filepath.Match + regStr += `\` + string(ch) + } else if ch == '\\' { + // escape next char. Note that a trailing \ in the pattern + // will be left alone (but need to escape it) + if sl == `\` { + // On windows map "\" to "\\", meaning an escaped backslash, + // and then just continue because filepath.Match on + // Windows doesn't allow escaping at all + regStr += escSL + continue + } + if scan.Peek() != scanner.EOF { + regStr += `\` + string(scan.Next()) + p.matchType = regexpMatch + } else { + regStr += `\` + } + } else if ch == '[' || ch == ']' { + regStr += string(ch) + p.matchType = regexpMatch + } else { + regStr += string(ch) + } + } + + if p.matchType != regexpMatch { + return nil + } + + regStr += "$" + + re, err := regexp.Compile(regStr) + if err != nil { + return err + } + + p.regexp = re + p.matchType = regexpMatch + return nil +} + +// Matches returns true if file matches any of the patterns +// and isn't excluded by any of the subsequent patterns. +// +// This implementation is buggy (it only checks a single parent dir against the +// pattern) and will be removed soon. Use MatchesOrParentMatches instead. +func Matches(file string, patterns []string) (bool, error) { + pm, err := New(patterns) + if err != nil { + return false, err + } + file = filepath.Clean(file) + + if file == "." { + // Don't let them exclude everything, kind of silly. + return false, nil + } + + return pm.Matches(file) +} + +// MatchesOrParentMatches returns true if file matches any of the patterns +// and isn't excluded by any of the subsequent patterns. +func MatchesOrParentMatches(file string, patterns []string) (bool, error) { + pm, err := New(patterns) + if err != nil { + return false, err + } + file = filepath.Clean(file) + + if file == "." { + // Don't let them exclude everything, kind of silly. + return false, nil + } + + return pm.MatchesOrParentMatches(file) +} |