pkg/subsystem: restructure the package

Remove the entity and match subpackages.

Regenerate the linux.go file.

1 files changed, 73 insertions, 0 deletions

diff --git a/pkg/subsystem/match.go b/pkg/subsystem/match.go
new file mode 100644
index 000000000..ad5d3a257
--- /dev/null
+++ b/pkg/subsystem/match.go
@@ -0,0 +1,73 @@
+// Copyright 2023 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package subsystem
+
+import (
+	"regexp"
+	"strings"
+)
+
+type PathMatcher struct {
+	matches []*match
+}
+
+type match struct {
+	include *regexp.Regexp
+	exclude *regexp.Regexp
+	object  *Subsystem
+}
+
+func MakePathMatcher(list []*Subsystem) *PathMatcher {
+	m := &PathMatcher{}
+	for _, item := range list {
+		m.register(item)
+	}
+	return m
+}
+
+func (p *PathMatcher) register(item *Subsystem) {
+	onlyInclude := []string{}
+	list := []PathRule{}
+	for _, r := range item.PathRules {
+		if r.ExcludeRegexp == "" {
+			// It's expected that almost everything will go to this branch.
+			onlyInclude = append(onlyInclude, r.IncludeRegexp)
+		} else {
+			list = append(list, r)
+		}
+	}
+	if len(onlyInclude) > 0 {
+		list = append(list, PathRule{
+			IncludeRegexp: strings.Join(onlyInclude, "|"),
+		})
+	}
+	for _, rule := range list {
+		p.matches = append(p.matches, buildMatch(rule, item))
+	}
+}
+
+func (p *PathMatcher) Match(path string) []*Subsystem {
+	ret := []*Subsystem{}
+	for _, m := range p.matches {
+		if m.exclude != nil && m.exclude.MatchString(path) {
+			continue
+		}
+		if m.include != nil && !m.include.MatchString(path) {
+			continue
+		}
+		ret = append(ret, m.object)
+	}
+	return ret
+}
+
+func buildMatch(rule PathRule, item *Subsystem) *match {
+	m := &match{object: item}
+	if rule.IncludeRegexp != "" {
+		m.include = regexp.MustCompile(rule.IncludeRegexp)
+	}
+	if rule.ExcludeRegexp != "" {
+		m.exclude = regexp.MustCompile(rule.ExcludeRegexp)
+	}
+	return m
+}