Initial commit

Initial public review release v0.10.0

lib/acl/match.go

@@ -0,0 +1,94 @@
+package acl
+
+import (
+	"github.com/nspcc-dev/neofs-api-go/acl"
+)
+
+// Maps MatchType to corresponding function.
+// 1st argument of function - header value, 2nd - header filter.
+var mMatchFns = map[acl.MatchType]func(acl.Header, acl.Header) bool{
+	acl.StringEqual: stringEqual,
+
+	acl.StringNotEqual: stringNotEqual,
+}
+
+const (
+	mResUndefined = iota
+	mResMatch
+	mResMismatch
+)
+
+// MatchFilters checks if passed source carry at least one header that satisfies passed filters.
+//
+// Nil header does not satisfy any filter. Any header does not satisfy nil filter.
+//
+// Returns mResMismatch if passed TypedHeaderSource is nil.
+// Returns mResMatch if passed filters are empty.
+//
+// If headers for some of the HeaderType could not be composed, mResUndefined returns.
+func MatchFilters(src TypedHeaderSource, filters []acl.HeaderFilter) int {
+	if src == nil {
+		return mResMismatch
+	} else if len(filters) == 0 {
+		return mResMatch
+	}
+
+	matched := 0
+
+	for _, filter := range filters {
+		// prevent NPE
+		if filter == nil {
+			continue
+		}
+
+		headers, ok := src.HeadersOfType(filter.HeaderType())
+		if !ok {
+			return mResUndefined
+		}
+
+		// get headers of filtering type
+		for _, header := range headers {
+			// prevent NPE
+			if header == nil {
+				continue
+			}
+
+			// check header name
+			if header.Name() != filter.Name() {
+				continue
+			}
+
+			// get match function
+			matchFn, ok := mMatchFns[filter.MatchType()]
+			if !ok {
+				continue
+			}
+
+			// check match
+			if !matchFn(header, filter) {
+				continue
+			}
+
+			// increment match counter
+			matched++
+
+			break
+		}
+	}
+
+	res := mResMismatch
+
+	if matched >= len(filters) {
+		res = mResMatch
+	}
+
+	return res
+}
+
+func stringEqual(header, filter acl.Header) bool {
+	return header.Value() == filter.Value()
+}
+
+func stringNotEqual(header, filter acl.Header) bool {
+	return header.Value() != filter.Value()
+}