make notification as separate package (#5294)

* Remove old notification files

* Add net package

* Add event package

* Modify minio to take new notification system

pkg/event/rules.go

@@ -0,0 +1,102 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package event
+
+import (
+	"strings"
+
+	"github.com/minio/minio/pkg/wildcard"
+)
+
+// NewPattern - create new pattern for prefix/suffix.
+func NewPattern(prefix, suffix string) (pattern string) {
+	if prefix != "" {
+		if !strings.HasSuffix(prefix, "*") {
+			prefix += "*"
+		}
+
+		pattern = prefix
+	}
+
+	if suffix != "" {
+		if !strings.HasPrefix(suffix, "*") {
+			suffix = "*" + suffix
+		}
+
+		pattern += suffix
+	}
+
+	pattern = strings.Replace(pattern, "**", "*", -1)
+
+	return pattern
+}
+
+// Rules - event rules
+type Rules map[string]TargetIDSet
+
+// Add - adds pattern and target ID.
+func (rules Rules) Add(pattern string, targetID TargetID) {
+	rules[pattern] = NewTargetIDSet(targetID).Union(rules[pattern])
+}
+
+// Match - returns TargetIDSet matching object name in rules.
+func (rules Rules) Match(objectName string) TargetIDSet {
+	targetIDs := NewTargetIDSet()
+
+	for pattern, targetIDSet := range rules {
+		if wildcard.MatchSimple(pattern, objectName) {
+			targetIDs = targetIDs.Union(targetIDSet)
+		}
+	}
+
+	return targetIDs
+}
+
+// Clone - returns copy of this rules.
+func (rules Rules) Clone() Rules {
+	rulesCopy := make(Rules)
+
+	for pattern, targetIDSet := range rules {
+		rulesCopy[pattern] = targetIDSet.Clone()
+	}
+
+	return rulesCopy
+}
+
+// Union - returns union with given rules as new rules.
+func (rules Rules) Union(rules2 Rules) Rules {
+	nrules := rules.Clone()
+
+	for pattern, targetIDSet := range rules2 {
+		nrules[pattern] = nrules[pattern].Union(targetIDSet)
+	}
+
+	return nrules
+}
+
+// Difference - returns diffrence with given rules as new rules.
+func (rules Rules) Difference(rules2 Rules) Rules {
+	nrules := make(Rules)
+
+	for pattern, targetIDSet := range rules {
+		if nv := targetIDSet.Difference(rules2[pattern]); len(nv) > 0 {
+			nrules[pattern] = nv
+		}
+	}
+
+	return nrules
+}