rpc, ui/qt/qwhisper, whisper, xeth: introduce complex topic filters

whisper/filter.go

@@ -2,12 +2,55 @@
 
 package whisper
 
-import "crypto/ecdsa"
+import (
+	"crypto/ecdsa"
+
+	"github.com/ethereum/go-ethereum/event/filter"
+)
 
 // Filter is used to subscribe to specific types of whisper messages.
 type Filter struct {
-	To     *ecdsa.PublicKey // Recipient of the message
-	From   *ecdsa.PublicKey // Sender of the message
-	Topics []Topic          // Topics to watch messages on
-	Fn     func(*Message)   // Handler in case of a match
+	To     *ecdsa.PublicKey   // Recipient of the message
+	From   *ecdsa.PublicKey   // Sender of the message
+	Topics [][]Topic          // Topics to filter messages with
+	Fn     func(msg *Message) // Handler in case of a match
+}
+
+// filterer is the internal, fully initialized filter ready to match inbound
+// messages to a variety of criteria.
+type filterer struct {
+	to      string                 // Recipient of the message
+	from    string                 // Sender of the message
+	matcher *topicMatcher          // Topics to filter messages with
+	fn      func(data interface{}) // Handler in case of a match
+}
+
+// Compare checks if the specified filter matches the current one.
+func (self filterer) Compare(f filter.Filter) bool {
+	filter := f.(filterer)
+
+	// Check the message sender and recipient
+	if len(self.to) > 0 && self.to != filter.to {
+		return false
+	}
+	if len(self.from) > 0 && self.from != filter.from {
+		return false
+	}
+	// Check the topic filtering
+	topics := make([]Topic, len(filter.matcher.conditions))
+	for i, group := range filter.matcher.conditions {
+		// Message should contain a single topic entry, extract
+		for topics[i], _ = range group {
+			break
+		}
+	}
+	if !self.matcher.Matches(topics) {
+		return false
+	}
+	return true
+}
+
+// Trigger is called when a filter successfully matches an inbound message.
+func (self filterer) Trigger(data interface{}) {
+	self.fn(data)
 }