1 files changed, 132 insertions, 0 deletions
diff --git a/whisper/whisperv2/filter.go b/whisper/whisperv2/filter.go
new file mode 100644
index 000000000..8ce4a54fb
--- /dev/null
+++ b/whisper/whisperv2/filter.go
@@ -0,0 +1,132 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Contains the message filter for fine grained subscriptions.
+
+package whisperv2
+
+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 filter messages with
+	Fn     func(msg *Message) // Handler in case of a match
+}
+
+// NewFilterTopics creates a 2D topic array used by whisper.Filter from binary
+// data elements.
+func NewFilterTopics(data ...[][]byte) [][]Topic {
+	filter := make([][]Topic, len(data))
+	for i, condition := range data {
+		// Handle the special case of condition == [[]byte{}]
+		if len(condition) == 1 && len(condition[0]) == 0 {
+			filter[i] = []Topic{}
+			continue
+		}
+		// Otherwise flatten normally
+		filter[i] = NewTopics(condition...)
+	}
+	return filter
+}
+
+// NewFilterTopicsFlat creates a 2D topic array used by whisper.Filter from flat
+// binary data elements.
+func NewFilterTopicsFlat(data ...[]byte) [][]Topic {
+	filter := make([][]Topic, len(data))
+	for i, element := range data {
+		// Only add non-wildcard topics
+		filter[i] = make([]Topic, 0, 1)
+		if len(element) > 0 {
+			filter[i] = append(filter[i], NewTopic(element))
+		}
+	}
+	return filter
+}
+
+// NewFilterTopicsFromStrings creates a 2D topic array used by whisper.Filter
+// from textual data elements.
+func NewFilterTopicsFromStrings(data ...[]string) [][]Topic {
+	filter := make([][]Topic, len(data))
+	for i, condition := range data {
+		// Handle the special case of condition == [""]
+		if len(condition) == 1 && condition[0] == "" {
+			filter[i] = []Topic{}
+			continue
+		}
+		// Otherwise flatten normally
+		filter[i] = NewTopicsFromStrings(condition...)
+	}
+	return filter
+}
+
+// NewFilterTopicsFromStringsFlat creates a 2D topic array used by whisper.Filter from flat
+// binary data elements.
+func NewFilterTopicsFromStringsFlat(data ...string) [][]Topic {
+	filter := make([][]Topic, len(data))
+	for i, element := range data {
+		// Only add non-wildcard topics
+		filter[i] = make([]Topic, 0, 1)
+		if element != "" {
+			filter[i] = append(filter[i], NewTopicFromString(element))
+		}
+	}
+	return filter
+}
+
+// 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)
+}