Added old filter. Needs some refactoring

event/filter/old_filter.go

@@ -0,0 +1,94 @@
+// XXX This is the old filter system specifically for messages. This is till in used and could use some refactoring
+package filter
+
+import (
+	"sync"
+
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/state"
+)
+
+type FilterManager struct {
+	eventMux *event.TypeMux
+
+	filterMu sync.RWMutex
+	filterId int
+	filters  map[int]*core.Filter
+
+	quit chan struct{}
+}
+
+func NewFilterManager(mux *event.TypeMux) *FilterManager {
+	return &FilterManager{
+		eventMux: mux,
+		filters:  make(map[int]*core.Filter),
+	}
+}
+
+func (self *FilterManager) Start() {
+	go self.filterLoop()
+}
+
+func (self *FilterManager) Stop() {
+	close(self.quit)
+}
+
+func (self *FilterManager) InstallFilter(filter *core.Filter) (id int) {
+	self.filterMu.Lock()
+	id = self.filterId
+	self.filters[id] = filter
+	self.filterId++
+	self.filterMu.Unlock()
+	return id
+}
+
+func (self *FilterManager) UninstallFilter(id int) {
+	self.filterMu.Lock()
+	delete(self.filters, id)
+	self.filterMu.Unlock()
+}
+
+// GetFilter retrieves a filter installed using InstallFilter.
+// The filter may not be modified.
+func (self *FilterManager) GetFilter(id int) *core.Filter {
+	self.filterMu.RLock()
+	defer self.filterMu.RUnlock()
+	return self.filters[id]
+}
+
+func (self *FilterManager) filterLoop() {
+	// Subscribe to events
+	events := self.eventMux.Subscribe(core.NewBlockEvent{}, state.Messages(nil))
+
+out:
+	for {
+		select {
+		case <-self.quit:
+			break out
+		case event := <-events.Chan():
+			switch event := event.(type) {
+			case core.NewBlockEvent:
+				self.filterMu.RLock()
+				for _, filter := range self.filters {
+					if filter.BlockCallback != nil {
+						filter.BlockCallback(event.Block)
+					}
+				}
+				self.filterMu.RUnlock()
+
+			case state.Messages:
+				self.filterMu.RLock()
+				for _, filter := range self.filters {
+					if filter.MessageCallback != nil {
+						msgs := filter.FilterMessages(event)
+						if len(msgs) > 0 {
+							filter.MessageCallback(msgs)
+						}
+					}
+				}
+				self.filterMu.RUnlock()
+			}
+		}
+	}
+}