96 lines
2.1 KiB
Go
96 lines
2.1 KiB
Go
// Copyright 2014 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// go-ethereum is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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// Package filter implements event filters.
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package filter
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import "reflect"
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type Filter interface {
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Compare(Filter) bool
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Trigger(data interface{})
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}
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type FilterEvent struct {
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filter Filter
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data interface{}
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}
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type Filters struct {
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id int
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watchers map[int]Filter
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ch chan FilterEvent
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quit chan struct{}
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}
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func New() *Filters {
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return &Filters{
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ch: make(chan FilterEvent),
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watchers: make(map[int]Filter),
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quit: make(chan struct{}),
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}
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}
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func (self *Filters) Start() {
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go self.loop()
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}
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func (self *Filters) Stop() {
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close(self.quit)
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}
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func (self *Filters) Notify(filter Filter, data interface{}) {
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self.ch <- FilterEvent{filter, data}
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}
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func (self *Filters) Install(watcher Filter) int {
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self.watchers[self.id] = watcher
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self.id++
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return self.id - 1
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}
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func (self *Filters) Uninstall(id int) {
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delete(self.watchers, id)
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}
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func (self *Filters) loop() {
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out:
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for {
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select {
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case <-self.quit:
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break out
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case event := <-self.ch:
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for _, watcher := range self.watchers {
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if reflect.TypeOf(watcher) == reflect.TypeOf(event.filter) {
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if watcher.Compare(event.filter) {
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watcher.Trigger(event.data)
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}
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}
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}
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}
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}
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}
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func (self *Filters) Match(a, b Filter) bool {
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return reflect.TypeOf(a) == reflect.TypeOf(b) && a.Compare(b)
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}
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func (self *Filters) Get(i int) Filter {
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return self.watchers[i]
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}
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