plugeth/whisper/filter.go

57 lines
1.6 KiB
Go

// Contains the message filter for fine grained subscriptions.
package whisper
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
}
// 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)
}