85 lines
2.2 KiB
Go
85 lines
2.2 KiB
Go
// Contains the external API side message filter for watching, pooling and polling
|
|
// matched whisper messages, also serializing data access to avoid duplications.
|
|
|
|
package xeth
|
|
|
|
import (
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
)
|
|
|
|
// whisperFilter is the message cache matching a specific filter, accumulating
|
|
// inbound messages until the are requested by the client.
|
|
type whisperFilter struct {
|
|
id int // Filter identifier for old message retrieval
|
|
ref *Whisper // Whisper reference for old message retrieval
|
|
|
|
cache []WhisperMessage // Cache of messages not yet polled
|
|
skip map[common.Hash]struct{} // List of retrieved messages to avoid duplication
|
|
update time.Time // Time of the last message query
|
|
|
|
lock sync.RWMutex // Lock protecting the filter internals
|
|
}
|
|
|
|
// newWhisperFilter creates a new serialized, poll based whisper topic filter.
|
|
func newWhisperFilter(id int, ref *Whisper) *whisperFilter {
|
|
return &whisperFilter{
|
|
id: id,
|
|
ref: ref,
|
|
|
|
update: time.Now(),
|
|
skip: make(map[common.Hash]struct{}),
|
|
}
|
|
}
|
|
|
|
// messages retrieves all the cached messages from the entire pool matching the
|
|
// filter, resetting the filter's change buffer.
|
|
func (w *whisperFilter) messages() []WhisperMessage {
|
|
w.lock.Lock()
|
|
defer w.lock.Unlock()
|
|
|
|
w.cache = nil
|
|
w.update = time.Now()
|
|
|
|
w.skip = make(map[common.Hash]struct{})
|
|
messages := w.ref.Messages(w.id)
|
|
for _, message := range messages {
|
|
w.skip[message.ref.Hash] = struct{}{}
|
|
}
|
|
return messages
|
|
}
|
|
|
|
// insert injects a new batch of messages into the filter cache.
|
|
func (w *whisperFilter) insert(messages ...WhisperMessage) {
|
|
w.lock.Lock()
|
|
defer w.lock.Unlock()
|
|
|
|
for _, message := range messages {
|
|
if _, ok := w.skip[message.ref.Hash]; !ok {
|
|
w.cache = append(w.cache, messages...)
|
|
}
|
|
}
|
|
}
|
|
|
|
// retrieve fetches all the cached messages from the filter.
|
|
func (w *whisperFilter) retrieve() (messages []WhisperMessage) {
|
|
w.lock.Lock()
|
|
defer w.lock.Unlock()
|
|
|
|
messages, w.cache = w.cache, nil
|
|
w.update = time.Now()
|
|
|
|
return
|
|
}
|
|
|
|
// activity returns the last time instance when client requests were executed on
|
|
// the filter.
|
|
func (w *whisperFilter) activity() time.Time {
|
|
w.lock.RLock()
|
|
defer w.lock.RUnlock()
|
|
|
|
return w.update
|
|
}
|