status-im/status-go

package rpcfilters

import (
    "errors"
    "sync"
    "time"

    "github.com/ethereum/go-ethereum/common"
)

type hashFilter struct {
    hashes []common.Hash
    mu     sync.Mutex
    done   chan struct{}
    timer  *time.Timer
}

// add adds a hash to the hashFilter
func (f *hashFilter) add(data interface{}) error {
    hash, ok := data.(common.Hash)
    if !ok {
        return errors.New("provided data is not a common.Hash")
    }
    f.mu.Lock()
    defer f.mu.Unlock()
    f.hashes = append(f.hashes, hash)
    return nil
}

// pop returns all the hashes stored in the hashFilter and clears the hashFilter contents
func (f *hashFilter) pop() interface{} {
    f.mu.Lock()
    defer f.mu.Unlock()
    hashes := f.hashes
    f.hashes = nil
    return hashes
}

func (f *hashFilter) stop() {
    select {
    case <-f.done:
        return
    default:
        close(f.done)
    }
}

func (f *hashFilter) deadline() *time.Timer {
    return f.timer
}

func newHashFilter() *hashFilter {
    return &hashFilter{
        done: make(chan struct{}),
    }
}