depot/packages/networking/ipfs-cluster/informer/numpin/numpin.go

124 lines
2.5 KiB
Go

// Package numpin implements an ipfs-cluster informer which determines how many
// items this peer is pinning and returns it as api.Metric
package numpin
import (
"context"
"fmt"
"sync"
"github.com/ipfs-cluster/ipfs-cluster/api"
rpc "github.com/libp2p/go-libp2p-gorpc"
"go.opencensus.io/trace"
)
// MetricName specifies the name of our metric
var MetricName = "numpin"
// Informer is a simple object to implement the ipfscluster.Informer
// and Component interfaces
type Informer struct {
config *Config
mu sync.Mutex
rpcClient *rpc.Client
}
// NewInformer returns an initialized Informer.
func NewInformer(cfg *Config) (*Informer, error) {
err := cfg.Validate()
if err != nil {
return nil, err
}
return &Informer{
config: cfg,
}, nil
}
// SetClient provides us with an rpc.Client which allows
// contacting other components in the cluster.
func (npi *Informer) SetClient(c *rpc.Client) {
npi.mu.Lock()
npi.rpcClient = c
npi.mu.Unlock()
}
// Shutdown is called on cluster shutdown. We just invalidate
// any metrics from this point.
func (npi *Informer) Shutdown(ctx context.Context) error {
_, span := trace.StartSpan(ctx, "informer/numpin/Shutdown")
defer span.End()
npi.mu.Lock()
npi.rpcClient = nil
npi.mu.Unlock()
return nil
}
// Name returns the name of this informer
func (npi *Informer) Name() string {
return MetricName
}
// GetMetrics contacts the IPFSConnector component and requests the `pin ls`
// command. We return the number of pins in IPFS. It must always return at
// least one metric.
func (npi *Informer) GetMetrics(ctx context.Context) []api.Metric {
ctx, span := trace.StartSpan(ctx, "informer/numpin/GetMetric")
defer span.End()
npi.mu.Lock()
rpcClient := npi.rpcClient
npi.mu.Unlock()
if rpcClient == nil {
return []api.Metric{
{
Valid: false,
},
}
}
// make use of the RPC API to obtain information
// about the number of pins in IPFS. See RPCAPI docs.
in := make(chan []string, 1)
in <- []string{"recursive", "direct"}
close(in)
out := make(chan api.IPFSPinInfo, 1024)
errCh := make(chan error, 1)
go func() {
defer close(errCh)
err := rpcClient.Stream(
ctx,
"", // Local call
"IPFSConnector", // Service name
"PinLs", // Method name
in,
out,
)
errCh <- err
}()
n := 0
for range out {
n++
}
err := <-errCh
valid := err == nil
m := api.Metric{
Name: MetricName,
Value: fmt.Sprintf("%d", n),
Valid: valid,
Partitionable: false,
}
m.SetTTL(npi.config.MetricTTL)
return []api.Metric{m}
}