reflector.go/store/cloudfront_ro.go
2020-11-04 16:03:45 -05:00

105 lines
2.7 KiB
Go

package store
import (
"io"
"io/ioutil"
"net/http"
"time"
"github.com/lbryio/reflector.go/internal/metrics"
"github.com/lbryio/reflector.go/meta"
"github.com/lbryio/lbry.go/v2/extras/errors"
"github.com/lbryio/lbry.go/v2/stream"
log "github.com/sirupsen/logrus"
)
// CloudFrontROStore reads from cloudfront. All writes panic.
type CloudFrontROStore struct {
endpoint string // cloudflare endpoint
}
// NewCloudFrontROStore returns an initialized CloudFrontROStore store pointer.
func NewCloudFrontROStore(endpoint string) *CloudFrontROStore {
return &CloudFrontROStore{endpoint: endpoint}
}
const nameCloudFrontRO = "cloudfront_ro"
// Name is the cache type name
func (c *CloudFrontROStore) Name() string { return nameCloudFrontRO }
// Has checks if the hash is in the store.
func (c *CloudFrontROStore) Has(hash string) (bool, error) {
status, body, err := c.cfRequest(http.MethodHead, hash)
if err != nil {
return false, err
}
defer body.Close()
switch status {
case http.StatusNotFound, http.StatusForbidden:
return false, nil
case http.StatusOK:
return true, nil
default:
return false, errors.Err("unexpected status %d", status)
}
}
// Get gets the blob from Cloudfront.
func (c *CloudFrontROStore) Get(hash string) (stream.Blob, error) {
log.Debugf("Getting %s from S3", hash[:8])
defer func(t time.Time) {
log.Debugf("Getting %s from S3 took %s", hash[:8], time.Since(t).String())
}(time.Now())
status, body, err := c.cfRequest(http.MethodGet, hash)
if err != nil {
return nil, err
}
defer body.Close()
switch status {
case http.StatusNotFound, http.StatusForbidden:
return nil, errors.Err(ErrBlobNotFound)
case http.StatusOK:
b, err := ioutil.ReadAll(body)
if err != nil {
return nil, errors.Err(err)
}
metrics.MtrInBytesS3.Add(float64(len(b)))
return b, nil
default:
return nil, errors.Err("unexpected status %d", status)
}
}
func (c *CloudFrontROStore) cfRequest(method, hash string) (int, io.ReadCloser, error) {
url := c.endpoint + hash
req, err := http.NewRequest(method, url, nil)
if err != nil {
return 0, nil, errors.Err(err)
}
req.Header.Add("User-Agent", "reflector.go/"+meta.Version)
res, err := http.DefaultClient.Do(req)
if err != nil {
return 0, nil, errors.Err(err)
}
return res.StatusCode, res.Body, nil
}
func (c *CloudFrontROStore) Put(_ string, _ stream.Blob) error {
panic("CloudFrontROStore cannot do writes. Use CloudFrontRWStore")
}
func (c *CloudFrontROStore) PutSD(_ string, _ stream.Blob) error {
panic("CloudFrontROStore cannot do writes. Use CloudFrontRWStore")
}
func (c *CloudFrontROStore) Delete(_ string) error {
panic("CloudFrontROStore cannot do writes. Use CloudFrontRWStore")
}