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package operation
import ( "encoding/json" "errors" "fmt" "math/rand" "net/url" "strings" "time"
"github.com/chrislusf/seaweedfs/go/util" )
type Location struct { Url string `json:"url,omitempty"` PublicUrl string `json:"publicUrl,omitempty"` } type LookupResult struct { VolumeId string `json:"volumeId,omitempty"` Locations []Location `json:"locations,omitempty"` Error string `json:"error,omitempty"` }
func (lr *LookupResult) String() string { return fmt.Sprintf("VolumeId:%s, Locations:%v, Error:%s", lr.VolumeId, lr.Locations, lr.Error) }
var ( vc VidCache // caching of volume locations, re-check if after 10 minutes
)
func Lookup(server string, vid string) (ret *LookupResult, err error) { locations, cache_err := vc.Get(vid) if cache_err != nil { if ret, err = do_lookup(server, vid); err == nil { vc.Set(vid, ret.Locations, 10*time.Minute) } } else { ret = &LookupResult{VolumeId: vid, Locations: locations} } return }
func do_lookup(server string, vid string) (*LookupResult, error) { values := make(url.Values) values.Add("volumeId", vid) jsonBlob, err := util.Post("http://"+server+"/dir/lookup", values) if err != nil { return nil, err } var ret LookupResult err = json.Unmarshal(jsonBlob, &ret) if err != nil { return nil, err } if ret.Error != "" { return nil, errors.New(ret.Error) } return &ret, nil }
func LookupFileId(server string, fileId string) (fullUrl string, err error) { parts := strings.Split(fileId, ",") if len(parts) != 2 { return "", errors.New("Invalid fileId " + fileId) } lookup, lookupError := Lookup(server, parts[0]) if lookupError != nil { return "", lookupError } if len(lookup.Locations) == 0 { return "", errors.New("File Not Found") } return "http://" + lookup.Locations[rand.Intn(len(lookup.Locations))].Url + "/" + fileId, nil }
// LookupVolumeIds find volume locations by cache and actual lookup
func LookupVolumeIds(server string, vids []string) (map[string]LookupResult, error) { ret := make(map[string]LookupResult) var unknown_vids []string
//check vid cache first
for _, vid := range vids { locations, cache_err := vc.Get(vid) if cache_err == nil { ret[vid] = LookupResult{VolumeId: vid, Locations: locations} } else { unknown_vids = append(unknown_vids, vid) } } //return success if all volume ids are known
if len(unknown_vids) == 0 { return ret, nil }
//only query unknown_vids
values := make(url.Values) for _, vid := range unknown_vids { values.Add("volumeId", vid) } jsonBlob, err := util.Post("http://"+server+"/vol/lookup", values) if err != nil { return nil, err } err = json.Unmarshal(jsonBlob, &ret) if err != nil { return nil, errors.New(err.Error() + " " + string(jsonBlob)) }
//set newly checked vids to cache
for _, vid := range unknown_vids { locations := ret[vid].Locations vc.Set(vid, locations, 10*time.Minute) }
return ret, nil }
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