func (p *Backend) Query(param specs.RrdQuery,
resp *specs.RrdResp) (err error) {
var (
e *cacheEntry
rrds []*specs.RRDData
ret []*specs.RRDData
)
statInc(ST_RPC_SERV_QUERY, 1)
e, err = p.queryGetCacheEntry(¶m, resp)
if err != nil {
return err
}
rrds, ret, err = p.queryGetData(¶m, resp, e)
if err != nil {
statInc(ST_RPC_SERV_QUERY_ITEM, len(resp.Vs))
return err
}
ret = queryPruneCache(ret, e, param.Start, param.End)
ret = queryMergeData(rrds, ret, param.Start, param.End, int64(e.e.step))
resp.Vs = queryPruneRet(ret, param.Start, param.End, int64(e.e.step))
statInc(ST_RPC_SERV_QUERY_ITEM, len(resp.Vs))
return nil
}
func (p *Backend) queryGetData(param *specs.RrdQuery, resp *specs.RrdResp,
e *cacheEntry) (rrds, caches []*specs.RRDData, err error) {
flag := atomic.LoadUint32(&e.flag)
caches, _ = e._getData(uint32(e.e.commitId), uint32(e.e.dataId))
if !p.Migrate.Disabled && flag&RRD_F_MISS != 0 {
node, _ := p.storageMigrateConsistent.Get(param.Id())
done := make(chan error, 1)
res := &specs.RrdRespCsum{}
p.storageNetTaskCh[node] <- &netTask{
Method: NET_TASK_M_QUERY,
Done: done,
Args: param,
Reply: res,
}
<-done
// fetch data from remote
rrds = res.Values
} else {
// read data from local rrd file
rrds, _ = p.taskRrdFetch(e.hashkey(), param.ConsolFun,
param.Start, param.End, int(e.e.step))
}
// larger than rra1point range, skip merge
now := p.timeNow()
if param.Start < now-now%int64(e.e.step)-RRA1PointCnt*int64(e.e.step) {
resp.Vs = rrds
return nil, nil, errors.New("skip merge")
}
// no cached caches, do not merge
if len(caches) < 1 {
resp.Vs = rrds
return nil, nil, errors.New("no caches")
}
return rrds, caches, nil
}
func (p *Backend) queryGetCacheEntry(param *specs.RrdQuery,
resp *specs.RrdResp) (*cacheEntry, error) {
// form empty response
resp.Vs = []*specs.RRDData{}
resp.Host = param.Host
resp.Name = param.Name
e := p.cache.get(param.Csum())
if e == nil {
return nil, specs.ErrNoent
}
resp.Type = e.typ()
resp.Step = int(e.e.step)
param.Start = param.Start - param.Start%int64(resp.Step)
param.End = param.End - param.End%int64(resp.Step) + int64(resp.Step)
if param.End-param.Start-int64(resp.Step) < 1 {
return nil, specs.ErrParam
}
return e, nil
}