// randomize order of each listing batch
func List(ss3 s3.Interface, output *StepLocation, ch chan s3.ListedObject) {
var marker string
for {
r, err := ss3.List(s3.ListRequest{MaxKeys: 1000, Bucket: output.Bucket, Prefix: output.Prefix, Marker: marker})
if err != nil {
panic(err)
}
p := rand.Perm(len(r.Contents))
for i := 0; i < len(r.Contents); i++ {
v := r.Contents[p[i]]
ch <- s3.ListedObject{
ListBucketResultContents: v,
Bucket: output.Bucket,
}
}
if r.IsTruncated {
marker = r.Contents[len(r.Contents)-1].Key
} else {
break
}
}
close(ch)
}
// enables transactional processing of files
func LoadLines3(ss3 s3.Interface, output *StepLocation, threads int, proc FileProcessor) {
var wg sync.WaitGroup
ch := make(chan s3.ListedObject)
for i := 0; i < threads; i++ {
wg.Add(1)
go func() {
for o := range ch {
fn := o.Object().Url()
p := proc.ForFile(fn, o.Size)
for p != nil {
r, err := ss3.Get(s3.GetRequest{Object: o.Object()})
if err != nil {
if p = proc.Failure(fn, o.Size, err); p != nil {
continue
} else {
break
}
}
if strings.HasSuffix(o.Key, ".gz") {
r, err = gzip.NewReader(r)
check(err)
}
scanner := bufio.NewScanner(r)
for scanner.Scan() {
kv := ParseLine(scanner.Text())
p(&kv)
}
if err := scanner.Err(); err != nil {
r.Close()
if p = proc.Failure(fn, o.Size, err); p != nil {
continue
} else {
break
}
} else {
proc.Success(fn)
p = nil
}
r.Close()
}
}
wg.Done()
}()
}
List(ss3, output, ch)
wg.Wait()
}
func LoadLines2(ss3 s3.Interface, output *StepLocation, threads int, decider UrlDeciderFunc, f func(string, *KeyValue)) {
var wg, wg2 sync.WaitGroup
ch2 := make(chan *FileKeyValue)
ch := make(chan s3.ListedObject)
wg2.Add(1)
go func() {
for fkv := range ch2 {
f(fkv.Filename, fkv.Item)
}
wg2.Done()
}()
for i := 0; i < threads; i++ {
wg.Add(1)
go func() {
for o := range ch {
fn := o.Object().Url()
if decider(fn) {
r, err := ss3.Get(s3.GetRequest{Object: o.Object()})
check(err)
defer r.Close()
if strings.HasSuffix(o.Key, ".gz") {
r, err = gzip.NewReader(r)
check(err)
}
scanner := bufio.NewScanner(r)
for scanner.Scan() {
kv := ParseLine(scanner.Text())
ch2 <- &FileKeyValue{
Filename: fn,
Item: &kv,
}
}
if err := scanner.Err(); err != nil {
panic(err)
}
}
}
wg.Done()
}()
}
List(ss3, output, ch)
wg.Wait()
close(ch2)
wg2.Wait()
}
