route/vendor/github.com/asdine/storm/sink.go

609 lines
10 KiB
Go

package storm
import (
"reflect"
"sort"
"github.com/asdine/storm/index"
"github.com/asdine/storm/q"
"github.com/boltdb/bolt"
)
type item struct {
value *reflect.Value
bucket *bolt.Bucket
k []byte
v []byte
}
func newSorter(n Node, snk sink) *sorter {
return &sorter{
node: n,
sink: snk,
skip: 0,
limit: -1,
list: make([]*item, 0),
err: make(chan error),
done: make(chan struct{}),
}
}
type sorter struct {
node Node
sink sink
list []*item
skip int
limit int
orderBy []string
reverse bool
err chan error
done chan struct{}
}
func (s *sorter) filter(tree q.Matcher, bucket *bolt.Bucket, k, v []byte) (bool, error) {
itm := &item{
bucket: bucket,
k: k,
v: v,
}
rsink, ok := s.sink.(reflectSink)
if !ok {
return s.add(itm)
}
newElem := rsink.elem()
if err := s.node.Codec().Unmarshal(v, newElem.Interface()); err != nil {
return false, err
}
itm.value = &newElem
if tree != nil {
ok, err := tree.Match(newElem.Interface())
if err != nil {
return false, err
}
if !ok {
return false, nil
}
}
if len(s.orderBy) == 0 {
return s.add(itm)
}
if _, ok := s.sink.(sliceSink); ok {
// add directly to sink, we'll apply skip/limits after sorting
return false, s.sink.add(itm)
}
s.list = append(s.list, itm)
return false, nil
}
func (s *sorter) add(itm *item) (stop bool, err error) {
if s.limit == 0 {
return true, nil
}
if s.skip > 0 {
s.skip--
return false, nil
}
if s.limit > 0 {
s.limit--
}
err = s.sink.add(itm)
return s.limit == 0, err
}
func (s *sorter) compareValue(left reflect.Value, right reflect.Value) int {
if !left.IsValid() || !right.IsValid() {
if left.IsValid() {
return 1
}
return -1
}
switch left.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
l, r := left.Int(), right.Int()
if l < r {
return -1
}
if l > r {
return 1
}
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
l, r := left.Uint(), right.Uint()
if l < r {
return -1
}
if l > r {
return 1
}
case reflect.Float32, reflect.Float64:
l, r := left.Float(), right.Float()
if l < r {
return -1
}
if l > r {
return 1
}
case reflect.String:
l, r := left.String(), right.String()
if l < r {
return -1
}
if l > r {
return 1
}
default:
rawLeft, err := toBytes(left.Interface(), s.node.Codec())
if err != nil {
return -1
}
rawRight, err := toBytes(right.Interface(), s.node.Codec())
if err != nil {
return 1
}
l, r := string(rawLeft), string(rawRight)
if l < r {
return -1
}
if l > r {
return 1
}
}
return 0
}
func (s *sorter) less(leftElem reflect.Value, rightElem reflect.Value) bool {
for _, orderBy := range s.orderBy {
leftField := reflect.Indirect(leftElem).FieldByName(orderBy)
if !leftField.IsValid() {
s.err <- ErrNotFound
return false
}
rightField := reflect.Indirect(rightElem).FieldByName(orderBy)
if !rightField.IsValid() {
s.err <- ErrNotFound
return false
}
direction := 1
if s.reverse {
direction = -1
}
switch s.compareValue(leftField, rightField) * direction {
case -1:
return true
case 1:
return false
default:
continue
}
}
return false
}
func (s *sorter) flush() error {
if len(s.orderBy) == 0 {
return s.sink.flush()
}
go func() {
sort.Sort(s)
close(s.err)
}()
err := <-s.err
close(s.done)
if err != nil {
return err
}
if ssink, ok := s.sink.(sliceSink); ok {
if !ssink.slice().IsValid() {
return s.sink.flush()
}
if s.skip >= ssink.slice().Len() {
ssink.reset()
return s.sink.flush()
}
leftBound := s.skip
if leftBound < 0 {
leftBound = 0
}
limit := s.limit
if s.limit < 0 {
limit = 0
}
rightBound := leftBound + limit
if rightBound > ssink.slice().Len() || rightBound == leftBound {
rightBound = ssink.slice().Len()
}
ssink.setSlice(ssink.slice().Slice(leftBound, rightBound))
return s.sink.flush()
}
for _, itm := range s.list {
if itm == nil {
break
}
stop, err := s.add(itm)
if err != nil {
return err
}
if stop {
break
}
}
return s.sink.flush()
}
func (s *sorter) Len() int {
// skip if we encountered an earlier error
select {
case <-s.done:
return 0
default:
}
if ssink, ok := s.sink.(sliceSink); ok {
return ssink.slice().Len()
}
return len(s.list)
}
func (s *sorter) Less(i, j int) bool {
// skip if we encountered an earlier error
select {
case <-s.done:
return false
default:
}
if ssink, ok := s.sink.(sliceSink); ok {
return s.less(ssink.slice().Index(i), ssink.slice().Index(j))
}
return s.less(*s.list[i].value, *s.list[j].value)
}
type sink interface {
bucketName() string
flush() error
add(*item) error
readOnly() bool
}
type reflectSink interface {
elem() reflect.Value
}
type sliceSink interface {
slice() reflect.Value
setSlice(reflect.Value)
reset()
}
func newListSink(node Node, to interface{}) (*listSink, error) {
ref := reflect.ValueOf(to)
if ref.Kind() != reflect.Ptr || reflect.Indirect(ref).Kind() != reflect.Slice {
return nil, ErrSlicePtrNeeded
}
sliceType := reflect.Indirect(ref).Type()
elemType := sliceType.Elem()
if elemType.Kind() == reflect.Ptr {
elemType = elemType.Elem()
}
if elemType.Name() == "" {
return nil, ErrNoName
}
return &listSink{
node: node,
ref: ref,
isPtr: sliceType.Elem().Kind() == reflect.Ptr,
elemType: elemType,
name: elemType.Name(),
results: reflect.MakeSlice(reflect.Indirect(ref).Type(), 0, 0),
}, nil
}
type listSink struct {
node Node
ref reflect.Value
results reflect.Value
elemType reflect.Type
name string
isPtr bool
idx int
}
func (l *listSink) slice() reflect.Value {
return l.results
}
func (l *listSink) setSlice(s reflect.Value) {
l.results = s
}
func (l *listSink) reset() {
l.results = reflect.MakeSlice(reflect.Indirect(l.ref).Type(), 0, 0)
}
func (l *listSink) elem() reflect.Value {
if l.results.IsValid() && l.idx < l.results.Len() {
return l.results.Index(l.idx).Addr()
}
return reflect.New(l.elemType)
}
func (l *listSink) bucketName() string {
return l.name
}
func (l *listSink) add(i *item) error {
if l.idx == l.results.Len() {
if l.isPtr {
l.results = reflect.Append(l.results, *i.value)
} else {
l.results = reflect.Append(l.results, reflect.Indirect(*i.value))
}
}
l.idx++
return nil
}
func (l *listSink) flush() error {
if l.results.IsValid() && l.results.Len() > 0 {
reflect.Indirect(l.ref).Set(l.results)
return nil
}
return ErrNotFound
}
func (l *listSink) readOnly() bool {
return true
}
func newFirstSink(node Node, to interface{}) (*firstSink, error) {
ref := reflect.ValueOf(to)
if !ref.IsValid() || ref.Kind() != reflect.Ptr || ref.Elem().Kind() != reflect.Struct {
return nil, ErrStructPtrNeeded
}
return &firstSink{
node: node,
ref: ref,
}, nil
}
type firstSink struct {
node Node
ref reflect.Value
found bool
}
func (f *firstSink) elem() reflect.Value {
return reflect.New(reflect.Indirect(f.ref).Type())
}
func (f *firstSink) bucketName() string {
return reflect.Indirect(f.ref).Type().Name()
}
func (f *firstSink) add(i *item) error {
reflect.Indirect(f.ref).Set(i.value.Elem())
f.found = true
return nil
}
func (f *firstSink) flush() error {
if !f.found {
return ErrNotFound
}
return nil
}
func (f *firstSink) readOnly() bool {
return true
}
func newDeleteSink(node Node, kind interface{}) (*deleteSink, error) {
ref := reflect.ValueOf(kind)
if !ref.IsValid() || ref.Kind() != reflect.Ptr || ref.Elem().Kind() != reflect.Struct {
return nil, ErrStructPtrNeeded
}
return &deleteSink{
node: node,
ref: ref,
}, nil
}
type deleteSink struct {
node Node
ref reflect.Value
removed int
}
func (d *deleteSink) elem() reflect.Value {
return reflect.New(reflect.Indirect(d.ref).Type())
}
func (d *deleteSink) bucketName() string {
return reflect.Indirect(d.ref).Type().Name()
}
func (d *deleteSink) add(i *item) error {
info, err := extract(&d.ref)
if err != nil {
return err
}
for fieldName, fieldCfg := range info.Fields {
if fieldCfg.Index == "" {
continue
}
idx, err := getIndex(i.bucket, fieldCfg.Index, fieldName)
if err != nil {
return err
}
err = idx.RemoveID(i.k)
if err != nil {
if err == index.ErrNotFound {
return ErrNotFound
}
return err
}
}
d.removed++
return i.bucket.Delete(i.k)
}
func (d *deleteSink) flush() error {
if d.removed == 0 {
return ErrNotFound
}
return nil
}
func (d *deleteSink) readOnly() bool {
return false
}
func newCountSink(node Node, kind interface{}) (*countSink, error) {
ref := reflect.ValueOf(kind)
if !ref.IsValid() || ref.Kind() != reflect.Ptr || ref.Elem().Kind() != reflect.Struct {
return nil, ErrStructPtrNeeded
}
return &countSink{
node: node,
ref: ref,
}, nil
}
type countSink struct {
node Node
ref reflect.Value
counter int
}
func (c *countSink) elem() reflect.Value {
return reflect.New(reflect.Indirect(c.ref).Type())
}
func (c *countSink) bucketName() string {
return reflect.Indirect(c.ref).Type().Name()
}
func (c *countSink) add(i *item) error {
c.counter++
return nil
}
func (c *countSink) flush() error {
return nil
}
func (c *countSink) readOnly() bool {
return true
}
func newRawSink() *rawSink {
return &rawSink{}
}
type rawSink struct {
results [][]byte
execFn func([]byte, []byte) error
}
func (r *rawSink) add(i *item) error {
if r.execFn != nil {
err := r.execFn(i.k, i.v)
if err != nil {
return err
}
} else {
r.results = append(r.results, i.v)
}
return nil
}
func (r *rawSink) bucketName() string {
return ""
}
func (r *rawSink) flush() error {
return nil
}
func (r *rawSink) readOnly() bool {
return true
}
func newEachSink(to interface{}) (*eachSink, error) {
ref := reflect.ValueOf(to)
if !ref.IsValid() || ref.Kind() != reflect.Ptr || ref.Elem().Kind() != reflect.Struct {
return nil, ErrStructPtrNeeded
}
return &eachSink{
ref: ref,
}, nil
}
type eachSink struct {
ref reflect.Value
execFn func(interface{}) error
}
func (e *eachSink) elem() reflect.Value {
return reflect.New(reflect.Indirect(e.ref).Type())
}
func (e *eachSink) bucketName() string {
return reflect.Indirect(e.ref).Type().Name()
}
func (e *eachSink) add(i *item) error {
return e.execFn(i.value.Interface())
}
func (e *eachSink) flush() error {
return nil
}
func (e *eachSink) readOnly() bool {
return true
}