gotosocial/vendor/github.com/vmihailenco/msgpack/v5/decode_query.go

158 lines
2.6 KiB
Go

package msgpack
import (
"fmt"
"strconv"
"strings"
"github.com/vmihailenco/msgpack/v5/msgpcode"
)
type queryResult struct {
query string
key string
values []interface{}
hasAsterisk bool
}
func (q *queryResult) nextKey() {
ind := strings.IndexByte(q.query, '.')
if ind == -1 {
q.key = q.query
q.query = ""
return
}
q.key = q.query[:ind]
q.query = q.query[ind+1:]
}
// Query extracts data specified by the query from the msgpack stream skipping
// any other data. Query consists of map keys and array indexes separated with dot,
// e.g. key1.0.key2.
func (d *Decoder) Query(query string) ([]interface{}, error) {
res := queryResult{
query: query,
}
if err := d.query(&res); err != nil {
return nil, err
}
return res.values, nil
}
func (d *Decoder) query(q *queryResult) error {
q.nextKey()
if q.key == "" {
v, err := d.decodeInterfaceCond()
if err != nil {
return err
}
q.values = append(q.values, v)
return nil
}
code, err := d.PeekCode()
if err != nil {
return err
}
switch {
case code == msgpcode.Map16 || code == msgpcode.Map32 || msgpcode.IsFixedMap(code):
err = d.queryMapKey(q)
case code == msgpcode.Array16 || code == msgpcode.Array32 || msgpcode.IsFixedArray(code):
err = d.queryArrayIndex(q)
default:
err = fmt.Errorf("msgpack: unsupported code=%x decoding key=%q", code, q.key)
}
return err
}
func (d *Decoder) queryMapKey(q *queryResult) error {
n, err := d.DecodeMapLen()
if err != nil {
return err
}
if n == -1 {
return nil
}
for i := 0; i < n; i++ {
key, err := d.decodeStringTemp()
if err != nil {
return err
}
if key == q.key {
if err := d.query(q); err != nil {
return err
}
if q.hasAsterisk {
return d.skipNext((n - i - 1) * 2)
}
return nil
}
if err := d.Skip(); err != nil {
return err
}
}
return nil
}
func (d *Decoder) queryArrayIndex(q *queryResult) error {
n, err := d.DecodeArrayLen()
if err != nil {
return err
}
if n == -1 {
return nil
}
if q.key == "*" {
q.hasAsterisk = true
query := q.query
for i := 0; i < n; i++ {
q.query = query
if err := d.query(q); err != nil {
return err
}
}
q.hasAsterisk = false
return nil
}
ind, err := strconv.Atoi(q.key)
if err != nil {
return err
}
for i := 0; i < n; i++ {
if i == ind {
if err := d.query(q); err != nil {
return err
}
if q.hasAsterisk {
return d.skipNext(n - i - 1)
}
return nil
}
if err := d.Skip(); err != nil {
return err
}
}
return nil
}
func (d *Decoder) skipNext(n int) error {
for i := 0; i < n; i++ {
if err := d.Skip(); err != nil {
return err
}
}
return nil
}