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