// Copyright (c) 2015-2021 MinIO, Inc.//// This file is part of MinIO Object Storage stack//// This program is free software: you can redistribute it and/or modify// it under the terms of the GNU Affero General Public License as published by// the Free Software Foundation, either version 3 of the License, or// (at your option) any later version.//// This program is distributed in the hope that it will be useful// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the// GNU Affero General Public License for more details.//// You should have received a copy of the GNU Affero General Public License// along with this program. If not, see <http://www.gnu.org/licenses/>.package jsonimport ( "io" "sync" "github.com/minio/minio/internal/s3select/sql" "github.com/bcicen/jstream")// Reader - JSON record reader for S3Select.type Reader struct { args *ReaderArgs decoder *jstream.Decoder valueCh chan *jstream.MetaValue readCloser io.ReadCloser}// Read - reads single record.func (r *Reader) Read(dst sql.Record) (sql.Record, error) { v, ok := <-r.valueCh if !ok { if err := r.decoder.Err(); err != nil { return nil, errJSONParsingError(err) } return nil, io.EOF } var kvs jstream.KVS if v.ValueType == jstream.Object { // This is a JSON object type (that preserves key // order) kvs = v.Value.(jstream.KVS) } else { // To be AWS S3 compatible Select for JSON needs to // output non-object JSON as single column value // i.e. a map with `_1` as key and value as the // non-object. kvs = jstream.KVS{jstream.KV{Key: "_1", Value: v.Value}} } dstRec, ok := dst.(*Record) if !ok { dstRec = &Record{} } dstRec.KVS = kvs dstRec.SelectFormat = sql.SelectFmtJSON return dstRec, nil}// Close - closes underlying reader.func (r *Reader) Close() error { // Close the input. err := r.readCloser.Close() for range r.valueCh { // Drain values so we don't leak a goroutine. // Since we have closed the input, it should fail rather quickly. } return err}// NewReader - creates new JSON reader using readCloser.func NewReader(readCloser io.ReadCloser, args *ReaderArgs) *Reader { readCloser = &syncReadCloser{rc: readCloser} d := jstream.NewDecoder(readCloser, 0).ObjectAsKVS() return &Reader{ args: args, decoder: d, valueCh: d.Stream(), readCloser: readCloser, }}// syncReadCloser will wrap a readcloser and make it safe to call Close while// reads are running.type syncReadCloser struct { rc io.ReadCloser mu sync.Mutex}func (pr *syncReadCloser) Read(p []byte) (n int, err error) { // This ensures that Close will block until Read has completed. // This allows another goroutine to close the reader. pr.mu.Lock() defer pr.mu.Unlock() if pr.rc == nil { return 0, io.EOF } return pr.rc.Read(p)}func (pr *syncReadCloser) Close() error { pr.mu.Lock() defer pr.mu.Unlock() if pr.rc != nil { err := pr.rc.Close() pr.rc = nil return err } return nil}
// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package json
import (
"io"
"sync"
"github.com/minio/minio/internal/s3select/sql"
"github.com/bcicen/jstream"
)
// Reader - JSON record reader for S3Select.
type Reader struct {
args *ReaderArgs
decoder *jstream.Decoder
valueCh chan *jstream.MetaValue
readCloser io.ReadCloser
}
// Read - reads single record.
func (r *Reader) Read(dst sql.Record) (sql.Record, error) {
v, ok := <-r.valueCh
if !ok {
if err := r.decoder.Err(); err != nil {
return nil, errJSONParsingError(err)
}
return nil, io.EOF
}
var kvs jstream.KVS
if v.ValueType == jstream.Object {
// This is a JSON object type (that preserves key
// order)
kvs = v.Value.(jstream.KVS)
} else {
// To be AWS S3 compatible Select for JSON needs to
// output non-object JSON as single column value
// i.e. a map with `_1` as key and value as the
// non-object.
kvs = jstream.KVS{jstream.KV{Key: "_1", Value: v.Value}}
}
dstRec, ok := dst.(*Record)
if !ok {
dstRec = &Record{}
}
dstRec.KVS = kvs
dstRec.SelectFormat = sql.SelectFmtJSON
return dstRec, nil
}
// Close - closes underlying reader.
func (r *Reader) Close() error {
// Close the input.
err := r.readCloser.Close()
for range r.valueCh {
// Drain values so we don't leak a goroutine.
// Since we have closed the input, it should fail rather quickly.
}
return err
}
// NewReader - creates new JSON reader using readCloser.
func NewReader(readCloser io.ReadCloser, args *ReaderArgs) *Reader {
readCloser = &syncReadCloser{rc: readCloser}
d := jstream.NewDecoder(readCloser, 0).ObjectAsKVS()
return &Reader{
args: args,
decoder: d,
valueCh: d.Stream(),
readCloser: readCloser,
}
}
// syncReadCloser will wrap a readcloser and make it safe to call Close while
// reads are running.
type syncReadCloser struct {
rc io.ReadCloser
mu sync.Mutex
}
func (pr *syncReadCloser) Read(p []byte) (n int, err error) {
// This ensures that Close will block until Read has completed.
// This allows another goroutine to close the reader.
pr.mu.Lock()
defer pr.mu.Unlock()
if pr.rc == nil {
return 0, io.EOF
}
return pr.rc.Read(p)
}
func (pr *syncReadCloser) Close() error {
pr.mu.Lock()
defer pr.mu.Unlock()
if pr.rc != nil {
err := pr.rc.Close()
pr.rc = nil
return err
}
return nil
}