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Copy pathselect.go
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432 lines (361 loc) · 11.3 KB
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/*
* Minio Cloud Storage, (C) 2019 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package s3select
import (
"encoding/xml"
"fmt"
"io"
"net/http"
"strings"
"github.com/minio/minio/pkg/s3select/csv"
"github.com/minio/minio/pkg/s3select/json"
"github.com/minio/minio/pkg/s3select/parquet"
"github.com/minio/minio/pkg/s3select/sql"
)
type recordReader interface {
Read() (sql.Record, error)
Close() error
}
const (
csvFormat = "csv"
jsonFormat = "json"
parquetFormat = "parquet"
)
// CompressionType - represents value inside <CompressionType/> in request XML.
type CompressionType string
const (
noneType CompressionType = "none"
gzipType CompressionType = "gzip"
bzip2Type CompressionType = "bzip2"
)
const (
maxRecordSize = 1 << 20 // 1 MiB
)
// UnmarshalXML - decodes XML data.
func (c *CompressionType) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
var s string
if err := d.DecodeElement(&s, &start); err != nil {
return errMalformedXML(err)
}
parsedType := CompressionType(strings.ToLower(s))
if s == "" {
parsedType = noneType
}
switch parsedType {
case noneType, gzipType, bzip2Type:
default:
return errInvalidCompressionFormat(fmt.Errorf("invalid compression format '%v'", s))
}
*c = parsedType
return nil
}
// InputSerialization - represents elements inside <InputSerialization/> in request XML.
type InputSerialization struct {
CompressionType CompressionType `xml:"CompressionType"`
CSVArgs csv.ReaderArgs `xml:"CSV"`
JSONArgs json.ReaderArgs `xml:"JSON"`
ParquetArgs parquet.ReaderArgs `xml:"Parquet"`
unmarshaled bool
format string
}
// IsEmpty - returns whether input serialization is empty or not.
func (input *InputSerialization) IsEmpty() bool {
return !input.unmarshaled
}
// UnmarshalXML - decodes XML data.
func (input *InputSerialization) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
// Make subtype to avoid recursive UnmarshalXML().
type subInputSerialization InputSerialization
parsedInput := subInputSerialization{}
if err := d.DecodeElement(&parsedInput, &start); err != nil {
return errMalformedXML(err)
}
// If no compression is specified, set to noneType
if parsedInput.CompressionType == CompressionType("") {
parsedInput.CompressionType = noneType
}
found := 0
if !parsedInput.CSVArgs.IsEmpty() {
parsedInput.format = csvFormat
found++
}
if !parsedInput.JSONArgs.IsEmpty() {
parsedInput.format = jsonFormat
found++
}
if !parsedInput.ParquetArgs.IsEmpty() {
if parsedInput.CompressionType != "" && parsedInput.CompressionType != noneType {
return errInvalidRequestParameter(fmt.Errorf("CompressionType must be NONE for Parquet format"))
}
parsedInput.format = parquetFormat
found++
}
if found != 1 {
return errInvalidDataSource(nil)
}
*input = InputSerialization(parsedInput)
input.unmarshaled = true
return nil
}
// OutputSerialization - represents elements inside <OutputSerialization/> in request XML.
type OutputSerialization struct {
CSVArgs csv.WriterArgs `xml:"CSV"`
JSONArgs json.WriterArgs `xml:"JSON"`
unmarshaled bool
format string
}
// IsEmpty - returns whether output serialization is empty or not.
func (output *OutputSerialization) IsEmpty() bool {
return !output.unmarshaled
}
// UnmarshalXML - decodes XML data.
func (output *OutputSerialization) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
// Make subtype to avoid recursive UnmarshalXML().
type subOutputSerialization OutputSerialization
parsedOutput := subOutputSerialization{}
if err := d.DecodeElement(&parsedOutput, &start); err != nil {
return errMalformedXML(err)
}
found := 0
if !parsedOutput.CSVArgs.IsEmpty() {
parsedOutput.format = csvFormat
found++
}
if !parsedOutput.JSONArgs.IsEmpty() {
parsedOutput.format = jsonFormat
found++
}
if found != 1 {
return errObjectSerializationConflict(fmt.Errorf("either CSV or JSON should be present in OutputSerialization"))
}
*output = OutputSerialization(parsedOutput)
output.unmarshaled = true
return nil
}
// RequestProgress - represents elements inside <RequestProgress/> in request XML.
type RequestProgress struct {
Enabled bool `xml:"Enabled"`
}
// S3Select - filters the contents on a simple structured query language (SQL) statement. It
// represents elements inside <SelectRequest/> in request XML specified in detail at
// https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectSELECTContent.html.
type S3Select struct {
XMLName xml.Name `xml:"SelectRequest"`
Expression string `xml:"Expression"`
ExpressionType string `xml:"ExpressionType"`
Input InputSerialization `xml:"InputSerialization"`
Output OutputSerialization `xml:"OutputSerialization"`
Progress RequestProgress `xml:"RequestProgress"`
statement *sql.SelectStatement
progressReader *progressReader
recordReader recordReader
}
var (
legacyXMLName = "SelectObjectContentRequest"
)
// UnmarshalXML - decodes XML data.
func (s3Select *S3Select) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
// S3 also supports the older SelectObjectContentRequest tag,
// though it is no longer found in documentation. This is
// checked and renamed below to allow older clients to also
// work.
if start.Name.Local == legacyXMLName {
start.Name = xml.Name{Space: "", Local: "SelectRequest"}
}
// Make subtype to avoid recursive UnmarshalXML().
type subS3Select S3Select
parsedS3Select := subS3Select{}
if err := d.DecodeElement(&parsedS3Select, &start); err != nil {
if _, ok := err.(*s3Error); ok {
return err
}
return errMalformedXML(err)
}
parsedS3Select.ExpressionType = strings.ToLower(parsedS3Select.ExpressionType)
if parsedS3Select.ExpressionType != "sql" {
return errInvalidExpressionType(fmt.Errorf("invalid expression type '%v'", parsedS3Select.ExpressionType))
}
if parsedS3Select.Input.IsEmpty() {
return errMissingRequiredParameter(fmt.Errorf("InputSerialization must be provided"))
}
if parsedS3Select.Output.IsEmpty() {
return errMissingRequiredParameter(fmt.Errorf("OutputSerialization must be provided"))
}
statement, err := sql.ParseSelectStatement(parsedS3Select.Expression)
if err != nil {
return err
}
parsedS3Select.statement = &statement
*s3Select = S3Select(parsedS3Select)
return nil
}
func (s3Select *S3Select) outputRecord() sql.Record {
switch s3Select.Output.format {
case csvFormat:
return csv.NewRecord()
case jsonFormat:
return json.NewRecord(sql.SelectFmtJSON)
}
panic(fmt.Errorf("unknown output format '%v'", s3Select.Output.format))
}
func (s3Select *S3Select) getProgress() (bytesScanned, bytesProcessed int64) {
if s3Select.progressReader != nil {
return s3Select.progressReader.Stats()
}
return -1, -1
}
// Open - opens S3 object by using callback for SQL selection query.
// Currently CSV, JSON and Apache Parquet formats are supported.
func (s3Select *S3Select) Open(getReader func(offset, length int64) (io.ReadCloser, error)) error {
switch s3Select.Input.format {
case csvFormat:
rc, err := getReader(0, -1)
if err != nil {
return err
}
s3Select.progressReader, err = newProgressReader(rc, s3Select.Input.CompressionType)
if err != nil {
return err
}
s3Select.recordReader, err = csv.NewReader(s3Select.progressReader, &s3Select.Input.CSVArgs)
if err != nil {
return err
}
return nil
case jsonFormat:
rc, err := getReader(0, -1)
if err != nil {
return err
}
s3Select.progressReader, err = newProgressReader(rc, s3Select.Input.CompressionType)
if err != nil {
return err
}
s3Select.recordReader = json.NewReader(s3Select.progressReader, &s3Select.Input.JSONArgs)
return nil
case parquetFormat:
var err error
s3Select.recordReader, err = parquet.NewReader(getReader, &s3Select.Input.ParquetArgs)
return err
}
panic(fmt.Errorf("unknown input format '%v'", s3Select.Input.format))
}
func (s3Select *S3Select) marshal(record sql.Record) ([]byte, error) {
switch s3Select.Output.format {
case csvFormat:
data, err := record.MarshalCSV([]rune(s3Select.Output.CSVArgs.FieldDelimiter)[0])
if err != nil {
return nil, err
}
return append(data, []byte(s3Select.Output.CSVArgs.RecordDelimiter)...), nil
case jsonFormat:
data, err := record.MarshalJSON()
if err != nil {
return nil, err
}
return append(data, []byte(s3Select.Output.JSONArgs.RecordDelimiter)...), nil
}
panic(fmt.Errorf("unknown output format '%v'", s3Select.Output.format))
}
// Evaluate - filters and sends records read from opened reader as per select statement to http response writer.
func (s3Select *S3Select) Evaluate(w http.ResponseWriter) {
getProgressFunc := s3Select.getProgress
if !s3Select.Progress.Enabled {
getProgressFunc = nil
}
writer := newMessageWriter(w, getProgressFunc)
var inputRecord sql.Record
var outputRecord sql.Record
var err error
var data []byte
sendRecord := func() bool {
if outputRecord == nil {
return true
}
if data, err = s3Select.marshal(outputRecord); err != nil {
return false
}
if len(data) > maxRecordSize {
writer.FinishWithError("OverMaxRecordSize", "The length of a record in the input or result is greater than maxCharsPerRecord of 1 MB.")
return false
}
if err = writer.SendRecord(data); err != nil {
// FIXME: log this error.
err = nil
return false
}
return true
}
for {
if s3Select.statement.LimitReached() {
if err = writer.Finish(s3Select.getProgress()); err != nil {
// FIXME: log this error.
err = nil
}
break
}
if inputRecord, err = s3Select.recordReader.Read(); err != nil {
if err != io.EOF {
break
}
if s3Select.statement.IsAggregated() {
outputRecord = s3Select.outputRecord()
if err = s3Select.statement.AggregateResult(outputRecord); err != nil {
break
}
if !sendRecord() {
break
}
}
if err = writer.Finish(s3Select.getProgress()); err != nil {
// FIXME: log this error.
err = nil
}
break
}
if inputRecord, err = s3Select.statement.EvalFrom(s3Select.Input.format, inputRecord); err != nil {
break
}
if s3Select.statement.IsAggregated() {
if err = s3Select.statement.AggregateRow(inputRecord); err != nil {
break
}
} else {
outputRecord = s3Select.outputRecord()
if outputRecord, err = s3Select.statement.Eval(inputRecord, outputRecord); err != nil {
break
}
if !sendRecord() {
break
}
}
}
if err != nil {
_ = writer.FinishWithError("InternalError", err.Error())
}
}
// Close - closes opened S3 object.
func (s3Select *S3Select) Close() error {
return s3Select.recordReader.Close()
}
// NewS3Select - creates new S3Select by given request XML reader.
func NewS3Select(r io.Reader) (*S3Select, error) {
s3Select := &S3Select{}
if err := xml.NewDecoder(r).Decode(s3Select); err != nil {
return nil, err
}
return s3Select, nil
}