SQL select query for CSV/JSON (#6648)

select * , select column names have been implemented for CSV.
select * is implemented for JSON.

pkg/s3select/datatypes.go

@@ -0,0 +1,110 @@
+/*
+ * Minio Cloud Storage, (C) 2018 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"
+)
+
+// CSVFileHeaderInfo -Can be either USE IGNORE OR NONE, defines what to do with
+// the first row
+type CSVFileHeaderInfo string
+
+// Constants for file header info.
+const (
+	CSVFileHeaderInfoNone   CSVFileHeaderInfo = "NONE"
+	CSVFileHeaderInfoIgnore                   = "IGNORE"
+	CSVFileHeaderInfoUse                      = "USE"
+)
+
+// The maximum character per record is set to be 1 MB.
+const (
+	MaxCharsPerRecord = 1000000
+)
+
+// SelectCompressionType - ONLY GZIP is supported
+type SelectCompressionType string
+
+// JSONType determines json input serialization type.
+type JSONType string
+
+// Constants for compression types under select API.
+const (
+	SelectCompressionNONE SelectCompressionType = "NONE"
+	SelectCompressionGZIP                       = "GZIP"
+	SelectCompressionBZIP                       = "BZIP2"
+)
+
+// CSVQuoteFields - Can be either Always or AsNeeded
+type CSVQuoteFields string
+
+// Constants for csv quote styles.
+const (
+	CSVQuoteFieldsAlways   CSVQuoteFields = "Always"
+	CSVQuoteFieldsAsNeeded                = "AsNeeded"
+)
+
+// QueryExpressionType - Currently can only be SQL
+type QueryExpressionType string
+
+// Constants for expression type.
+const (
+	QueryExpressionTypeSQL QueryExpressionType = "SQL"
+)
+
+// Constants for JSONTypes.
+const (
+	JSONTypeDocument JSONType = "DOCUMENT"
+	JSONLinesType             = "LINES"
+)
+
+// ObjectSelectRequest - represents the input select body
+type ObjectSelectRequest struct {
+	XMLName            xml.Name `xml:"SelectObjectContentRequest" json:"-"`
+	Expression         string
+	ExpressionType     QueryExpressionType
+	InputSerialization struct {
+		CompressionType SelectCompressionType
+		Parquet         *struct{}
+		CSV             *struct {
+			FileHeaderInfo       CSVFileHeaderInfo
+			RecordDelimiter      string
+			FieldDelimiter       string
+			QuoteCharacter       string
+			QuoteEscapeCharacter string
+			Comments             string
+		}
+		JSON *struct {
+			Type JSONType
+		}
+	}
+	OutputSerialization struct {
+		CSV *struct {
+			QuoteFields          CSVQuoteFields
+			RecordDelimiter      string
+			FieldDelimiter       string
+			QuoteCharacter       string
+			QuoteEscapeCharacter string
+		}
+		JSON *struct {
+			RecordDelimiter string
+		}
+	}
+	RequestProgress struct {
+		Enabled bool
+	}
+}