From a435aa0161a8ab50d29241a8d6f578f69e7a0c06 Mon Sep 17 00:00:00 2001
From: LeeHyeonHee <ddrtocna@gmail.com>
Date: Thu, 16 May 2024 16:45:03 +0900
Subject: [PATCH] (feature) Added column case sensitivity option when reading
 parquet read

---
 reader/reader.go | 54 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 14 deletions(-)

diff --git a/reader/reader.go b/reader/reader.go
index 0c9253b6..795a19f6 100644
--- a/reader/reader.go
+++ b/reader/reader.go
@@ -17,6 +17,10 @@ import (
 	"github.com/xitongsys/parquet-go/source"
 )
 
+type ParquetReaderOptions struct {
+	CaseInsensitive bool
+}
+
 type ParquetReader struct {
 	SchemaHandler *schema.SchemaHandler
 	NP            int64 //parallel number
@@ -28,14 +32,23 @@ type ParquetReader struct {
 	//One reader can only read one type objects
 	ObjType        reflect.Type
 	ObjPartialType reflect.Type
+
+	//Determines whether case sensitivity is enabled
+	CaseInsensitive bool
 }
 
-//Create a parquet reader: obj is a object with schema tags or a JSON schema string
-func NewParquetReader(pFile source.ParquetFile, obj interface{}, np int64) (*ParquetReader, error) {
+// Create a parquet reader: obj is a object with schema tags or a JSON schema string
+func NewParquetReader(pFile source.ParquetFile, obj interface{}, np int64, opts ...ParquetReaderOptions) (*ParquetReader, error) {
+	var caseInsensitive bool
+	if len(opts) > 0 {
+		caseInsensitive = opts[0].CaseInsensitive
+	}
+
 	var err error
 	res := new(ParquetReader)
 	res.NP = np
 	res.PFile = pFile
+	res.CaseInsensitive = caseInsensitive
 	if err = res.ReadFooter(); err != nil {
 		return nil, err
 	}
@@ -95,19 +108,32 @@ func (pr *ParquetReader) SetSchemaHandlerFromJSON(jsonSchema string) error {
 	return nil
 }
 
-//Rename schema name to inname
+// Rename schema name to inname
 func (pr *ParquetReader) RenameSchema() {
 	for i := 0; i < len(pr.SchemaHandler.Infos); i++ {
 		pr.Footer.Schema[i].Name = pr.SchemaHandler.Infos[i].InName
 	}
+
+	exPathToInPath := make(map[string]string)
+	if pr.CaseInsensitive {
+		for exPath, inPath := range pr.SchemaHandler.ExPathToInPath {
+			lowerCaseKey := strings.ToLower(exPath)
+			exPathToInPath[lowerCaseKey] = inPath
+		}
+	} else {
+		exPathToInPath = pr.SchemaHandler.ExPathToInPath
+	}
+
 	for _, rowGroup := range pr.Footer.RowGroups {
 		for _, chunk := range rowGroup.Columns {
-			exPath := make([]string, 0)
-			exPath = append(exPath, pr.SchemaHandler.GetRootExName())
-			exPath = append(exPath, chunk.MetaData.GetPathInSchema()...)
+			exPath := append([]string{pr.SchemaHandler.GetRootExName()}, chunk.MetaData.GetPathInSchema()...)
 			exPathStr := common.PathToStr(exPath)
 
-			inPathStr := pr.SchemaHandler.ExPathToInPath[exPathStr]
+			if pr.CaseInsensitive {
+				exPathStr = strings.ToLower(exPathStr)
+			}
+
+			inPathStr := exPathToInPath[exPathStr]
 			inPath := common.StrToPath(inPathStr)[1:]
 			chunk.MetaData.PathInSchema = inPath
 		}
@@ -118,7 +144,7 @@ func (pr *ParquetReader) GetNumRows() int64 {
 	return pr.Footer.GetNumRows()
 }
 
-//Get the footer size
+// Get the footer size
 func (pr *ParquetReader) GetFooterSize() (uint32, error) {
 	var err error
 	buf := make([]byte, 4)
@@ -132,7 +158,7 @@ func (pr *ParquetReader) GetFooterSize() (uint32, error) {
 	return size, err
 }
 
-//Read footer from parquet file
+// Read footer from parquet file
 func (pr *ParquetReader) ReadFooter() error {
 	size, err := pr.GetFooterSize()
 	if err != nil {
@@ -149,7 +175,7 @@ func (pr *ParquetReader) ReadFooter() error {
 	return pr.Footer.Read(context.TODO(), protocol)
 }
 
-//Skip rows of parquet file
+// Skip rows of parquet file
 func (pr *ParquetReader) SkipRows(num int64) error {
 	var err error
 	if num <= 0 {
@@ -195,7 +221,7 @@ func (pr *ParquetReader) SkipRows(num int64) error {
 	return err
 }
 
-//Read rows of parquet file and unmarshal all to dst
+// Read rows of parquet file and unmarshal all to dst
 func (pr *ParquetReader) Read(dstInterface interface{}) error {
 	return pr.read(dstInterface, "")
 }
@@ -226,7 +252,7 @@ func (pr *ParquetReader) ReadByNumber(maxReadNumber int) ([]interface{}, error)
 	return ret, nil
 }
 
-//Read rows of parquet file and unmarshal all to dst
+// Read rows of parquet file and unmarshal all to dst
 func (pr *ParquetReader) ReadPartial(dstInterface interface{}, prefixPath string) error {
 	prefixPath, err := pr.SchemaHandler.ConvertToInPathStr(prefixPath)
 	if err != nil {
@@ -262,7 +288,7 @@ func (pr *ParquetReader) ReadPartialByNumber(maxReadNumber int, prefixPath strin
 	return ret, nil
 }
 
-//Read rows of parquet file with a prefixPath
+// Read rows of parquet file with a prefixPath
 func (pr *ParquetReader) read(dstInterface interface{}, prefixPath string) error {
 	var err error
 	tmap := make(map[string]*layout.Table)
@@ -352,7 +378,7 @@ func (pr *ParquetReader) read(dstInterface interface{}, prefixPath string) error
 	return err
 }
 
-//Stop Read
+// Stop Read
 func (pr *ParquetReader) ReadStop() {
 	for _, cb := range pr.ColumnBuffers {
 		if cb != nil {