Add ORDER BY selecting for clients

pkg/auth/krb5.go

@@ -3,13 +3,14 @@
 import (
 	"encoding/hex"
 	"fmt"
+	"log"
+
 	"github.com/jackc/pgx/v5/pgproto3"
 	"github.com/jcmturner/gokrb5/v8/credentials"
 	"github.com/jcmturner/gokrb5/v8/gssapi"
 	"github.com/jcmturner/gokrb5/v8/keytab"
 	"github.com/jcmturner/gokrb5/v8/service"
 	"github.com/pg-sharding/spqr/pkg/client"
-	"log"
 )
 
 type BaseAuthModule struct {
@@ -91,12 +92,12 @@
 	if status.Code != gssapi.StatusComplete && status.Code != gssapi.StatusContinueNeeded {
 		errText := fmt.Sprintf("Kerberos validation error: %v", status)
 		log.Print(errText)
 		return nil, fmt.Errorf(errText)
 	}
 	if status.Code == gssapi.StatusContinueNeeded {
 		errText := "Kerberos GSS-API continue needed"
 		log.Print(errText)
-		return nil, fmt.Errorf(errText)
+		return nil, fmt.Errorf("%s", errText)
 	}
 	if authed {
 		ctx := st.Context()
@@ -105,6 +106,6 @@
 	} else {
 		errText := "Kerberos authentication failed"
 		log.Print(errText)
 		return nil, fmt.Errorf(errText)
 	}
 }

pkg/clientinteractor/interactor.go

@@ -720,16 +720,17 @@ func GetColumnsMap(desc TableDesc) map[string]int {
 //
 // Returns:
 // - error: An error if any occurred during the operation.
-func (pi *PSQLInteractor) Clients(ctx context.Context, clients []client.ClientInfo, condition spqrparser.WhereClauseNode) error {
+func (pi *PSQLInteractor) Clients(ctx context.Context, clients []client.ClientInfo, query *spqrparser.Show) error {
 	desc := ClientDesc{}
 	header := desc.GetHeader()
 	rowDesc := GetColumnsMap(desc)
-
+	condition := query.Where
+	order := query.Order
 	if err := pi.WriteHeader(header...); err != nil {
 		spqrlog.Zero.Error().Err(err).Msg("")
 		return err
 	}
-
+	var data [][]string
 	for _, cl := range clients {
 		if len(cl.Shards()) > 0 {
 			for _, sh := range cl.Shards() {
@@ -745,11 +746,7 @@ func (pi *PSQLInteractor) Clients(ctx context.Context, clients []client.ClientIn
 				if !match {
 					continue
 				}
-
-				if err := pi.WriteDataRow(row...); err != nil {
-					spqrlog.Zero.Error().Err(err).Msg("")
-					return err
-				}
+				data = append(data, row)
 			}
 		} else {
 			row := desc.GetRow(cl, "no backend connection", cl.RAddr())
@@ -762,17 +759,58 @@ func (pi *PSQLInteractor) Clients(ctx context.Context, clients []client.ClientIn
 				continue
 			}
 
-			if err := pi.WriteDataRow(row...); err != nil {
-				spqrlog.Zero.Error().Err(err).Msg("")
-				return err
-			}
+			data = append(data, row)
 		}
 
 	}
+	switch order.(type) {
+	case spqrparser.Order:
+		ord := order.(spqrparser.Order)
+		var asc_desc int
 
+		switch ord.OptAscDesc.(type) {
+		case spqrparser.SortByAsc:
+			asc_desc = ASC
+		case spqrparser.SortByDesc:
+			asc_desc = DESC
+		case spqrparser.SortByDefault:
+			asc_desc = ASC
+		default:
+			return fmt.Errorf("wrong sorting option (asc/desc)")
+		}
+		sortable := SortableWithContext{data, rowDesc[ord.Col.ColName], asc_desc}
+		sort.Sort(sortable)
+	}
+	for i := 0; i < len(data); i++ {
+		if err := pi.WriteDataRow(data[i]...); err != nil {
+			spqrlog.Zero.Error().Err(err).Msg("")
+			return err
+		}
+	}
 	return pi.CompleteMsg(len(clients))
 }
 
+const (
+	ASC = iota
+	DESC
+)
+
+type SortableWithContext struct {
+	Data      [][]string
+	Col_index int
+	Order     int
+}
+
+func (a SortableWithContext) Len() int      { return len(a.Data) }
+func (a SortableWithContext) Swap(i, j int) { a.Data[i], a.Data[j] = a.Data[j], a.Data[i] }
+func (a SortableWithContext) Less(i, j int) bool {
+	if a.Order == ASC {
+		return a.Data[i][a.Col_index] < a.Data[j][a.Col_index]
+	} else {
+		return a.Data[i][a.Col_index] > a.Data[j][a.Col_index]
+	}
+}
+
 // TODO : unit tests
 
 // Distributions sends distribution data to the PSQL client.

pkg/clientinteractor/interactor_test.go

@@ -1,9 +1,11 @@
 package clientinteractor_test
 
 import (
+	"sort"
+	"testing"
+
 	"github.com/golang/mock/gomock"
 	mock "github.com/pg-sharding/spqr/pkg/mock/clientinteractor"
-	"testing"
 
 	"github.com/stretchr/testify/assert"
 
@@ -175,3 +177,11 @@ func TestGetColumnsMap(t *testing.T) {
 	}
 
 }
+
+func TestSortableWithContext(t *testing.T) {
+	data := [][]string{[]string{"a", "b"}, []string{"b", "a"}}
+	rev_data := [][]string{[]string{"b", "a"}, []string{"a", "b"}}
+	sortable := clientinteractor.SortableWithContext{data, 0, clientinteractor.DESC}
+	sort.Sort(sortable)
+	assert.Equal(t, data, rev_data)
+}

pkg/meta/meta.go

@@ -489,7 +489,7 @@ func ProcessShow(ctx context.Context, stmt *spqrparser.Show, mngr EntityMgr, ci
 			return err
 		}
 
-		return cli.Clients(ctx, resp, stmt.Where)
+		return cli.Clients(ctx, resp, stmt)
 	case spqrparser.PoolsStr:
 		var respPools []pool.Pool
 		if err := ci.ForEachPool(func(p pool.Pool) error {

pkg/models/spqrerror/spqrerror.go

@@ -79,7 +79,7 @@ type SpqrError struct {
 //   - *SpqrError: The created SpqrError.
 func New(errorCode string, errorMsg string) *SpqrError {
 	err := &SpqrError{
-		Err:       fmt.Errorf(errorMsg),
+		Err:       fmt.Errorf("%s", errorMsg),
 		ErrorCode: errorCode,
 	}
 	return err
@@ -95,7 +95,7 @@ func New(errorCode string, errorMsg string) *SpqrError {
 //   - *SpqrError: The created SpqrError.
 func NewByCode(errorCode string) *SpqrError {
 	err := &SpqrError{
-		Err:       fmt.Errorf(GetMessageByCode(errorCode)),
+		Err:       fmt.Errorf("%s", GetMessageByCode(errorCode)),
 		ErrorCode: errorCode,
 	}
 	return err

router/statistics/query_time_statistics.go

@@ -38,7 +38,8 @@ var queryStatistics = statistics{
 
 func InitStatistics(q []float64) {
 	queryStatistics.Quantiles = q
-	if queryStatistics.Quantiles != nil && len(queryStatistics.Quantiles) > 0 {
+
+	if len(queryStatistics.Quantiles) > 0 { // also not nil
 		queryStatistics.NeedToCollectData = false
 	} else {
 		queryStatistics.NeedToCollectData = true

yacc/console/ast.go

@@ -4,6 +4,24 @@ type ColumnRef struct {
 	TableAlias string
 	ColName    string
 }
+type OptAscDesc interface{}
+
+type SortByDefault struct {
+	OptAscDesc
+}
+type SortByAsc struct {
+	OptAscDesc
+}
+type SortByDesc struct {
+	OptAscDesc
+}
+type OrderClause interface{}
+
+type Order struct {
+	OrderClause
+	OptAscDesc OptAscDesc
+	Col        ColumnRef
+}
 
 type WhereClauseNode interface {
 }
@@ -31,6 +49,7 @@ type WhereClauseOp struct {
 type Show struct {
 	Cmd   string
 	Where WhereClauseNode
+	Order OrderClause
 }
 
 type Set struct {