rename all remaining packages to internal/ (#12418)

This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`

internal/s3select/sql/utils.go

@@ -0,0 +1,134 @@
+// 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 sql
+
+import (
+	"fmt"
+	"strings"
+)
+
+// String functions
+
+// String - returns the JSONPath representation
+func (e *JSONPath) String() string {
+	if len(e.pathString) == 0 {
+		parts := make([]string, len(e.PathExpr)+1)
+		parts[0] = e.BaseKey.String()
+		for i, pe := range e.PathExpr {
+			parts[i+1] = pe.String()
+		}
+		e.pathString = strings.Join(parts, "")
+	}
+	return e.pathString
+}
+
+// StripTableAlias removes a table alias from the path. The result is also
+// cached for repeated lookups during SQL query evaluation.
+func (e *JSONPath) StripTableAlias(tableAlias string) []*JSONPathElement {
+	if e.strippedTableAlias == tableAlias {
+		return e.strippedPathExpr
+	}
+
+	hasTableAlias := e.BaseKey.String() == tableAlias || strings.ToLower(e.BaseKey.String()) == baseTableName
+	var pathExpr []*JSONPathElement
+	if hasTableAlias {
+		pathExpr = e.PathExpr
+	} else {
+		pathExpr = make([]*JSONPathElement, len(e.PathExpr)+1)
+		pathExpr[0] = &JSONPathElement{Key: &ObjectKey{ID: e.BaseKey}}
+		copy(pathExpr[1:], e.PathExpr)
+	}
+	e.strippedTableAlias = tableAlias
+	e.strippedPathExpr = pathExpr
+	return e.strippedPathExpr
+}
+
+func (e *JSONPathElement) String() string {
+	switch {
+	case e.Key != nil:
+		return e.Key.String()
+	case e.Index != nil:
+		return fmt.Sprintf("[%d]", *e.Index)
+	case e.ObjectWildcard:
+		return ".*"
+	case e.ArrayWildcard:
+		return "[*]"
+	}
+	return ""
+}
+
+// String removes double quotes in quoted identifiers
+func (i *Identifier) String() string {
+	if i.Unquoted != nil {
+		return *i.Unquoted
+	}
+	return string(*i.Quoted)
+}
+
+func (o *ObjectKey) String() string {
+	if o.Lit != nil {
+		return fmt.Sprintf("['%s']", string(*o.Lit))
+	}
+	return fmt.Sprintf(".%s", o.ID.String())
+}
+
+func (o *ObjectKey) keyString() string {
+	if o.Lit != nil {
+		return string(*o.Lit)
+	}
+	return o.ID.String()
+}
+
+// getLastKeypathComponent checks if the given expression is a path
+// expression, and if so extracts the last dot separated component of
+// the path. Otherwise it returns false.
+func getLastKeypathComponent(e *Expression) (string, bool) {
+	if len(e.And) > 1 ||
+		len(e.And[0].Condition) > 1 ||
+		e.And[0].Condition[0].Not != nil ||
+		e.And[0].Condition[0].Operand.ConditionRHS != nil {
+		return "", false
+	}
+
+	operand := e.And[0].Condition[0].Operand.Operand
+	if operand.Right != nil ||
+		operand.Left.Right != nil ||
+		operand.Left.Left.Negated != nil ||
+		operand.Left.Left.Primary.JPathExpr == nil {
+		return "", false
+	}
+
+	// Check if path expression ends in a key
+	jpath := operand.Left.Left.Primary.JPathExpr
+	n := len(jpath.PathExpr)
+	if n > 0 && jpath.PathExpr[n-1].Key == nil {
+		return "", false
+	}
+	ps := jpath.String()
+	if idx := strings.LastIndex(ps, "."); idx >= 0 {
+		// Get last part of path string.
+		ps = ps[idx+1:]
+	}
+	return ps, true
+}
+
+// HasKeypath returns if the from clause has a key path -
+// e.g. S3object[*].id
+func (from *TableExpression) HasKeypath() bool {
+	return len(from.Table.PathExpr) > 1
+}