forgejo/vendor/github.com/pingcap/tidb/sessionctx/variable/session.go
Thomas Boerger b6a95a8cb3 Integrate public as bindata optionally (#293)
* Dropped unused codekit config

* Integrated dynamic and static bindata for public

* Ignore public bindata

* Add a general generate make task

* Integrated flexible public assets into web command

* Updated vendoring, added all missiong govendor deps

* Made the linter happy with the bindata and dynamic code

* Moved public bindata definition to modules directory

* Ignoring the new bindata path now

* Updated to the new public modules import path

* Updated public bindata command and drop the new prefix
2016-11-30 00:26:36 +08:00

144 lines
4.3 KiB
Go

// Copyright 2015 PingCAP, 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package variable
import (
"github.com/pingcap/tidb/context"
)
// SessionVars is to handle user-defined or global variables in current session.
type SessionVars struct {
// user-defined variables
Users map[string]string
// system variables
Systems map[string]string
// prepared statement
PreparedStmts map[uint32]interface{}
PreparedStmtNameToID map[string]uint32
// prepared statement auto increment id
preparedStmtID uint32
// following variables are special for current session
Status uint16
LastInsertID uint64
AffectedRows uint64
// Client capability
ClientCapability uint32
// Connection ID
ConnectionID uint64
// Found rows
FoundRows uint64
// Current user
User string
}
// sessionVarsKeyType is a dummy type to avoid naming collision in context.
type sessionVarsKeyType int
// String defines a Stringer function for debugging and pretty printing.
func (k sessionVarsKeyType) String() string {
return "session_vars"
}
const sessionVarsKey sessionVarsKeyType = 0
// BindSessionVars creates a session vars object and binds it to context.
func BindSessionVars(ctx context.Context) {
v := &SessionVars{
Users: make(map[string]string),
Systems: make(map[string]string),
PreparedStmts: make(map[uint32]interface{}),
PreparedStmtNameToID: make(map[string]uint32),
}
ctx.SetValue(sessionVarsKey, v)
}
// GetSessionVars gets the session vars from context.
func GetSessionVars(ctx context.Context) *SessionVars {
v, ok := ctx.Value(sessionVarsKey).(*SessionVars)
if !ok {
return nil
}
return v
}
const (
characterSetConnection = "character_set_connection"
collationConnection = "collation_connection"
)
// GetCharsetInfo gets charset and collation for current context.
// What character set should the server translate a statement to after receiving it?
// For this, the server uses the character_set_connection and collation_connection system variables.
// It converts statements sent by the client from character_set_client to character_set_connection
// (except for string literals that have an introducer such as _latin1 or _utf8).
// collation_connection is important for comparisons of literal strings.
// For comparisons of strings with column values, collation_connection does not matter because columns
// have their own collation, which has a higher collation precedence.
// See: https://dev.mysql.com/doc/refman/5.7/en/charset-connection.html
func GetCharsetInfo(ctx context.Context) (charset, collation string) {
sessionVars := GetSessionVars(ctx)
charset = sessionVars.Systems[characterSetConnection]
collation = sessionVars.Systems[collationConnection]
return
}
// SetLastInsertID saves the last insert id to the session context.
// TODO: we may store the result for last_insert_id sys var later.
func (s *SessionVars) SetLastInsertID(insertID uint64) {
s.LastInsertID = insertID
}
// SetAffectedRows saves the affected rows to the session context.
func (s *SessionVars) SetAffectedRows(affectedRows uint64) {
s.AffectedRows = affectedRows
}
// AddAffectedRows adds affected rows with the argument rows.
func (s *SessionVars) AddAffectedRows(rows uint64) {
s.AffectedRows += rows
}
// AddFoundRows adds found rows with the argument rows.
func (s *SessionVars) AddFoundRows(rows uint64) {
s.FoundRows += rows
}
// SetStatusFlag sets the session server status variable.
// If on is ture sets the flag in session status,
// otherwise removes the flag.
func (s *SessionVars) SetStatusFlag(flag uint16, on bool) {
if on {
s.Status |= flag
return
}
s.Status &= (^flag)
}
// GetNextPreparedStmtID generates and returns the next session scope prepared statement id.
func (s *SessionVars) GetNextPreparedStmtID() uint32 {
s.preparedStmtID++
return s.preparedStmtID
}
// SetCurrentUser saves the current user to the session context.
func (s *SessionVars) SetCurrentUser(user string) {
s.User = user
}