示例#1
0
文件: compiler.go 项目: XuHuaiyu/tidb
// Compile compiles an ast.StmtNode to a stmt.Statement.
// If it is supported to use new plan and executer, it optimizes the node to
// a plan, and we wrap the plan in an adapter as stmt.Statement.
// If it is not supported, the node will be converted to old statement.
func (c *Compiler) Compile(ctx context.Context, node ast.StmtNode) (ast.Statement, error) {
	ast.SetFlag(node)
	if _, ok := node.(*ast.UpdateStmt); ok {
		sVars := variable.GetSessionVars(ctx)
		sVars.InUpdateStmt = true
		defer func() {
			sVars.InUpdateStmt = false
		}()
	}

	is := sessionctx.GetDomain(ctx).InfoSchema()
	if err := plan.Preprocess(node, is, ctx); err != nil {
		return nil, errors.Trace(err)
	}
	// Validate should be after NameResolve.
	if err := plan.Validate(node, false); err != nil {
		return nil, errors.Trace(err)
	}
	sb := NewSubQueryBuilder(is)

	p, err := plan.Optimize(ctx, node, sb, is)
	if err != nil {
		return nil, errors.Trace(err)
	}
	_, isDDL := node.(ast.DDLNode)
	sa := &statement{
		is:    is,
		plan:  p,
		text:  node.Text(),
		isDDL: isDDL,
	}
	return sa, nil
}
示例#2
0
文件: prepared.go 项目: anywhy/tidb
// Build builds a prepared statement into an executor.
func (e *ExecuteExec) Build() error {
	vars := variable.GetSessionVars(e.Ctx)
	if e.Name != "" {
		e.ID = vars.PreparedStmtNameToID[e.Name]
	}
	v := vars.PreparedStmts[e.ID]
	if v == nil {
		return ErrStmtNotFound
	}
	prepared := v.(*Prepared)

	if len(prepared.Params) != len(e.UsingVars) {
		return ErrWrongParamCount
	}

	for i, usingVar := range e.UsingVars {
		val, err := evaluator.Eval(e.Ctx, usingVar)
		if err != nil {
			return errors.Trace(err)
		}
		prepared.Params[i].SetDatum(val)
	}

	ast.ResetEvaluatedFlag(prepared.Stmt)
	if prepared.SchemaVersion != e.IS.SchemaMetaVersion() {
		// If the schema version has changed we need to prepare it again,
		// if this time it failed, the real reason for the error is schema changed.
		err := plan.PrepareStmt(e.IS, e.Ctx, prepared.Stmt)
		if err != nil {
			return ErrSchemaChanged.Gen("Schema change casued error: %s", err.Error())
		}
		prepared.SchemaVersion = e.IS.SchemaMetaVersion()
	}
	sb := &subqueryBuilder{is: e.IS}
	p, err := plan.Optimize(e.Ctx, prepared.Stmt, sb, e.IS)
	if err != nil {
		return errors.Trace(err)
	}
	b := newExecutorBuilder(e.Ctx, e.IS)
	stmtExec := b.build(p)
	if b.err != nil {
		return errors.Trace(b.err)
	}
	e.StmtExec = stmtExec
	e.Stmt = prepared.Stmt
	return nil
}
示例#3
0
// Compile compiles an ast.StmtNode to an ast.Statement.
// After preprocessed and validated, it will be optimized to a plan,
// then wrappped to an adapter *statement as stmt.Statement.
func (c *Compiler) Compile(ctx context.Context, node ast.StmtNode) (ast.Statement, error) {
	stmtNodeCounter.WithLabelValues(statementLabel(node)).Inc()
	if _, ok := node.(*ast.UpdateStmt); ok {
		sVars := variable.GetSessionVars(ctx)
		sVars.InUpdateStmt = true
		defer func() {
			sVars.InUpdateStmt = false
		}()
	}

	var is infoschema.InfoSchema
	if snap := variable.GetSessionVars(ctx).SnapshotInfoschema; snap != nil {
		is = snap.(infoschema.InfoSchema)
		log.Infof("use snapshot schema %d", is.SchemaMetaVersion())
	} else {
		is = sessionctx.GetDomain(ctx).InfoSchema()
		binloginfo.SetSchemaVersion(ctx, is.SchemaMetaVersion())
	}
	if err := plan.Preprocess(node, is, ctx); err != nil {
		return nil, errors.Trace(err)
	}
	// Validate should be after NameResolve.
	if err := plan.Validate(node, false); err != nil {
		return nil, errors.Trace(err)
	}
	p, err := plan.Optimize(ctx, node, is)
	if err != nil {
		return nil, errors.Trace(err)
	}
	_, isDDL := node.(ast.DDLNode)
	sa := &statement{
		is:    is,
		plan:  p,
		text:  node.Text(),
		isDDL: isDDL,
	}
	return sa, nil
}
示例#4
0
文件: compiler.go 项目: pingcap/tidb
// Compile compiles an ast.StmtNode to an ast.Statement.
// After preprocessed and validated, it will be optimized to a plan,
// then wrappped to an adapter *statement as stmt.Statement.
func (c *Compiler) Compile(ctx context.Context, node ast.StmtNode) (ast.Statement, error) {
	stmtCount(node)
	is := GetInfoSchema(ctx)
	if err := plan.Preprocess(node, is, ctx); err != nil {
		return nil, errors.Trace(err)
	}
	// Validate should be after NameResolve.
	if err := plan.Validate(node, false); err != nil {
		return nil, errors.Trace(err)
	}
	p, err := plan.Optimize(ctx, node, is)
	if err != nil {
		return nil, errors.Trace(err)
	}
	_, isDDL := node.(ast.DDLNode)
	sa := &statement{
		is:    is,
		plan:  p,
		text:  node.Text(),
		isDDL: isDDL,
	}
	return sa, nil
}