8e88825f55
- Rename *_js.go to *_wasm.go to satisfy both wasm/js and wasm/wasi - Use +build instruction instead of *_GOOS pattern to reduce file Signed-off-by: lucklove <gnu.crazier@gmail.com>
114 lines
2.6 KiB
Go
114 lines
2.6 KiB
Go
// Copyright 2016 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package executor
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import (
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"context"
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"github.com/pingcap/errors"
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"github.com/pingcap/tidb/planner/core"
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"github.com/pingcap/tidb/util/chunk"
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"github.com/pingcap/tidb/util/mathutil"
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)
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// ExplainExec represents an explain executor.
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type ExplainExec struct {
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baseExecutor
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explain *core.Explain
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analyzeExec Executor
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rows [][]string
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cursor int
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}
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// Open implements the Executor Open interface.
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func (e *ExplainExec) Open(ctx context.Context) error {
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if e.analyzeExec != nil {
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return e.analyzeExec.Open(ctx)
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}
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return nil
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}
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// Close implements the Executor Close interface.
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func (e *ExplainExec) Close() error {
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e.rows = nil
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return nil
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}
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// Next implements the Executor Next interface.
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func (e *ExplainExec) Next(ctx context.Context, req *chunk.Chunk) error {
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if e.rows == nil {
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var err error
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e.rows, err = e.generateExplainInfo(ctx)
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if err != nil {
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return err
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}
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}
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req.GrowAndReset(e.maxChunkSize)
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if e.cursor >= len(e.rows) {
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return nil
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}
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numCurRows := mathutil.Min(req.Capacity(), len(e.rows)-e.cursor)
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for i := e.cursor; i < e.cursor+numCurRows; i++ {
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for j := range e.rows[i] {
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req.AppendString(j, e.rows[i][j])
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}
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}
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e.cursor += numCurRows
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return nil
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}
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func (e *ExplainExec) generateExplainInfo(ctx context.Context) (rows [][]string, err error) {
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closed := false
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defer func() {
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if !closed && e.analyzeExec != nil {
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err = e.analyzeExec.Close()
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closed = true
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}
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}()
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if e.analyzeExec != nil {
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chk := newFirstChunk(e.analyzeExec)
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var nextErr, closeErr error
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for {
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nextErr = Next(ctx, e.analyzeExec, chk)
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if nextErr != nil || chk.NumRows() == 0 {
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break
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}
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}
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closeErr = e.analyzeExec.Close()
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closed = true
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if nextErr != nil {
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if closeErr != nil {
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err = errors.New(nextErr.Error() + ", " + closeErr.Error())
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} else {
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err = nextErr
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}
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} else if closeErr != nil {
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err = closeErr
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}
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if err != nil {
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return nil, err
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}
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}
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if err = e.explain.RenderResult(); err != nil {
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return nil, err
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}
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if e.analyzeExec != nil {
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e.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl = nil
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}
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return e.explain.Rows, nil
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}
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