forked from Shiloh/githaven
92 lines
2.6 KiB
Go
92 lines
2.6 KiB
Go
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// Copyright 2015 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 parser
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import (
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"regexp"
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"strings"
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"github.com/juju/errors"
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"github.com/pingcap/tidb/ast"
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"github.com/pingcap/tidb/mysql"
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"github.com/pingcap/tidb/terror"
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)
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// Error instances.
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var (
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ErrSyntax = terror.ClassParser.New(CodeSyntaxErr, "syntax error")
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)
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// Error codes.
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const (
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CodeSyntaxErr terror.ErrCode = 1
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)
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var (
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specCodePattern = regexp.MustCompile(`\/\*!(M?[0-9]{5,6})?([^*]|\*+[^*/])*\*+\/`)
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specCodeStart = regexp.MustCompile(`^\/\*!(M?[0-9]{5,6} )?[ \t]*`)
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specCodeEnd = regexp.MustCompile(`[ \t]*\*\/$`)
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)
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func trimComment(txt string) string {
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txt = specCodeStart.ReplaceAllString(txt, "")
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return specCodeEnd.ReplaceAllString(txt, "")
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}
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// See: http://dev.mysql.com/doc/refman/5.7/en/comments.html
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// Convert "/*!VersionNumber MySQL-specific-code */" to "MySQL-specific-code".
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// TODO: Find a better way:
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// 1. RegExpr is slow.
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// 2. Handle nested comment.
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func handleMySQLSpecificCode(sql string) string {
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if strings.Index(sql, "/*!") == -1 {
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// Fast way to check if text contains MySQL-specific code.
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return sql
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}
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// SQL text contains MySQL-specific code. We should convert it to normal SQL text.
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return specCodePattern.ReplaceAllStringFunc(sql, trimComment)
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}
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// Parse parses a query string to raw ast.StmtNode.
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// If charset or collation is "", default charset and collation will be used.
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func Parse(sql, charset, collation string) ([]ast.StmtNode, error) {
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if charset == "" {
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charset = mysql.DefaultCharset
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}
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if collation == "" {
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collation = mysql.DefaultCollationName
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}
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sql = handleMySQLSpecificCode(sql)
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l := NewLexer(sql)
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l.SetCharsetInfo(charset, collation)
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yyParse(l)
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if len(l.Errors()) != 0 {
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return nil, errors.Trace(l.Errors()[0])
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}
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return l.Stmts(), nil
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}
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// ParseOneStmt parses a query and returns an ast.StmtNode.
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// The query must have one statement, otherwise ErrSyntax is returned.
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func ParseOneStmt(sql, charset, collation string) (ast.StmtNode, error) {
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stmts, err := Parse(sql, charset, collation)
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if err != nil {
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return nil, errors.Trace(err)
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}
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if len(stmts) != 1 {
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return nil, ErrSyntax
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}
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return stmts[0], nil
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}
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