codekingpro/portable-devtools

1#2# Copyright (C) 2009-2020 the sqlparse authors and contributors3# <see AUTHORS file>4#5# This module is part of python-sqlparse and is released under6# the BSD License: https://opensource.org/licenses/BSD-3-Clause7 8from sqlparse import sql, tokens as T9 10 11class StatementSplitter:12    """Filter that split stream at individual statements"""13 14    def __init__(self):15        self._reset()16 17    def _reset(self):18        """Set the filter attributes to its default values"""19        self._in_declare = False20        self._is_create = False21        self._begin_depth = 022 23        self.consume_ws = False24        self.tokens = []25        self.level = 026 27    def _change_splitlevel(self, ttype, value):28        """Get the new split level (increase, decrease or remain equal)"""29 30        # parenthesis increase/decrease a level31        if ttype is T.Punctuation and value == '(':32            return 133        elif ttype is T.Punctuation and value == ')':34            return -135        elif ttype not in T.Keyword:  # if normal token return36            return 037 38        # Everything after here is ttype = T.Keyword39        # Also to note, once entered an If statement you are done and basically40        # returning41        unified = value.upper()42 43        # three keywords begin with CREATE, but only one of them is DDL44        # DDL Create though can contain more words such as "or replace"45        if ttype is T.Keyword.DDL and unified.startswith('CREATE'):46            self._is_create = True47            return 048 49        # can have nested declare inside of being...50        if unified == 'DECLARE' and self._is_create and self._begin_depth == 0:51            self._in_declare = True52            return 153 54        if unified == 'BEGIN':55            self._begin_depth += 156            if self._is_create:57                # FIXME(andi): This makes no sense.  ## this comment neither58                return 159            return 060 61        # Should this respect a preceding BEGIN?62        # In CASE ... WHEN ... END this results in a split level -1.63        # Would having multiple CASE WHEN END and a Assignment Operator64        # cause the statement to cut off prematurely?65        if unified == 'END':66            self._begin_depth = max(0, self._begin_depth - 1)67            return -168 69        if (unified in ('IF', 'FOR', 'WHILE', 'CASE')70                and self._is_create and self._begin_depth > 0):71            return 172 73        if unified in ('END IF', 'END FOR', 'END WHILE'):74            return -175 76        # Default77        return 078 79    def process(self, stream):80        """Process the stream"""81        EOS_TTYPE = T.Whitespace, T.Comment.Single82 83        # Run over all stream tokens84        for ttype, value in stream:85            # Yield token if we finished a statement and there's no whitespaces86            # It will count newline token as a non whitespace. In this context87            # whitespace ignores newlines.88            # why don't multi line comments also count?89            if self.consume_ws and ttype not in EOS_TTYPE:90                yield sql.Statement(self.tokens)91 92                # Reset filter and prepare to process next statement93                self._reset()94 95            # Change current split level (increase, decrease or remain equal)96            self.level += self._change_splitlevel(ttype, value)97 98            # Append the token to the current statement99            self.tokens.append(sql.Token(ttype, value))100 101            # Check if we get the end of a statement102            # Issue762: Allow GO (or "GO 2") as statement splitter.103            # When implementing a language toggle, it's not only to add104            # keywords it's also to change some rules, like this splitting105            # rule.106            if (self.level <= 0 and ttype is T.Punctuation and value == ';') \107                    or (ttype is T.Keyword and value.split()[0] == 'GO'):108                self.consume_ws = True109 110        # Yield pending statement (if any)111        if self.tokens and not all(t.is_whitespace for t in self.tokens):112            yield sql.Statement(self.tokens)113