/*
* DBeaver - Universal Database Manager
* Copyright (C) 2010-2017 Serge Rider (serge@jkiss.org)
*
* 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jkiss.dbeaver.ui.editors.sql.indent;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.jface.text.TextUtilities;
import org.jkiss.dbeaver.model.DBPKeywordType;
import org.jkiss.dbeaver.model.sql.SQLSyntaxManager;
import org.jkiss.dbeaver.ui.editors.sql.syntax.SQLPartitionScanner;
/**
* Utility methods for heuristic based SQL manipulations in an incomplete SQL source file.
* <p/>
* <p>
* An instance holds some internal position in the document and is therefore not threadsafe.
* </p>
*
* @author Li Huang, Serge Rider
*/
public class SQLHeuristicScanner implements SQLIndentSymbols {
/**
* Returned by all methods when the requested position could not be found, or if a {@link BadLocationException}was
* thrown while scanning.
*/
public static final int NOT_FOUND = -1;
/**
* Special bound parameter that means either -1 (backward scanning) or <code>fDocument.getLength()</code> (forward
* scanning).
*/
public static final int UNBOUND = -2;
/**
* Stops upon a non-whitespace (as defined by {@link Character#isWhitespace(char)}) character.
*/
private static class NonWhitespace implements StopCondition {
@Override
public boolean stop(char ch, int position, boolean forward) {
return !Character.isWhitespace(ch);
}
}
/**
* Stops upon a non-whitespace character in the default partition.
*
* @see NonWhitespace
*/
private class NonWhitespaceDefaultPartition extends NonWhitespace {
@Override
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true) && isDefaultPartition(position);
}
}
/**
* Stops upon a non-sql identifier (as defined by {@link Character#isJavaIdentifierPart(char)}) character.
*/
private static class NonSQLIdentifierPart implements StopCondition {
@Override
public boolean stop(char ch, int position, boolean forward) {
return !Character.isJavaIdentifierPart(ch);
}
}
/**
* Stops upon a non-sql identifier character in the default partition.
*
* @see NonSQLIdentifierPart
*/
private class NonSQLIdentifierPartDefaultPartition extends NonSQLIdentifierPart {
@Override
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true) || !isDefaultPartition(position);
}
}
/**
* The document being scanned.
*/
private IDocument _document;
/**
* The partitioning being used for scanning.
*/
private String _partitioning;
/**
* The partition to scan in.
*/
private String _partition;
private SQLSyntaxManager syntaxManager;
/**
* the most recently read character.
*/
private char _char;
/**
* the most recently read position.
*/
private int _pos;
/* preset stop conditions */
private final StopCondition _nonWSDefaultPart = new NonWhitespaceDefaultPartition();
private final static StopCondition _nonWS = new NonWhitespace();
private final StopCondition _nonIdent = new NonSQLIdentifierPartDefaultPartition();
public SQLHeuristicScanner(IDocument document, String partitioning, String partition, SQLSyntaxManager syntaxManager) {
assert (document != null);
assert (partitioning != null);
assert (partition != null);
_document = document;
_partitioning = partitioning;
_partition = partition;
this.syntaxManager = syntaxManager;
}
public SQLHeuristicScanner(IDocument document, SQLSyntaxManager syntaxManager) {
this(document, SQLPartitionScanner.SQL_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE, syntaxManager);
}
public int getPosition() {
return _pos;
}
/**
* Returns the next token in forward direction, starting at <code>start</code>, and not extending further than
* <code>bound</code>. The return value is one of the constants defined in {@link SQLIndentSymbols}. After a call,
* {@link #getPosition()}will return the position just after the scanned token (i.e. the next position that will be
* scanned).
*
* @param start the first character position in the document to consider
* @param bound the first position not to consider any more
* @return a constant from {@link SQLIndentSymbols}describing the next token
*/
public int nextToken(int start, int bound) {
int pos = scanForward(start, bound, _nonWSDefaultPart);
if (pos == NOT_FOUND) {
return TokenEOF;
}
_pos++;
if (Character.isJavaIdentifierPart(_char)) {
// assume an ident or keyword
int from = pos, to;
pos = scanForward(pos + 1, bound, _nonIdent);
if (pos == NOT_FOUND) {
to = bound == UNBOUND ? _document.getLength() : bound;
} else {
to = pos;
}
String identOrKeyword;
try {
identOrKeyword = _document.get(from, to - from);
} catch (BadLocationException e) {
// _log.debug(EditorMessages.error_badLocationException, e);
return TokenEOF;
}
return getToken(identOrKeyword);
} else {
// operators, number literals etc
return TokenOTHER;
}
}
/**
* Returns the next token in backward direction, starting at <code>start</code>, and not extending further than
* <code>bound</code>. The return value is one of the constants defined in {@link SQLIndentSymbols}. After a call,
* {@link #getPosition()}will return the position just before the scanned token starts (i.e. the next position that
* will be scanned).
*
* @param start the first character position in the document to consider
* @param bound the first position not to consider any more
* @return a constant from {@link SQLIndentSymbols}describing the previous token
*/
public int previousToken(int start, int bound) {
int pos = scanBackward(start, bound, _nonWSDefaultPart);
if (pos == NOT_FOUND) {
return TokenEOF;
}
_pos--;
if (Character.isJavaIdentifierPart(_char)) {
// assume an ident or keyword
int from, to = pos + 1;
pos = scanBackward(pos - 1, bound, _nonIdent);
if (pos == NOT_FOUND) {
from = bound == UNBOUND ? 0 : bound + 1;
} else {
from = pos + 1;
}
String identOrKeyword;
try {
identOrKeyword = _document.get(from, to - from);
} catch (BadLocationException e) {
// _log.debug(EditorMessages.error_badLocationException, e);
return TokenEOF;
}
return getToken(identOrKeyword);
} else {
// operators, number literals etc
return TokenOTHER;
}
}
/**
* Returns one of the keyword constants or <code>TokenIDENT</code> for a scanned identifier.
*
* @param s a scanned identifier
* @return one of the constants defined in {@link SQLIndentSymbols}
*/
private int getToken(String s) {
assert (s != null);
switch (s.length()) {
case 3:
if (SQLIndentSymbols.end.equals(s)) {
return Tokenend;
}
if (SQLIndentSymbols.END.equalsIgnoreCase(s)) {
return TokenEND;
}
break;
case 5:
if (SQLIndentSymbols.begin.equals(s)) {
return Tokenbegin;
}
if (SQLIndentSymbols.BEGIN.equalsIgnoreCase(s)) {
return TokenBEGIN;
}
break;
}
final DBPKeywordType keywordType = syntaxManager.getDialect().getKeywordType(s);
if (keywordType == DBPKeywordType.KEYWORD) {
return TokenKeyword;
}
// if (syntaxManager.getDialect().isKeywordStart(s)) {
// return TokenKeywordStart;
// }
return TokenOTHER;
}
/**
* Finds the smallest position in <code>fDocument</code> such that the position is >= <code>position</code>
* and < <code>bound</code> and <code>Character.isWhitespace(fDocument.getChar(pos))</code> evaluates to
* <code>false</code>.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code>
* > <code>position</code>, or <code>UNBOUND</code>
* @return the smallest position of a non-whitespace character in [<code>position</code>,<code>bound</code>),
* or <code>NOT_FOUND</code> if none can be found
*/
public int findNonWhitespaceForwardInAnyPartition(int position, int bound) {
return scanForward(position, bound, _nonWS);
}
/**
* Finds the lowest position <code>p</code> in <code>fDocument</code> such that <code>start</code> <= p
* < <code>bound</code> and <code>condition.stop(fDocument.getChar(p), p)</code> evaluates to
* <code>true</code>.
*
* @param start the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code>
* > <code>start</code>, or <code>UNBOUND</code>
* @param condition the <code>StopCondition</code> to check
* @return the lowest position in [<code>start</code>,<code>bound</code>) for which <code>condition</code>
* holds, or <code>NOT_FOUND</code> if none can be found
*/
public int scanForward(int start, int bound, StopCondition condition) {
assert (start >= 0);
if (bound == UNBOUND) {
bound = _document.getLength();
}
assert (bound <= _document.getLength());
try {
_pos = start;
while (_pos < bound) {
_char = _document.getChar(_pos);
if (condition.stop(_char, _pos, true)) {
return _pos;
}
_pos++;
}
} catch (BadLocationException e) {
// _log.debug(EditorMessages.error_badLocationException, e);
}
return NOT_FOUND;
}
/**
* Finds the highest position <code>p</code> in <code>fDocument</code> such that <code>bound</code> <
* <code>p</code> <= <code>start</code> and <code>condition.stop(fDocument.getChar(p), p)</code> evaluates
* to <code>true</code>.
*
* @param start the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code>
* < <code>start</code>, or <code>UNBOUND</code>
* @param condition the <code>StopCondition</code> to check
* @return the highest position in (<code>bound</code>,<code>start</code> for which <code>condition</code>
* holds, or <code>NOT_FOUND</code> if none can be found
*/
public int scanBackward(int start, int bound, StopCondition condition) {
if (bound == UNBOUND) {
bound = -1;
}
assert (bound >= -1);
assert (start < _document.getLength());
try {
_pos = start;
while (_pos > bound) {
_char = _document.getChar(_pos);
if (condition.stop(_char, _pos, false)) {
return _pos;
}
_pos--;
}
} catch (BadLocationException e) {
// _log.debug(EditorMessages.error_badLocationException, e);
}
return NOT_FOUND;
}
/**
* Checks whether <code>position</code> resides in a default (SQL) partition of <code>_document</code>.
*
* @param position the position to be checked
* @return <code>true</code> if <code>position</code> is in the default partition of <code>_document</code>,
* <code>false</code> otherwise
*/
public boolean isDefaultPartition(int position) {
assert (position >= 0);
assert (position <= _document.getLength());
try {
ITypedRegion region = TextUtilities.getPartition(_document, _partitioning, position, false);
return region.getType().equals(_partition);
} catch (BadLocationException e) {
// _log.debug(EditorMessages.error_badLocationException, e);
}
return false;
}
/**
* Returns the position of the opening peer token (backward search). Any scopes introduced by closing peers are
* skipped. All peers accounted for must reside in the default partition.
* <p/>
* <p>
* Note that <code>start</code> must not point to the closing peer, but to the first token being searched.
* </p>
*
* @param start the start position
* @param openingPeer the opening peer token (e.g. 'begin')
* @param closingPeer the closing peer token (e.g. 'end')
* @return the matching peer character position, or <code>NOT_FOUND</code>
*/
public int findOpeningPeer(int start, int openingPeer, int closingPeer) {
assert (start < _document.getLength());
int depth = 1;
start += 1;
int token;
int offset = start;
while (true) {
token = previousToken(offset, UNBOUND);
offset = getPosition();
if (token == SQLIndentSymbols.TokenEOF) {
return NOT_FOUND;
}
if (isSameToken(token, closingPeer)) {
depth++;
} else if (isSameToken(token, openingPeer)) {
depth--;
}
if (depth == 0) {
if (offset == -1) {
return 0;
}
return offset;
}
}
}
/**
* Returns the position of the closing peer token (forward search). Any scopes introduced by opening peers
* are skipped. All peers accounted for must reside in the default partition.
* <p/>
* <p>Note that <code>start</code> must not point to the opening peer, but to the first
* token being searched.</p>
*
* @param start the start position
* @param openingPeer the opening peer character (e.g. 'begin')
* @param closingPeer the closing peer character (e.g. 'end')
* @return the matching peer character position, or <code>NOT_FOUND</code>
*/
public int findClosingPeer(int start, int openingPeer, int closingPeer) {
assert (start <= _document.getLength());
int depth = 1;
start += 1;
int token;
int offset = start;
while (true) {
token = nextToken(offset, _document.getLength());
offset = getPosition();
if (token == SQLIndentSymbols.TokenEOF) {
return NOT_FOUND;
}
if (isSameToken(token, openingPeer)) {
depth++;
} else if (isSameToken(token, closingPeer)) {
depth--;
}
if (depth == 0) {
return offset;
}
}
}
public boolean isSameToken(int firstToken, int secondToken) {
return firstToken == secondToken ||
(firstToken == TokenBEGIN && secondToken == Tokenbegin) ||
(firstToken == Tokenbegin && secondToken == TokenBEGIN) ||
(firstToken == TokenEND && secondToken == Tokenend) ||
(firstToken == Tokenend && secondToken == TokenEND);
}
}