/*
* Copyright (c) 2008-2012, Hazel Bilisim Ltd. All Rights Reserved.
*
* 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 com.hazelcast.query;
import com.hazelcast.core.MapEntry;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.*;
import static com.hazelcast.query.Predicates.*;
public class SqlPredicate extends AbstractPredicate implements IndexAwarePredicate {
private transient Predicate predicate;
private String sql;
public SqlPredicate(String sql) {
this.sql = sql;
predicate = createPredicate(sql);
}
public SqlPredicate() {
}
public boolean apply(MapEntry mapEntry) {
return predicate.apply(mapEntry);
}
public boolean collectIndexAwarePredicates(List<IndexAwarePredicate> lsIndexPredicates, Map<Expression, Index> mapIndexes) {
if (predicate instanceof IndexAwarePredicate) {
return ((IndexAwarePredicate) predicate).collectIndexAwarePredicates(lsIndexPredicates, mapIndexes);
}
return false;
}
public boolean isIndexed(QueryContext queryContext) {
return false;
}
public Set<MapEntry> filter(QueryContext queryContext) {
return ((IndexAwarePredicate) predicate).filter(queryContext);
}
public void collectAppliedIndexes(Set<Index> setAppliedIndexes, Map<Expression, Index> mapIndexes) {
if (predicate instanceof IndexAwarePredicate) {
((IndexAwarePredicate) predicate).collectAppliedIndexes(setAppliedIndexes, mapIndexes);
}
}
public void writeData(DataOutput out) throws IOException {
out.writeUTF(sql);
}
public void readData(DataInput in) throws IOException {
sql = in.readUTF();
predicate = createPredicate(sql);
}
private int getApostropheIndex(String str, int start) {
return str.indexOf("'", start);
}
private Predicate createPredicate(String sql) {
Map<String, String> mapPhrases = new HashMap<String, String>(1);
int apoIndex = getApostropheIndex(sql, 0);
if (apoIndex != -1) {
int phraseId = 0;
StringBuilder newSql = new StringBuilder();
while (apoIndex != -1) {
phraseId++;
int start = apoIndex + 1;
int end = getApostropheIndex(sql, apoIndex + 1);
if (end == -1) {
throw new RuntimeException("Missing ' in sql");
}
String phrase = sql.substring(start, end);
String key = "$" + phraseId;
mapPhrases.put(key, phrase);
String before = sql.substring(0, apoIndex);
sql = sql.substring(end + 1);
newSql.append(before);
newSql.append(key);
apoIndex = getApostropheIndex(sql, 0);
}
newSql.append(sql);
sql = newSql.toString();
}
Parser parser = new Parser();
List<String> sqlTokens = parser.toPrefix(sql);
List<Object> tokens = new ArrayList<Object>(sqlTokens);
if (tokens.size() == 0) throw new RuntimeException("Invalid SQL: [" + sql + "]");
if (tokens.size() == 1) {
return eval(tokens.get(0));
}
root:
while (tokens.size() > 1) {
boolean foundOperand = false;
for (int i = 0; i < tokens.size(); i++) {
Object tokenObj = tokens.get(i);
if (tokenObj instanceof String && parser.isOperand((String) tokenObj)) {
foundOperand = true;
String token = (String) tokenObj;
if ("=".equals(token) || "==".equals(token)) {
int position = (i - 2);
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, equal(get((String) first), second));
} else if ("!=".equals(token)) {
int position = (i - 2);
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, notEqual(get((String) first), second));
} else if (">".equals(token)) {
int position = (i - 2);
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, greaterThan(get((String) first), (Comparable) second));
} else if (">=".equals(token)) {
int position = (i - 2);
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, greaterEqual(get((String) first), (Comparable) second));
} else if ("<=".equals(token)) {
int position = (i - 2);
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, lessEqual(get((String) first), (Comparable) second));
} else if ("<".equals(token)) {
int position = (i - 2);
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, lessThan(get((String) first), (Comparable) second));
} else if ("LIKE".equalsIgnoreCase(token)) {
int position = (i - 2);
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, like(get((String) first), (String) second));
} else if ("IN".equalsIgnoreCase(token)) {
int position = i - 2;
validateOperandPosition(position);
Object exp = toValue(tokens.remove(position), mapPhrases);
String[] values = toValue(((String) tokens.remove(position)).split(","), mapPhrases);
setOrAdd(tokens, position, Predicates.in(get((String) exp), values));
} else if ("NOT".equalsIgnoreCase(token)) {
int position = i - 1;
validateOperandPosition(position);
Object exp = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, Predicates.not(eval(exp)));
} else if ("BETWEEN".equalsIgnoreCase(token)) {
int position = i - 3;
validateOperandPosition(position);
Object expression = tokens.remove(position);
Object from = tokens.remove(position);
Object to = tokens.remove(position);
setOrAdd(tokens, position, between(get((String) expression), (Comparable) from, (Comparable) to));
} else if ("AND".equalsIgnoreCase(token)) {
int position = i - 2;
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, and(eval(first), eval(second)));
} else if ("OR".equalsIgnoreCase(token)) {
int position = i - 2;
validateOperandPosition(position);
Object first = toValue(tokens.remove(position), mapPhrases);
Object second = toValue(tokens.remove(position), mapPhrases);
setOrAdd(tokens, position, or(eval(first), eval(second)));
} else throw new RuntimeException("Unknown token " + token);
continue root;
}
}
if (!foundOperand) {
throw new RuntimeException("Invalid SQL: [" + sql + "]");
}
}
return (Predicate) tokens.get(0);
}
private void validateOperandPosition(int pos) {
if (pos < 0) {
throw new RuntimeException("Invalid SQL: [" + sql + "]");
}
}
private Object toValue(final Object key, final Map<String, String> phrases) {
final String value = phrases.get(key);
if (value != null) {
return value;
} else if (key instanceof String && ("null".equalsIgnoreCase((String) key))) {
return null;
} else {
return key;
}
}
private String[] toValue(final String[] keys, final Map<String, String> phrases) {
for (int i = 0; i < keys.length; i++) {
final String value = phrases.get(keys[i]);
if (value != null) keys[i] = value;
}
return keys;
}
private void setOrAdd(List tokens, int position, Predicate predicate) {
if (tokens.size() == 0) {
tokens.add(predicate);
} else {
tokens.set(position, predicate);
}
}
private Predicate eval(Object statement) {
if (statement instanceof String) {
return equal(get((String) statement), "true");
} else {
return (Predicate) statement;
}
}
@Override
public String toString() {
return predicate.toString();
}
}