add limit to rewrite module (c33a09b7) · Commits · SUMMER2020 / students / proj-2004142

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/rewrite/LimitUtils.java

0 → 100644

+49 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 1999-2015 dangdang.com.
		* <p>
		* 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.
		* </p>
		*/

		package com.dangdang.ddframe.rdb.sharding.rewrite;

		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.LimitContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SQLContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.exception.SQLParsingException;

		import java.util.List;

		/**
		* 补列工具类.
		*
		* @author zhangliang
		*/
		public final class LimitUtils {

		/**
		* 追加分页.
		*
		* @param sqlContext SQL上下文
		* @param parameters 参数
		*/
		public static void appendLimit(final SQLContext sqlContext, final List<Object> parameters) {
		int offset = -1 == sqlContext.getLimitContext().getOffsetParameterIndex()
		? sqlContext.getLimitContext().getOffset() : (int) parameters.get(sqlContext.getLimitContext().getOffsetParameterIndex());
		int rowCount = -1 == sqlContext.getLimitContext().getRowCountParameterIndex()
		? sqlContext.getLimitContext().getRowCount() : (int) parameters.get(sqlContext.getLimitContext().getRowCountParameterIndex());
		sqlContext.setLimitContext(new LimitContext(offset, rowCount, sqlContext.getLimitContext().getOffsetParameterIndex(), sqlContext.getLimitContext().getRowCountParameterIndex()));
		if (offset < 0 \|\| rowCount < 0) {
		throw new SQLParsingException("LIMIT offset and row count can not be a negative value.");
		}
		}
		}

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/rewrite/SQLRewriteEngine.java

+5 −1

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		package com.dangdang.ddframe.rdb.sharding.rewrite;


		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.LimitContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SQLContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.TableContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.ItemsToken;
		@@ -46,6 +47,8 @@ public final class SQLRewriteEngine {

		private final Collection<String> tableNames = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);

		private final LimitContext limit;

		private SQLBuilder sqlBuilder;

		public SQLRewriteEngine(final String originalSQL, final SQLContext sqlContext) {
		@@ -54,10 +57,11 @@ public final class SQLRewriteEngine {
		for (TableContext each : sqlContext.getTables()) {
		tableNames.add(each.getName());
		}
		limit = sqlContext.getLimitContext();
		}

		/**
		* SQL重写.
		* SQL改写.
		*
		* @return SQL构建器
		*/

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/router/PreparedSQLRouter.java

+0 −18

Original line number	Diff line number	Diff line
		@@ -21,9 +21,7 @@ import com.dangdang.ddframe.rdb.sharding.api.rule.ShardingRule;
		import com.dangdang.ddframe.rdb.sharding.api.rule.TableRule;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.GeneratedKeyContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.InsertSQLContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.LimitContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SQLContext;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.exception.SQLParsingException;
		import com.google.common.base.Optional;
		import lombok.RequiredArgsConstructor;

		@@ -61,25 +59,9 @@ public class PreparedSQLRouter {
		List<Number> generatedIds = generateId();
		parameters.addAll(generatedIds);
		}
		// TODO 提炼至rewrite模块
		setLimit(parameters);
		return engine.routeSQL(logicSql, sqlContext, parameters);
		}

		private void setLimit(final List<Object> parameters) {
		if (null == sqlContext.getLimitContext()) {
		return;
		}
		int offset = -1 == sqlContext.getLimitContext().getOffsetParameterIndex()
		? sqlContext.getLimitContext().getOffset() : (int) parameters.get(sqlContext.getLimitContext().getOffsetParameterIndex());
		int rowCount = -1 == sqlContext.getLimitContext().getRowCountParameterIndex()
		? sqlContext.getLimitContext().getRowCount() : (int) parameters.get(sqlContext.getLimitContext().getRowCountParameterIndex());
		sqlContext.setLimitContext(new LimitContext(offset, rowCount, sqlContext.getLimitContext().getOffsetParameterIndex(), sqlContext.getLimitContext().getRowCountParameterIndex()));
		if (offset < 0 \|\| rowCount < 0) {
		throw new SQLParsingException("LIMIT offset and row count can not be a negative value.");
		}
		}

		private List<Number> generateId() {
		if (!(sqlContext instanceof InsertSQLContext)) {
		return Collections.emptyList();

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/router/SQLRouteEngine.java

+4 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@ import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.OffsetLimitToken;
		import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.RowCountLimitToken;
		import com.dangdang.ddframe.rdb.sharding.rewrite.DerivedColumnUtils;
		import com.dangdang.ddframe.rdb.sharding.rewrite.GenerateKeysUtils;
		import com.dangdang.ddframe.rdb.sharding.rewrite.LimitUtils;
		import com.dangdang.ddframe.rdb.sharding.rewrite.SQLBuilder;
		import com.dangdang.ddframe.rdb.sharding.rewrite.SQLRewriteEngine;
		import com.dangdang.ddframe.rdb.sharding.router.binding.BindingTablesRouter;
		@@ -102,6 +103,9 @@ public final class SQLRouteEngine {
		if (result instanceof SelectSQLContext) {
		DerivedColumnUtils.appendDerivedColumns((SelectSQLContext) result);
		}
		if (null != result.getLimitContext()) {
		LimitUtils.appendLimit(result, parameters);
		}
		return result;
		}