#1268 - SQL Server fix for "for update" plus Sequences support plus refactor of sequences

src/main/java/io/ebeaninternal/dbmigration/ddlgeneration/platform/PlatformDdl.java

@@ -308,9 +308,7 @@ public class PlatformDdl {
     if (initialValue > 1) {
       sb.append(" start with ").append(initialValue);
     }
-    if (allocationSize > 0 && allocationSize != 50) {
-      // at this stage ignoring allocationSize 50 as this is the 'default' and
-      // not consistent with the way Ebean batch fetches sequence values
+    if (allocationSize > 1) {
       sb.append(" increment by ").append(allocationSize);
     }
     sb.append(";");

src/main/java/io/ebeaninternal/dbmigration/ddlgeneration/platform/SqlServerDdl.java

@@ -121,9 +121,7 @@ public class SqlServerDdl extends PlatformDdl {
     } else {
       sb.append(" start with 1 ");
     }
-    if (allocationSize > 0 && allocationSize != 50) {
-      // at this stage ignoring allocationSize 50 as this is the 'default' and
-      // not consistent with the way Ebean batch fetches sequence values
+    if (allocationSize > 1) {
       sb.append(" increment by ").append(allocationSize);
     }
     sb.append(";");

src/main/java/io/ebeaninternal/server/core/DefaultContainer.java

@@ -270,7 +270,7 @@ public class DefaultContainer implements SpiContainer {
       config.setDatabasePlatform(platform);
     }
     logger.info("DatabasePlatform name:{} platform:{}", config.getName(), platform.getName());
-    platform.configure(config.getDbTypeConfig(), config.isAllQuotedIdentifiers());
+    platform.configure(config);
   }
 
   /**

src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorManager.java

@@ -173,8 +173,6 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
 
   private final BackgroundExecutor backgroundExecutor;
 
-  private final int dbSequenceBatchSize;
-
   private final EncryptKeyManager encryptKeyManager;
 
   private final IdBinderFactory idBinderFactory;
@@ -206,7 +204,6 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
     this.serverName = InternString.intern(serverConfig.getName());
     this.cacheManager = config.getCacheManager();
     this.docStoreFactory = config.getDocStoreFactory();
-    this.dbSequenceBatchSize = serverConfig.getDatabaseSequenceBatchSize();
     this.backgroundExecutor = config.getBackgroundExecutor();
     this.dataSource = serverConfig.getDataSource();
     this.encryptKeyManager = serverConfig.getEncryptKeyManager();
@@ -1391,12 +1388,16 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
       seqName = namingConvention.getSequenceName(desc.getBaseTable(), primaryKeyColumn);
     }
 
-    // create the sequence based IdGenerator
-    desc.setIdGenerator(createSequenceIdGenerator(seqName));
+    if (databasePlatform.isSequenceBatchMode()) {
+      // use sequence next step 1 as we are going to batch fetch them instead
+      desc.setSequenceAllocationSize(1);
+    }
+    int stepSize = desc.getSequenceAllocationSize();
+    desc.setIdGenerator(createSequenceIdGenerator(seqName, stepSize));
   }
 
-  private PlatformIdGenerator createSequenceIdGenerator(String seqName) {
-    return databasePlatform.createSequenceIdGenerator(backgroundExecutor, dataSource, seqName, dbSequenceBatchSize);
+  private PlatformIdGenerator createSequenceIdGenerator(String seqName, int stepSize) {
+    return databasePlatform.createSequenceIdGenerator(backgroundExecutor, dataSource, stepSize, seqName);
   }
 
   private void createByteCode(DeployBeanDescriptor<?> deploy) {

src/main/java/io/ebeaninternal/server/deploy/DbSqlContext.java

@@ -129,4 +129,9 @@ public interface DbSqlContext {
    * Start group by clause.
    */
   void startGroupBy();
+
+  /**
+   * Append 'for update' lock hints on FROM clause (sql server only).
+   */
+  void appendFromForUpdate();
 }

src/main/java/io/ebeaninternal/server/deploy/meta/DeployBeanDescriptor.java

@@ -107,7 +107,7 @@ public class DeployBeanDescriptor<T> {
 
   private int sequenceInitialValue;
 
-  private int sequenceAllocationSize;
+  private int sequenceAllocationSize = 50;
 
   /**
    * Used with Identity columns but no getGeneratedKeys support.

src/main/java/io/ebeaninternal/server/query/CQueryBuilder.java

@@ -1,5 +1,6 @@
 package io.ebeaninternal.server.query;
 
+import io.ebean.Query;
 import io.ebean.RawSql;
 import io.ebean.RawSqlBuilder;
 import io.ebean.annotation.Platform;
@@ -671,4 +672,16 @@ class CQueryBuilder {
   boolean isPlatformDistinctOn() {
     return dbPlatform.isPlatform(Platform.POSTGRES);
   }
+
+  /**
+   * Return the 'for update' FROM hint (sql server).
+   */
+  public String fromForUpdate(SpiQuery<?> query) {
+    Query.ForUpdate mode = query.getForUpdateMode();
+    if (mode == null) {
+      return null;
+    } else {
+      return dbPlatform.fromForUpdate(mode);
+    }
+  }
 }

src/main/java/io/ebeaninternal/server/query/DefaultDbSqlContext.java

@@ -26,6 +26,8 @@ class DefaultDbSqlContext implements DbSqlContext {
 
   private final ArrayStack<String> prefixStack = new ArrayStack<>();
 
+  private final String fromForUpdate;
+
   private boolean useColumnAlias;
 
   private int columnIndex;
@@ -55,7 +57,8 @@ class DefaultDbSqlContext implements DbSqlContext {
    * Construct for SELECT clause (with column alias settings).
    */
   DefaultDbSqlContext(SqlTreeAlias alias, CQueryBuilder builder,
-                      boolean alwaysUseColumnAlias, CQueryHistorySupport historySupport, CQueryDraftSupport draftSupport) {
+                      boolean alwaysUseColumnAlias, CQueryHistorySupport historySupport,
+                      CQueryDraftSupport draftSupport, String fromForUpdate) {
 
     this.alias = alias;
     this.tableAliasPlaceHolder = builder.tableAliasPlaceHolder;
@@ -64,6 +67,14 @@ class DefaultDbSqlContext implements DbSqlContext {
     this.draftSupport = draftSupport;
     this.historySupport = historySupport;
     this.historyQuery = (historySupport != null);
+    this.fromForUpdate = fromForUpdate;
+  }
+
+  @Override
+  public void appendFromForUpdate() {
+    if (fromForUpdate != null) {
+      append(" ").append(fromForUpdate);
+    }
   }
 
   @Override

src/main/java/io/ebeaninternal/server/query/SqlTreeBuilder.java

@@ -119,9 +119,10 @@ public final class SqlTreeBuilder {
     this.alias = new SqlTreeAlias(request.getBaseTableAlias());
     this.distinctOnPlatform = builder.isPlatformDistinctOn();
 
+    String fromForUpdate = builder.fromForUpdate(query);
     CQueryHistorySupport historySupport = builder.getHistorySupport(query);
     CQueryDraftSupport draftSupport = builder.getDraftSupport(query);
-    this.ctx = new DefaultDbSqlContext(alias, builder, !subQuery, historySupport, draftSupport);
+    this.ctx = new DefaultDbSqlContext(alias, builder, !subQuery, historySupport, draftSupport, fromForUpdate);
   }
 
   /**

src/main/java/io/ebeaninternal/server/query/SqlTreeNodeRoot.java

@@ -68,6 +68,7 @@ final class SqlTreeNodeRoot extends SqlTreeNodeBean {
 
     ctx.append(desc.getBaseTable(temporalMode));
     ctx.append(" ").append(baseTableAlias);
+    ctx.appendFromForUpdate();
 
     if (includeJoin != null) {
       String a1 = baseTableAlias;

src/main/java/io/ebeaninternal/util/JdbcClose.java

@@ -6,6 +6,7 @@ import org.slf4j.LoggerFactory;
 import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.sql.Statement;
 
 /**
  * Utility for closing raw Jdbc resources.
@@ -14,6 +15,19 @@ public class JdbcClose {
 
   private static final Logger logger = LoggerFactory.getLogger(JdbcClose.class);
 
+  /**
+   * Close the resultSet logging if an error occurs.
+   */
+  public static void close(Statement statement) {
+    try {
+      if (statement != null) {
+        statement.close();
+      }
+    } catch (SQLException e) {
+      logger.warn("Error closing statement", e);
+    }
+  }
+
   /**
    * Close the resultSet logging if an error occurs.
    */