#919 - io.ebean package initial

src/main/java/io/ebeaninternal/server/persist/dml/UpdateMeta.java

@@ -0,0 +1,167 @@
+package io.ebeaninternal.server.persist.dml;
+
+import io.ebean.bean.EntityBean;
+import io.ebeaninternal.api.ConcurrencyMode;
+import io.ebeaninternal.api.SpiUpdatePlan;
+import io.ebeaninternal.server.core.PersistRequestBean;
+import io.ebeaninternal.server.deploy.BeanDescriptor;
+import io.ebeaninternal.server.persist.dmlbind.Bindable;
+import io.ebeaninternal.server.persist.dmlbind.BindableId;
+import io.ebeaninternal.server.persist.dmlbind.BindableList;
+
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Meta data for update handler. The meta data is for a particular bean type. It
+ * is considered immutable and is thread safe.
+ */
+public final class UpdateMeta {
+
+  private final BindableList set;
+  private final BindableId id;
+  private final Bindable version;
+
+  private final String tableName;
+
+  private final UpdatePlan modeNoneUpdatePlan;
+  private final UpdatePlan modeVersionUpdatePlan;
+
+  private final boolean emptyStringAsNull;
+
+  public UpdateMeta(boolean emptyStringAsNull, BeanDescriptor<?> desc, BindableList set, BindableId id, Bindable version) {
+    this.emptyStringAsNull = emptyStringAsNull;
+    this.tableName = desc.getBaseTable();
+    this.set = set;
+    this.id = id;
+    this.version = version;
+
+    String sqlNone = genSql(ConcurrencyMode.NONE, set, desc.getBaseTable());
+    String sqlVersion = genSql(ConcurrencyMode.VERSION, set, desc.getBaseTable());
+
+    this.modeNoneUpdatePlan = new UpdatePlan(ConcurrencyMode.NONE, sqlNone, set);
+    this.modeVersionUpdatePlan = new UpdatePlan(ConcurrencyMode.VERSION, sqlVersion, set);
+  }
+
+  /**
+   * Return true if empty strings should be treated as null.
+   */
+  public boolean isEmptyStringAsNull() {
+    return emptyStringAsNull;
+  }
+
+  /**
+   * Return the base table name.
+   */
+  public String getTableName() {
+    return tableName;
+  }
+
+  /**
+   * Bind the request based on the concurrency mode.
+   */
+  public void bind(PersistRequestBean<?> persist, DmlHandler bind, SpiUpdatePlan updatePlan) throws SQLException {
+
+    EntityBean bean = persist.getEntityBean();
+
+    updatePlan.bindSet(bind, bean);
+
+    id.dmlBind(bind, bean);
+
+    switch (persist.getConcurrencyMode()) {
+      case VERSION:
+        version.dmlBind(bind, bean);
+        break;
+
+      default:
+        break;
+    }
+  }
+
+  /**
+   * get or generate the sql based on the concurrency mode.
+   */
+  public SpiUpdatePlan getUpdatePlan(PersistRequestBean<?> request) {
+
+    if (request.isDynamicUpdateSql()) {
+      return getDynamicUpdatePlan(request);
+    }
+
+    // 'full bean' update...
+    ConcurrencyMode mode = request.determineConcurrencyMode();
+    switch (mode) {
+      case NONE:
+        return modeNoneUpdatePlan;
+
+      case VERSION:
+        return modeVersionUpdatePlan;
+
+      default:
+        throw new RuntimeException("Invalid mode " + mode);
+    }
+  }
+
+  private SpiUpdatePlan getDynamicUpdatePlan(PersistRequestBean<?> persistRequest) {
+
+    String key = persistRequest.getUpdatePlanHash();
+
+    // check if we can use a cached UpdatePlan
+    BeanDescriptor<?> beanDescriptor = persistRequest.getBeanDescriptor();
+    SpiUpdatePlan updatePlan = beanDescriptor.getUpdatePlan(key);
+    if (updatePlan != null) {
+      return updatePlan;
+    }
+
+    // build a new UpdatePlan and cache it
+
+    // build a bindableList that only contains the changed properties
+    List<Bindable> list = new ArrayList<>();
+    set.addToUpdate(persistRequest, list);
+    BindableList bindableList = new BindableList(list);
+
+    ConcurrencyMode mode = persistRequest.determineConcurrencyMode();
+
+    // build the SQL for this update statement
+    String sql = genSql(mode, bindableList, persistRequest.getUpdateTable());
+
+    updatePlan = new UpdatePlan(key, mode, sql, bindableList);
+
+    // add the UpdatePlan to the cache
+    beanDescriptor.putUpdatePlan(key, updatePlan);
+
+    return updatePlan;
+  }
+
+  private String genSql(ConcurrencyMode conMode, BindableList bindableList, String tableName) {
+
+    // update set col0=?, col1=?, col2=? where bcol=? and bc1=? and bc2=?
+
+    GenerateDmlRequest request = new GenerateDmlRequest();
+    request.append("update ").append(tableName).append(" set ");
+
+    request.setUpdateSetMode();
+    bindableList.dmlAppend(request);
+
+    if (request.getBindColumnCount() == 0) {
+      // update properties must have been updatable=false
+      // with the result that nothing is in the set clause
+      return null;
+    }
+
+    request.append(" where ");
+
+    request.setWhereIdMode();
+    id.dmlAppend(request);
+
+    if (ConcurrencyMode.VERSION.equals(conMode)) {
+      if (version == null) {
+        return null;
+      }
+      version.dmlAppend(request);
+    }
+
+    return request.toString();
+  }
+
+}