#919 - io.ebean package initial

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

@@ -0,0 +1,148 @@
+package io.ebeaninternal.server.deploy;
+
+import io.ebeaninternal.server.core.InternString;
+import io.ebeaninternal.server.deploy.meta.DeployTableJoin;
+import io.ebeaninternal.server.deploy.meta.DeployTableJoinColumn;
+import io.ebeaninternal.server.query.SplitName;
+import io.ebeaninternal.server.query.SqlJoinType;
+
+/**
+ * Represents a join to another table.
+ */
+public final class TableJoin {
+
+  /**
+   * The joined table.
+   */
+  private final String table;
+
+  /**
+   * The type of join as per deployment (cardinality and optionality).
+   */
+  private final SqlJoinType type;
+
+  private final InheritInfo inheritInfo;
+
+  /**
+   * Columns as an array.
+   */
+  private final TableJoinColumn[] columns;
+
+  /**
+   * A hash that can be used with the query plan.
+   */
+  private final int queryHash;
+
+  /**
+   * Create a TableJoin.
+   */
+  public TableJoin(DeployTableJoin deploy) {
+
+    this.table = InternString.intern(deploy.getTable());
+    this.type = deploy.getType();
+    this.inheritInfo = deploy.getInheritInfo();
+
+    DeployTableJoinColumn[] deployCols = deploy.columns();
+    this.columns = new TableJoinColumn[deployCols.length];
+    for (int i = 0; i < deployCols.length; i++) {
+      this.columns[i] = new TableJoinColumn(deployCols[i]);
+    }
+
+    this.queryHash = calcQueryHash();
+  }
+
+  /**
+   * Calculate a hash value for adding to a query plan.
+   */
+  private int calcQueryHash() {
+    int hc = type.hashCode();
+    hc = hc * 92821 + (table == null ? 0 : table.hashCode());
+    for (TableJoinColumn column : columns) {
+      hc = hc * 92821 + column.queryHash();
+    }
+    return hc;
+  }
+
+  @Override
+  public int hashCode() {
+    return queryHash;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    TableJoin that = (TableJoin) o;
+
+    if (!table.equals(that.table)) return false;
+    if (type != that.type) return false;
+    if (columns.length != that.columns.length) return false;
+
+    for (int i = 0; i < columns.length; i++) {
+      if (!columns[i].equals(that.columns[i])) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+
+
+  /**
+   * Return a hash value for adding to a query plan.
+   */
+  public int queryHash() {
+    return queryHash;
+  }
+
+  public String toString() {
+    StringBuilder sb = new StringBuilder(30);
+    sb.append(type).append(" ").append(table).append(" ");
+    for (TableJoinColumn column : columns) {
+      sb.append(column).append(" ");
+    }
+    return sb.toString();
+  }
+
+  /**
+   * Return the join columns.
+   */
+  public TableJoinColumn[] columns() {
+    return columns;
+  }
+
+  /**
+   * Return the joined table name.
+   */
+  public String getTable() {
+    return table;
+  }
+
+  /**
+   * Return the type of join. LEFT JOIN etc.
+   */
+  public SqlJoinType getType() {
+    return type;
+  }
+
+  public SqlJoinType addJoin(SqlJoinType joinType, String prefix, DbSqlContext ctx) {
+
+    String[] names = SplitName.split(prefix);
+    String a1 = ctx.getTableAlias(names[0]);
+    String a2 = ctx.getTableAlias(prefix);
+
+    return addJoin(joinType, a1, a2, ctx);
+  }
+
+  public SqlJoinType addJoin(SqlJoinType joinType, String a1, String a2, DbSqlContext ctx) {
+
+   	String inheritance = inheritInfo != null ? inheritInfo.getWhere() : null;
+
+   	String joinLiteral = joinType.getLiteral(type);
+   	ctx.addJoin(joinLiteral, table, columns(), a1, a2, inheritance);
+
+   	return joinType.autoToOuter(type);
+  }
+
+}