#15 prototype VTable

Author: shroffk

epics-vtype/vtype/src/main/java/org/epics/vtype/IVTable.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright (C) 2010-18 diirt developers. See COPYRIGHT.TXT
+ * All rights reserved. Use is subject to license terms. See LICENSE.TXT
+ */
+package org.epics.vtype;
+
+import java.util.List;
+import org.epics.util.array.ListNumber;
+
+/**
+ * An immutable table that extends {@link VTable}
+ * 
+ * @author carcassi, shroff
+ */
+class IVTable extends VTable {
+
+    private final List<Class<?>> types;
+    private final List<String> names;
+    private final List<Object> values;
+    private final int rowCount;
+
+    IVTable(List<Class<?>> types, List<String> names, List<Object> values) {
+        this.types = types;
+        this.names = names;
+        this.values = values;
+        int maxCount = 0;
+        for (Object array : values) {
+            maxCount = Math.max(maxCount, getDataSize(array));
+        }
+        this.rowCount = maxCount;
+    }
+
+    private static int getDataSize(Object data) {
+        if (data instanceof List) {
+            return ((List) data).size();
+        } else if (data instanceof ListNumber) {
+            return ((ListNumber) data).size();
+        }
+
+        throw new IllegalArgumentException("Object " + data + " is not supported");
+    }
+
+    @Override
+    public int getColumnCount() {
+        return names.size();
+    }
+
+    @Override
+    public int getRowCount() {
+        return rowCount;
+    }
+
+    @Override
+    public Class<?> getColumnType(int column) {
+        return types.get(column);
+    }
+
+    @Override
+    public String getColumnName(int column) {
+        return names.get(column);
+    }
+
+    @Override
+    public Object getColumnData(int column) {
+        return values.get(column);
+    }
+
+}

epics-vtype/vtype/src/main/java/org/epics/vtype/VTable.java

@@ -0,0 +1,79 @@
+/**
+ * Copyright (C) 2010-18 diirt developers. See COPYRIGHT.TXT
+ * All rights reserved. Use is subject to license terms. See LICENSE.TXT
+ */
+package org.epics.vtype;
+
+import java.util.List;
+import org.epics.util.array.ListNumber;
+
+/**
+ * A table. Tables are collections of columns, each of which is composed of a
+ * String representing the name of the column and a list of a particular type
+ * (all elements of the same column must be of the same type).
+ *
+ * @author carcassi, shroff
+ */
+public abstract class VTable extends VType {
+
+    /**
+     * The number of columns in the table.
+     *
+     * @return the number of columns
+     */
+    abstract int getColumnCount();
+
+    /**
+     * The number of rows in the table.
+     * <p>
+     * Currently, it is not clear whether all columns actually have the same number
+     * of rows, that is if all arrays have the same length. In the case of variable
+     * row, this will return the maximum row count, that is the length of the
+     * longest array/column.
+     *
+     * @return the number of rows
+     */
+    abstract int getRowCount();
+
+    /**
+     * The type of the elements in the column. The column array will be an array of
+     * the given type. For primitive types, this function will return the TYPE class
+     * (such as {@link Double#TYPE}, while {@link #getColumnData(int) } will return
+     * a {@link ListNumber}.
+     *
+     * @param column the column index
+     * @return the type of this column
+     */
+    abstract Class<?> getColumnType(int column);
+
+    /**
+     * The name of the given column.
+     *
+     * @param column the column index
+     * @return the name of the column
+     */
+    abstract String getColumnName(int column);
+
+    /**
+     * The data for the given column.
+     * <p>
+     * The data is going to be a {@link List} in case of objects or a
+     * {@link ListNumber} in case of a numeric primitive.
+     *
+     * @param column the column index
+     * @return the data of the column
+     */
+    abstract Object getColumnData(int column);
+
+    /**
+     * Create a new VTable
+     * 
+     * @param types the types of each column
+     * @param names the name of each column
+     * @param values the values of each column
+     * @return an immutable instance of the VTable
+     */
+    public static VTable of(List<Class<?>> types, List<String> names, List<Object> values) {
+        return new IVTable(types, names, values);
+    }
+}

epics-vtype/vtype/src/main/java/org/epics/vtype/VType.java

@@ -40,7 +40,8 @@ public abstract class VType {
             VShortArray.class,
             VUByteArray.class,
             VByteArray.class,
-            VImage.class);
+            VImage.class, 
+            VTable.class);
 
     /**
      * Returns the type of the object by returning the class object of one