org.apache.aurora.common.thrift.Util.java Source code

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Here is the source code for org.apache.aurora.common.thrift.Util.java

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/**
 * 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.
 */
package org.apache.aurora.common.thrift;

import java.util.List;
import java.util.Map;
import java.util.Set;

import com.google.common.base.Joiner;
import com.google.common.base.Strings;
import com.google.common.collect.Lists;

import org.apache.thrift.TBase;
import org.apache.thrift.TFieldIdEnum;
import org.apache.thrift.meta_data.FieldMetaData;

/**
 * Utility functions for thrift.
 *
 * @author William Farner
 */
public class Util {
    /**
     * Pretty-prints a thrift object contents.
     *
     * @param t The thrift object to print.
     * @return The pretty-printed version of the thrift object.
     */
    public static String prettyPrint(TBase t) {
        return t == null ? "null" : printTbase(t, 0);
    }

    /**
     * Prints an object contained in a thrift message.
     *
     * @param o The object to print.
     * @param depth The print nesting level.
     * @return The pretty-printed version of the thrift field.
     */
    private static String printValue(Object o, int depth) {
        if (o == null) {
            return "null";
        } else if (TBase.class.isAssignableFrom(o.getClass())) {
            return "\n" + printTbase((TBase) o, depth + 1);
        } else if (Map.class.isAssignableFrom(o.getClass())) {
            return printMap((Map) o, depth + 1);
        } else if (List.class.isAssignableFrom(o.getClass())) {
            return printList((List) o, depth + 1);
        } else if (Set.class.isAssignableFrom(o.getClass())) {
            return printSet((Set) o, depth + 1);
        } else if (String.class == o.getClass()) {
            return '"' + o.toString() + '"';
        } else {
            return o.toString();
        }
    }

    /**
     * Prints a TBase.
     *
     * @param t The object to print.
     * @param depth The print nesting level.
     * @return The pretty-printed version of the TBase.
     */
    private static String printTbase(TBase t, int depth) {
        List<String> fields = Lists.newArrayList();
        for (Map.Entry<? extends TFieldIdEnum, FieldMetaData> entry : FieldMetaData
                .getStructMetaDataMap(t.getClass()).entrySet()) {
            @SuppressWarnings("unchecked")
            boolean fieldSet = t.isSet(entry.getKey());
            String strValue;
            if (fieldSet) {
                @SuppressWarnings("unchecked")
                Object value = t.getFieldValue(entry.getKey());
                strValue = printValue(value, depth);
            } else {
                strValue = "not set";
            }
            fields.add(tabs(depth) + entry.getValue().fieldName + ": " + strValue);
        }

        return Joiner.on("\n").join(fields);
    }

    /**
     * Prints a map in a style that is consistent with TBase pretty printing.
     *
     * @param map The map to print
     * @param depth The print nesting level.
     * @return The pretty-printed version of the map.
     */
    private static String printMap(Map<?, ?> map, int depth) {
        List<String> entries = Lists.newArrayList();
        for (Map.Entry entry : map.entrySet()) {
            entries.add(
                    tabs(depth) + printValue(entry.getKey(), depth) + " = " + printValue(entry.getValue(), depth));
        }

        return entries.isEmpty() ? "{}"
                : String.format("{\n%s\n%s}", Joiner.on(",\n").join(entries), tabs(depth - 1));
    }

    /**
     * Prints a list in a style that is consistent with TBase pretty printing.
     *
     * @param list The list to print
     * @param depth The print nesting level.
     * @return The pretty-printed version of the list
     */
    private static String printList(List<?> list, int depth) {
        List<String> entries = Lists.newArrayList();
        for (int i = 0; i < list.size(); i++) {
            entries.add(String.format("%sItem[%d] = %s", tabs(depth), i, printValue(list.get(i), depth)));
        }

        return entries.isEmpty() ? "[]"
                : String.format("[\n%s\n%s]", Joiner.on(",\n").join(entries), tabs(depth - 1));
    }

    /**
     * Prints a set in a style that is consistent with TBase pretty printing.
     *
     * @param set The set to print
     * @param depth The print nesting level.
     * @return The pretty-printed version of the set
     */
    private static String printSet(Set<?> set, int depth) {
        List<String> entries = Lists.newArrayList();
        for (Object item : set) {
            entries.add(String.format("%sItem = %s", tabs(depth), printValue(item, depth)));
        }

        return entries.isEmpty() ? "{}"
                : String.format("{\n%s\n%s}", Joiner.on(",\n").join(entries), tabs(depth - 1));
    }

    private static String tabs(int n) {
        return Strings.repeat("  ", n);
    }

    private Util() {
        // Utility class.
    }
}