/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.elasticsearch.common.logging;
import java.util.HashSet;
import java.util.Set;
/**
* Format string for Elasticsearch log messages.
*/
public class LoggerMessageFormat {
static final char DELIM_START = '{';
static final char DELIM_STOP = '}';
static final String DELIM_STR = "{}";
private static final char ESCAPE_CHAR = '\\';
public static String format(final String messagePattern, final Object... argArray) {
return format(null, messagePattern, argArray);
}
public static String format(final String prefix, final String messagePattern, final Object... argArray) {
if (messagePattern == null) {
return null;
}
if (argArray == null) {
if (prefix == null) {
return messagePattern;
} else {
return prefix + messagePattern;
}
}
int i = 0;
int j;
final StringBuilder sbuf = new StringBuilder(messagePattern.length() + 50);
if (prefix != null) {
sbuf.append(prefix);
}
for (int L = 0; L < argArray.length; L++) {
j = messagePattern.indexOf(DELIM_STR, i);
if (j == -1) {
// no more variables
if (i == 0) { // this is a simple string
return messagePattern;
} else { // add the tail string which contains no variables and return
// the result.
sbuf.append(messagePattern.substring(i, messagePattern.length()));
return sbuf.toString();
}
} else {
if (isEscapedDelimiter(messagePattern, j)) {
if (!isDoubleEscaped(messagePattern, j)) {
L--; // DELIM_START was escaped, thus should not be incremented
sbuf.append(messagePattern.substring(i, j - 1));
sbuf.append(DELIM_START);
i = j + 1;
} else {
// The escape character preceding the delimiter start is
// itself escaped: "abc x:\\{}"
// we have to consume one backward slash
sbuf.append(messagePattern.substring(i, j - 1));
deeplyAppendParameter(sbuf, argArray[L], new HashSet<Object[]>());
i = j + 2;
}
} else {
// normal case
sbuf.append(messagePattern.substring(i, j));
deeplyAppendParameter(sbuf, argArray[L], new HashSet<Object[]>());
i = j + 2;
}
}
}
// append the characters following the last {} pair.
sbuf.append(messagePattern.substring(i, messagePattern.length()));
return sbuf.toString();
}
static boolean isEscapedDelimiter(String messagePattern,
int delimiterStartIndex) {
if (delimiterStartIndex == 0) {
return false;
}
char potentialEscape = messagePattern.charAt(delimiterStartIndex - 1);
if (potentialEscape == ESCAPE_CHAR) {
return true;
} else {
return false;
}
}
static boolean isDoubleEscaped(String messagePattern, int delimiterStartIndex) {
if (delimiterStartIndex >= 2 && messagePattern.charAt(delimiterStartIndex - 2) == ESCAPE_CHAR) {
return true;
} else {
return false;
}
}
private static void deeplyAppendParameter(StringBuilder sbuf, Object o, Set<Object[]> seen) {
if (o == null) {
sbuf.append("null");
return;
}
if (!o.getClass().isArray()) {
safeObjectAppend(sbuf, o);
} else {
// check for primitive array types because they
// unfortunately cannot be cast to Object[]
if (o instanceof boolean[]) {
booleanArrayAppend(sbuf, (boolean[]) o);
} else if (o instanceof byte[]) {
byteArrayAppend(sbuf, (byte[]) o);
} else if (o instanceof char[]) {
charArrayAppend(sbuf, (char[]) o);
} else if (o instanceof short[]) {
shortArrayAppend(sbuf, (short[]) o);
} else if (o instanceof int[]) {
intArrayAppend(sbuf, (int[]) o);
} else if (o instanceof long[]) {
longArrayAppend(sbuf, (long[]) o);
} else if (o instanceof float[]) {
floatArrayAppend(sbuf, (float[]) o);
} else if (o instanceof double[]) {
doubleArrayAppend(sbuf, (double[]) o);
} else {
objectArrayAppend(sbuf, (Object[]) o, seen);
}
}
}
private static void safeObjectAppend(StringBuilder sbuf, Object o) {
try {
String oAsString = o.toString();
sbuf.append(oAsString);
} catch (Exception e) {
sbuf.append("[FAILED toString()]");
}
}
private static void objectArrayAppend(StringBuilder sbuf, Object[] a, Set<Object[]> seen) {
sbuf.append('[');
if (!seen.contains(a)) {
seen.add(a);
final int len = a.length;
for (int i = 0; i < len; i++) {
deeplyAppendParameter(sbuf, a[i], seen);
if (i != len - 1)
sbuf.append(", ");
}
// allow repeats in siblings
seen.remove(a);
} else {
sbuf.append("...");
}
sbuf.append(']');
}
private static void booleanArrayAppend(StringBuilder sbuf, boolean[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
private static void byteArrayAppend(StringBuilder sbuf, byte[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
private static void charArrayAppend(StringBuilder sbuf, char[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
private static void shortArrayAppend(StringBuilder sbuf, short[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
private static void intArrayAppend(StringBuilder sbuf, int[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
private static void longArrayAppend(StringBuilder sbuf, long[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
private static void floatArrayAppend(StringBuilder sbuf, float[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
private static void doubleArrayAppend(StringBuilder sbuf, double[] a) {
sbuf.append('[');
final int len = a.length;
for (int i = 0; i < len; i++) {
sbuf.append(a[i]);
if (i != len - 1)
sbuf.append(", ");
}
sbuf.append(']');
}
}