org.glowroot.instrumentation.api.Message Maven / Gradle / Ivy
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/*
* Copyright 2011-2019 the original author or authors.
*
* 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.glowroot.instrumentation.api;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.glowroot.instrumentation.api.checker.Nullable;
import org.glowroot.instrumentation.api.checker.PolyNull;
import org.glowroot.instrumentation.api.internal.ReadableMessage;
/**
* The detail map can contain only {@link String}, {@link Number}, {@link Boolean} and null values.
* It can also contain nested lists and maps whose values are one of the above types (including
* other lists and maps). Nested maps cannot have null keys.
*
* The detail map does not need to be thread safe as long as it is only instantiated in response to
* either MessageSupplier.get() or Message.getDetail() which are called by the thread that needs the
* map.
*/
public abstract class Message {
private static final int MESSAGE_CHAR_LIMIT = 100000;
private static final int MESSAGE_DETAIL_CHAR_LIMIT = 10000;
private static final String[] EMPTY_ARGS = new String[0];
private static final Map EMPTY_DETAIL = Collections.emptyMap();
// accepts null message so callers don't have to check if passing it in from elsewhere
public static Message create(@Nullable String message) {
return new MessageImpl(message, EMPTY_ARGS, EMPTY_DETAIL);
}
// does not copy args
public static Message create(String template, @Nullable String... args) {
return new MessageImpl(template, args, EMPTY_DETAIL);
}
// accepts null message so callers don't have to check if passing it in from elsewhere
public static Message create(@Nullable String message, Map detail) {
return new MessageImpl(message, EMPTY_ARGS, detail);
}
Message() {}
// implementing ReadableMessage is just a way to access this class by agent implementors without
// making it (obviously) accessible to instrumentation implementations
private static class MessageImpl extends Message implements ReadableMessage {
private static final Logger logger = Logger.getLogger(MessageImpl.class);
private final @Nullable String template;
private final @Nullable String[] args;
private final Map detail;
private MessageImpl(@Nullable String template, @Nullable String[] args,
Map detail) {
this.template = truncateMessageIfNeeded(template);
for (int i = 0; i < args.length; i++) {
args[i] = truncateMessageIfNeeded(args[i]);
}
this.args = args;
if (needsTruncateDetail(detail)) {
this.detail = truncateDetail(detail);
} else {
this.detail = detail;
}
}
@Override
public String getText() {
if (template == null) {
return "";
}
if (args.length == 0) {
return template;
}
// Matcher.appendReplacement() can't be used here since appendReplacement() applies
// special meaning to slashes '\' and dollar signs '$' in the replacement text.
// These special characters can be escaped in the replacement text via
// Matcher.quoteReplacemenet(), but the implementation below feels slightly more
// performant and not much more complex
StringBuilder text = new StringBuilder();
int curr = 0;
int next;
int argIndex = 0;
while ((next = template.indexOf("{}", curr)) != -1) {
text.append(template.substring(curr, next));
if (argIndex < args.length) {
// arg may be null but that is ok, StringBuilder will append "null"
text.append(args[argIndex++]);
curr = next + 2; // +2 to skip over "{}"
} else {
text.append("");
curr = next + 2; // +2 to skip over "{}"
logger.warn("not enough args provided for template: {}", template);
}
}
text.append(template.substring(curr));
return truncateMessageIfNeeded(text.toString());
}
@Override
public Map getDetail() {
return detail;
}
private static @PolyNull String truncateMessageIfNeeded(@PolyNull String s) {
if (s == null || s.length() <= MESSAGE_CHAR_LIMIT) {
return s;
} else {
return s.substring(0, MESSAGE_CHAR_LIMIT) + " [truncated to " + MESSAGE_CHAR_LIMIT
+ " characters]";
}
}
private static boolean needsTruncateDetail(Map detail) {
for (Map.Entry entry : detail.entrySet()) {
Object key = entry.getKey();
if (key instanceof String && needsTruncateDetail((String) key)) {
return true;
}
if (needsTruncateDetail(entry.getValue())) {
return true;
}
}
return false;
}
private static boolean needsTruncateDetail(@Nullable Object value) {
if (value instanceof Map) {
return needsTruncateDetail((Map) value);
} else if (value instanceof List) {
return needsTruncateDetail((List) value);
} else if (value instanceof String) {
return needsTruncateDetail((String) value);
} else {
return false;
}
}
private static boolean needsTruncateDetail(List detail) {
for (Object value : detail) {
if (needsTruncateDetail(value)) {
return true;
}
}
return false;
}
private static boolean needsTruncateDetail(String value) {
return value.length() > MESSAGE_DETAIL_CHAR_LIMIT;
}
private static Map truncateDetail(Map detail) {
// cannot use immutable map since detail map may contain null values
Map truncatedDetail =
new HashMap();
for (Map.Entry entry : detail.entrySet()) {
truncatedDetail.put(truncateDetailIfNeeded(entry.getKey()),
truncate(entry.getValue()));
}
return truncatedDetail;
}
private static @Nullable Object truncate(@Nullable Object value) {
if (value instanceof Map) {
return truncateDetailNested((Map) value);
} else if (value instanceof List) {
return truncateDetail((List) value);
} else if (value instanceof String) {
return truncateDetailIfNeeded((String) value);
} else {
return value;
}
}
private static Map truncateDetailNested(Map detail) {
// cannot use immutable map since detail map may contain null values
Map truncatedDetail =
new HashMap();
for (Map.Entry entry : detail.entrySet()) {
Object key = entry.getKey();
if (key instanceof String) {
key = truncateDetailIfNeeded((String) key);
}
truncatedDetail.put(key, truncate(entry.getValue()));
}
return truncatedDetail;
}
private static List truncateDetail(List detail) {
// cannot use immutable list since detail list may contain null values
List truncatedDetail = new ArrayList();
for (Object value : detail) {
truncatedDetail.add(truncate(value));
}
return truncatedDetail;
}
private static String truncateDetailIfNeeded(String s) {
if (s.length() <= MESSAGE_DETAIL_CHAR_LIMIT) {
return s;
} else {
return s.substring(0, MESSAGE_DETAIL_CHAR_LIMIT) + " [truncated to "
+ MESSAGE_DETAIL_CHAR_LIMIT + " characters]";
}
}
}
}