| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * 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 android.util; |
| |
| import android.os.DeadSystemException; |
| |
| import com.android.internal.os.RuntimeInit; |
| import com.android.internal.util.FastPrintWriter; |
| import com.android.internal.util.LineBreakBufferedWriter; |
| |
| import java.io.PrintWriter; |
| import java.io.StringWriter; |
| import java.io.Writer; |
| import java.net.UnknownHostException; |
| |
| /** |
| * API for sending log output. |
| * |
| * <p>Generally, you should use the {@link #v Log.v()}, {@link #d Log.d()}, |
| * {@link #i Log.i()}, {@link #w Log.w()}, and {@link #e Log.e()} methods to write logs. |
| * You can then <a href="{@docRoot}studio/debug/am-logcat.html">view the logs in logcat</a>. |
| * |
| * <p>The order in terms of verbosity, from least to most is |
| * ERROR, WARN, INFO, DEBUG, VERBOSE. Verbose should never be compiled |
| * into an application except during development. Debug logs are compiled |
| * in but stripped at runtime. Error, warning and info logs are always kept. |
| * |
| * <p><b>Tip:</b> A good convention is to declare a <code>TAG</code> constant |
| * in your class: |
| * |
| * <pre>private static final String TAG = "MyActivity";</pre> |
| * |
| * and use that in subsequent calls to the log methods. |
| * </p> |
| * |
| * <p><b>Tip:</b> Don't forget that when you make a call like |
| * <pre>Log.v(TAG, "index=" + i);</pre> |
| * that when you're building the string to pass into Log.d, the compiler uses a |
| * StringBuilder and at least three allocations occur: the StringBuilder |
| * itself, the buffer, and the String object. Realistically, there is also |
| * another buffer allocation and copy, and even more pressure on the gc. |
| * That means that if your log message is filtered out, you might be doing |
| * significant work and incurring significant overhead. |
| */ |
| public final class Log { |
| |
| /** |
| * Priority constant for the println method; use Log.v. |
| */ |
| public static final int VERBOSE = 2; |
| |
| /** |
| * Priority constant for the println method; use Log.d. |
| */ |
| public static final int DEBUG = 3; |
| |
| /** |
| * Priority constant for the println method; use Log.i. |
| */ |
| public static final int INFO = 4; |
| |
| /** |
| * Priority constant for the println method; use Log.w. |
| */ |
| public static final int WARN = 5; |
| |
| /** |
| * Priority constant for the println method; use Log.e. |
| */ |
| public static final int ERROR = 6; |
| |
| /** |
| * Priority constant for the println method. |
| */ |
| public static final int ASSERT = 7; |
| |
| /** |
| * Exception class used to capture a stack trace in {@link #wtf}. |
| * @hide |
| */ |
| public static class TerribleFailure extends Exception { |
| TerribleFailure(String msg, Throwable cause) { super(msg, cause); } |
| } |
| |
| /** |
| * Interface to handle terrible failures from {@link #wtf}. |
| * |
| * @hide |
| */ |
| public interface TerribleFailureHandler { |
| void onTerribleFailure(String tag, TerribleFailure what, boolean system); |
| } |
| |
| private static TerribleFailureHandler sWtfHandler = new TerribleFailureHandler() { |
| public void onTerribleFailure(String tag, TerribleFailure what, boolean system) { |
| RuntimeInit.wtf(tag, what, system); |
| } |
| }; |
| |
| private Log() { |
| } |
| |
| /** |
| * Send a {@link #VERBOSE} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int v(String tag, String msg) { |
| return println_native(LOG_ID_MAIN, VERBOSE, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #VERBOSE} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int v(String tag, String msg, Throwable tr) { |
| return printlns(LOG_ID_MAIN, VERBOSE, tag, msg, tr); |
| } |
| |
| /** |
| * Send a {@link #DEBUG} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int d(String tag, String msg) { |
| return println_native(LOG_ID_MAIN, DEBUG, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #DEBUG} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int d(String tag, String msg, Throwable tr) { |
| return printlns(LOG_ID_MAIN, DEBUG, tag, msg, tr); |
| } |
| |
| /** |
| * Send an {@link #INFO} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int i(String tag, String msg) { |
| return println_native(LOG_ID_MAIN, INFO, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #INFO} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int i(String tag, String msg, Throwable tr) { |
| return printlns(LOG_ID_MAIN, INFO, tag, msg, tr); |
| } |
| |
| /** |
| * Send a {@link #WARN} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int w(String tag, String msg) { |
| return println_native(LOG_ID_MAIN, WARN, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #WARN} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int w(String tag, String msg, Throwable tr) { |
| return printlns(LOG_ID_MAIN, WARN, tag, msg, tr); |
| } |
| |
| /** |
| * Checks to see whether or not a log for the specified tag is loggable at the specified level. |
| * |
| * The default level of any tag is set to INFO. This means that any level above and including |
| * INFO will be logged. Before you make any calls to a logging method you should check to see |
| * if your tag should be logged. You can change the default level by setting a system property: |
| * 'setprop log.tag.<YOUR_LOG_TAG> <LEVEL>' |
| * Where level is either VERBOSE, DEBUG, INFO, WARN, ERROR, ASSERT, or SUPPRESS. SUPPRESS will |
| * turn off all logging for your tag. You can also create a local.prop file that with the |
| * following in it: |
| * 'log.tag.<YOUR_LOG_TAG>=<LEVEL>' |
| * and place that in /data/local.prop. |
| * |
| * @param tag The tag to check. |
| * @param level The level to check. |
| * @return Whether or not that this is allowed to be logged. |
| * @throws IllegalArgumentException is thrown if the tag.length() > 23 |
| * for Nougat (7.0) releases (API <= 23) and prior, there is no |
| * tag limit of concern after this API level. |
| */ |
| public static native boolean isLoggable(String tag, int level); |
| |
| /* |
| * Send a {@link #WARN} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param tr An exception to log |
| */ |
| public static int w(String tag, Throwable tr) { |
| return printlns(LOG_ID_MAIN, WARN, tag, "", tr); |
| } |
| |
| /** |
| * Send an {@link #ERROR} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int e(String tag, String msg) { |
| return println_native(LOG_ID_MAIN, ERROR, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #ERROR} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int e(String tag, String msg, Throwable tr) { |
| return printlns(LOG_ID_MAIN, ERROR, tag, msg, tr); |
| } |
| |
| /** |
| * What a Terrible Failure: Report a condition that should never happen. |
| * The error will always be logged at level ASSERT with the call stack. |
| * Depending on system configuration, a report may be added to the |
| * {@link android.os.DropBoxManager} and/or the process may be terminated |
| * immediately with an error dialog. |
| * @param tag Used to identify the source of a log message. |
| * @param msg The message you would like logged. |
| */ |
| public static int wtf(String tag, String msg) { |
| return wtf(LOG_ID_MAIN, tag, msg, null, false, false); |
| } |
| |
| /** |
| * Like {@link #wtf(String, String)}, but also writes to the log the full |
| * call stack. |
| * @hide |
| */ |
| public static int wtfStack(String tag, String msg) { |
| return wtf(LOG_ID_MAIN, tag, msg, null, true, false); |
| } |
| |
| /** |
| * What a Terrible Failure: Report an exception that should never happen. |
| * Similar to {@link #wtf(String, String)}, with an exception to log. |
| * @param tag Used to identify the source of a log message. |
| * @param tr An exception to log. |
| */ |
| public static int wtf(String tag, Throwable tr) { |
| return wtf(LOG_ID_MAIN, tag, tr.getMessage(), tr, false, false); |
| } |
| |
| /** |
| * What a Terrible Failure: Report an exception that should never happen. |
| * Similar to {@link #wtf(String, Throwable)}, with a message as well. |
| * @param tag Used to identify the source of a log message. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log. May be null. |
| */ |
| public static int wtf(String tag, String msg, Throwable tr) { |
| return wtf(LOG_ID_MAIN, tag, msg, tr, false, false); |
| } |
| |
| static int wtf(int logId, String tag, String msg, Throwable tr, boolean localStack, |
| boolean system) { |
| TerribleFailure what = new TerribleFailure(msg, tr); |
| // Only mark this as ERROR, do not use ASSERT since that should be |
| // reserved for cases where the system is guaranteed to abort. |
| // The onTerribleFailure call does not always cause a crash. |
| int bytes = printlns(logId, ERROR, tag, msg, localStack ? what : tr); |
| sWtfHandler.onTerribleFailure(tag, what, system); |
| return bytes; |
| } |
| |
| static void wtfQuiet(int logId, String tag, String msg, boolean system) { |
| TerribleFailure what = new TerribleFailure(msg, null); |
| sWtfHandler.onTerribleFailure(tag, what, system); |
| } |
| |
| /** |
| * Sets the terrible failure handler, for testing. |
| * |
| * @return the old handler |
| * |
| * @hide |
| */ |
| public static TerribleFailureHandler setWtfHandler(TerribleFailureHandler handler) { |
| if (handler == null) { |
| throw new NullPointerException("handler == null"); |
| } |
| TerribleFailureHandler oldHandler = sWtfHandler; |
| sWtfHandler = handler; |
| return oldHandler; |
| } |
| |
| /** |
| * Handy function to get a loggable stack trace from a Throwable |
| * @param tr An exception to log |
| */ |
| public static String getStackTraceString(Throwable tr) { |
| if (tr == null) { |
| return ""; |
| } |
| |
| // This is to reduce the amount of log spew that apps do in the non-error |
| // condition of the network being unavailable. |
| Throwable t = tr; |
| while (t != null) { |
| if (t instanceof UnknownHostException) { |
| return ""; |
| } |
| t = t.getCause(); |
| } |
| |
| StringWriter sw = new StringWriter(); |
| PrintWriter pw = new FastPrintWriter(sw, false, 256); |
| tr.printStackTrace(pw); |
| pw.flush(); |
| return sw.toString(); |
| } |
| |
| /** |
| * Low-level logging call. |
| * @param priority The priority/type of this log message |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @return The number of bytes written. |
| */ |
| public static int println(int priority, String tag, String msg) { |
| return println_native(LOG_ID_MAIN, priority, tag, msg); |
| } |
| |
| /** @hide */ public static final int LOG_ID_MAIN = 0; |
| /** @hide */ public static final int LOG_ID_RADIO = 1; |
| /** @hide */ public static final int LOG_ID_EVENTS = 2; |
| /** @hide */ public static final int LOG_ID_SYSTEM = 3; |
| /** @hide */ public static final int LOG_ID_CRASH = 4; |
| |
| /** @hide */ |
| public static native int println_native(int bufID, int priority, String tag, String msg); |
| |
| /** |
| * Return the maximum payload the log daemon accepts without truncation. |
| * @return LOGGER_ENTRY_MAX_PAYLOAD. |
| */ |
| private static native int logger_entry_max_payload_native(); |
| |
| /** |
| * Helper function for long messages. Uses the LineBreakBufferedWriter to break |
| * up long messages and stacktraces along newlines, but tries to write in large |
| * chunks. This is to avoid truncation. |
| * @hide |
| */ |
| public static int printlns(int bufID, int priority, String tag, String msg, |
| Throwable tr) { |
| ImmediateLogWriter logWriter = new ImmediateLogWriter(bufID, priority, tag); |
| // Acceptable buffer size. Get the native buffer size, subtract two zero terminators, |
| // and the length of the tag. |
| // Note: we implicitly accept possible truncation for Modified-UTF8 differences. It |
| // is too expensive to compute that ahead of time. |
| int bufferSize = PreloadHolder.LOGGER_ENTRY_MAX_PAYLOAD // Base. |
| - 2 // Two terminators. |
| - (tag != null ? tag.length() : 0) // Tag length. |
| - 32; // Some slack. |
| // At least assume you can print *some* characters (tag is not too large). |
| bufferSize = Math.max(bufferSize, 100); |
| |
| LineBreakBufferedWriter lbbw = new LineBreakBufferedWriter(logWriter, bufferSize); |
| |
| lbbw.println(msg); |
| |
| if (tr != null) { |
| // This is to reduce the amount of log spew that apps do in the non-error |
| // condition of the network being unavailable. |
| Throwable t = tr; |
| while (t != null) { |
| if (t instanceof UnknownHostException) { |
| break; |
| } |
| if (t instanceof DeadSystemException) { |
| lbbw.println("DeadSystemException: The system died; " |
| + "earlier logs will point to the root cause"); |
| break; |
| } |
| t = t.getCause(); |
| } |
| if (t == null) { |
| tr.printStackTrace(lbbw); |
| } |
| } |
| |
| lbbw.flush(); |
| |
| return logWriter.getWritten(); |
| } |
| |
| /** |
| * PreloadHelper class. Caches the LOGGER_ENTRY_MAX_PAYLOAD value to avoid |
| * a JNI call during logging. |
| */ |
| static class PreloadHolder { |
| public final static int LOGGER_ENTRY_MAX_PAYLOAD = |
| logger_entry_max_payload_native(); |
| } |
| |
| /** |
| * Helper class to write to the logcat. Different from LogWriter, this writes |
| * the whole given buffer and does not break along newlines. |
| */ |
| private static class ImmediateLogWriter extends Writer { |
| |
| private int bufID; |
| private int priority; |
| private String tag; |
| |
| private int written = 0; |
| |
| /** |
| * Create a writer that immediately writes to the log, using the given |
| * parameters. |
| */ |
| public ImmediateLogWriter(int bufID, int priority, String tag) { |
| this.bufID = bufID; |
| this.priority = priority; |
| this.tag = tag; |
| } |
| |
| public int getWritten() { |
| return written; |
| } |
| |
| @Override |
| public void write(char[] cbuf, int off, int len) { |
| // Note: using String here has a bit of overhead as a Java object is created, |
| // but using the char[] directly is not easier, as it needs to be translated |
| // to a C char[] for logging. |
| written += println_native(bufID, priority, tag, new String(cbuf, off, len)); |
| } |
| |
| @Override |
| public void flush() { |
| // Ignored. |
| } |
| |
| @Override |
| public void close() { |
| // Ignored. |
| } |
| } |
| } |