Move Android TraceEvent interface to base

content/public/android/java/src/org/chromium/content/common/PerfTraceEvent.java

Index: content/public/android/java/src/org/chromium/content/common/PerfTraceEvent.java
diff --git a/content/public/android/java/src/org/chromium/content/common/PerfTraceEvent.java b/content/public/android/java/src/org/chromium/content/common/PerfTraceEvent.java
deleted file mode 100644
index b86fadcbb116014bf0048162c238308e2056c3ab..0000000000000000000000000000000000000000
--- a/content/public/android/java/src/org/chromium/content/common/PerfTraceEvent.java
+++ /dev/null
@@ -1,366 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.

[bulach, 2014/01/09 14:54:50]

see below, I think it'd be simpler to keep the public interface for a bit rather
than deleting it all at once..

[aberent, 2014/01/09 17:35:29]

Done.

-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.content.common;
-
-import android.os.Debug;
-import android.os.Debug.MemoryInfo;
-import android.util.Log;
-
-import org.json.JSONArray;
-import org.json.JSONException;
-import org.json.JSONObject;
-
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.PrintStream;
-import java.util.LinkedList;
-import java.util.List;
-
-/**
- * PerfTraceEvent can be used like TraceEvent, but is intended for
- * performance measurement.  By limiting the types of tracing we hope
- * to minimize impact on measurement.
- *
- * All PerfTraceEvent events funnel into TraceEvent. When not doing
- * performance measurements, they act the same.  However,
- * PerfTraceEvents can be enabled even when TraceEvent is not.
- *
- * Unlike TraceEvent, PerfTraceEvent data is sent to the system log,
- * not to a trace file.
- *
- * Performance events need to have very specific names so we find
- * the right ones.  For example, we specify the name exactly in
- * the @TracePerf annotation.  Thus, unlike TraceEvent, we do not
- * support an implicit trace name based on the callstack.
- */
-public class PerfTraceEvent {
-    private static final int MAX_NAME_LENGTH = 40;
-    private static final String MEMORY_TRACE_NAME_SUFFIX = "_BZR_PSS";
-    private static File sOutputFile = null;
-
-    /** The event types understood by the perf trace scripts. */
-    private enum EventType {
-        START("S"),
-        FINISH("F"),
-        INSTANT("I");
-
-        // The string understood by the trace scripts.
-        private final String mTypeStr;
-
-        EventType(String typeStr) {
-            mTypeStr = typeStr;
-        }
-
-        @Override
-        public String toString() {
-            return mTypeStr;
-        }
-    }
-
-    private static boolean sEnabled = false;
-    private static boolean sTrackTiming = true;
-    private static boolean sTrackMemory = false;
-
-    // A list of performance trace event strings.
-    // Events are stored as a JSON dict much like TraceEvent.
-    // E.g. timestamp is in microseconds.
-    private static JSONArray sPerfTraceStrings;
-
-    // A filter for performance tracing.  Only events that match a
-    // string in the list are saved.  Presence of a filter does not
-    // necessarily mean perf tracing is enabled.
-    private static List<String> sFilter;
-
-    // Nanosecond start time of performance tracing.
-    private static long sBeginNanoTime;
-
-    /**
-     * Specifies what event names will be tracked.
-     *
-     * @param strings Event names we will record.
-     */
-    public static synchronized void setFilter(List<String> strings) {
-        sFilter = new LinkedList<String>(strings);
-    }
-
-    /**
-     * Enable or disable perf tracing.
-     * Disabling of perf tracing will dump trace data to the system log.
-     */
-    public static synchronized void setEnabled(boolean enabled) {
-        if (sEnabled == enabled) {
-            return;
-        }
-        if (enabled) {
-            sBeginNanoTime = System.nanoTime();
-            sPerfTraceStrings = new JSONArray();
-        } else {
-            dumpPerf();
-            sPerfTraceStrings = null;
-            sFilter = null;
-        }
-        sEnabled = enabled;
-    }
-
-    /**
-     * Enables memory tracking for all timing perf events tracked.
-     *
-     * <p>
-     * Only works when called in combination with {@link #setEnabled(boolean)}.
-     *
-     * <p>
-     * By enabling this feature, an additional perf event containing the memory usage will be
-     * logged whenever {@link #instant(String)}, {@link #begin(String)}, or {@link #end(String)}
-     * is called.
-     *
-     * @param enabled Whether to enable memory tracking for all perf events.
-     */
-    public static synchronized void setMemoryTrackingEnabled(boolean enabled) {
-        sTrackMemory = enabled;
-    }
-
-    /**
-     * Enables timing tracking for all perf events tracked.
-     *
-     * <p>
-     * Only works when called in combination with {@link #setEnabled(boolean)}.
-     *
-     * <p>
-     * If this feature is enabled, whenever {@link #instant(String)}, {@link #begin(String)},
-     * or {@link #end(String)} is called the time since start of tracking will be logged.
-     *
-     * @param enabled Whether to enable timing tracking for all perf events.
-     */
-    public static synchronized void setTimingTrackingEnabled(boolean enabled) {
-        sTrackTiming = enabled;
-    }
-
-    /**
-     * @return True if tracing is enabled, false otherwise.
-     * It is safe to call trace methods without checking if PerfTraceEvent
-     * is enabled.
-     */
-    public static synchronized boolean enabled() {
-        return sEnabled;
-    }
-
-    /**
-     * Record an "instant" perf trace event.  E.g. "screen update happened".
-     */
-    public static synchronized void instant(String name) {
-        // Instant doesn't really need/take an event id, but this should be okay.
-        final long eventId = name.hashCode();
-        TraceEvent.instant(name);
-        if (sEnabled && matchesFilter(name)) {
-            savePerfString(name, eventId, EventType.INSTANT, false);
-        }
-    }
-
-
-    /**
-     * Record an "begin" perf trace event.
-     * Begin trace events should have a matching end event.
-     */
-    public static synchronized void begin(String name) {
-        final long eventId = name.hashCode();
-        TraceEvent.startAsync(name, eventId);
-        if (sEnabled && matchesFilter(name)) {
-            // Done before calculating the starting perf data to ensure calculating the memory usage
-            // does not influence the timing data.
-            if (sTrackMemory) {
-                savePerfString(makeMemoryTraceNameFromTimingName(name), eventId, EventType.START,
-                        true);
-            }
-            if (sTrackTiming) {
-                savePerfString(name, eventId, EventType.START, false);
-            }
-        }
-    }
-
-    /**
-     * Record an "end" perf trace event, to match a begin event.  The
-     * time delta between begin and end is usually interesting to
-     * graph code.
-     */
-    public static synchronized void end(String name) {
-        final long eventId = name.hashCode();
-        TraceEvent.finishAsync(name, eventId);
-        if (sEnabled && matchesFilter(name)) {
-            if (sTrackTiming) {
-                savePerfString(name, eventId, EventType.FINISH, false);
-            }
-            // Done after calculating the ending perf data to ensure calculating the memory usage
-            // does not influence the timing data.
-            if (sTrackMemory) {
-                savePerfString(makeMemoryTraceNameFromTimingName(name), eventId, EventType.FINISH,
-                        true);
-            }
-        }
-    }
-
-    /**
-     * Record an "begin" memory trace event.
-     * Begin trace events should have a matching end event.
-     */
-    public static synchronized void begin(String name, MemoryInfo memoryInfo) {
-        final long eventId = name.hashCode();
-        TraceEvent.startAsync(name, eventId);
-        if (sEnabled && matchesFilter(name)) {
-            // Done before calculating the starting perf data to ensure calculating the memory usage
-            // does not influence the timing data.
-            long timestampUs = (System.nanoTime() - sBeginNanoTime) / 1000;
-            savePerfString(makeMemoryTraceNameFromTimingName(name), eventId, EventType.START,
-                    timestampUs, memoryInfo);
-            if (sTrackTiming) {
-                savePerfString(name, eventId, EventType.START, false);
-            }
-        }
-    }
-
-    /**
-     * Record an "end" memory trace event, to match a begin event.  The
-     * memory usage delta between begin and end is usually interesting to
-     * graph code.
-     */
-    public static synchronized void end(String name, MemoryInfo memoryInfo) {
-        final long eventId = name.hashCode();
-        TraceEvent.finishAsync(name, eventId);
-        if (sEnabled && matchesFilter(name)) {
-            if (sTrackTiming) {
-                savePerfString(name, eventId, EventType.FINISH, false);
-            }
-            // Done after calculating the instant perf data to ensure calculating the memory usage
-            // does not influence the timing data.
-            long timestampUs = (System.nanoTime() - sBeginNanoTime) / 1000;
-            savePerfString(makeMemoryTraceNameFromTimingName(name), eventId, EventType.FINISH,
-                    timestampUs, memoryInfo);
-        }
-    }
-
-    /**
-     * Determine if we are interested in this trace event.
-     * @return True if the name matches the allowed filter; else false.
-     */
-    private static boolean matchesFilter(String name) {
-        return sFilter != null ? sFilter.contains(name) : false;
-    }
-
-    /**
-     * Save a perf trace event as a JSON dict.  The format mirrors a TraceEvent dict.
-     *
-     * @param name The trace data
-     * @param id The id of the event
-     * @param type the type of trace event (I, S, F)
-     * @param includeMemory Whether to include current browser process memory usage in the trace.
-     */
-    private static void savePerfString(String name, long id, EventType type,
-            boolean includeMemory) {
-        long timestampUs = (System.nanoTime() - sBeginNanoTime) / 1000;
-        MemoryInfo memInfo = null;
-        if (includeMemory) {
-            memInfo = new MemoryInfo();
-            Debug.getMemoryInfo(memInfo);
-        }
-        savePerfString(name, id, type, timestampUs, memInfo);
-    }
-
-    /**
-     * Save a perf trace event as a JSON dict.  The format mirrors a TraceEvent dict.
-     *
-     * @param name The trace data
-     * @param id The id of the event
-     * @param type the type of trace event (I, S, F)
-     * @param timestampUs The time stamp at which this event was recorded
-     * @param memoryInfo Memory details to be included in this perf string, null if
-     *                   no memory details are to be included.
-     */
-    private static void savePerfString(String name, long id, EventType type, long timestampUs,
-            MemoryInfo memoryInfo) {
-        try {
-            JSONObject traceObj = new JSONObject();
-            traceObj.put("cat", "Java");
-            traceObj.put("ts", timestampUs);
-            traceObj.put("ph", type);
-            traceObj.put("name", name);
-            traceObj.put("id", id);
-            if (memoryInfo != null) {
-                int pss = memoryInfo.nativePss + memoryInfo.dalvikPss + memoryInfo.otherPss;
-                traceObj.put("mem", pss);
-            }
-            sPerfTraceStrings.put(traceObj);
-        } catch (JSONException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    /**
-     * Generating a trace name for tracking memory based on the timing name passed in.
-     *
-     * @param name The timing name to use as a base for the memory perf name.
-     * @return The memory perf name to use.
-     */
-    public static String makeMemoryTraceNameFromTimingName(String name) {
-        return makeSafeTraceName(name, MEMORY_TRACE_NAME_SUFFIX);
-    }
-
-    /**
-     * Builds a name to be used in the perf trace framework.  The framework has length requirements
-     * for names, so this ensures the generated name does not exceed the maximum (trimming the
-     * base name if necessary).
-     *
-     * @param baseName The base name to use when generating the name.
-     * @param suffix The required suffix to be appended to the name.
-     * @return A name that is safe for the perf trace framework.
-     */
-    public static String makeSafeTraceName(String baseName, String suffix) {
-        int suffixLength = suffix.length();
-
-        if (baseName.length() + suffixLength > MAX_NAME_LENGTH) {
-            baseName = baseName.substring(0, MAX_NAME_LENGTH - suffixLength);
-        }
-        return baseName + suffix;
-    }
-
-    /**
-     * Sets a file to dump the results to.  If {@code file} is {@code null}, it will be dumped
-     * to STDOUT, otherwise the JSON performance data will be appended to {@code file}.  This should
-     * be called before the performance run starts.  When {@link #setEnabled(boolean)} is called
-     * with {@code false}, the perf data will be dumped.
-     *
-     * @param file Which file to append the performance data to.  If {@code null}, the performance
-     *             data will be sent to STDOUT.
-     */
-    public static synchronized void setOutputFile(File file) {
-        sOutputFile = file;
-    }
-
-    /**
-     * Dump all performance data we have saved up to the log.
-     * Output as JSON for parsing convenience.
-     */
-    private static void dumpPerf() {
-        String json = sPerfTraceStrings.toString();
-
-        if (sOutputFile == null) {
-            System.out.println(json);
-        } else {
-            try {
-                PrintStream stream = new PrintStream(new FileOutputStream(sOutputFile, true));
-                try {
-                    stream.print(json);
-                } finally {
-                    try {
-                        stream.close();
-                    } catch (Exception ex) {
-                        Log.e("PerfTraceEvent", "Unable to close perf trace output file.");
-                    }
-                }
-            } catch (FileNotFoundException ex) {
-                Log.e("PerfTraceEvent", "Unable to dump perf trace data to output file.");
-            }
-        }
-    }
-}