Various improvements to the tracking system

- Trackers are created per-user, meaning multiple people can run
   /computercraft track at once.
 - Allow sorting the tracking information by arbitrary fields.
 - Add support for tracking arbitrary fields (though none are currently
   implemented).

src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java

@@ -11,6 +11,7 @@ import dan200.computercraft.core.computer.Computer;
 import dan200.computercraft.core.computer.IComputerEnvironment;
 import dan200.computercraft.core.filesystem.FileSystem;
 import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.core.tracking.TrackingField;
 
 public interface IAPIEnvironment
 {
@@ -42,4 +43,6 @@ public interface IAPIEnvironment
 
     String getLabel();
     void setLabel( String label );
+
+    void addTrackingChange( TrackingField field, long change );
 }

src/main/java/dan200/computercraft/core/computer/Computer.java

@@ -20,6 +20,8 @@ import dan200.computercraft.core.filesystem.FileSystemException;
 import dan200.computercraft.core.lua.CobaltLuaMachine;
 import dan200.computercraft.core.lua.ILuaMachine;
 import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.core.tracking.Tracking;
+import dan200.computercraft.core.tracking.TrackingField;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -167,6 +169,12 @@ public class Computer
             m_computer.setLabel( label );
         }
 
+        @Override
+        public void addTrackingChange( TrackingField field, long change )
+        {
+            Tracking.addValue( m_computer, field, change );
+        }
+
         public void onPeripheralChanged( int side, IPeripheral peripheral )
         {
             synchronized( m_computer.m_peripherals )

src/main/java/dan200/computercraft/core/computer/ComputerThread.java

@@ -7,6 +7,7 @@
 package dan200.computercraft.core.computer;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.core.tracking.Tracking;
 
 import java.util.HashSet;
 import java.util.Set;
@@ -233,7 +234,7 @@ public class ComputerThread
             {
                 long stop = System.nanoTime();
                 Computer computer = task.getOwner();
-                if( computer != null ) ComputerTimeTracker.addTiming( computer, stop - start );
+                if( computer != null ) Tracking.addTiming( computer, stop - start );
                 
                 // Re-add it back onto the queue or remove it
                 synchronized( s_taskLock )

src/main/java/dan200/computercraft/core/computer/ComputerTimeTracker.java

@@ -1,116 +0,0 @@
-package dan200.computercraft.core.computer;
-
-import com.google.common.collect.MapMaker;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import java.lang.ref.WeakReference;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-
-/**
- * Tracks timing information about computers, including how long they ran for
- * and the number of events they handled.
- *
- * Note that this <em>will</em> track computers which have been deleted (hence
- * the presence of {@link #timingLookup} and {@link #timings}
- */
-public class ComputerTimeTracker
-{
-    public static class Timings
-    {
-        private final WeakReference<Computer> computer;
-        private final int computerId;
-
-        private int tasks;
-
-        private long totalTime;
-        private long maxTime;
-
-        public Timings( @Nonnull Computer computer )
-        {
-            this.computer = new WeakReference<>( computer );
-            this.computerId = computer.getID();
-        }
-
-        @Nullable
-        public Computer getComputer()
-        {
-            return computer.get();
-        }
-
-        public int getComputerId()
-        {
-            return computerId;
-        }
-
-        public int getTasks()
-        {
-            return tasks;
-        }
-
-        public long getTotalTime()
-        {
-            return totalTime;
-        }
-
-        public long getMaxTime()
-        {
-            return maxTime;
-        }
-
-        public double getAverage()
-        {
-            return totalTime / (double) tasks;
-        }
-
-        void update( long time )
-        {
-            tasks++;
-            totalTime += time;
-            if( time > maxTime ) maxTime = time;
-        }
-    }
-
-    private static boolean tracking;
-    private static final List<Timings> timings = new ArrayList<>();
-    private static final Map<Computer, Timings> timingLookup = new MapMaker().weakKeys().makeMap();
-
-    public synchronized static void start()
-    {
-        tracking = true;
-
-        timings.clear();
-        timingLookup.clear();
-    }
-
-    public synchronized static boolean stop()
-    {
-        if( !tracking ) return false;
-
-        tracking = false;
-        timingLookup.clear();
-        return true;
-    }
-
-    public static synchronized List<Timings> getTimings()
-    {
-        return new ArrayList<>( timings );
-    }
-
-    public static synchronized void addTiming( Computer computer, long time )
-    {
-        if( !tracking ) return;
-
-        Timings timings = ComputerTimeTracker.timingLookup.get( computer );
-        if( timings == null )
-        {
-            timings = new Timings( computer );
-            timingLookup.put( computer, timings );
-            ComputerTimeTracker.timings.add( timings );
-        }
-
-        timings.update( time );
-    }
-}

src/main/java/dan200/computercraft/core/tracking/ComputerTracker.java

@@ -0,0 +1,96 @@
+package dan200.computercraft.core.tracking;
+
+import dan200.computercraft.core.computer.Computer;
+import gnu.trove.map.hash.TObjectLongHashMap;
+
+import javax.annotation.Nullable;
+import java.lang.ref.WeakReference;
+
+public class ComputerTracker
+{
+    private final WeakReference<Computer> computer;
+    private final int computerId;
+
+    private long tasks;
+    private long totalTime;
+    private long maxTime;
+
+    private final TObjectLongHashMap<TrackingField> fields;
+
+    public ComputerTracker( Computer computer )
+    {
+        this.computer = new WeakReference<>( computer );
+        this.computerId = computer.getID();
+        this.fields = new TObjectLongHashMap<>();
+    }
+
+    ComputerTracker( ComputerTracker timings )
+    {
+        this.computer = timings.computer;
+        this.computerId = timings.computerId;
+
+        this.tasks = timings.tasks;
+        this.totalTime = timings.totalTime;
+        this.maxTime = timings.maxTime;
+        this.fields = new TObjectLongHashMap<>( timings.fields );
+    }
+
+
+    @Nullable
+    public Computer getComputer()
+    {
+        return computer.get();
+    }
+
+    public int getComputerId()
+    {
+        return computerId;
+    }
+
+    public long getTasks()
+    {
+        return tasks;
+    }
+
+    public long getTotalTime()
+    {
+        return totalTime;
+    }
+
+    public long getMaxTime()
+    {
+        return maxTime;
+    }
+
+    public long getAverage()
+    {
+        return totalTime / tasks;
+    }
+
+    void addTiming( long time )
+    {
+        tasks++;
+        totalTime += time;
+        if( time > maxTime ) maxTime = time;
+    }
+
+    void addValue( TrackingField field, long change )
+    {
+        fields.adjustOrPutValue( field, change, change );
+    }
+
+    public long get( TrackingField field )
+    {
+        if( field == TrackingField.TASKS ) return tasks;
+        if( field == TrackingField.MAX_TIME ) return maxTime;
+        if( field == TrackingField.TOTAL_TIME ) return totalTime;
+        if( field == TrackingField.AVERAGE_TIME ) return totalTime / tasks;
+
+        return fields.get( field );
+    }
+
+    public String getFormatted( TrackingField field )
+    {
+        return field.format( get( field ) );
+    }
+}

src/main/java/dan200/computercraft/core/tracking/Tracking.java

@@ -0,0 +1,52 @@
+package dan200.computercraft.core.tracking;
+
+import dan200.computercraft.core.computer.Computer;
+
+import java.util.HashMap;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class Tracking
+{
+    static final AtomicInteger tracking = new AtomicInteger( 0 );
+    private static final HashMap<UUID, TrackingContext> contexts = new HashMap<>();
+
+    public static TrackingContext getContext( UUID uuid )
+    {
+        synchronized( contexts )
+        {
+            TrackingContext context = contexts.get( uuid );
+            if( context == null ) contexts.put( uuid, context = new TrackingContext() );
+            return context;
+        }
+    }
+
+    public static void addTiming( Computer computer, long time )
+    {
+        if( tracking.get() == 0 ) return;
+
+        synchronized( contexts )
+        {
+            for( TrackingContext context : contexts.values() ) context.addTiming( computer, time );
+        }
+    }
+
+    public static void addValue( Computer computer, TrackingField field, long change )
+    {
+        if( tracking.get() == 0 ) return;
+
+        synchronized( contexts )
+        {
+            for( TrackingContext context : contexts.values() ) context.addValue( computer, field, change );
+        }
+    }
+
+    public static void reset()
+    {
+        synchronized( contexts )
+        {
+            contexts.clear();
+            tracking.set( 0 );
+        }
+    }
+}

src/main/java/dan200/computercraft/core/tracking/TrackingContext.java

@@ -0,0 +1,85 @@
+package dan200.computercraft.core.tracking;
+
+import com.google.common.collect.MapMaker;
+import dan200.computercraft.core.computer.Computer;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Tracks timing information about computers, including how long they ran for
+ * and the number of events they handled.
+ *
+ * Note that this <em>will</em> track computers which have been deleted (hence
+ * the presence of {@link #timingLookup} and {@link #timings}
+ */
+public class TrackingContext
+{
+    private boolean tracking = false;
+
+    private final List<ComputerTracker> timings = new ArrayList<>();
+    private final Map<Computer, ComputerTracker> timingLookup = new MapMaker().weakKeys().makeMap();
+
+    public synchronized void start()
+    {
+        if( !tracking ) Tracking.tracking.incrementAndGet();
+        tracking = true;
+
+        timings.clear();
+        timingLookup.clear();
+    }
+
+    public synchronized boolean stop()
+    {
+        if( !tracking ) return false;
+
+        Tracking.tracking.decrementAndGet();
+        tracking = false;
+        timingLookup.clear();
+        return true;
+    }
+
+    public synchronized List<ComputerTracker> getTimings()
+    {
+        ArrayList<ComputerTracker> timings = new ArrayList<>( this.timings.size() );
+        for( ComputerTracker timing : this.timings ) timings.add( new ComputerTracker( timing ) );
+        return timings;
+    }
+
+    public void addTiming( Computer computer, long time )
+    {
+        if( !tracking ) return;
+
+        synchronized( this )
+        {
+            ComputerTracker computerTimings = timingLookup.get( computer );
+            if( computerTimings == null )
+            {
+                computerTimings = new ComputerTracker( computer );
+                timingLookup.put( computer, computerTimings );
+                timings.add( computerTimings );
+            }
+
+            computerTimings.addTiming( time );
+        }
+    }
+
+    public synchronized void addValue( Computer computer, TrackingField field, long change )
+    {
+        if( !tracking ) return;
+
+        synchronized( this )
+        {
+            ComputerTracker computerTimings = timingLookup.get( computer );
+            if( computerTimings == null )
+            {
+                computerTimings = new ComputerTracker( computer );
+                timingLookup.put( computer, computerTimings );
+                timings.add( computerTimings );
+            }
+
+            computerTimings.addValue( field, change );
+        }
+    }
+}

src/main/java/dan200/computercraft/core/tracking/TrackingField.java

@@ -0,0 +1,54 @@
+package dan200.computercraft.core.tracking;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.LongFunction;
+
+public class TrackingField
+{
+    private static final Map<String, TrackingField> fields = new HashMap<>();
+
+    public static final TrackingField TASKS = TrackingField.of( "tasks", "Tasks", x -> String.format( "%4d", x ) );
+    public static final TrackingField TOTAL_TIME = TrackingField.of( "total", "Total time", x -> String.format( "%7.1fms", x / 1e6 ) );
+    public static final TrackingField AVERAGE_TIME = TrackingField.of( "average", "Average time", x -> String.format( "%4.1fms", x / 1e6 ) );
+    public static final TrackingField MAX_TIME = TrackingField.of( "max", "Max time", x -> String.format( "%5.1fms", x / 1e6 ) );
+
+    private final String id;
+    private final String displayName;
+    private final LongFunction<String> format;
+
+    public String id()
+    {
+        return id;
+    }
+
+    public String displayName()
+    {
+        return displayName;
+    }
+
+    private TrackingField( String id, String displayName, LongFunction<String> format )
+    {
+        this.id = id;
+        this.displayName = displayName;
+        this.format = format;
+    }
+
+    public String format( long value )
+    {
+        return format.apply( value );
+    }
+
+    public static TrackingField of( String id, String displayName, LongFunction<String> format )
+    {
+        TrackingField field = new TrackingField( id, displayName, format );
+        fields.put( id, field );
+        return field;
+    }
+
+    public static Map<String, TrackingField> fields()
+    {
+        return Collections.unmodifiableMap( fields );
+    }
+}

src/main/java/dan200/computercraft/shared/command/CommandComputerCraft.java

@@ -4,9 +4,13 @@ import com.google.common.collect.Sets;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.computer.Computer;
-import dan200.computercraft.core.computer.ComputerTimeTracker;
+import dan200.computercraft.core.tracking.ComputerTracker;
+import dan200.computercraft.core.tracking.Tracking;
+import dan200.computercraft.core.tracking.TrackingContext;
+import dan200.computercraft.core.tracking.TrackingField;
 import dan200.computercraft.shared.command.framework.*;
 import dan200.computercraft.shared.computer.core.ServerComputer;
+import net.minecraft.command.CommandBase;
 import net.minecraft.command.CommandException;
 import net.minecraft.command.ICommandSender;
 import net.minecraft.entity.Entity;
@@ -25,6 +29,8 @@ import static dan200.computercraft.shared.command.framework.ChatHelpers.*;
 
 public final class CommandComputerCraft extends CommandDelegate
 {
+    public static final UUID SYSTEM_UUID = new UUID( 0, 0 );
+
     public CommandComputerCraft()
     {
         super( create() );
@@ -311,7 +317,7 @@ public final class CommandComputerCraft extends CommandDelegate
             @Override
             public void execute( @Nonnull CommandContext context, @Nonnull List<String> arguments )
             {
-                ComputerTimeTracker.start();
+                getTimingContext( context ).start();
 
                 String stopCommand = "/" + context.parent().getFullPath() + " stop";
                 context.getSender().sendMessage( list(
@@ -330,20 +336,51 @@ public final class CommandComputerCraft extends CommandDelegate
             @Override
             public void execute( @Nonnull CommandContext context, @Nonnull List<String> arguments ) throws CommandException
             {
-                if( !ComputerTimeTracker.stop() ) throw new CommandException( "Tracking not enabled" );
-                displayTimings( context );
+                TrackingContext timings = getTimingContext( context );
+                if( !timings.stop() ) throw new CommandException( "Tracking not enabled" );
+                displayTimings( context, timings.getTimings(), TrackingField.AVERAGE_TIME );
             }
         } );
 
         track.register( new SubCommandBase(
-            "dump", "Dump the latest track results", UserLevel.OWNER_OP,
+            "dump", "[kind]", "Dump the latest track results", UserLevel.OWNER_OP,
             "Dump the latest results of computer tracking."
         )
         {
             @Override
             public void execute( @Nonnull CommandContext context, @Nonnull List<String> arguments ) throws CommandException
             {
-                displayTimings( context );
+                TrackingField field = TrackingField.AVERAGE_TIME;
+                if( arguments.size() >= 1 )
+                {
+                    field = TrackingField.fields().get( arguments.get( 0 ) );
+                    if( field == null ) throw new CommandException( "Unknown field '" + arguments.get( 0 ) + "'" );
+                }
+
+                displayTimings( context, getTimingContext( context ).getTimings(), field );
+            }
+
+            @Nonnull
+            @Override
+            public List<String> getCompletion( @Nonnull CommandContext context, @Nonnull List<String> arguments )
+            {
+                if( arguments.size() == 1 )
+                {
+                    String match = arguments.get( 0 );
+
+                    List<String> out = new ArrayList<>();
+                    for( String key : TrackingField.fields().keySet() )
+                    {
+                        if( CommandBase.doesStringStartWith( match, key ) ) out.add( key );
+                    }
+
+                    out.sort( Comparator.naturalOrder() );
+                    return out;
+                }
+                else
+                {
+                    return super.getCompletion( context, arguments );
+                }
             }
         } );
 
@@ -390,13 +427,22 @@ public final class CommandComputerCraft extends CommandDelegate
         }
     }
 
-    private static void displayTimings( CommandContext context ) throws CommandException
+    private static TrackingContext getTimingContext( CommandContext context )
     {
-        List<ComputerTimeTracker.Timings> timings = ComputerTimeTracker.getTimings();
-        if( timings.isEmpty() ) throw new CommandException( "No timings available" );
+        Entity entity = context.getSender().getCommandSenderEntity();
+        if( entity instanceof EntityPlayerMP )
+        {
+            return Tracking.getContext( entity.getUniqueID() );
+        }
+        else
+        {
+            return Tracking.getContext( SYSTEM_UUID );
+        }
+    }
 
-        timings.sort( Comparator.comparing( ComputerTimeTracker.Timings::getAverage ).reversed() );
-        TextTable table = new TextTable( "Computer", "Tasks", "Total", "Average", "Maximum" );
+    private static void displayTimings( CommandContext context, List<ComputerTracker> timings, TrackingField field ) throws CommandException
+    {
+        if( timings.isEmpty() ) throw new CommandException( "No timings available" );
 
         Map<Computer, ServerComputer> lookup = new HashMap<>();
         int maxId = 0, maxInstance = 0;
@@ -411,7 +457,17 @@ public final class CommandComputerCraft extends CommandDelegate
         ICommandSender sender = context.getSender();
         boolean isPlayer = sender instanceof EntityPlayerMP && !(sender instanceof FakePlayer);
 
-        for( ComputerTimeTracker.Timings entry : timings )
+        timings.sort( Comparator.<ComputerTracker, Long>comparing( x -> x.get( field ) ).reversed() );
+
+        boolean defaultLayout = field == TrackingField.TASKS || field == TrackingField.TOTAL_TIME
+            || field == TrackingField.AVERAGE_TIME || field == TrackingField.MAX_TIME;
+
+
+        TextTable table = defaultLayout
+            ? new TextTable( "Computer", "Tasks", "Total", "Average", "Maximum" )
+            : new TextTable( "Computer", field.displayName() );
+
+        for( ComputerTracker entry : timings )
         {
             Computer computer = entry.getComputer();
             ServerComputer serverComputer = computer == null ? null : lookup.get( computer );
@@ -437,14 +493,21 @@ public final class CommandComputerCraft extends CommandDelegate
                     ) );
             }
 
+            if( defaultLayout )
+            {
                 table.addRow(
                     computerComponent,
-                formatted( "%4d", entry.getTasks() ),
-                text( String.format( "%7.1f", entry.getTotalTime() / 1e6 ) + "ms" ),
-                text( String.format( "%4.1f", entry.getAverage() / 1e6 ) + "ms" ),
-                text( String.format( "%5.1f", entry.getMaxTime() / 1e6 ) + "ms" )
+                    text( entry.getFormatted( TrackingField.TASKS ) ),
+                    text( entry.getFormatted( TrackingField.TOTAL_TIME ) ),
+                    text( entry.getFormatted( TrackingField.AVERAGE_TIME ) ),
+                    text( entry.getFormatted( TrackingField.MAX_TIME ) )
                 );
             }
+            else
+            {
+                table.addRow( computerComponent, text( entry.getFormatted( field ) ) );
+            }
+        }
 
         table.displayTo( context.getSender() );
     }