src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandEventHandler.java - bazel - Git at Google

 // Copyright 2014 The Bazel Authors. All rights reserved.
 //
 // 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 com.google.devtools.build.lib.runtime;

 import com.google.common.eventbus.Subscribe;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.events.EventKind;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
 import com.google.devtools.build.lib.util.io.OutErr;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.common.options.EnumConverter;
 import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionDocumentationCategory;
 import com.google.devtools.common.options.OptionEffectTag;
 import com.google.devtools.common.options.OptionMetadataTag;
 import com.google.devtools.common.options.OptionsBase;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintStream;
 import java.nio.charset.StandardCharsets;
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.EnumSet;
 import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;

 /**
  * BlazeCommandEventHandler: an event handler established for the duration of a
  * single Blaze command.
  */
 public class BlazeCommandEventHandler implements EventHandler {

   private static final Logger logger = Logger.getLogger(BlazeCommandEventHandler.class.getName());

   public enum UseColor { YES, NO, AUTO }
   public enum UseCurses { YES, NO, AUTO }

   public static class UseColorConverter extends EnumConverter<UseColor> {
     public UseColorConverter() {
       super(UseColor.class, "--color setting");
     }
   }

   public static class UseCursesConverter extends EnumConverter<UseCurses> {
     public UseCursesConverter() {
       super(UseCurses.class, "--curses setting");
     }
   }

   public static class Options extends OptionsBase {

     @Option(
       name = "show_progress",
       defaultValue = "true",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Display progress messages during a build."
     )
     public boolean showProgress;

     @Option(
       name = "show_task_finish",
       defaultValue = "false",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Display progress messages when tasks complete, not just when they start."
     )
     public boolean showTaskFinish;

     @Option(
       name = "show_progress_rate_limit",
       defaultValue = "0.2", // A nice middle ground; snappy but not too spammy in logs.
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Minimum number of seconds between progress messages in the output."
     )
     public double showProgressRateLimit;

     @Option(
       name = "color",
       defaultValue = "auto",
       converter = UseColorConverter.class,
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Use terminal controls to colorize output going to stderr."
     )
     public UseColor useColorEnum;

     @Option(
       name = "curses",
       defaultValue = "auto",
       converter = UseCursesConverter.class,
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Use terminal cursor controls to minimize scrolling output going to stderr."
     )
     public UseCurses useCursesEnum;

     @Option(
       name = "terminal_columns",
       defaultValue = "80",
       metadataTags = {OptionMetadataTag.HIDDEN},
       documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "A system-generated parameter which specifies the terminal width in columns."
     )
     public int terminalColumns;

     @Option(
       name = "is_stderr_atty",
       // TODO(b/63386499): Old name should be removed after 2019-02-28.
       oldName = "isatty",
       defaultValue = "false",
       metadataTags = {OptionMetadataTag.HIDDEN},
       documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help =
           "A system-generated parameter which is used to notify the server whether this client is"
               + " running in a terminal.  If this is set to false, then '--color=auto' will be"
               + " treated as '--color=no'.  If this is set to true, then '--color=auto' will be"
               + " treated as '--color=yes'.  As we only treat the stderr as a terminal, we only"
               + " care if that file descriptor is connected to a TTY."
     )
     public boolean isStderrATty;

     // This lives here (as opposed to the more logical BuildRequest.Options)
     // because the client passes it to the server *always*.  We don't want the
     // client to have to figure out when it should or shouldn't to send it.
     @Option(
       name = "emacs",
       defaultValue = "false",
       documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help =
           "A system-generated parameter which is true iff EMACS=t or INSIDE_EMACS is set "
               + "in the environment of the client.  This option controls certain display "
               + "features."
     )
     public boolean runningInEmacs;

     @Option(
       name = "show_timestamps",
       defaultValue = "false",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Include timestamps in messages"
     )
     public boolean showTimestamp;

     @Option(
         name = "progress_in_terminal_title",
         defaultValue = "false",
         documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
         effectTags = {OptionEffectTag.UNKNOWN},
         help =
             "Show the command progress in the terminal title. "
                 + "Useful to see what bazel is doing when having multiple terminal tabs.")
     public boolean progressInTermTitle;

     @Option(
       name = "experimental_external_repositories",
       defaultValue = "false",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Use external repositories for improved stability and speed when available."
     )
     public boolean externalRepositories;

     @Option(
       name = "force_experimental_external_repositories",
       defaultValue = "false",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Forces --experimental_external_repositories."
     )
     public boolean forceExternalRepositories;

     @Option(
         name = "attempt_to_print_relative_paths",
         oldName = "experimental_ui_attempt_to_print_relative_paths",
         defaultValue = "false",
         documentationCategory = OptionDocumentationCategory.LOGGING,
         effectTags = {OptionEffectTag.TERMINAL_OUTPUT},
         help =
             "When printing the location part of messages, attempt to use a path relative to the "
                 + "workspace directory or one of the directories specified by --package_path.")
     public boolean attemptToPrintRelativePaths;

     @Option(
       name = "experimental_ui",
       defaultValue = "true",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help =
           "Switches to an alternative progress bar that more explicitly shows progress, such "
               + "as loaded packages and executed actions."
     )
     public boolean experimentalUi;

     @Option(
       name = "experimental_ui_debug_all_events",
       defaultValue = "false",
       metadataTags = {OptionMetadataTag.HIDDEN},
       documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help = "Report all events known to the experimental new Bazel UI."
     )
     public boolean experimentalUiDebugAllEvents;

     @Option(
       name = "experimental_ui_actions_shown",
       defaultValue = "8",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help =
           "Number of concurrent actions shown in the alternative progress bar; each "
               + "action is shown on a separate line. The alternative progress bar always shows "
               + "at least one one, all numbers less than 1 are mapped to 1. "
               + "This option has no effect unless --experimental_ui is set."
     )
     public int experimentalUiActionsShown;

     @Option(
       name = "experimental_ui_limit_console_output",
       defaultValue = "0",
       documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
       effectTags = {OptionEffectTag.UNKNOWN},
       help =
           "Number of bytes to which the experimental UI will limit its output (non-positive "
               + "values indicate unlimited). Once the limit is approaching, the experimental UI "
               + "will try hard to limit in a meaningful way, but will ultimately just drop all "
               + "output."
     )
     public int experimentalUiLimitConsoleOutput;

     @Option(
         name = "experimental_ui_deduplicate",
         defaultValue = "false",
         documentationCategory = OptionDocumentationCategory.LOGGING,
         effectTags = {OptionEffectTag.TERMINAL_OUTPUT},
         help = "Make the experimental UI deduplicate messages to have a cleaner scroll-back log.")
     public boolean experimentalUiDeduplicate;

     public boolean useColor() {
       return useColorEnum == UseColor.YES || (useColorEnum == UseColor.AUTO && isStderrATty);
     }

     public boolean useCursorControl() {
       return useCursesEnum == UseCurses.YES || (useCursesEnum == UseCurses.AUTO && isStderrATty);
     }
   }

   private static final DateTimeFormatter TIMESTAMP_FORMAT =
       DateTimeFormatter.ofPattern("(MM-dd HH:mm:ss.SSS) ");

   protected final OutErr outErr;

   private final PrintStream errPrintStream;

   protected final Set<EventKind> eventMask =
       EnumSet.copyOf(EventKind.ERRORS_WARNINGS_AND_INFO_AND_OUTPUT);

   protected final boolean showTimestamp;

   protected final LocationPrinter locationPrinter;

   public BlazeCommandEventHandler(
       OutErr outErr, Options eventOptions, PathFragment workspacePathFragment) {
     this.outErr = outErr;
     this.errPrintStream = new PrintStream(outErr.getErrorStream(), true);
     if (eventOptions.showProgress) {
       eventMask.add(EventKind.PROGRESS);
       eventMask.add(EventKind.START);
     } else {
       // Skip PASS events if --noshow_progress is requested.
       eventMask.remove(EventKind.PASS);
     }
     if (eventOptions.showTaskFinish) {
       eventMask.add(EventKind.FINISH);
     }
     eventMask.add(EventKind.SUBCOMMAND);
     this.showTimestamp = eventOptions.showTimestamp;
     this.locationPrinter =
         new LocationPrinter(eventOptions.attemptToPrintRelativePaths, workspacePathFragment);
   }

   /** See EventHandler.handle. */
   @Override
   public void handle(Event event) {
     if (!eventMask.contains(event.getKind())) {
       return;
     }
     String prefix;
     switch (event.getKind()) {
       case STDOUT:
         putOutput(outErr.getOutputStream(), event);
         return;
       case STDERR:
         putOutput(outErr.getErrorStream(), event);
         return;
       case PASS:
       case FAIL:
       case TIMEOUT:
       case ERROR:
       case WARNING:
       case DEBUG:
       case DEPCHECKER:
         prefix = event.getKind() + ": ";
         break;
       case SUBCOMMAND:
         prefix = ">>>>>>>>> ";
         break;
       case INFO:
       case PROGRESS:
       case START:
       case FINISH:
         prefix = "____";
         break;
       default:
         throw new IllegalStateException("" + event.getKind());
     }
     StringBuilder buf = new StringBuilder();
     buf.append(prefix);

     if (showTimestamp) {
       buf.append(timestamp());
     }

     Location location = event.getLocation();
     if (location != null) {
       buf.append(locationPrinter.getLocationString(location)).append(": ");
     }

     buf.append(event.getMessage());
     if (event.getKind() == EventKind.FINISH) {
       buf.append(" DONE");
     }

     // Add a trailing period for ERROR and WARNING messages, which are
     // typically English sentences composed from exception messages.
     if (event.getKind() == EventKind.WARNING ||
         event.getKind() == EventKind.ERROR) {
       buf.append('.');
     }

     // Event messages go to stderr; results (e.g. 'blaze query') go to stdout.
     errPrintStream.println(buf);

     if (event.getStdErr() != null) {
       handle(
           Event.of(
               EventKind.STDERR, null, event.getStdErr().getBytes(StandardCharsets.ISO_8859_1)));
     }
     if (event.getStdOut() != null) {
       handle(
           Event.of(
               EventKind.STDOUT, null, event.getStdOut().getBytes(StandardCharsets.ISO_8859_1)));
     }
   }

   private void putOutput(OutputStream out, Event event) {
     try {
       out.write(event.getMessageBytes());
       out.flush();
     } catch (IOException e) {
       // This can happen in server mode if the blaze client has exited, or if output is redirected
       // to a file and the disk is full, etc. May be moot in the case of full disk, or useful in
       // the case of real bug in our handling of streams.
       logger.log(Level.WARNING, "Failed to write event", e);
     }
   }

   /**
    * @return a string representing the current time, eg "04-26 13:47:32.124".
    */
   protected String timestamp() {
     return TIMESTAMP_FORMAT.format(ZonedDateTime.now(ZoneId.systemDefault()));
   }

   @Subscribe
   public void packageLocatorCreated(PathPackageLocator packageLocator) {
     locationPrinter.packageLocatorCreated(packageLocator);
   }
 }
	// Copyright 2014 The Bazel Authors. All rights reserved.
	//
	// 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 com.google.devtools.build.lib.runtime;

	import com.google.common.eventbus.Subscribe;
	import com.google.devtools.build.lib.events.Event;
	import com.google.devtools.build.lib.events.EventHandler;
	import com.google.devtools.build.lib.events.EventKind;
	import com.google.devtools.build.lib.events.Location;
	import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
	import com.google.devtools.build.lib.util.io.OutErr;
	import com.google.devtools.build.lib.vfs.PathFragment;
	import com.google.devtools.common.options.EnumConverter;
	import com.google.devtools.common.options.Option;
	import com.google.devtools.common.options.OptionDocumentationCategory;
	import com.google.devtools.common.options.OptionEffectTag;
	import com.google.devtools.common.options.OptionMetadataTag;
	import com.google.devtools.common.options.OptionsBase;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.io.PrintStream;
	import java.nio.charset.StandardCharsets;
	import java.time.ZoneId;
	import java.time.ZonedDateTime;
	import java.time.format.DateTimeFormatter;
	import java.util.EnumSet;
	import java.util.Set;
	import java.util.logging.Level;
	import java.util.logging.Logger;

	/**
	* BlazeCommandEventHandler: an event handler established for the duration of a
	* single Blaze command.
	*/
	public class BlazeCommandEventHandler implements EventHandler {

	private static final Logger logger = Logger.getLogger(BlazeCommandEventHandler.class.getName());

	public enum UseColor { YES, NO, AUTO }
	public enum UseCurses { YES, NO, AUTO }

	public static class UseColorConverter extends EnumConverter<UseColor> {
	public UseColorConverter() {
	super(UseColor.class, "--color setting");
	}
	}

	public static class UseCursesConverter extends EnumConverter<UseCurses> {
	public UseCursesConverter() {
	super(UseCurses.class, "--curses setting");
	}
	}

	public static class Options extends OptionsBase {

	@Option(
	name = "show_progress",
	defaultValue = "true",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Display progress messages during a build."
	)
	public boolean showProgress;

	@Option(
	name = "show_task_finish",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Display progress messages when tasks complete, not just when they start."
	)
	public boolean showTaskFinish;

	@Option(
	name = "show_progress_rate_limit",
	defaultValue = "0.2", // A nice middle ground; snappy but not too spammy in logs.
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Minimum number of seconds between progress messages in the output."
	)
	public double showProgressRateLimit;

	@Option(
	name = "color",
	defaultValue = "auto",
	converter = UseColorConverter.class,
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Use terminal controls to colorize output going to stderr."
	)
	public UseColor useColorEnum;

	@Option(
	name = "curses",
	defaultValue = "auto",
	converter = UseCursesConverter.class,
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Use terminal cursor controls to minimize scrolling output going to stderr."
	)
	public UseCurses useCursesEnum;

	@Option(
	name = "terminal_columns",
	defaultValue = "80",
	metadataTags = {OptionMetadataTag.HIDDEN},
	documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "A system-generated parameter which specifies the terminal width in columns."
	)
	public int terminalColumns;

	@Option(
	name = "is_stderr_atty",
	// TODO(b/63386499): Old name should be removed after 2019-02-28.
	oldName = "isatty",
	defaultValue = "false",
	metadataTags = {OptionMetadataTag.HIDDEN},
	documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help =
	"A system-generated parameter which is used to notify the server whether this client is"
	+ " running in a terminal. If this is set to false, then '--color=auto' will be"
	+ " treated as '--color=no'. If this is set to true, then '--color=auto' will be"
	+ " treated as '--color=yes'. As we only treat the stderr as a terminal, we only"
	+ " care if that file descriptor is connected to a TTY."
	)
	public boolean isStderrATty;

	// This lives here (as opposed to the more logical BuildRequest.Options)
	// because the client passes it to the server always. We don't want the
	// client to have to figure out when it should or shouldn't to send it.
	@Option(
	name = "emacs",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help =
	"A system-generated parameter which is true iff EMACS=t or INSIDE_EMACS is set "
	+ "in the environment of the client. This option controls certain display "
	+ "features."
	)
	public boolean runningInEmacs;

	@Option(
	name = "show_timestamps",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Include timestamps in messages"
	)
	public boolean showTimestamp;

	@Option(
	name = "progress_in_terminal_title",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help =
	"Show the command progress in the terminal title. "
	+ "Useful to see what bazel is doing when having multiple terminal tabs.")
	public boolean progressInTermTitle;

	@Option(
	name = "experimental_external_repositories",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Use external repositories for improved stability and speed when available."
	)
	public boolean externalRepositories;

	@Option(
	name = "force_experimental_external_repositories",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Forces --experimental_external_repositories."
	)
	public boolean forceExternalRepositories;

	@Option(
	name = "attempt_to_print_relative_paths",
	oldName = "experimental_ui_attempt_to_print_relative_paths",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.LOGGING,
	effectTags = {OptionEffectTag.TERMINAL_OUTPUT},
	help =
	"When printing the location part of messages, attempt to use a path relative to the "
	+ "workspace directory or one of the directories specified by --package_path.")
	public boolean attemptToPrintRelativePaths;

	@Option(
	name = "experimental_ui",
	defaultValue = "true",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help =
	"Switches to an alternative progress bar that more explicitly shows progress, such "
	+ "as loaded packages and executed actions."
	)
	public boolean experimentalUi;

	@Option(
	name = "experimental_ui_debug_all_events",
	defaultValue = "false",
	metadataTags = {OptionMetadataTag.HIDDEN},
	documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help = "Report all events known to the experimental new Bazel UI."
	)
	public boolean experimentalUiDebugAllEvents;

	@Option(
	name = "experimental_ui_actions_shown",
	defaultValue = "8",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help =
	"Number of concurrent actions shown in the alternative progress bar; each "
	+ "action is shown on a separate line. The alternative progress bar always shows "
	+ "at least one one, all numbers less than 1 are mapped to 1. "
	+ "This option has no effect unless --experimental_ui is set."
	)
	public int experimentalUiActionsShown;

	@Option(
	name = "experimental_ui_limit_console_output",
	defaultValue = "0",
	documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
	effectTags = {OptionEffectTag.UNKNOWN},
	help =
	"Number of bytes to which the experimental UI will limit its output (non-positive "
	+ "values indicate unlimited). Once the limit is approaching, the experimental UI "
	+ "will try hard to limit in a meaningful way, but will ultimately just drop all "
	+ "output."
	)
	public int experimentalUiLimitConsoleOutput;

	@Option(
	name = "experimental_ui_deduplicate",
	defaultValue = "false",
	documentationCategory = OptionDocumentationCategory.LOGGING,
	effectTags = {OptionEffectTag.TERMINAL_OUTPUT},
	help = "Make the experimental UI deduplicate messages to have a cleaner scroll-back log.")
	public boolean experimentalUiDeduplicate;

	public boolean useColor() {
	return useColorEnum == UseColor.YES \|\| (useColorEnum == UseColor.AUTO && isStderrATty);
	}

	public boolean useCursorControl() {
	return useCursesEnum == UseCurses.YES \|\| (useCursesEnum == UseCurses.AUTO && isStderrATty);
	}
	}

	private static final DateTimeFormatter TIMESTAMP_FORMAT =
	DateTimeFormatter.ofPattern("(MM-dd HH:mm:ss.SSS) ");

	protected final OutErr outErr;

	private final PrintStream errPrintStream;

	protected final Set<EventKind> eventMask =
	EnumSet.copyOf(EventKind.ERRORS_WARNINGS_AND_INFO_AND_OUTPUT);

	protected final boolean showTimestamp;

	protected final LocationPrinter locationPrinter;

	public BlazeCommandEventHandler(
	OutErr outErr, Options eventOptions, PathFragment workspacePathFragment) {
	this.outErr = outErr;
	this.errPrintStream = new PrintStream(outErr.getErrorStream(), true);
	if (eventOptions.showProgress) {
	eventMask.add(EventKind.PROGRESS);
	eventMask.add(EventKind.START);
	} else {
	// Skip PASS events if --noshow_progress is requested.
	eventMask.remove(EventKind.PASS);
	}
	if (eventOptions.showTaskFinish) {
	eventMask.add(EventKind.FINISH);
	}
	eventMask.add(EventKind.SUBCOMMAND);
	this.showTimestamp = eventOptions.showTimestamp;
	this.locationPrinter =
	new LocationPrinter(eventOptions.attemptToPrintRelativePaths, workspacePathFragment);
	}

	/** See EventHandler.handle. */
	@Override
	public void handle(Event event) {
	if (!eventMask.contains(event.getKind())) {
	return;
	}
	String prefix;
	switch (event.getKind()) {
	case STDOUT:
	putOutput(outErr.getOutputStream(), event);
	return;
	case STDERR:
	putOutput(outErr.getErrorStream(), event);
	return;
	case PASS:
	case FAIL:
	case TIMEOUT:
	case ERROR:
	case WARNING:
	case DEBUG:
	case DEPCHECKER:
	prefix = event.getKind() + ": ";
	break;
	case SUBCOMMAND:
	prefix = ">>>>>>>>> ";
	break;
	case INFO:
	case PROGRESS:
	case START:
	case FINISH:
	prefix = "____";
	break;
	default:
	throw new IllegalStateException("" + event.getKind());
	}
	StringBuilder buf = new StringBuilder();
	buf.append(prefix);

	if (showTimestamp) {
	buf.append(timestamp());
	}

	Location location = event.getLocation();
	if (location != null) {
	buf.append(locationPrinter.getLocationString(location)).append(": ");
	}

	buf.append(event.getMessage());
	if (event.getKind() == EventKind.FINISH) {
	buf.append(" DONE");
	}

	// Add a trailing period for ERROR and WARNING messages, which are
	// typically English sentences composed from exception messages.
	if (event.getKind() == EventKind.WARNING \|\|
	event.getKind() == EventKind.ERROR) {
	buf.append('.');
	}

	// Event messages go to stderr; results (e.g. 'blaze query') go to stdout.
	errPrintStream.println(buf);

	if (event.getStdErr() != null) {
	handle(
	Event.of(
	EventKind.STDERR, null, event.getStdErr().getBytes(StandardCharsets.ISO_8859_1)));
	}
	if (event.getStdOut() != null) {
	handle(
	Event.of(
	EventKind.STDOUT, null, event.getStdOut().getBytes(StandardCharsets.ISO_8859_1)));
	}
	}

	private void putOutput(OutputStream out, Event event) {
	try {
	out.write(event.getMessageBytes());
	out.flush();
	} catch (IOException e) {
	// This can happen in server mode if the blaze client has exited, or if output is redirected
	// to a file and the disk is full, etc. May be moot in the case of full disk, or useful in
	// the case of real bug in our handling of streams.
	logger.log(Level.WARNING, "Failed to write event", e);
	}
	}

	/**
	* @return a string representing the current time, eg "04-26 13:47:32.124".
	*/
	protected String timestamp() {
	return TIMESTAMP_FORMAT.format(ZonedDateTime.now(ZoneId.systemDefault()));
	}

	@Subscribe
	public void packageLocatorCreated(PathPackageLocator packageLocator) {
	locationPrinter.packageLocatorCreated(packageLocator);
	}
	}