jenkinsci#185 Add RunListener.onFinalized listener. Inject START Acti…

…onNote after build finishes to trigger plugin's logic also on partial log output

src/main/java/hudson/plugins/ansicolor/log/LogInjector.java

@@ -0,0 +1,93 @@
+package hudson.plugins.ansicolor.log;
+
+import hudson.Extension;
+import hudson.model.Run;
+import hudson.model.listeners.RunListener;
+import hudson.plugins.ansicolor.action.ActionNote;
+import hudson.plugins.ansicolor.action.ColorizedAction;
+import org.apache.commons.io.output.CountingOutputStream;
+
+import java.io.*;
+import java.util.Optional;
+import java.util.logging.Logger;
+
+public class LogInjector {
+    private static final Logger LOGGER = Logger.getLogger(LogInjector.class.getName());
+    private static final int CONSOLE_TAIL_DEFAULT = 150;
+    private static final int BUFFER_SIZE = 64 * 1024;
+
+    public void injectShortlogAction(File logFile, int injectionFromEnd, ActionNote actionNote) {
+        final File logTmp = new File(String.format("%s.ansicolor.tmp", logFile));
+        final File logFileBkp = new File(String.format("%s.bkp", logFile));
+        try {
+            try (
+                BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(logFile));
+                FileOutputStream outputStream = new FileOutputStream(logTmp);
+            ) {
+                final long injectionPoint = logFile.length() - injectionFromEnd * 1024;
+                final byte[] buf = new byte[BUFFER_SIZE];
+                int read;
+                int totalRead = 0;
+                int i = 0;
+                boolean injected = false;
+                do {
+                    read = inputStream.read(buf);
+                    if (read != -1) {
+                        i++;
+                        if (!injected && totalRead + read >= injectionPoint) {
+                            final BufferedOutputStream bufferedStream = new BufferedOutputStream(outputStream);
+                            final CountingOutputStream countingStream = new CountingOutputStream(bufferedStream);
+                            actionNote.encodeTo(countingStream);
+                            final long actionNoteLength = countingStream.getByteCount();
+                            // todo When (if doable) in the middle of another ActionNote render afterwards in order to preserve it
+                            final int spot = (int) (injectionPoint - totalRead + actionNoteLength);
+                            outputStream.write(buf, 0, spot);
+                            bufferedStream.flush();
+                            outputStream.write(buf, spot, read - spot);
+                            injected = true;
+                        } else {
+                            outputStream.write(buf, 0, read);
+                        }
+                        totalRead += read;
+                    }
+                } while (read != -1);
+            }
+
+            if (logFile.renameTo(logFileBkp) && logTmp.renameTo(logFile) && logFileBkp.delete()) {
+                LOGGER.fine("Substituted original log with the injected one.");
+            } else {
+                LOGGER.warning("Error while substituting log file");
+            }
+        } catch (IOException e) {
+            if (logTmp.exists() && !logTmp.getPath().equals(logFile.getPath())) {
+                if (!logTmp.delete()) {
+                    LOGGER.fine("Error while deleting tmp file");
+                }
+            }
+            if (logFileBkp.exists()) {
+                if (!logFileBkp.delete()) {
+                    LOGGER.fine("Error while deleting backup file");
+                }
+            }
+            LOGGER.warning("Error while injecting shortlog action: " + e.getMessage());
+        }
+    }
+
+    @Extension
+    public static class InjectorRunListener extends RunListener<Run<?, ?>> {
+        @Override
+        public void onFinalized(Run<?, ?> run) {
+            super.onFinalized(run);
+            // todo Find the actual last start action before tail
+            final Optional<ColorizedAction> startAction = run.getActions(ColorizedAction.class).stream().filter(a -> a.getCommand().equals(ColorizedAction.Command.START)).findAny();
+            if (startAction.isPresent()) {
+                final File logFile = new File(run.getRootDir(), "log");
+                if (logFile.isFile()) {
+                    final LogInjector logInjector = new LogInjector();
+                    final String consoleTail = System.getProperty("hudson.consoleTailKB");
+                    logInjector.injectShortlogAction(logFile, consoleTail != null ? Integer.parseInt(consoleTail) : CONSOLE_TAIL_DEFAULT, new ActionNote(startAction.get()));
+                }
+            }
+        }
+    }
+}