add workflow

slb-agent/src/main/java/com/dianping/platform/slb/agent/core/workflow/Context.java

@@ -0,0 +1,44 @@
+package com.dianping.platform.slb.agent.core.workflow;
+
+import com.dianping.platform.slb.agent.core.task.Task;
+
+import java.io.OutputStream;
+
+/**
+ * dianping.com @2015
+ * slb - soft load balance
+ * <p/>
+ * Created by leon.li(Li Yang)
+ */
+public class Context {
+
+	private Task m_task;
+
+	private OutputStream m_output;
+
+	private boolean m_isKilled;
+
+	public Task getTask() {
+		return m_task;
+	}
+
+	public void setTask(Task task) {
+		m_task = task;
+	}
+
+	public OutputStream getOutput() {
+		return m_output;
+	}
+
+	public void setOutput(OutputStream output) {
+		m_output = output;
+	}
+
+	public boolean isKilled() {
+		return m_isKilled;
+	}
+
+	public void kill() {
+		m_isKilled = true;
+	}
+}

slb-agent/src/main/java/com/dianping/platform/slb/agent/core/workflow/Engine.java

@@ -0,0 +1,81 @@
+package com.dianping.platform.slb.agent.core.workflow;
+
+import com.dianping.platform.slb.agent.core.task.LogFormatter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.io.OutputStream;
+import java.util.Map;
+
+/**
+ * dianping.com @2015
+ * slb - soft load balance
+ * <p/>
+ * Created by leon.li(Li Yang)
+ */
+@Service
+public class Engine {
+
+	private static Logger logger = LoggerFactory.getLogger(Engine.class);
+
+	@Autowired
+	LogFormatter logFormatter;
+
+	public int start(Step startStep, Context ctx) {
+		Step curStep = startStep;
+
+		int exitCode = 0;
+
+		OutputStream logOut = ctx.getOutput();
+
+		while (curStep != null) {
+			if (ctx.isKilled()) {
+				break;
+			}
+			writeLogChunkHeader(curStep.getLogChunkHeader(), logOut);
+			logger.info(String.format(">>>>> Current Step Is [%s] <<<<<", curStep));
+			try {
+				exitCode = curStep.doStep(ctx);
+			} catch (Exception e) {
+				logger.error(String.format(">>>>> Exception When Doing Step %s <<<<<", curStep), e);
+				exitCode = Step.CODE_ERROR;
+			}
+			logger.info(String.format("##### Current Step [%s] Is [%s] ####", curStep,
+					exitCode == Step.CODE_OK ? "SUCCESS" : "FAILED"));
+			writeLogChunkTerminator(logOut);
+			curStep = curStep.getNextStep(exitCode);
+		}
+		writeLogTerminator(logOut);
+		return exitCode;
+	}
+
+	private void writeLogChunkHeader(Map<String, String> headers, OutputStream logOut) {
+		try {
+			logFormatter.writeHeader(logOut, headers);
+		} catch (Exception e) {
+			logger.error("error write log chunk header", e);
+		}
+	}
+
+	private void writeLogChunkTerminator(OutputStream logOut) {
+		try {
+			logFormatter.writeChunkTerminator(logOut);
+		} catch (Exception e) {
+			logger.error("error write log chunk terminator", e);
+		}
+	}
+
+	private void writeLogTerminator(OutputStream logOut) {
+		try {
+			logFormatter.writeTerminator(logOut);
+		} catch (Exception e) {
+			logger.error("error write log terminator", e);
+		}
+	}
+
+	public void kill(Context ctx) {
+		ctx.kill();
+	}
+}