Github user pwendell commented on a diff in the pull request:
https://github.com/apache/spark/pull/290#discussion_r11517882
--- Diff: core/src/main/scala/org/apache/spark/ui/WebUI.scala ---
@@ -17,53 +17,134 @@
package org.apache.spark.ui
-import java.text.SimpleDateFormat
-import java.util.Date
+import javax.servlet.http.HttpServletRequest
-private[spark] abstract class WebUI(name: String) {
+import scala.collection.mutable.ArrayBuffer
+import scala.xml.Node
+
+import org.eclipse.jetty.servlet.ServletContextHandler
+import org.json4s.JsonAST.{JNothing, JValue}
+
+import org.apache.spark.{Logging, SecurityManager, SparkConf}
+import org.apache.spark.ui.JettyUtils._
+import org.apache.spark.util.Utils
+
+/**
+ * The top level component of the UI hierarchy that contains the server.
+ *
+ * Each WebUI represents a collection of tabs, each of which in turn
represents a collection of
+ * pages. The use of tabs is optional, however; a WebUI may choose to
include pages directly.
+ */
+private[spark] abstract class WebUI(
+ securityManager: SecurityManager,
+ port: Int,
+ conf: SparkConf,
+ basePath: String = "")
+ extends Logging {
+
+ protected val tabs = ArrayBuffer[WebUITab]()
+ protected val handlers = ArrayBuffer[ServletContextHandler]()
protected var serverInfo: Option[ServerInfo] = None
+ protected val localHostName = Utils.localHostName()
+ protected val publicHostName =
Option(System.getenv("SPARK_PUBLIC_DNS")).getOrElse(localHostName)
+ private val className = Utils.getFormattedClassName(this)
+
+ def getTabs: Seq[WebUITab] = tabs.toSeq
+ def getHandlers: Seq[ServletContextHandler] = handlers.toSeq
- /**
- * Bind to the HTTP server behind this web interface.
- * Overridden implementation should set serverInfo.
- */
- def bind() { }
+ /** Attach a tab to this UI, along with all of its attached pages. */
+ def attachTab(tab: WebUITab) {
+ tab.pages.foreach(attachPage)
+ tabs += tab
+ }
+
+ /** Attach a page to this UI. */
+ def attachPage(page: WebUIPage) {
+ val pagePath = "/" + page.prefix
+ attachHandler(createServletHandler(pagePath,
+ (request: HttpServletRequest) => page.render(request),
securityManager, basePath))
+ if (page.includeJson) {
+ attachHandler(createServletHandler(pagePath.stripSuffix("/") +
"/json",
+ (request: HttpServletRequest) => page.renderJson(request),
securityManager, basePath))
+ }
+ }
+
+ /** Attach a handler to this UI. */
+ def attachHandler(handler: ServletContextHandler) {
+ handlers += handler
+ serverInfo.foreach { info =>
+ info.rootHandler.addHandler(handler)
+ if (!handler.isStarted) {
+ handler.start()
+ }
+ }
+ }
+
+ /** Detach a handler from this UI. */
+ def detachHandler(handler: ServletContextHandler) {
+ handlers -= handler
+ serverInfo.foreach { info =>
+ info.rootHandler.removeHandler(handler)
+ if (handler.isStarted) {
+ handler.stop()
+ }
+ }
+ }
+
+ /** Initialize all components of the server. */
+ def initialize()
+
+ /** Bind to the HTTP server behind this web interface. */
+ def bind() {
+ assert(!serverInfo.isDefined, "Attempted to bind %s more than
once!".format(className))
+ try {
+ serverInfo = Some(startJettyServer("0.0.0.0", port, handlers, conf))
+ logInfo("Started %s at http://%s:%d".format(className,
publicHostName, boundPort))
+ } catch {
+ case e: Exception =>
+ logError("Failed to bind %s".format(className), e)
+ System.exit(1)
+ }
+ }
/** Return the actual port to which this server is bound. Only valid
after bind(). */
def boundPort: Int = serverInfo.map(_.boundPort).getOrElse(-1)
/** Stop the server behind this web interface. Only valid after bind().
*/
def stop() {
- assert(serverInfo.isDefined, "Attempted to stop %s before binding to a
server!".format(name))
+ assert(serverInfo.isDefined,
+ "Attempted to stop %s before binding to a server!".format(className))
serverInfo.get.server.stop()
}
}
+
/**
- * Utilities used throughout the web UI.
+ * A tab that represents a collection of pages.
*/
-private[spark] object WebUI {
- // SimpleDateFormat is not thread-safe. Don't expose it to avoid
improper use.
- private val dateFormat = new ThreadLocal[SimpleDateFormat]() {
- override def initialValue(): SimpleDateFormat = new
SimpleDateFormat("yyyy/MM/dd HH:mm:ss")
+private[spark] abstract class WebUITab(parent: WebUI, val prefix: String) {
+ val pages = ArrayBuffer[WebUIPage]()
+ val name = prefix.capitalize
+
+ /** Attach a page to this tab. This prepends the page's prefix with the
tab's own prefix. */
+ def attachPage(page: WebUIPage) {
+ page.prefix = (prefix + "/" + page.prefix).stripSuffix("/")
+ pages += page
}
- def formatDate(date: Date): String = dateFormat.get.format(date)
+ /** Get a list of header tabs from the parent UI. */
+ def headerTabs: Seq[WebUITab] = parent.getTabs
+}
- def formatDate(timestamp: Long): String = dateFormat.get.format(new
Date(timestamp))
- def formatDuration(milliseconds: Long): String = {
- val seconds = milliseconds.toDouble / 1000
- if (seconds < 60) {
- return "%.0f s".format(seconds)
- }
- val minutes = seconds / 60
- if (minutes < 10) {
- return "%.1f min".format(minutes)
- } else if (minutes < 60) {
- return "%.0f min".format(minutes)
- }
- val hours = minutes / 60
- "%.1f h".format(hours)
- }
+/**
+ * A page that represents the leaf node in the UI hierarchy.
+ *
+ * The direct parent of a WebUIPage is not specified as it can be either a
WebUI or a WebUITab.
+ * If includeJson is true, the parent WebUI (direct or indirect) creates
handlers for both the
+ * HTML and the JSON content, rather than just the former.
+ */
+private[spark] abstract class WebUIPage(var prefix: String, val
includeJson: Boolean = false) {
--- End diff --
I noticed that `includeJson` is only used to determine whether or not to
add a handler at the `/json` path. What about just always adding a `/json`
handler and just having it return `{}` for the UI's that chose not to implement
it? Like you could have it be an optionally overriden method.
Anyways, not a strong preference, just wondering if you considered this.
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