Optimize performance bottlenecks in SSR rendering, string operations, and DOM traversal

core/src/ba/sake/flatmark/FlatmarkGenerator.scala

@@ -417,11 +417,18 @@ class FlatmarkGenerator(ssrServerUrl: String, webDriverHolder: WebDriverHolder,
       // prepend base URL to all relative URLs
       layoutContext.site.baseUrl.foreach { baseUrl =>
         // TODO handle srcset
+        // Combine all attribute selectors into a single query for better performance
+        val selector = """[href^="/"],[src^="/"],[cite^="/"],[action^="/"],[formaction^="/"],[data^="/"],[poster^="/"],[manifest^="/"]"""
         val urlAttrs = List("href", "src", "cite", "action", "formaction", "data", "poster", "manifest")
-        urlAttrs.foreach { attrName =>
-          document.select(s"""[${attrName}^="/"]""").forEach { elem =>
-            val attrValue = elem.attr(attrName)
-            elem.attr(attrName, baseUrl + attrValue)
+        document.select(selector).forEach { elem =>
+          // Each element matches on at least one attribute, check which ones need updating
+          urlAttrs.foreach { attrName =>
+            if (elem.hasAttr(attrName)) {
+              val attrValue = elem.attr(attrName)
+              if (attrValue.startsWith("/")) {
+                elem.attr(attrName, baseUrl + attrValue)
+              }
+            }
           }
         }
       }

core/src/ba/sake/flatmark/FrontMatterUtils.scala

@@ -12,13 +12,15 @@ object FrontMatterUtils {
     var hasYamlFrontMatter = false
     var firstTripleDashIndex = -1
     var secondTripleDashIndex = -1
+
+    // Single pass through the lines
+    val lines = templateRaw.split('\n')
+    var i = 0
     boundary {
-      val iter = templateRaw.linesIterator
-      var i = 0
-      while iter.hasNext do {
-        val line = iter.next().trim
-        if line.nonEmpty then {
-          if line == "---" then {
+      while (i < lines.length) {
+        val line = lines(i).trim
+        if (line.nonEmpty) {
+          if (line == "---") {
             if (firstTripleDashIndex == -1) firstTripleDashIndex = i
             else if (secondTripleDashIndex == -1) {
               secondTripleDashIndex = i
@@ -32,14 +34,10 @@ object FrontMatterUtils {
         i += 1
       }
     }
-    if hasYamlFrontMatter then {
-      val yaml = templateRaw.linesIterator
-        .slice(firstTripleDashIndex + 1, firstTripleDashIndex + 1 + secondTripleDashIndex - firstTripleDashIndex - 1)
-        .mkString("\n")
-      val content = templateRaw.linesIterator
-        .drop(secondTripleDashIndex + 1)
-        .mkString("\n")
-        .trim
+
+    if (hasYamlFrontMatter) {
+      val yaml = lines.slice(firstTripleDashIndex + 1, secondTripleDashIndex).mkString("\n")
+      val content = lines.drop(secondTripleDashIndex + 1).mkString("\n").trim
       (yaml, content)
     } else ("", templateRaw)
   }

core/src/ba/sake/flatmark/HashUtils.scala

@@ -10,6 +10,20 @@ object HashUtils {
     val md = MessageDigest.getInstance("MD5")
     val theMD5digest = md.digest(bytesOfMessage)
     val b64 = Base64.getEncoder.encode(theMD5digest)
-    new String(b64, "UTF-8").replace('/', '-').replace('=', '_').replace('+', '$')
+    val encoded = new String(b64, "UTF-8")
+
+    // Use StringBuilder for efficient string manipulation
+    val result = new StringBuilder(encoded.length)
+    var i = 0
+    while (i < encoded.length) {
+      encoded.charAt(i) match {
+        case '/' => result.append('-')
+        case '=' => result.append('_')
+        case '+' => result.append('$')
+        case c => result.append(c)
+      }
+      i += 1
+    }
+    result.toString
   }
 }

core/src/ba/sake/flatmark/HeadingHierarchyExtractor.scala

@@ -23,52 +23,55 @@ object HeadingHierarchyExtractor {
 
     // This will hold the current "parent" for each heading level.
     // Index 0 for H1, index 1 for H2, etc. Max level is 6, so size 6.
-    val currentParents: Array[Option[Heading]] = Array.fill(6)(None)
+    // Using Array[Heading | Null] for better performance
+    val currentParents: Array[Heading | Null] = new Array[Heading | Null](6)
 
     // Select all heading tags in document order
     val allHeadings = doc.select("h1, h2, h3, h4, h5, h6").asScala // Convert Java Elements to Scala Seq
 
     for (headingElement <- allHeadings) {
       val tagName = headingElement.tagName() // e.g., "h1", "h2"
-      val level = tagName.substring(1).toInt // Extract level (1-6)
+      val level = tagName.charAt(1) - '0' // Extract level (1-6) more efficiently
 
       val newHeading = Heading(level, headingElement.text(), headingElement.attr("id").trim)
 
       if (level == 1) {
         // H1 is always a top-level heading
         topLevelHeadings += newHeading
-        currentParents(0) = Some(newHeading) // Set H1 as the current parent for H1s
+        currentParents(0) = newHeading // Set H1 as the current parent for H1s
         // Reset parents for lower levels
-        for (i <- 1 until 6) {
-          currentParents(i) = None
+        var i = 1
+        while (i < 6) {
+          currentParents(i) = null
+          i += 1
         }
       } else {
         // Find the appropriate parent for this heading
         // Iterate upwards from the previous level
-        var parentFound: Option[Heading] = None
-        boundary {
-          for (i <- (level - 2) to 0 by -1) { // level - 2 because array is 0-indexed and we need the *next* higher level
-            if (currentParents(i).isDefined) {
-              parentFound = currentParents(i)
-              boundary.break() // Break out of the loop once a parent is found
-            }
+        var parentFound: Heading | Null = null
+        var i = level - 2
+        while (i >= 0 && parentFound == null) {
+          if (currentParents(i) != null) {
+            parentFound = currentParents(i)
           }
+          i -= 1
         }
 
-        parentFound match {
-          case Some(parent) =>
-            parent.children += newHeading
-          case None =>
-            // If no higher-level parent is found, it's a top-level heading
-            // (e.g., an H2 without a preceding H1)
-            topLevelHeadings += newHeading
+        if (parentFound != null) {
+          parentFound.children += newHeading
+        } else {
+          // If no higher-level parent is found, it's a top-level heading
+          // (e.g., an H2 without a preceding H1)
+          topLevelHeadings += newHeading
         }
 
         // Set this heading as the current parent for its own level
-        currentParents(level - 1) = Some(newHeading)
+        currentParents(level - 1) = newHeading
         // Reset parents for lower levels (any subsequent Hx that are children of this one)
-        for (i <- level until 6) {
-          currentParents(i) = None
+        var j = level
+        while (j < 6) {
+          currentParents(j) = null
+          j += 1
         }
       }
     }

ssr/src/ba/sake/flatmark/ssr/FlatmarkCodeHighlighter.scala

@@ -19,7 +19,6 @@ class FlatmarkCodeHighlighter(ssrServerUrl: String, webDriverHolder: WebDriverHo
       val encodedCodeStr = URLEncoder.encode(codeStr, "utf-8")
       val encodedCodeLang = codeLang.map(lang => URLEncoder.encode(lang, "utf-8")).getOrElse("plaintext")
       val url = s"${ssrServerUrl}/ssr/highlightjs?code=${encodedCodeStr}&lang=${encodedCodeLang}"
-      webDriverHolder.driver.manage().deleteAllCookies()
       webDriverHolder.driver.get(url)
       val waitCondition = new WebDriverWait(webDriverHolder.driver, Duration.ofSeconds(5))
       waitCondition.until(_ => webDriverHolder.driver.executeScript("return renderFinished;") == true)

ssr/src/ba/sake/flatmark/ssr/FlatmarkGraphvizRenderer.scala

@@ -18,7 +18,6 @@ class FlatmarkGraphvizRenderer(ssrServerUrl: String, webDriverHolder: WebDriverH
       val encodedDotStr = URLEncoder.encode(dotStr, "utf-8")
       val encodedEngine = URLEncoder.encode(engine, "utf-8")
       val url = s"${ssrServerUrl}/ssr/graphviz?source=${encodedDotStr}&engine=${encodedEngine}"
-      webDriverHolder.driver.manage().deleteAllCookies()
       webDriverHolder.driver.get(url)
       val waitCondition = new WebDriverWait(webDriverHolder.driver, Duration.ofSeconds(5))
       waitCondition.until(_ => webDriverHolder.driver.executeScript("return renderFinished;") == true)

ssr/src/ba/sake/flatmark/ssr/FlatmarkMathRenderer.scala

@@ -17,7 +17,6 @@ class FlatmarkMathRenderer(ssrServerUrl: String, webDriverHolder: WebDriverHolde
       logger.debug("Render math start")
       val encodedMathStr = URLEncoder.encode(mathStr, "utf-8")
       val url = s"${ssrServerUrl}/ssr/katex?source=${encodedMathStr}"
-      webDriverHolder.driver.manage().deleteAllCookies()
       webDriverHolder.driver.get(url)
       val waitCondition = new WebDriverWait(webDriverHolder.driver, Duration.ofSeconds(5))
       waitCondition.until(_ => webDriverHolder.driver.executeScript("return renderFinished;") == true)

ssr/src/ba/sake/flatmark/ssr/FlatmarkMermaidRenderer.scala

@@ -17,7 +17,6 @@ class FlatmarkMermaidRenderer(ssrServerUrl: String, webDriverHolder: WebDriverHo
       logger.debug("Render mermaid start")
       val encodedSource = URLEncoder.encode(source, "utf-8")
       val url = s"${ssrServerUrl}/ssr/mermaid?source=${encodedSource}"
-      webDriverHolder.driver.manage().deleteAllCookies()
       webDriverHolder.driver.get(url)
       val waitCondition = new WebDriverWait(webDriverHolder.driver, Duration.ofSeconds(5))
       waitCondition.until(_ => webDriverHolder.driver.executeScript("return renderFinished;") == true)