perf(chat): memoize inline LaTeX and match bare URLs once (#1316) (#1342)

app/src/main/java/com/m57/hermescontrol/ui/chat/markdown/MarkdownInlineStyler.kt

@@ -68,6 +68,9 @@ object MarkdownInlineStyler {
             val src = text
 
             while (i < src.length) {
+                // Cheap prefix gate: URL_PATTERN only matches at "http(s)://", so skip the regex elsewhere.
+                val urlMatch =
+                    if (src.startsWith("http", i, ignoreCase = true)) URL_PATTERN.matchAt(src, i) else null
                 when {
                     // Inline code is opaque to emphasis parsing, and delimiters must match by run length.
                     src[i] == '`' -> {
@@ -312,9 +315,8 @@ object MarkdownInlineStyler {
                     }
 
                     // bare URL
-                    URL_PATTERN.matchAt(src, i) != null -> {
+                    urlMatch != null -> {
-                        val match = URL_PATTERN.matchAt(src, i)!!
+                        val url = urlMatch.value
-                        val url = match.value
                         val urlToAppend = if (isRtl) BidiUtils.wrapLtrIsolate(url) else url
                         pushLink(LinkAnnotation.Url(url))
                         withStyle(
@@ -326,7 +328,7 @@ object MarkdownInlineStyler {
                             append(urlToAppend)
                         }
                         pop()
-                        i = match.range.last + 1
+                        i = urlMatch.range.last + 1
                     }
 
                     // Plain text / words in RTL

app/src/main/java/com/m57/hermescontrol/ui/chat/markdown/MarkdownInlineText.kt

@@ -66,24 +66,41 @@ fun MarkdownInlineText(
         }
 
         val config =
+            remember(style.fontSize, textColor) {
                 LatexConfig(
                     fontSize = style.fontSize,
                     theme = LatexTheme.light(color = textColor, backgroundColor = Color.Transparent),
                     accessibilityEnabled = true,
                 )
-        val inlineContent = mutableMapOf<String, InlineTextContent>()
+            }
+        val inlineContent =
+            remember(segments, latexMeasurer, config) {
+                val map = mutableMapOf<String, InlineTextContent>()
                 segments.forEachIndexed { index, segment ->
                     if (segment is InlineMathSegment.Math) {
-                latexMeasurer.inlineContent(segment.latex, config)?.let { inlineContent["latex-$index"] = it }
+                        latexMeasurer.inlineContent(segment.latex, config)?.let { map["latex-$index"] = it }
                     }
                 }
+                map
+            }
         val annotated =
+            remember(
+                segments,
+                inlineContent,
+                textColor,
+                searchQuery,
+                isCurrentMatch,
+                linkColor,
+                highlights,
+                isRtl,
+            ) {
                 buildAnnotatedString {
                     segments.forEachIndexed { index, segment ->
                         when (segment) {
                             is InlineMathSegment.Math -> {
                                 val id = "latex-$index"
-                            if (id in inlineContent) appendInlineContent(id, segment.latex) else append(segment.latex)
+                                val measured = id in inlineContent
+                                if (measured) appendInlineContent(id, segment.latex) else append(segment.latex)
                             }
 
                             is InlineMathSegment.Text -> {
@@ -102,6 +119,7 @@ fun MarkdownInlineText(
                         }
                     }
                 }
+            }
         Text(
             text = annotated,
             inlineContent = inlineContent,