feat(svg): Pre-encoding Base64 strings

Author: Fuwn

src/cache.gleam

@@ -1,3 +1,4 @@
+import gleam/bit_array
 import gleam/dict.{type Dict}
 import gleam/int
 import gleam/list
@@ -8,7 +9,7 @@ import simplifile
 import wisp
 
 pub type CachedImage {
-  CachedImage(data: BitArray, info: image.ImageInformation)
+  CachedImage(base64: String, info: image.ImageInformation)
 }
 
 pub type ThemeCache =
@@ -49,7 +50,10 @@ pub fn load_themes() {
                     dict.insert(
                       accumulated_digits,
                       digit,
-                      CachedImage(data: image_data, info: info),
+                      CachedImage(
+                        base64: bit_array.base64_encode(image_data, False),
+                        info: info,
+                      ),
                     )
                   Error(_) -> {
                     wisp.log_error(

src/svg.gleam

@@ -1,5 +1,4 @@
 import cache
-import gleam/bit_array
 import gleam/int
 import gleam/list
 import gleam/option.{Some}
@@ -10,16 +9,20 @@ type XmlImages {
   XmlImages(xml: String, width: Int, height: Int)
 }
 
-fn image(data, image: image.ImageInformation, width) {
-  "<image
-    height=\"" <> int.to_string(image.height) <> "\"
-    width=\"" <> int.to_string(image.width) <> "\"
-    x=\"" <> int.to_string(width) <> "\"
-    y=\"0\"
-    xlink:href=\"data:image/" <> image.extension <> ";base64," <> bit_array.base64_encode(
-    data,
-    False,
-  ) <> "\"/>"
+fn image(base64, image: image.ImageInformation, width) {
+  string_builder.new()
+  |> string_builder.append("<image height=\"")
+  |> string_builder.append(int.to_string(image.height))
+  |> string_builder.append("\" width=\"")
+  |> string_builder.append(int.to_string(image.width))
+  |> string_builder.append("\" x=\"")
+  |> string_builder.append(int.to_string(width))
+  |> string_builder.append("\" y=\"0\" xlink:href=\"data:image/")
+  |> string_builder.append(image.extension)
+  |> string_builder.append(";base64,")
+  |> string_builder.append(base64)
+  |> string_builder.append("\"/>")
+  |> string_builder.to_string()
 }
 
 fn images(image_cache, theme, digits, width, height, svgs) {
@@ -34,7 +37,10 @@ fn images(image_cache, theme, digits, width, height, svgs) {
             rest,
             width + cached.info.width,
             int.max(height, cached.info.height),
-            string_builder.append(svgs, image(cached.data, cached.info, width)),
+            string_builder.append(
+              svgs,
+              image(cached.base64, cached.info, width),
+            ),
           )
         _ -> images(image_cache, theme, rest, width, height, svgs)
       }
@@ -60,17 +66,19 @@ pub fn xml(image_cache, theme, number, padding) {
       string_builder.new(),
     )
 
-  "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?>
-  <svg
-    height=\"" <> int.to_string(xml.height) <> "\"
-    style=\"image-rendering: pixelated;\"
-    version=\"1.1\"
-    width=\"" <> int.to_string(xml.width) <> "\"
-    xmlns=\"http://www.w3.org/2000/svg\"
-    xmlns:xlink=\"http://www.w3.org/1999/xlink\"
-  >
-    <title>Mayu</title>
-
-    <g>" <> xml.xml <> "</g>
-  </svg>"
+  string_builder.new()
+  |> string_builder.append(
+    "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?><svg height=\"",
+  )
+  |> string_builder.append(int.to_string(xml.height))
+  |> string_builder.append(
+    "\" style=\"image-rendering: pixelated;\" version=\"1.1\" width=\"",
+  )
+  |> string_builder.append(int.to_string(xml.width))
+  |> string_builder.append(
+    "\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><title>Mayu</title><g>",
+  )
+  |> string_builder.append(xml.xml)
+  |> string_builder.append("</g></svg>")
+  |> string_builder.to_string()
 }