Cache URL derivation during generation

Resolves #2386 Co-Authored-By: @ajesshope

Author: Gerrit0

CHANGELOG.md

@@ -12,6 +12,7 @@
 - TypeDoc will now attempt to cache icons when `DefaultThemeRenderContext.icons` is overwritten by a custom theme.
  Note: To perform this optimization, TypeDoc relies on `DefaultThemeRenderContext.iconCache` being rendered within
  each page. TypeDoc does it in the `defaultLayout` template.
+- Cache URL derivation during generation, #2386.
 
 ### Bug Fixes
 
@@ -24,6 +25,7 @@
 
 ### Thanks!
 
+- @ajesshope
 - @HemalPatil
 - @hrueger
 - @typhonrt

src/lib/output/components.ts

@@ -46,9 +46,12 @@ export abstract class ContextAwareRendererComponent extends RendererComponent {
  this.listenTo(this.owner, {
  [RendererEvent.BEGIN]: this.onBeginRenderer,
  [PageEvent.BEGIN]: this.onBeginPage,
+ [RendererEvent.END]: () => this.absoluteToRelativePathMap.clear(),
  });
  }
 
+ private absoluteToRelativePathMap = new Map<string, string>();
+
  /**
  * Transform the given absolute path into a relative path.
  *
@@ -59,7 +62,12 @@ export abstract class ContextAwareRendererComponent extends RendererComponent {
  if (this.urlPrefix.test(absolute)) {
  return absolute;
  } else {
- return Path.posix.relative(this.location, absolute) || ".";
+ const key = `${this.location}:${absolute}`;
+ let path = this.absoluteToRelativePathMap.get(key);
+ if (path) return path;
+ path = Path.posix.relative(this.location, absolute) || ".";
+ this.absoluteToRelativePathMap.set(key, path);
+ return path;
  }
  }