Optimize findApiResourceByGroupVersionKind method by using a HashMap for faster lookups

Author: scovl

util/src/main/java/io/kubernetes/client/util/ModelMapper.java

@@ -340,20 +340,15 @@ public static GroupVersionKind groupVersionKindFromApiVersionAndKind(
  }
 
  public static Discovery.APIResource findApiResourceByGroupVersionKind(GroupVersionKind gvk) {
- // TODO: Create another hash map to make this lookup fast? For now I don't think it matters, but
- // it's definitely slow.
+ Map<String, Discovery.APIResource> apiResourcesByKey = new HashMap<>();
  for (Discovery.APIResource apiResource : lastAPIDiscovery) {
- if (!apiResource.getGroup().equals(gvk.getGroup())
- || !apiResource.getKind().equals(gvk.getKind())) {
- continue;
- }
  for (String version : apiResource.getVersions()) {
- if (version.equals(gvk.getVersion())) {
- return apiResource;
- }
+ String key = apiResource.getKind() + "/" + apiResource.getGroup() + "/" + version;
+ apiResourcesByKey.put(key, apiResource);
  }
  }
- return null;
+ String key = gvk.getKind() + "/" + gvk.getGroup() + "/" + gvk.getVersion();
+ return apiResourcesByKey.get(key);
  }
 
  private static void initApiGroupMap() {