Add map indexes for O(1) lookups in Registry

Address review feedback to use maps for collections. Added lookup maps
(toolsByName, resourcesByURI, promptsByName) while keeping slices for
ordered iteration. This provides O(1) lookup for:

- FindToolByName
- filterToolsByName (used by ForMCPRequest)
- filterResourcesByURI
- filterPromptsByName

Maps are built once during Build() and shared in ForMCPRequest copies.

Author: SamMorrowDrums

.gitignore

@@ -19,4 +19,5 @@ bin/
 # binary
 github-mcp-server
 
-.historyconformance-report/
+.history
+conformance-report/

pkg/registry/builder.go

@@ -124,6 +124,22 @@ func (b *Builder) Build() *Registry {
 		featureChecker:    b.featureChecker,
 	}
 
+	// Build lookup maps for O(1) access
+	r.toolsByName = make(map[string]*ServerTool, len(b.tools))
+	for i := range r.tools {
+		r.toolsByName[r.tools[i].Tool.Name] = &r.tools[i]
+	}
+
+	r.resourcesByURI = make(map[string]*ServerResourceTemplate, len(b.resourceTemplates))
+	for i := range r.resourceTemplates {
+		r.resourcesByURI[r.resourceTemplates[i].Template.URITemplate] = &r.resourceTemplates[i]
+	}
+
+	r.promptsByName = make(map[string]*ServerPrompt, len(b.prompts))
+	for i := range r.prompts {
+		r.promptsByName[r.prompts[i].Prompt.Name] = &r.prompts[i]
+	}
+
 	// Process toolsets
 	r.enabledToolsets, r.unrecognizedToolsets = b.processToolsets()
 

pkg/registry/filters.go

@@ -151,40 +151,31 @@ func (r *Registry) AvailablePrompts(ctx context.Context) []ServerPrompt {
 // filterToolsByName returns tools matching the given name, checking deprecated aliases.
 // Returns from the current tools slice (respects existing filter chain).
 func (r *Registry) filterToolsByName(name string) []ServerTool {
-	// First check for exact match
-	for i := range r.tools {
-		if r.tools[i].Tool.Name == name {
-			return []ServerTool{r.tools[i]}
-		}
+	// First check for exact match using map
+	if tool, ok := r.toolsByName[name]; ok {
+		return []ServerTool{*tool}
 	}
 	// Check if name is a deprecated alias
 	if canonical, isAlias := r.deprecatedAliases[name]; isAlias {
-		for i := range r.tools {
-			if r.tools[i].Tool.Name == canonical {
-				return []ServerTool{r.tools[i]}
-			}
+		if tool, ok := r.toolsByName[canonical]; ok {
+			return []ServerTool{*tool}
 		}
 	}
 	return []ServerTool{}
 }
 
 // filterResourcesByURI returns resource templates matching the given URI pattern.
 func (r *Registry) filterResourcesByURI(uri string) []ServerResourceTemplate {
-	for i := range r.resourceTemplates {
-		// Check if URI matches the template pattern (exact match on URITemplate string)
-		if r.resourceTemplates[i].Template.URITemplate == uri {
-			return []ServerResourceTemplate{r.resourceTemplates[i]}
-		}
+	if res, ok := r.resourcesByURI[uri]; ok {
+		return []ServerResourceTemplate{*res}
 	}
 	return []ServerResourceTemplate{}
 }
 
 // filterPromptsByName returns prompts matching the given name.
 func (r *Registry) filterPromptsByName(name string) []ServerPrompt {
-	for i := range r.prompts {
-		if r.prompts[i].Prompt.Name == name {
-			return []ServerPrompt{r.prompts[i]}
-		}
+	if prompt, ok := r.promptsByName[name]; ok {
+		return []ServerPrompt{*prompt}
 	}
 	return []ServerPrompt{}
 }

pkg/registry/registry.go

@@ -25,12 +25,18 @@ import (
 //   - Lazy dependency injection during registration via RegisterAll()
 //   - Runtime toolset enabling for dynamic toolsets mode
 type Registry struct {
-	// tools holds all tools in this group
+	// tools holds all tools in this group (ordered for iteration)
 	tools []ServerTool
-	// resourceTemplates holds all resource templates in this group
+	// toolsByName provides O(1) lookup by tool name
+	toolsByName map[string]*ServerTool
+	// resourceTemplates holds all resource templates in this group (ordered for iteration)
 	resourceTemplates []ServerResourceTemplate
-	// prompts holds all prompts in this group
+	// resourcesByURI provides O(1) lookup by URI template
+	resourcesByURI map[string]*ServerResourceTemplate
+	// prompts holds all prompts in this group (ordered for iteration)
 	prompts []ServerPrompt
+	// promptsByName provides O(1) lookup by prompt name
+	promptsByName map[string]*ServerPrompt
 	// deprecatedAliases maps old tool names to new canonical names
 	deprecatedAliases map[string]string
 
@@ -92,8 +98,11 @@ func (r *Registry) ForMCPRequest(method string, itemName string) *Registry {
 	// Create a shallow copy with shared filter settings
 	result := &Registry{
 		tools:                r.tools,
+		toolsByName:          r.toolsByName,
 		resourceTemplates:    r.resourceTemplates,
+		resourcesByURI:       r.resourcesByURI,
 		prompts:              r.prompts,
+		promptsByName:        r.promptsByName,
 		deprecatedAliases:    r.deprecatedAliases,
 		readOnly:             r.readOnly,
 		enabledToolsets:      r.enabledToolsets, // shared, not modified
@@ -269,11 +278,8 @@ func (r *Registry) ResolveToolAliases(toolNames []string) (resolved []string, al
 // Returns the tool, its toolset ID, and an error if not found.
 // This searches ALL tools regardless of filters.
 func (r *Registry) FindToolByName(toolName string) (*ServerTool, ToolsetID, error) {
-	for i := range r.tools {
-		tool := &r.tools[i]
-		if tool.Tool.Name == toolName {
-			return tool, tool.Toolset.ID, nil
-		}
+	if tool, ok := r.toolsByName[toolName]; ok {
+		return tool, tool.Toolset.ID, nil
 	}
 	return nil, "", NewToolDoesNotExistError(toolName)
 }