improving Pod::Installer::Analyzer#deduplicate_targets performance, by avoiding…

improving Pod::Installer::Analyzer#deduplicate_targets performance, by avoiding computing previously computed dependency trees

lib/cocoapods/installer/analyzer.rb

@@ -277,6 +277,8 @@ module Pod
       #
       def generate_pod_targets(specs_by_target)
         if config.deduplicate_targets?
+          dedupe_cache = {}
+
           all_specs = specs_by_target.flat_map do |target_definition, dependent_specs|
             dependent_specs.group_by(&:root).map do |root_spec, specs|
               [root_spec, specs, target_definition]
@@ -294,7 +296,7 @@ module Pod
               # There are different sets of subspecs or the spec is used across different platforms
               targets_by_distinctors.flat_map do |distinctor, target_definitions|
                 specs, = *distinctor
-                generate_pod_target(target_definitions, specs).scoped
+                generate_pod_target(target_definitions, specs).scoped(dedupe_cache)
               end
             else
               (specs, _), target_definitions = targets_by_distinctors.first
@@ -308,7 +310,7 @@ module Pod
             dependent_targets = transitive_dependencies_for_pod_target(target, pod_targets)
             target.dependent_targets = dependent_targets
             if dependent_targets.any?(&:scoped?)
-              target.scoped
+              target.scoped(dedupe_cache)
             else
               target
             end
@@ -317,7 +319,7 @@ module Pod
           pod_targets = specs_by_target.flat_map do |target_definition, specs|
             grouped_specs = specs.group_by.group_by(&:root).values.uniq
             grouped_specs.flat_map do |pod_specs|
-              generate_pod_target([target_definition], pod_specs).scoped
+              generate_pod_target([target_definition], pod_specs).scoped(dedupe_cache)
             end
           end
           pod_targets.each do |target|

lib/cocoapods/target/pod_target.rb

@@ -59,14 +59,19 @@ module Pod
 
     # @return [Array<PodTarget>] a scoped copy for each target definition.
     #
-    def scoped
+    def scoped(cache = {})
       target_definitions.map do |target_definition|
-        PodTarget.new(specs, [target_definition], sandbox, true).tap do |target|
+        cash_key = [specs, target_definition]
+        if cache[cash_key]
+          cache[cash_key]
+        else
+          target = PodTarget.new(specs, [target_definition], sandbox, true)
           target.file_accessors = file_accessors
           target.user_build_configurations = user_build_configurations
           target.native_target = native_target
           target.archs = archs
-          target.dependent_targets = dependent_targets.flat_map(&:scoped).select { |pt| pt.target_definitions == [target_definition] }
+          target.dependent_targets = dependent_targets.flat_map { |pt| pt.scoped(cache)}.select { |pt| pt.target_definitions == [target_definition] }
+          cache[cash_key] = target
         end
       end
     end