import conanfile just once

conans/client/loader.py

@@ -40,10 +40,15 @@ def __init__(self, runner, output, python_requires):
         self._output = output
         self._python_requires = python_requires
         sys.modules["conans"].python_requires = python_requires
+        self.cached_conanfiles = {}
 
     def load_class(self, conanfile_path):
-        _, conanfile = parse_conanfile(conanfile_path, self._python_requires)
-        return conanfile
+        try:
+            return self.cached_conanfiles[conanfile_path]
+        except KeyError:
+            _, conanfile = parse_conanfile(conanfile_path, self._python_requires)
+            self.cached_conanfiles[conanfile_path] = conanfile
+            return conanfile
 
     def load_name_version(self, conanfile_path, name, version):
         conanfile = self.load_class(conanfile_path)

conans/test/model/transitive_reqs_test.py

@@ -115,6 +115,7 @@ def setUp(self):
 
     def root(self, content):
         processed_profile = ProcessedProfile()
+        self.loader.cached_conanfiles = {}
         root_conan = self.retriever.root(content, processed_profile)
         deps_graph = self.builder.load_graph(root_conan, False, False, None,
                                              processed_profile)

conans/test/model/version_ranges_test.py

@@ -181,6 +181,7 @@ class SayConan(ConanFile):
 
     def root(self, content, update=False):
         processed_profile = ProcessedProfile()
+        self.loader.cached_conanfiles = {}
         root_conan = self.retriever.root(content, processed_profile)
         deps_graph = self.builder.load_graph(root_conan, update, update, None, processed_profile)
         return deps_graph

conans/test/optimize_conanfile_load_test.py

@@ -0,0 +1,27 @@
+import unittest
+
+from conans.test.utils.tools import TestClient
+
+
+class OptimizeConanFileLoadTest(unittest.TestCase):
+
+    def test_multiple_load(self):
+        client = TestClient()
+        conanfile = """from conans import ConanFile
+mycounter = 0
+class Pkg(ConanFile):
+    def configure(self):
+        global mycounter
+        mycounter += 1
+        self.output.info("My Counter %s" % mycounter)
+"""
+        client.save({"conanfile.py": conanfile})
+
+        client.run("create . Build/0.1@user/testing")
+
+        client.save({"conanfile.py": conanfile,
+                     "test_package/conanfile.py": conanfile + "    def test(self): pass",
+                     "myprofile": "[build_requires]\nBuild/0.1@user/testing"})
+
+        client.run("create . Pkg/0.1@user/testing -pr=myprofile")
+        self.assertIn("Build/0.1@user/testing: My Counter 2", client.out)