add download cache msg (#14716)

conans/client/downloaders/caching_file_downloader.py

@@ -4,11 +4,12 @@
 from urllib.parse import urlparse
 from urllib.request import url2pathname
 
+from conan.api.output import ConanOutput
 from conans.client.downloaders.file_downloader import FileDownloader
 from conans.client.downloaders.download_cache import DownloadCache
 from conans.errors import NotFoundException, ConanException, AuthenticationException, \
     ForbiddenException
-from conans.util.files import mkdir, set_dirty_context_manager, remove_if_dirty
+from conans.util.files import mkdir, set_dirty_context_manager, remove_if_dirty, human_size
 
 
 class SourcesCachingDownloader:
@@ -158,6 +159,7 @@ def __init__(self, requester, config, scope=None):
         if self._download_cache and not os.path.isabs(self._download_cache):
             raise ConanException("core.download:download_cache must be an absolute path")
         self._file_downloader = FileDownloader(requester, scope=scope)
+        self._scope = scope
 
     def download(self, url, file_path, auth, verify_ssl, retry, retry_wait, metadata=False):
         if not self._download_cache or metadata:  # Metadata not cached and can be overwritten
@@ -175,6 +177,15 @@ def download(self, url, file_path, auth, verify_ssl, retry, retry_wait, metadata
                     self._file_downloader.download(url, cached_path, retry=retry,
                                                    retry_wait=retry_wait, verify_ssl=verify_ssl,
                                                    auth=auth, overwrite=False)
+            else:  # Found in cache!
+                total_length = os.path.getsize(cached_path)
+                is_large_file = total_length > 10000000  # 10 MB
+                if is_large_file:
+                    base_name = os.path.basename(file_path)
+                    hs = human_size(total_length)
+                    ConanOutput(scope=self._scope).info(f"Copying {hs} {base_name} from download "
+                                                        f"cache, instead of downloading it")
+
             # Everything good, file in the cache, just copy it to final destination
             mkdir(os.path.dirname(file_path))
             shutil.copy2(cached_path, file_path)

conans/test/integration/cache/download_cache_test.py

@@ -14,7 +14,18 @@ def test_download_skip(self):
         """ basic proof that enabling download_cache avoids downloading things again
         """
         client = TestClient(default_server_user=True)
-        client.save({"conanfile.py": GenConanfile().with_package_file("file.txt", "content")})
+        # generate large random package file
+        conanfile = textwrap.dedent("""
+            import os
+            from conan import ConanFile
+            from conan.tools.files import save
+            class Pkg(ConanFile):
+                def package(self):
+                    fileSizeInBytes = 11000000
+                    with open(os.path.join(self.package_folder, "data.txt"), 'wb') as fout:
+                        fout.write(os.urandom(fileSizeInBytes))
+                """)
+        client.save({"conanfile.py": conanfile})
         client.run("create . --name=mypkg --version=0.1 --user=user --channel=testing")
         client.run("upload * --confirm -r default")
         client.run("remove * -c")
@@ -24,24 +35,25 @@ def test_download_skip(self):
         client.save({"global.conf": f"core.download:download_cache={tmp_folder}"},
                     path=client.cache.cache_folder)
         client.run("install --requires=mypkg/0.1@user/testing")
-        assert "Downloading" in client.out
+        assert "mypkg/0.1@user/testing: Downloading" in client.out
 
         client.run("remove * -c")
         client.run("install --requires=mypkg/0.1@user/testing")
-        # TODO assert "Downloading" not in client.out
-
+        assert "mypkg/0.1@user/testing: Downloading" not in client.out
+        assert "conan_package.tgz from download cache, instead of downloading it" in client.out
         # removing the config downloads things
         client.save({"global.conf": ""}, path=client.cache.cache_folder)
         client.run("remove * -c")
         client.run("install --requires=mypkg/0.1@user/testing")
-        assert "Downloading" in client.out
+        assert "mypkg/0.1@user/testing: Downloading" in client.out
 
         client.save({"global.conf": f"core.download:download_cache={tmp_folder}"},
                     path=client.cache.cache_folder)
 
         client.run("remove * -c")
         client.run("install --requires=mypkg/0.1@user/testing")
-        # TODO assert "Downloading" not in client.out
+        assert "mypkg/0.1@user/testing: Downloading" not in client.out
+        assert "conan_package.tgz from download cache, instead of downloading it" in client.out
 
     def test_dirty_download(self):
         # https://github.com/conan-io/conan/issues/8578