WIP: progress dots

Based on @chriskuehl's branch here:
- f7213054ac

pre_commit/commands/run.py

@@ -110,16 +110,25 @@ def _run_single_hook(classifier, hook, args, skips, cols, use_color):
 
     # Print the hook and the dots first in case the hook takes hella long to
     # run.
-    output.write(
+    msg, num_dots = get_hook_message(
-        get_hook_message(
         _hook_msg_start(hook, args.verbose), end_len=6, cols=cols,
-        ),
     )
+    output.write(msg)
     sys.stdout.flush()
 
+    dots_printed = [0]
+
+    def progress(perc):
+        dots_to_print = int(round(num_dots * perc))
+
+        sys.stdout.write('.' * (dots_to_print - dots_printed[0]))
+        sys.stdout.flush()
+
+        dots_printed[0] = dots_to_print
+
     diff_before = cmd_output_b('git', 'diff', '--no-ext-diff', retcode=None)
     filenames = tuple(filenames) if hook.pass_filenames else ()
-    retcode, out = hook.run(filenames, use_color)
+    retcode, out = hook.run(filenames, use_color, progress)
     diff_after = cmd_output_b('git', 'diff', '--no-ext-diff', retcode=None)
 
     file_modifications = diff_before != diff_after

pre_commit/languages/all.py

@@ -38,7 +38,7 @@ from pre_commit.languages import system
 #         version - A version specified in the hook configuration or 'default'.
 #     """
 #
-# def run_hook(hook, file_args, color):
+# def run_hook(hook, file_args, color, progress):
 #     """Runs a hook and returns the returncode and output of running that
 #     hook.
 #
@@ -46,6 +46,7 @@ from pre_commit.languages import system
 #         hook - `Hook`
 #         file_args - The files to be run
 #         color - whether the hook should be given a pty (when supported)
+#         progress - report progress as a float percentage
 #
 #     Returns:
 #         (returncode, output)

pre_commit/languages/docker.py

@@ -95,7 +95,7 @@ def docker_cmd():  # pragma: windows no cover
     )
 
 
-def run_hook(hook, file_args, color):  # pragma: windows no cover
+def run_hook(hook, file_args, color, progress):  # pragma: windows no cover
     assert_docker_available()
     # Rebuild the docker image in case it has gone missing, as many people do
     # automated cleanup of docker images.
@@ -106,4 +106,6 @@ def run_hook(hook, file_args, color):  # pragma: windows no cover
 
     entry_tag = ('--entrypoint', entry_exe, docker_tag(hook.prefix))
     cmd = docker_cmd() + entry_tag + cmd_rest
-    return helpers.run_xargs(hook, cmd, file_args, color=color)
+    return helpers.run_xargs(
+        hook, cmd, file_args, color=color, progress=progress,
+    )

pre_commit/languages/docker_image.py

@@ -12,7 +12,9 @@ healthy = helpers.basic_healthy
 install_environment = helpers.no_install
 
 
-def run_hook(hook, file_args, color):  # pragma: windows no cover
+def run_hook(hook, file_args, color, progress):  # pragma: windows no cover
     assert_docker_available()
     cmd = docker_cmd() + hook.cmd
-    return helpers.run_xargs(hook, cmd, file_args, color=color)
+    return helpers.run_xargs(
+        hook, cmd, file_args, color=color, progress=progress,
+    )

pre_commit/languages/golang.py

@@ -81,6 +81,8 @@ def install_environment(prefix, version, additional_dependencies):
             rmtree(pkgdir)
 
 
-def run_hook(hook, file_args, color):
+def run_hook(hook, file_args, color, progress):
     with in_env(hook.prefix):
-        return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+        return helpers.run_xargs(
+            hook, hook.cmd, file_args, color=color, progress=progress,
+        )

pre_commit/languages/node.py

@@ -78,6 +78,8 @@ def install_environment(
             )
 
 
-def run_hook(hook, file_args, color):  # pragma: windows no cover
+def run_hook(hook, file_args, color, progress):  # pragma: windows no cover
     with in_env(hook.prefix, hook.language_version):
-        return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+        return helpers.run_xargs(
+            hook, hook.cmd, file_args, color=color, progress=progress,
+        )

pre_commit/languages/python.py

@@ -151,9 +151,11 @@ def py_interface(_dir, _make_venv):
             )
         return retcode == 0
 
-    def run_hook(hook, file_args, color):
+    def run_hook(hook, file_args, color, progress):
         with in_env(hook.prefix, hook.language_version):
-            return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+            return helpers.run_xargs(
+                hook, hook.cmd, file_args, color=color, progress=progress,
+            )
 
     def install_environment(prefix, version, additional_dependencies):
         additional_dependencies = tuple(additional_dependencies)

pre_commit/languages/ruby.py

@@ -124,6 +124,8 @@ def install_environment(
             )
 
 
-def run_hook(hook, file_args, color):  # pragma: windows no cover
+def run_hook(hook, file_args, color, progress):  # pragma: windows no cover
     with in_env(hook.prefix, hook.language_version):
-        return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+        return helpers.run_xargs(
+            hook, hook.cmd, file_args, color=color, progress=progress,
+        )

pre_commit/languages/rust.py

@@ -89,6 +89,8 @@ def install_environment(prefix, version, additional_dependencies):
             )
 
 
-def run_hook(hook, file_args, color):
+def run_hook(hook, file_args, color, progress):
     with in_env(hook.prefix):
-        return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+        return helpers.run_xargs(
+            hook, hook.cmd, file_args, color=color, progress=progress,
+        )

pre_commit/languages/script.py

@@ -9,7 +9,9 @@ healthy = helpers.basic_healthy
 install_environment = helpers.no_install
 
 
-def run_hook(hook, file_args, color):
+def run_hook(hook, file_args, color, progress):
     cmd = hook.cmd
     cmd = (hook.prefix.path(cmd[0]),) + cmd[1:]
-    return helpers.run_xargs(hook, cmd, file_args, color=color)
+    return helpers.run_xargs(
+        hook, cmd, file_args, color=color, progress=progress,
+    )

pre_commit/languages/swift.py

@@ -51,6 +51,8 @@ def install_environment(
         )
 
 
-def run_hook(hook, file_args, color):  # pragma: windows no cover
+def run_hook(hook, file_args, color, progress):  # pragma: windows no cover
     with in_env(hook.prefix):
-        return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+        return helpers.run_xargs(
+            hook, hook.cmd, file_args, color=color, progress=progress,
+        )

pre_commit/languages/system.py

@@ -9,5 +9,7 @@ healthy = helpers.basic_healthy
 install_environment = helpers.no_install
 
 
-def run_hook(hook, file_args, color):
+def run_hook(hook, file_args, color, progress):
-    return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+    return helpers.run_xargs(
+        hook, hook.cmd, file_args, color=color, progress=progress,
+    )

pre_commit/output.py

@@ -54,7 +54,10 @@ def get_hook_message(
         )
 
     if end_len:
-        return start + '.' * (cols - len(start) - end_len - 1)
+        num_dots = cols - len(start) - end_len - 1
+        if end_msg is None:
+            return start, num_dots
+        return start + '.' * num_dots
     else:
         return '{}{}{}{}\n'.format(
             start,

pre_commit/repository.py

@@ -100,9 +100,9 @@ class Hook(collections.namedtuple('Hook', ('src', 'prefix') + _KEYS)):
         # Write our state to indicate we're installed
         _write_state(self.prefix, venv, _state(self.additional_dependencies))
 
-    def run(self, file_args, color):
+    def run(self, file_args, color, progress):
         lang = languages[self.language]
-        return lang.run_hook(self, file_args, color)
+        return lang.run_hook(self, file_args, color, progress)
 
     @classmethod
     def create(cls, src, prefix, dct):

pre_commit/xargs.py

@@ -112,6 +112,7 @@ def xargs(cmd, varargs, **kwargs):
     color = kwargs.pop('color', False)
     negate = kwargs.pop('negate', False)
     target_concurrency = kwargs.pop('target_concurrency', 1)
+    progress = kwargs.pop('progress', lambda _: None)
     max_length = kwargs.pop('_max_length', _get_platform_max_length())
     cmd_fn = cmd_output_p if color else cmd_output_b
     retcode = 0
@@ -125,15 +126,17 @@ def xargs(cmd, varargs, **kwargs):
     partitions = partition(cmd, varargs, target_concurrency, max_length)
 
     def run_cmd_partition(run_cmd):
-        return cmd_fn(
+        ret = cmd_fn(
             *run_cmd, retcode=None, stderr=subprocess.STDOUT, **kwargs
         )
+        return ret, len(run_cmd) - len(cmd)
 
     threads = min(len(partitions), target_concurrency)
     with _thread_mapper(threads) as thread_map:
         results = thread_map(run_cmd_partition, partitions)
 
-        for proc_retcode, proc_out, _ in results:
+        total_processed = 0
+        for (proc_retcode, proc_out, _), processed in results:
             # This is *slightly* too clever so I'll explain it.
             # First the xor boolean table:
             #     T | F |
@@ -146,5 +149,7 @@ def xargs(cmd, varargs, **kwargs):
             # code. Otherwise, the returncode is unchanged.
             retcode |= bool(proc_retcode) ^ negate
             stdout += proc_out
+            total_processed += processed
+            progress(float(total_processed) / len(varargs))
 
     return retcode, stdout