Add tracer code and basic raw json report

This patch includes:

  * Add main module that can be called by "profimp"
    If no args it will display help message otherwise
    it will do it's job

  * Add tracer code that knows how to trace imports

  * Add reporter that knows hot to show traces in json

  * Cover everything by unit tests

  * Improve a bit Readme

README.rst

@@ -1,6 +1,26 @@
-==============================
-Profimp - python import tracer
-==============================
+===============================
+Profimp - python imports tracer
+===============================
 
 
+Profimp allows you to trace imports of your code.
 
+This lib should be used to simplify optimization of imports in your code.
+At least you will find what consumes the most part of time and do the
+right decisions.
+
+Syntax:
+
+.. code-block::
+
+    profimp [import_module_line]
+
+Samples:
+
+.. code-block::
+
+    profimp "import re"
+
+    or
+
+    profimp "from somemoudle import something"

doc/source/index.rst

@@ -14,8 +14,27 @@
       under the License.
 
 
-Profimp - python import tracer
-==============================
+Profimp - python imports tracer
+===============================
 
+Profimp allows you to trace imports of your code.
 
+This lib should be used to simplify optimization of imports in your code.
+At least you will find what consumes the most part of time and do the
+right decisions.
 
+Syntax:
+
+.. code-block::
+
+    profimp [import_module_line]
+
+Samples:
+
+.. code-block::
+
+    profimp "import re"
+
+    or
+
+    profimp "from somemoudle import something"

profimp/main.py

@@ -13,9 +13,54 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from __future__ import print_function
+
+import sys
+
+from profimp import reports
+from profimp import tracer
+
+
+HELP_MESSAGE = """
+    Profimp allows you to trace imports of your code.
+
+    This lib should be used to simplify optimization of imports in your code.
+    At least you will find what consumes the most part of time and do the
+    right decisions.
+
+    Syntax:
+        profimp [import_module_line]
+
+    Samples:
+        profimp "import re"
+
+        or
+
+        profimp "from somemoudle import something"
+"""
+
+
+def print_help():
+    print(HELP_MESSAGE)
+
+
+def trace_module(import_line):
+    root_pt = tracer.init_stack()
+    with tracer.patch_import():
+        exec(import_line)
+    return root_pt
+
 
 def main():
-    return "Hello world"
+    if len(sys.argv) == 1:
+        print_help()
+    elif len(sys.argv) == 2:
+        report = reports.to_json(trace_module(sys.argv[1]))
+        sys.stdout.write(report)
+    else:
+        print_help()
+        raise SystemExit("Wrong input arguments: %s" % sys.argv)
+
 
 if __name__ == "__main__":
     main()

tests/unit/test_noop.py → profimp/reports.py

@@ -13,11 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from tests.unit import test
+import json
 
 
-class NoopTestCase(test.TestCase):
-    """Test case base class for all unit tests."""
-
-    def test_noop(self):
-        self.assertEqual(4, 2 + 2)
+def to_json(results):
+    return json.dumps(results.to_dict(), indent=2)

profimp/tracer.py

@@ -0,0 +1,98 @@
+# Copyright 2015: Boris Pavlovic
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import contextlib
+import time
+
+from six.moves import builtins
+
+
+class TracePoint(object):
+
+    def __init__(self, import_line, level=0):
+        self.started_at = 0
+        self.finished_at = 0
+        self.import_line = import_line
+        self.level = level
+        self.children = []
+
+    def __enter__(self):
+        self.start()
+        return self
+
+    def __exit__(self, etype, value, traceback):
+        self.stop()
+
+    def to_dict(self):
+
+        result = {
+            "started_at": self.started_at,
+            "finished_at": self.finished_at,
+            "duration": (self.finished_at - self.started_at) * 1000,
+            "import_line": self.import_line,
+            "level": self.level,
+            "children": []
+        }
+
+        for child in self.children:
+            result["children"].append(child.to_dict())
+
+        return result
+
+    def start(self):
+        self.started_at = time.time()
+
+    def stop(self):
+        self.finished_at = time.time()
+
+    def add_child(self, child):
+        self.children.append(child)
+        child.level = self.level + 1
+
+
+TRACE_STACK = []
+
+
+def init_stack():
+    global TRACE_STACK
+    TRACE_STACK = [TracePoint("root", 0)]
+    return TRACE_STACK[0]
+
+
+@contextlib.contextmanager
+def patch_import():
+    old_import = builtins.__import__
+    builtins.__import__ = _traceit(builtins.__import__)
+    yield
+    builtins.__import__ = old_import
+
+
+def _traceit(f):
+    def w(*args, **kwargs):
+        import_line = ""
+
+        if len(args) > 3 and args[3]:
+            import_line = "from %s import %s" % (args[0], ", ".join(args[3]))
+        else:
+            import_line = "import %s" % args[0]
+
+        with TracePoint(import_line) as trace_pt:
+            TRACE_STACK[-1].add_child(trace_pt)
+            TRACE_STACK.append(trace_pt)
+            try:
+                return f(*args, **kwargs)
+            finally:
+                TRACE_STACK.pop()
+    return w

tests/unit/test.py

@@ -14,7 +14,6 @@
 # under the License.
 
 import mock
-
 import testtools
 
 

tests/unit/test_main.py

@@ -0,0 +1,60 @@
+# Copyright 2015: Boris Pavlovic
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import mock
+
+from profimp import main
+from tests.unit import test
+
+
+class MainTestCase(test.TestCase):
+
+    @mock.patch("profimp.main.print", create=True)
+    def test_print_help(self, mock_print):
+        main.print_help()
+        mock_print.assert_called_once_with(main.HELP_MESSAGE)
+
+    def test_trace_module(self):
+        root_pt = main.trace_module("import re")
+
+        self.assertEqual(1, len(root_pt.children))
+        self.assertEqual("import re", root_pt.children[0].import_line)
+
+    @mock.patch("profimp.main.print_help")
+    @mock.patch("profimp.main.sys")
+    def test_main_too_few_args(self, mock_sys, mock_print_help):
+        mock_sys.argv = ["profimp"]
+        main.main()
+        mock_print_help.assert_called_once_with()
+
+    @mock.patch("profimp.main.reports")
+    @mock.patch("profimp.main.trace_module")
+    @mock.patch("profimp.main.sys")
+    def test_main(self, mock_sys, mock_trace_module, mock_reports):
+        mock_sys.argv = ["profimp", "import re"]
+
+        mock_trace_module.return_value
+        main.main()
+
+        mock_trace_module.assert_called_once_with("import re")
+        mock_reports.to_json.assert_called_once_with(
+            mock_trace_module.return_value)
+
+    @mock.patch("profimp.main.print_help")
+    @mock.patch("profimp.main.sys")
+    def test_main_with_too_many_args(self, mock_sys, mock_print_help):
+        mock_sys.argv = ["profimp", "module_one", "something else"]
+        self.assertRaises(SystemExit, main.main)
+        mock_print_help.assert_called_once_with()

tests/unit/test_reports.py

@@ -0,0 +1,32 @@
+# Copyright 2015: Boris Pavlovic
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import json
+
+import mock
+
+from profimp import reports
+from tests.unit import test
+
+
+class ReportsTestCase(test.TestCase):
+
+    def test_to_json(self):
+
+        results = mock.MagicMock()
+        results.to_dict.return_value = {"a": 1, "b": 20}
+
+        self.assertEqual(json.dumps(results.to_dict.return_value, indent=2),
+                         reports.to_json(results))