Use new Scheme model for wheel installation

3 files changed, 27 insertions, 21 deletions

diff --git a/src/pip/_internal/req/req_install.py b/src/pip/_internal/req/req_install.py
index fb378d28f..5a86532cc 100644
--- a/src/pip/_internal/req/req_install.py
+++ b/src/pip/_internal/req/req_install.py
@@ -22,7 +22,7 @@ from pip._vendor.pep517.wrappers import Pep517HookCaller
 from pip._internal import pep425tags, wheel
 from pip._internal.build_env import NoOpBuildEnvironment
 from pip._internal.exceptions import InstallationError
-from pip._internal.locations import distutils_scheme
+from pip._internal.locations import get_scheme
 from pip._internal.models.link import Link
 from pip._internal.operations.build.metadata import generate_metadata
 from pip._internal.operations.build.metadata_legacy import \
@@ -65,11 +65,12 @@ from pip._internal.vcs import vcs
 
 if MYPY_CHECK_RUNNING:
     from typing import (
-        Any, Dict, Iterable, List, Mapping, Optional, Sequence, Union,
+        Any, Dict, Iterable, List, Optional, Sequence, Union,
     )
     from pip._internal.build_env import BuildEnvironment
     from pip._internal.cache import WheelCache
     from pip._internal.index.package_finder import PackageFinder
+    from pip._internal.models.scheme import Scheme
     from pip._vendor.pkg_resources import Distribution
     from pip._vendor.packaging.specifiers import SpecifierSet
     from pip._vendor.packaging.markers import Marker
@@ -540,7 +541,7 @@ class InstallRequirement(object):
     def move_wheel_files(
         self,
         wheeldir,  # type: str
-        scheme,  # type: Mapping[str, str]
+        scheme,  # type: Scheme
         warn_script_location=True,  # type: bool
         pycompile=True  # type: bool
     ):
@@ -852,7 +853,7 @@ class InstallRequirement(object):
         pycompile=True  # type: bool
     ):
         # type: (...) -> None
-        scheme = distutils_scheme(
+        scheme = get_scheme(
             self.name,
             user=use_user_site,
             home=home,
diff --git a/src/pip/_internal/wheel.py b/src/pip/_internal/wheel.py
index 85a9e2b60..682a37e49 100644
--- a/src/pip/_internal/wheel.py
+++ b/src/pip/_internal/wheel.py
@@ -36,9 +36,11 @@ from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
 if MYPY_CHECK_RUNNING:
     from typing import (
-        Dict, List, Optional, Sequence, Mapping, Tuple, IO, Text, Any,
+        Dict, List, Optional, Sequence, Tuple, IO, Text, Any,
         Iterable, Callable, Set,
     )
+
+    from pip._internal.models.scheme import Scheme
     from pip._internal.pep425tags import Pep425Tag
 
     InstalledCSVRow = Tuple[str, ...]
@@ -289,7 +291,7 @@ class PipScriptMaker(ScriptMaker):
 def install_unpacked_wheel(
     name,  # type: str
     wheeldir,  # type: str
-    scheme,  # type: Mapping[str, str]
+    scheme,  # type: Scheme
     req_description,  # type: str
     pycompile=True,  # type: bool
     warn_script_location=True  # type: bool
@@ -311,9 +313,9 @@ def install_unpacked_wheel(
     #       installation.
 
     if root_is_purelib(name, wheeldir):
-        lib_dir = scheme['purelib']
+        lib_dir = scheme.purelib
     else:
-        lib_dir = scheme['platlib']
+        lib_dir = scheme.platlib
 
     info_dir = []  # type: List[str]
     data_dirs = []
@@ -458,10 +460,10 @@ def install_unpacked_wheel(
                 fixer = fix_script
                 filter = is_entrypoint_wrapper
             source = os.path.join(wheeldir, datadir, subdir)
-            dest = scheme[subdir]
+            dest = getattr(scheme, subdir)
             clobber(source, dest, False, fixer=fixer, filter=filter)
 
-    maker = PipScriptMaker(None, scheme['scripts'])
+    maker = PipScriptMaker(None, scheme.scripts)
 
     # Ensure old scripts are overwritten.
     # See https://github.com/pypa/pip/issues/1800
diff --git a/tests/unit/test_wheel.py b/tests/unit/test_wheel.py
index 3153f2a82..ea145d722 100644
--- a/tests/unit/test_wheel.py
+++ b/tests/unit/test_wheel.py
@@ -11,8 +11,9 @@ from pip._vendor.packaging.requirements import Requirement
 from pip._internal import pep425tags, wheel
 from pip._internal.commands.wheel import WheelCommand
 from pip._internal.exceptions import InvalidWheelFilename, UnsupportedWheel
-from pip._internal.locations import distutils_scheme
+from pip._internal.locations import get_scheme
 from pip._internal.models.link import Link
+from pip._internal.models.scheme import Scheme
 from pip._internal.req.req_install import InstallRequirement
 from pip._internal.utils.compat import WINDOWS
 from pip._internal.utils.misc import hash_file
@@ -482,29 +483,31 @@ class TestInstallUnpackedWheel(object):
         self.src = os.path.join(tmpdir, 'src')
         self.dest = os.path.join(tmpdir, 'dest')
         unpack_file(self.wheelpath, self.src)
-        self.scheme = {
-            'scripts': os.path.join(self.dest, 'bin'),
-            'purelib': os.path.join(self.dest, 'lib'),
-            'data': os.path.join(self.dest, 'data'),
-        }
+        self.scheme = Scheme(
+            purelib=os.path.join(self.dest, 'lib'),
+            platlib=os.path.join(self.dest, 'lib'),
+            headers=os.path.join(self.dest, 'headers'),
+            scripts=os.path.join(self.dest, 'bin'),
+            data=os.path.join(self.dest, 'data'),
+        )
         self.src_dist_info = os.path.join(
             self.src, 'sample-1.2.0.dist-info')
         self.dest_dist_info = os.path.join(
-            self.scheme['purelib'], 'sample-1.2.0.dist-info')
+            self.scheme.purelib, 'sample-1.2.0.dist-info')
 
     def assert_installed(self):
         # lib
         assert os.path.isdir(
-            os.path.join(self.scheme['purelib'], 'sample'))
+            os.path.join(self.scheme.purelib, 'sample'))
         # dist-info
         metadata = os.path.join(self.dest_dist_info, 'METADATA')
         assert os.path.isfile(metadata)
         # data files
-        data_file = os.path.join(self.scheme['data'], 'my_data', 'data_file')
+        data_file = os.path.join(self.scheme.data, 'my_data', 'data_file')
         assert os.path.isfile(data_file)
         # package data
         pkg_data = os.path.join(
-            self.scheme['purelib'], 'sample', 'package_data.dat')
+            self.scheme.purelib, 'sample', 'package_data.dat')
         assert os.path.isfile(pkg_data)
 
     def test_std_install(self, data, tmpdir):
@@ -520,7 +523,7 @@ class TestInstallUnpackedWheel(object):
     def test_install_prefix(self, data, tmpdir):
         prefix = os.path.join(os.path.sep, 'some', 'path')
         self.prep(data, tmpdir)
-        scheme = distutils_scheme(
+        scheme = get_scheme(
             self.name,
             user=False,
             home=None,