inst/builder.py: Split function in three to reduce indentation levels

Signed-off-by: Niels Thykier <niels@thykier.net>

britney2/installability/builder.py

@@ -23,13 +23,19 @@ from britney2.installability.solver import InstallabilitySolver
 def build_installability_tester(suite_info, archs):
     """Create the installability tester"""
 
-    solvers = get_dependency_solvers
     builder = InstallabilityTesterBuilder()
 
     for (suite, arch) in product(suite_info, archs):
+        _build_inst_tester_on_suite_arch(builder, suite_info, suite, arch)
+
+    return builder.build()
+
+
+def _build_inst_tester_on_suite_arch(builder, suite_info, suite, arch):
     packages_s_a = suite.binaries[arch][0]
     is_target = suite.suite_class.is_target
     bin_prov = [s.binaries[arch] for s in suite_info]
+    solvers = get_dependency_solvers
     for pkgdata in packages_s_a.values():
         pkg_id = pkgdata.pkg_id
         if not builder.add_binary(pkg_id,
@@ -51,6 +57,14 @@ def build_installability_tester(suite_info, archs):
             conflicts = None
 
         if pkgdata.depends:
+            depends = _compute_depends(pkgdata, bin_prov, solvers)
+        else:
+            depends = None
+
+        builder.set_relations(pkg_id, depends, conflicts)
+
+
+def _compute_depends(pkgdata, bin_prov, solvers):
     depends = []
     possible_dep_ranges = {}
     for block in apt_pkg.parse_depends(pkgdata.depends, False):
@@ -87,12 +101,8 @@ def build_installability_tester(suite_info, archs):
 
     if possible_dep_ranges:
         depends.extend(possible_dep_ranges.values())
-            else:
-                depends = None
-
-            builder.set_relations(pkg_id, depends, conflicts)
 
-    return builder.build()
+    return depends
 
 
 class InstallabilityTesterBuilder(object):