Extract signature_trie.py from verify_overlaps.py

Makes the efficient pattern matching of hidden API flags that is used
by verify_overlaps.py available for use in other scripts.

As part of the move this cleans up the python to use consistent quotes,
and fix pylint issues.

Bug: 202154151
Test: m out/soong/hiddenapi/hiddenapi-flags.csv
      atest --host signature_trie_test verify_overlaps_test
      pyformat -s 4 --force_quote_type double -i scripts/hiddenapi/signature_trie*
      /usr/bin/pylint --rcfile $ANDROID_BUILD_TOP/tools/repohooks/tools/pylintrc scripts/hiddenapi/signature_trie*
Change-Id: I758ca70bb5b7e6806f14b72fd04f821a069f188f

Change-Id: I73fdb7e02127a8c0171a285221d9e6024310953d
diff --git a/scripts/hiddenapi/signature_trie_test.py b/scripts/hiddenapi/signature_trie_test.py
new file mode 100755
index 0000000..2dc79d0
--- /dev/null
+++ b/scripts/hiddenapi/signature_trie_test.py
@@ -0,0 +1,192 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2022 The Android Open Source Project
+#
+# 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.
+"""Unit tests for verify_overlaps_test.py."""
+import io
+import unittest
+
+from signature_trie import InteriorNode
+from signature_trie import signature_trie
+
+
+class TestSignatureToElements(unittest.TestCase):
+
+    @staticmethod
+    def signature_to_elements(signature):
+        return InteriorNode.signature_to_elements(signature)
+
+    def test_nested_inner_classes(self):
+        elements = [
+            "package:java",
+            "package:lang",
+            "class:ProcessBuilder",
+            "class:Redirect",
+            "class:1",
+            "member:<init>()V",
+        ]
+        signature = "Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_basic_member(self):
+        elements = [
+            "package:java",
+            "package:lang",
+            "class:Object",
+            "member:hashCode()I",
+        ]
+        signature = "Ljava/lang/Object;->hashCode()I"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_double_dollar_class(self):
+        elements = [
+            "package:java",
+            "package:lang",
+            "class:CharSequence",
+            "class:",
+            "class:ExternalSyntheticLambda0",
+            "member:<init>(Ljava/lang/CharSequence;)V",
+        ]
+        signature = "Ljava/lang/CharSequence$$ExternalSyntheticLambda0;" \
+                    "-><init>(Ljava/lang/CharSequence;)V"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_no_member(self):
+        elements = [
+            "package:java",
+            "package:lang",
+            "class:CharSequence",
+            "class:",
+            "class:ExternalSyntheticLambda0",
+        ]
+        signature = "Ljava/lang/CharSequence$$ExternalSyntheticLambda0"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_wildcard(self):
+        elements = [
+            "package:java",
+            "package:lang",
+            "*",
+        ]
+        signature = "java/lang/*"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_recursive_wildcard(self):
+        elements = [
+            "package:java",
+            "package:lang",
+            "**",
+        ]
+        signature = "java/lang/**"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_no_packages_wildcard(self):
+        elements = [
+            "*",
+        ]
+        signature = "*"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_no_packages_recursive_wildcard(self):
+        elements = [
+            "**",
+        ]
+        signature = "**"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_non_standard_class_name(self):
+        elements = [
+            "package:javax",
+            "package:crypto",
+            "class:extObjectInputStream",
+        ]
+        signature = "Ljavax/crypto/extObjectInputStream"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+
+    def test_invalid_pattern_wildcard_and_member(self):
+        pattern = "Ljava/lang/*;->hashCode()I"
+        with self.assertRaises(Exception) as context:
+            self.signature_to_elements(pattern)
+        self.assertIn("contains wildcard * and member signature hashCode()I",
+                      str(context.exception))
+
+
+class TestGetMatchingRows(unittest.TestCase):
+    extractInput = """
+Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;
+Ljava/lang/Character;->serialVersionUID:J
+Ljava/lang/Object;->hashCode()I
+Ljava/lang/Object;->toString()Ljava/lang/String;
+Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V
+Ljava/util/zip/ZipFile;-><clinit>()V
+"""
+
+    def read_trie(self):
+        trie = signature_trie()
+        with io.StringIO(self.extractInput.strip()) as f:
+            for line in iter(f.readline, ""):
+                line = line.rstrip()
+                trie.add(line, line)
+        return trie
+
+    def check_patterns(self, pattern, expected):
+        trie = self.read_trie()
+        self.check_node_patterns(trie, pattern, expected)
+
+    def check_node_patterns(self, node, pattern, expected):
+        actual = list(node.get_matching_rows(pattern))
+        actual.sort()
+        self.assertEqual(expected, actual)
+
+    def test_member_pattern(self):
+        self.check_patterns("java/util/zip/ZipFile;-><clinit>()V",
+                            ["Ljava/util/zip/ZipFile;-><clinit>()V"])
+
+    def test_class_pattern(self):
+        self.check_patterns("java/lang/Object", [
+            "Ljava/lang/Object;->hashCode()I",
+            "Ljava/lang/Object;->toString()Ljava/lang/String;",
+        ])
+
+    # pylint: disable=line-too-long
+    def test_nested_class_pattern(self):
+        self.check_patterns("java/lang/Character", [
+            "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;",
+            "Ljava/lang/Character;->serialVersionUID:J",
+        ])
+
+    def test_wildcard(self):
+        self.check_patterns("java/lang/*", [
+            "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;",
+            "Ljava/lang/Character;->serialVersionUID:J",
+            "Ljava/lang/Object;->hashCode()I",
+            "Ljava/lang/Object;->toString()Ljava/lang/String;",
+            "Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V",
+        ])
+
+    def test_recursive_wildcard(self):
+        self.check_patterns("java/**", [
+            "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;",
+            "Ljava/lang/Character;->serialVersionUID:J",
+            "Ljava/lang/Object;->hashCode()I",
+            "Ljava/lang/Object;->toString()Ljava/lang/String;",
+            "Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V",
+            "Ljava/util/zip/ZipFile;-><clinit>()V",
+        ])
+
+    # pylint: enable=line-too-long
+
+
+if __name__ == "__main__":
+    unittest.main(verbosity=2)