Always check prefix matches array at each node

Currently, we only check if the name of a given node in the trie is a
prefix match and the prefix matches array of the final node.  This is
incorrect however, as the prefix matches array of intermediate nodes
may contain the prefix for a given property.  This change adds that
check and test cases for this case.

Bug: 36001741
Test: new unit tests
Change-Id: I9f58ebc559f2ac591aa44df9e71205704bf18f66

3 files changed, 105 insertions, 12 deletions

diff --git a/property_service/libpropertyinfoparser/include/property_info_parser/property_info_parser.h b/property_service/libpropertyinfoparser/include/property_info_parser/property_info_parser.h
index c2114ccff..8c3507e4f 100644
--- a/property_service/libpropertyinfoparser/include/property_info_parser/property_info_parser.h
+++ b/property_service/libpropertyinfoparser/include/property_info_parser/property_info_parser.h
@@ -172,6 +172,9 @@ class PropertyInfoArea : private SerializedData {
   TrieNode root_node() const { return trie(header()->root_offset); }
 
  private:
+  void CheckPrefixMatch(const char* remaining_name, const TrieNode& trie_node,
+                        uint32_t* context_index, uint32_t* schema_index) const;
+
   const PropertyInfoAreaHeader* header() const {
     return reinterpret_cast<const PropertyInfoAreaHeader*>(data_base());
   }
diff --git a/property_service/libpropertyinfoparser/property_info_parser.cpp b/property_service/libpropertyinfoparser/property_info_parser.cpp
index 84f8c29f8..89864dd78 100644
--- a/property_service/libpropertyinfoparser/property_info_parser.cpp
+++ b/property_service/libpropertyinfoparser/property_info_parser.cpp
@@ -87,6 +87,21 @@ bool TrieNode::FindChildForString(const char* name, uint32_t namelen, TrieNode*
   return true;
 }
 
+void PropertyInfoArea::CheckPrefixMatch(const char* remaining_name, const TrieNode& trie_node,
+                                        uint32_t* context_index, uint32_t* schema_index) const {
+  const uint32_t remaining_name_size = strlen(remaining_name);
+  for (uint32_t i = 0; i < trie_node.num_prefixes(); ++i) {
+    auto prefix_len = trie_node.prefix(i)->namelen;
+    if (prefix_len > remaining_name_size) continue;
+
+    if (!strncmp(c_string(trie_node.prefix(i)->name_offset), remaining_name, prefix_len)) {
+      *context_index = trie_node.prefix(i)->context_index;
+      *schema_index = trie_node.prefix(i)->schema_index;
+      return;
+    }
+  }
+}
+
 void PropertyInfoArea::GetPropertyInfoIndexes(const char* name, uint32_t* context_index,
                                               uint32_t* schema_index) const {
   uint32_t return_context_index = ~0u;
@@ -104,6 +119,10 @@ void PropertyInfoArea::GetPropertyInfoIndexes(const char* name, uint32_t* contex
       return_schema_index = trie_node.schema_index();
     }
 
+    // Check prefixes at this node.  This comes after the node check since these prefixes are by
+    // definition longer than the node itself.
+    CheckPrefixMatch(remaining_name, trie_node, &return_context_index, &return_schema_index);
+
     if (sep == nullptr) {
       break;
     }
@@ -128,18 +147,8 @@ void PropertyInfoArea::GetPropertyInfoIndexes(const char* name, uint32_t* contex
     }
   }
   // Check prefix matches for prefixes not deliminated with '.'
-  const uint32_t remaining_name_size = strlen(remaining_name);
-  for (uint32_t i = 0; i < trie_node.num_prefixes(); ++i) {
-    auto prefix_len = trie_node.prefix(i)->namelen;
-    if (prefix_len > remaining_name_size) continue;
-
-    if (!strncmp(c_string(trie_node.prefix(i)->name_offset), remaining_name, prefix_len)) {
-      if (context_index != nullptr) *context_index = trie_node.prefix(i)->context_index;
-      if (schema_index != nullptr) *schema_index = trie_node.prefix(i)->schema_index;
-      return;
-    }
-  }
-  // Return previously found '.' deliminated prefix match.
+  CheckPrefixMatch(remaining_name, trie_node, &return_context_index, &return_schema_index);
+  // Return previously found prefix match.
   if (context_index != nullptr) *context_index = return_context_index;
   if (schema_index != nullptr) *schema_index = return_schema_index;
   return;
diff --git a/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp b/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
index 5fa3463e1..b3fae268e 100644
--- a/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
+++ b/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
@@ -763,5 +763,86 @@ TEST(propertyinfoserializer, RealProperties) {
   }
 }
 
+TEST(propertyinfoserializer, GetPropertyInfo_prefix_without_dot) {
+  auto property_info = std::vector<PropertyInfoEntry>{
+      {"persist.radio", "1st", "1st", false},
+      {"persist.radio.something.else.here", "2nd", "2nd", false},
+  };
+
+  auto serialized_trie = std::string();
+  auto build_trie_error = std::string();
+  ASSERT_TRUE(BuildTrie(property_info, "default", "default", &serialized_trie, &build_trie_error))
+      << build_trie_error;
+
+  auto property_info_area = reinterpret_cast<const PropertyInfoArea*>(serialized_trie.data());
+
+  const char* context;
+  const char* schema;
+  property_info_area->GetPropertyInfo("persist.radio", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("1st", schema);
+  property_info_area->GetPropertyInfo("persist.radio.subproperty", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("1st", schema);
+  property_info_area->GetPropertyInfo("persist.radiowords", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("1st", schema);
+  property_info_area->GetPropertyInfo("persist.radio.long.long.long.sub.property", &context,
+                                      &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("1st", schema);
+  property_info_area->GetPropertyInfo("persist.radio.something.else.here", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("2nd", schema);
+  property_info_area->GetPropertyInfo("persist.radio.something.else.here2", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("2nd", schema);
+  property_info_area->GetPropertyInfo("persist.radio.something.else.here.after", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("2nd", schema);
+  property_info_area->GetPropertyInfo("persist.radio.something.else.nothere", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("1st", schema);
+  property_info_area->GetPropertyInfo("persist.radio.something.else", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("1st", schema);
+}
+
+TEST(propertyinfoserializer, GetPropertyInfo_prefix_with_dot_vs_without) {
+  auto property_info = std::vector<PropertyInfoEntry>{
+      {"persist.", "1st", "1st", false},
+      {"persist.radio", "2nd", "2nd", false},
+      {"persist.radio.long.property.exact.match", "3rd", "3rd", true},
+  };
+
+  auto serialized_trie = std::string();
+  auto build_trie_error = std::string();
+  ASSERT_TRUE(BuildTrie(property_info, "default", "default", &serialized_trie, &build_trie_error))
+      << build_trie_error;
+
+  auto property_info_area = reinterpret_cast<const PropertyInfoArea*>(serialized_trie.data());
+
+  const char* context;
+  const char* schema;
+  property_info_area->GetPropertyInfo("persist.notradio", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("1st", schema);
+  property_info_area->GetPropertyInfo("persist.radio", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("2nd", schema);
+  property_info_area->GetPropertyInfo("persist.radio.subproperty", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("2nd", schema);
+  property_info_area->GetPropertyInfo("persist.radiowords", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("2nd", schema);
+  property_info_area->GetPropertyInfo("persist.radio.long.property.prefix.match", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("2nd", schema);
+  property_info_area->GetPropertyInfo("persist.radio.long.property.exact.match", &context, &schema);
+  EXPECT_STREQ("3rd", context);
+  EXPECT_STREQ("3rd", schema);
+}
+
 }  // namespace properties
 }  // namespace android