Merge remote-tracking branch 'goog/androidx-platform-dev'

* goog/androidx-platform-dev:
  Sync from upstream.

Descriptions:
======================================================================
Add ScoringSpec into JoinSpec. Rename joined_document to child_document.
======================================================================
Create JoinedScoredDocumentHit class and refactor ScoredDocumentHitsRanker.
======================================================================
Implement initial Join workflow
======================================================================
Implement the Lexer for Icing Advanced Query Language
======================================================================
Create struct Options for PersistentHashMap
======================================================================
Premapping FileBackedVector
======================================================================
Create class PersistentHashMapKeyMapper
======================================================================
Add integer sections into TokenizedDocument and rename string sections
======================================================================
Create NumericIndex interface and DocHitInfoIteratorNumeric
======================================================================
Implement DummyNumericIndex and unit test
======================================================================
Change PostingListAccessor::Finalize to rvalue member function
======================================================================
Define the Abstract Syntax Tree for Icing's list_filter parser.
======================================================================
Refactor query processing and score
======================================================================
Refactor IcingSearchEngine for AppSearch Dynamite Module 0p APIs
======================================================================
Implement the Lexer for Icing Advanced Scoring Language
======================================================================
Add a common interface for IcingSearchEngine and dynamite client
======================================================================
Implement a subset of the query grammar.
======================================================================
Refactor index processor
======================================================================
Add integer index into IcingSearchEngine and IndexProcessor
======================================================================
Implement the parser for Icing Advanced Scoring Language
======================================================================
Implement IntegerIndexData and PostingListUsedIntegerIndexDataSerializer
======================================================================
Add PostingListAccessor abstract class for common components and methods
======================================================================
Implement PostingListIntegerIndexDataAccessor
======================================================================
Create PostingListIntegerIndexDataAccessorTest
======================================================================
Fix Icing Segmentation tests for word connectors that changed in ICU 72.
======================================================================
Modify the Advanced Query grammar to allow functions to accept expressions.
======================================================================
Implement QueryVisitor.
======================================================================
Enable the Advanced Query Parser to handle member functions
======================================================================
Refactor the Scorer class to support the Advanced Scoring Language
======================================================================
Integrate advanced query parser with the query processor.
======================================================================
Implement support for JoinSpec in Icing.
======================================================================
Implement the Advanced Scoring Language for basic functions and operators
======================================================================

Bug: 208654892
Bug: 249829533
Bug: 256022027
Bug: 261474063
Bug: 240333360
Bug: 193919210

Change-Id: Iffcbff7daa4a519e97e03c3c62dfa5e09524491e

2 files changed, 38 insertions, 15 deletions

diff --git a/proto/icing/proto/scoring.proto b/proto/icing/proto/scoring.proto
index 13861c9..a8040a1 100644
--- a/proto/icing/proto/scoring.proto
+++ b/proto/icing/proto/scoring.proto
@@ -25,7 +25,7 @@ option objc_class_prefix = "ICNG";
 // Encapsulates the configurations on how Icing should score and rank the search
 // results.
 // TODO(b/170347684): Change all timestamps to seconds.
-// Next tag: 4
+// Next tag: 12
 message ScoringSpecProto {
   // OPTIONAL: Indicates how the search results will be ranked.
   message RankingStrategy {
@@ -71,6 +71,9 @@ message ScoringSpecProto {
 
       // Ranked by the aggregated score of the joined documents.
       JOIN_AGGREGATE_SCORE = 10;
+
+      // Ranked by the advanced scoring expression provided.
+      ADVANCED_SCORING_EXPRESSION = 11;
     }
   }
   optional RankingStrategy.Code rank_by = 1;
@@ -99,6 +102,10 @@ message ScoringSpecProto {
   // all properties that are not specified are given a raw, pre-normalized
   // weight of 1.0 when scoring.
   repeated TypePropertyWeights type_property_weights = 3;
+
+  // OPTIONAL: Specifies the scoring expression for ADVANCED_SCORING_EXPRESSION
+  // RankingStrategy.
+  optional string advanced_scoring_expression = 4;
 }
 
 // Next tag: 3
diff --git a/proto/icing/proto/search.proto b/proto/icing/proto/search.proto
index 181c63c..e7e0208 100644
--- a/proto/icing/proto/search.proto
+++ b/proto/icing/proto/search.proto
@@ -299,7 +299,7 @@ message SearchResultProto {
     // determined by ScoringSpecProto.rank_by.
     optional double score = 3;
 
-    // The documents that were joined to a parent document.
+    // The child documents that were joined to a parent document.
     repeated ResultProto joined_results = 4;
   }
   repeated ResultProto results = 2;
@@ -430,37 +430,53 @@ message SuggestionResponse {
 //
 // Next tag: 7
 message JoinSpecProto {
-  // A nested SearchSpec that will be used to retrieve joined documents. If you
-  // are only looking to join on Action type documents, you could set a schema
-  // filter in this SearchSpec. This includes the nested search query. See
-  // SearchSpecProto.
-  optional SearchSpecProto nested_search_spec = 1;
+  // Collection of several specs that will be used for searching and joining
+  // child documents.
+  //
+  // Next tag: 4
+  message NestedSpecProto {
+    // A nested SearchSpec that will be used to retrieve child documents. If you
+    // are only looking to join on a specific type documents, you could set a
+    // schema filter in this SearchSpec. This includes the nested search query.
+    // See SearchSpecProto.
+    optional SearchSpecProto search_spec = 1;
+
+    // A nested ScoringSpec that will be used to score child documents.
+    // See ScoringSpecProto.
+    optional ScoringSpecProto scoring_spec = 2;
+
+    // A nested ResultSpec that will be used to format child documents in the
+    // result joined documents, e.g. snippeting, projection.
+    // See ResultSpecProto.
+    optional ResultSpecProto result_spec = 3;
+  }
+  optional NestedSpecProto nested_spec = 1;
 
   // The equivalent of a primary key in SQL. This is an expression that will be
   // used to match child documents from the nested search to this document. One
-  // such expression is qualifiedId(). When used, it means the
-  // child_property_expression in the joined documents must be equal to the
-  // qualified id.
+  // such expression is qualifiedId(). When used, it means the contents of
+  // child_property_expression property in the child documents must be equal to
+  // the qualified id.
   // TODO(b/256022027) allow for parent_property_expression to be any property
   // of the parent document.
   optional string parent_property_expression = 2;
 
   // The equivalent of a foreign key in SQL. This defines an equality constraint
   // between a property in a child document and a property in the parent
-  // document. For example, if you want to join Action documents which an
+  // document. For example, if you want to join child documents which an
   // entityId property containing a fully qualified document id,
   // child_property_expression can be set to "entityId".
   // TODO(b/256022027) figure out how to allow this to refer to documents
   // outside of same pkg+db+ns.
   optional string child_property_expression = 3;
 
-  // The max amount of joined documents to join to a parent document.
-  optional int32 max_joined_result_count = 4;
+  // The max number of child documents to join to a parent document.
+  optional int32 max_joined_child_count = 4;
 
-  // The strategy by which to score the aggregation of joined documents. For
+  // The strategy by which to score the aggregation of child documents. For
   // example, you might want to know which entity document has the most actions
   // taken on it. If JOIN_AGGREGATE_SCORE is used in the base SearchSpecProto,
-  // the COUNT value will rank entity documents based on the number of joined
+  // the COUNT value will rank entity documents based on the number of child
   // documents.
   enum AggregationScore {
     UNDEFINED = 0;