Make LowerBound nullable

Author: schmidt-sebastian

firebase-firestore/src/main/java/com/google/firebase/firestore/FirebaseFirestore.java

@@ -312,7 +312,7 @@ Task<Void> configureIndices(String json) {
             JSONObject field = fields.getJSONObject(f);
             FieldPath fieldPath = FieldPath.fromServerFormat(field.getString("fieldPath"));
             if ("CONTAINS".equals(field.optString("arrayConfig"))) {
-              fieldIndex = fieldIndex.withAddedField(fieldPath, FieldIndex.Segment.Kind.CONTAINS);
+              fieldIndex = fieldIndex.withAddedField(fieldPath, FieldIndex.Segment.Kind.ARRAYS);
             } else {
               fieldIndex = fieldIndex.withAddedField(fieldPath, FieldIndex.Segment.Kind.ORDERED);
             }

firebase-firestore/src/main/java/com/google/firebase/firestore/core/Target.java

@@ -25,6 +25,7 @@
 import com.google.firestore.v1.ArrayValue;
 import com.google.firestore.v1.Value;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -114,6 +115,36 @@ public boolean hasLimit() {
     return endAt;
   }
 
+  /**
+   * Returns a lower bound of field values that can be used as a starting point to scan the index
+   * defined by {@code fieldIndex}.
+   *
+   * <p>Unlike {@link #getUpperBound}, lower bounds always exist as the SDK can use {@code null} as
+   * a starting point for missing boundary values.
+   */
+  public List<Value> getArrayValues(FieldIndex fieldIndex) {
+    // Go through all filters to find a value for the current field segment
+    for (FieldIndex.Segment segment : fieldIndex) {
+      if (!segment.getKind().equals(FieldIndex.Segment.Kind.ARRAYS)) {
+        continue;
+      }
+
+      for (Filter filter : filters) {
+        if (filter.getField().equals(segment.getFieldPath())) {
+          FieldFilter fieldFilter = (FieldFilter) filter;
+          switch (fieldFilter.getOperator()) {
+            case ARRAY_CONTAINS_ANY:
+              return fieldFilter.getValue().getArrayValue().getValuesList();
+            case ARRAY_CONTAINS:
+              return Collections.singletonList(fieldFilter.getValue());
+          }
+        }
+      }
+    }
+
+    return null;
+  }
+
   /**
    * Returns a lower bound of field values that can be used as a starting point to scan the index
    * defined by {@code fieldIndex}.
@@ -127,6 +158,9 @@ public Bound getLowerBound(FieldIndex fieldIndex) {
 
     // Go through all filters to find a value for the current field segment
     for (FieldIndex.Segment segment : fieldIndex) {
+      if (!segment.getKind().equals(FieldIndex.Segment.Kind.ORDERED)) {
+        continue;
+      }
       Value segmentValue = Values.NULL_VALUE;
       boolean segmentInclusive = true;
 

firebase-firestore/src/main/java/com/google/firebase/firestore/index/IndexEntry.java

@@ -21,13 +21,16 @@
 // TODO(indexing)
 public class IndexEntry {
   private final int indexId;
-  private final byte[] indexValue;
+  private final byte[] arrayValue;
+  private final byte[] directionalValue;
   private final String uid;
   private final String documentName;
 
-  public IndexEntry(int indexId, byte[] indexValue, String uid, String documentName) {
+  public IndexEntry(
+      int indexId, byte[] arrayValue, byte[] directionalValue, String uid, String documentName) {
     this.indexId = indexId;
-    this.indexValue = indexValue;
+    this.arrayValue = arrayValue;
+    this.directionalValue = directionalValue;
     this.uid = uid;
     this.documentName = documentName;
   }
@@ -36,8 +39,12 @@ public int getIndexId() {
     return indexId;
   }
 
-  public byte[] getIndexValue() {
-    return indexValue;
+  public byte[] getArrayValue() {
+    return arrayValue;
+  }
+
+  public byte[] getDirectionalValue() {
+    return directionalValue;
   }
 
   public String getUid() {

firebase-firestore/src/main/java/com/google/firebase/firestore/local/IndexBackfiller.java

@@ -115,11 +115,13 @@ void addIndexEntry(IndexEntry entry) {
     persistence.execute(
         "INSERT OR IGNORE INTO index_entries ("
             + "index_id, "
-            + "index_value, "
+            + "array_index, "
+            + "directional_index, "
             + "uid, "
             + "document_name) VALUES(?, ?, ?, ?)",
         entry.getIndexId(),
-        entry.getIndexValue(),
+        entry.getArrayValue(),
+        entry.getDirectionalValue(),
         entry.getUid(),
         entry.getDocumentName());
   }
@@ -141,12 +143,18 @@ void removeIndexEntry(int indexId, String uid, String documentName) {
   @VisibleForTesting
   IndexEntry getIndexEntry(int indexId) {
     return persistence
-        .query("SELECT index_value, uid, document_name FROM index_entries WHERE index_id = ?")
+        .query(
+            "SELECT array_index, directional_index, uid, document_name FROM index_entries WHERE index_id = ?")
         .binding(indexId)
         .firstValue(
             row ->
                 row == null
                     ? null
-                    : new IndexEntry(indexId, row.getBlob(0), row.getString(1), row.getString(2)));
+                    : new IndexEntry(
+                        indexId,
+                        row.getBlob(0),
+                        row.getBlob(1),
+                        row.getString(2),
+                        row.getString(3)));
   }
 }

firebase-firestore/src/main/java/com/google/firebase/firestore/local/LocalSerializer.java

@@ -300,7 +300,7 @@ public Index encodeFieldIndex(FieldIndex fieldIndex) {
     for (FieldIndex.Segment segment : fieldIndex) {
       Index.IndexField.Builder indexField = Index.IndexField.newBuilder();
       indexField.setFieldPath(segment.getFieldPath().canonicalString());
-      if (segment.getKind() == FieldIndex.Segment.Kind.CONTAINS) {
+      if (segment.getKind() == FieldIndex.Segment.Kind.ARRAYS) {
         indexField.setArrayConfig(Index.IndexField.ArrayConfig.CONTAINS);
       } else {
         indexField.setOrder(Index.IndexField.Order.ASCENDING);
@@ -319,7 +319,7 @@ public FieldIndex decodeFieldIndex(
           fieldIndex.withAddedField(
               FieldPath.fromServerFormat(field.getFieldPath()),
               field.getValueModeCase().equals(Index.IndexField.ValueModeCase.ARRAY_CONFIG)
-                  ? FieldIndex.Segment.Kind.CONTAINS
+                  ? FieldIndex.Segment.Kind.ARRAYS
                   : FieldIndex.Segment.Kind.ORDERED);
     }
     fieldIndex =