Implement Index Scanning (#6008)

Author: schmidt-sebastian

packages/firestore/src/core/target.ts

@@ -259,7 +259,7 @@ export function targetGetNotInValues(
   target: Target,
   fieldIndex: FieldIndex
 ): ProtoValue[] | null {
-  const values: ProtoValue[] = [];
+  const values = new Map</* fieldPath = */ string, ProtoValue>();
 
   for (const segment of fieldIndexGetDirectionalSegments(fieldIndex)) {
     for (const fieldFilter of targetGetFieldFiltersForPath(
@@ -272,14 +272,14 @@ export function targetGetNotInValues(
           // Encode equality prefix, which is encoded in the index value before
           // the inequality (e.g. `a == 'a' && b != 'b'` is encoded to
           // `value != 'ab'`).
-          values.push(fieldFilter.value);
+          values.set(segment.fieldPath.canonicalString(), fieldFilter.value);
           break;
         case Operator.NOT_IN:
         case Operator.NOT_EQUAL:
           // NotIn/NotEqual is always a suffix. There cannot be any remaining
           // segments and hence we can return early here.
-          values.push(fieldFilter.value);
-          return values;
+          values.set(segment.fieldPath.canonicalString(), fieldFilter.value);
+          return Array.from(values.values());
         default:
         // Remaining filters cannot be used as notIn bounds.
       }
@@ -330,13 +330,8 @@ export function targetGetLowerBound(
           filterInclusive = false;
           break;
         case Operator.NOT_EQUAL:
-          filterValue = MIN_VALUE;
-          break;
         case Operator.NOT_IN:
-          const length = (fieldFilter.value.arrayValue!.values || []).length;
-          filterValue = {
-            arrayValue: { values: new Array(length).fill(MIN_VALUE) }
-          };
+          filterValue = MIN_VALUE;
           break;
         default:
         // Remaining filters cannot be used as lower bounds.
@@ -415,13 +410,8 @@ export function targetGetUpperBound(
           filterInclusive = false;
           break;
         case Operator.NOT_EQUAL:
-          filterValue = MAX_VALUE;
-          break;
         case Operator.NOT_IN:
-          const length = (fieldFilter.value.arrayValue!.values || []).length;
-          filterValue = {
-            arrayValue: { values: new Array(length).fill(MIN_VALUE) }
-          };
+          filterValue = MAX_VALUE;
           break;
         default:
         // Remaining filters cannot be used as upper bounds.
@@ -450,7 +440,7 @@ export function targetGetUpperBound(
     }
 
     if (segmentValue === undefined) {
-      // No lower bound exists
+      // No upper bound exists
       return null;
     }
     values.push(segmentValue);

packages/firestore/src/index/index_entry.ts

@@ -25,6 +25,33 @@ export class IndexEntry {
     readonly arrayValue: Uint8Array,
     readonly directionalValue: Uint8Array
   ) {}
+
+  /**
+   * Returns an IndexEntry entry that sorts immediately after the current
+   * directional value.
+   */
+  successor(): IndexEntry {
+    const currentLength = this.directionalValue.length;
+    const newLength =
+      currentLength === 0 || this.directionalValue[currentLength - 1] === 255
+        ? currentLength + 1
+        : currentLength;
+
+    const successor = new Uint8Array(newLength);
+    successor.set(this.directionalValue, 0);
+    if (newLength !== currentLength) {
+      successor.set([0], this.directionalValue.length);
+    } else {
+      ++successor[successor.length - 1];
+    }
+
+    return new IndexEntry(
+      this.indexId,
+      this.documentKey,
+      this.arrayValue,
+      successor
+    );
+  }
 }
 
 export function indexEntryComparator(
@@ -36,20 +63,20 @@ export function indexEntryComparator(
     return cmp;
   }
 
-  cmp = DocumentKey.comparator(left.documentKey, right.documentKey);
+  cmp = compareByteArrays(left.arrayValue, right.arrayValue);
   if (cmp !== 0) {
     return cmp;
   }
 
-  cmp = compareByteArrays(left.arrayValue, right.arrayValue);
+  cmp = compareByteArrays(left.directionalValue, right.directionalValue);
   if (cmp !== 0) {
     return cmp;
   }
 
-  return compareByteArrays(left.directionalValue, right.directionalValue);
+  return DocumentKey.comparator(left.documentKey, right.documentKey);
 }
 
-function compareByteArrays(left: Uint8Array, right: Uint8Array): number {
+export function compareByteArrays(left: Uint8Array, right: Uint8Array): number {
   for (let i = 0; i < left.length && i < right.length; ++i) {
     const compare = left[i] - right[i];
     if (compare !== 0) {

packages/firestore/src/local/index_manager.ts

@@ -103,13 +103,12 @@ export interface IndexManager {
 
   /**
    * Returns the documents that match the given target based on the provided
-   * index.
+   * index or `null` if the target does not have a matching index.
    */
   getDocumentsMatchingTarget(
     transaction: PersistenceTransaction,
-    fieldIndex: FieldIndex,
     target: Target
-  ): PersistencePromise<DocumentKeySet>;
+  ): PersistencePromise<DocumentKeySet | null>;
 
   /**
    * Returns the next collection group to update. Returns `null` if no group