LibWeb/IDB: Implement retrieve_multiple_items_from_an_object_store

Author: https://github.com/stelar7
Commit: 839ffd45f3
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5385
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp

@@ -25,6 +25,7 @@
 #include <LibWeb/IndexedDB/IDBDatabase.h>
 #include <LibWeb/IndexedDB/IDBIndex.h>
 #include <LibWeb/IndexedDB/IDBObjectStore.h>
+#include <LibWeb/IndexedDB/IDBRecord.h>
 #include <LibWeb/IndexedDB/IDBRequest.h>
 #include <LibWeb/IndexedDB/IDBTransaction.h>
 #include <LibWeb/IndexedDB/IDBVersionChangeEvent.h>
@@ -1930,6 +1931,77 @@ GC::Ref<JS::Array> retrieve_multiple_values_from_an_object_store(JS::Realm& real
     return list;
 }
 
+// https://pr-preview.s3.amazonaws.com/w3c/IndexedDB/pull/461.html#retrieve-multiple-items-from-an-object-store
+GC::Ref<JS::Array> retrieve_multiple_items_from_an_object_store(JS::Realm& realm, GC::Ref<ObjectStore> store, GC::Ref<IDBKeyRange> range, RecordKind kind, Bindings::IDBCursorDirection direction, Optional<WebIDL::UnsignedLong> count)
+{
+    // 1. If count is not given or is 0 (zero), let count be infinity.
+    if (count.has_value() && *count == 0)
+        count = OptionalNone();
+
+    // 2. Let records an empty list.
+    GC::ConservativeVector<ObjectStoreRecord> records(realm.heap());
+
+    // 3. If direction is "next" or "nextunique", set records to the first count of store’s list of records whose key is in range.
+    if (direction == Bindings::IDBCursorDirection::Next || direction == Bindings::IDBCursorDirection::Nextunique) {
+        records.extend(store->first_n_in_range(range, count));
+    }
+
+    // 4. If direction is "prev" or "prevunique", set records to the last count of store’s list of records whose key is in range.
+    if (direction == Bindings::IDBCursorDirection::Prev || direction == Bindings::IDBCursorDirection::Prevunique) {
+        records.extend(store->last_n_in_range(range, count));
+    }
+
+    // 5. Let list be an empty list.
+    auto list = MUST(JS::Array::create(realm, records.size()));
+
+    // 6. For each record of records, switching on kind:
+    for (u32 i = 0; i < records.size(); ++i) {
+        auto& record = records[i];
+
+        switch (kind) {
+        case RecordKind::Key: {
+            // 1. Let key be the result of converting a key to a value with record’s key.
+            auto key = convert_a_key_to_a_value(realm, record.key);
+
+            // 2. Append key to list.
+            MUST(list->create_data_property_or_throw(i, key));
+            break;
+        }
+        case RecordKind::Value: {
+            // 1. Let serialized be record’s value.
+            auto serialized = record.value;
+
+            // 2. Let value be ! StructuredDeserialize(serialized, targetRealm).
+            auto entry = MUST(HTML::structured_deserialize(realm.vm(), serialized, realm));
+
+            // 3. Append entry to list.
+            MUST(list->create_data_property_or_throw(i, entry));
+            break;
+        }
+        case RecordKind::Record: {
+            // 1. Let key be the record’s key.
+            auto key = record.key;
+
+            // 2. Let serialized be record’s value.
+            auto serialized = record.value;
+
+            // 3. Let value be ! StructuredDeserialize(serialized, targetRealm).
+            auto value = MUST(HTML::structured_deserialize(realm.vm(), serialized, realm));
+
+            // 4. Let record snapshot be a new record snapshot with its key set to key, value set to value, and primary key set to key.
+            auto record_snapshot = IDBRecord::create(realm, key, value, key);
+
+            // 5. Append record snapshot to list.
+            MUST(list->create_data_property_or_throw(i, record_snapshot));
+            break;
+        }
+        }
+    }
+
+    // 5. Return list.
+    return list;
+}
+
 // https://w3c.github.io/IndexedDB/#retrieve-multiple-keys-from-an-object-store
 GC::Ref<JS::Array> retrieve_multiple_keys_from_an_object_store(JS::Realm& realm, GC::Ref<ObjectStore> store, GC::Ref<IDBKeyRange> range, Optional<WebIDL::UnsignedLong> count)
 {

Libraries/LibWeb/IndexedDB/Internal/Algorithms.h

@@ -8,6 +8,7 @@
 
 #include <AK/Variant.h>
 #include <LibJS/Runtime/Realm.h>
+#include <LibWeb/Bindings/IDBCursorPrototype.h>
 #include <LibWeb/HTML/DOMStringList.h>
 #include <LibWeb/IndexedDB/IDBKeyRange.h>
 #include <LibWeb/IndexedDB/IDBRequest.h>
@@ -17,6 +18,12 @@
 
 namespace Web::IndexedDB {
 
+enum class RecordKind {
+    Key,
+    Value,
+    Record
+};
+
 using KeyPath = Variant<String, Vector<String>>;
 using RecordSource = Variant<GC::Ref<ObjectStore>, GC::Ref<Index>>;
 
@@ -59,5 +66,6 @@ GC::Ref<JS::Array> retrieve_multiple_values_from_an_index(JS::Realm&, GC::Ref<In
 void queue_a_database_task(GC::Ref<GC::Function<void()>>);
 bool cleanup_indexed_database_transactions(GC::Ref<HTML::EventLoop>);
 bool is_a_potentially_valid_key_range(JS::Realm&, JS::Value);
+GC::Ref<JS::Array> retrieve_multiple_items_from_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>, RecordKind, Bindings::IDBCursorDirection, Optional<WebIDL::UnsignedLong>);
 
 }

Libraries/LibWeb/IndexedDB/Internal/ObjectStore.cpp

@@ -103,4 +103,18 @@ GC::ConservativeVector<ObjectStoreRecord> ObjectStore::first_n_in_range(GC::Ref<
     return records;
 }
 
+GC::ConservativeVector<ObjectStoreRecord> ObjectStore::last_n_in_range(GC::Ref<IDBKeyRange> range, Optional<WebIDL::UnsignedLong> count)
+{
+    GC::ConservativeVector<ObjectStoreRecord> records(range->heap());
+    for (auto const& record : m_records.in_reverse()) {
+        if (range->is_in_range(record.key))
+            records.append(record);
+
+        if (count.has_value() && records.size() >= *count)
+            break;
+    }
+
+    return records;
+}
+
 }

Libraries/LibWeb/IndexedDB/Internal/ObjectStore.h

@@ -52,6 +52,7 @@ public:
     Optional<ObjectStoreRecord&> first_in_range(GC::Ref<IDBKeyRange> range);
     void clear_records();
     GC::ConservativeVector<ObjectStoreRecord> first_n_in_range(GC::Ref<IDBKeyRange> range, Optional<WebIDL::UnsignedLong> count);
+    GC::ConservativeVector<ObjectStoreRecord> last_n_in_range(GC::Ref<IDBKeyRange> range, Optional<WebIDL::UnsignedLong> count);
 
 protected:
     virtual void visit_edges(Visitor&) override;