From bef981534db136325ca09786ae952ecd78da2bc1 Mon Sep 17 00:00:00 2001
From: Siedlerchr <siedlerkiller@gmail.com>
Date: Thu, 11 Aug 2022 17:13:39 +0200
Subject: [PATCH] Fix performance regresssion

Revert bibdatabasemode to previous state

Fixes #9041
---
 CHANGELOG.md                                  |  2 +
 .../jabref/model/database/BibDatabase.java    | 40 ++++---------------
 2 files changed, 9 insertions(+), 33 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 838fe4387c0..ccdb936299d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,8 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 
 ### Fixed
 
+- We fixed a performance regression when opening large libraries [#9041](https://github.com/JabRef/jabref/issues/9041)
+
 ### Removed
 
 
diff --git a/src/main/java/org/jabref/model/database/BibDatabase.java b/src/main/java/org/jabref/model/database/BibDatabase.java
index 52e4e841ce9..72a559ff663 100644
--- a/src/main/java/org/jabref/model/database/BibDatabase.java
+++ b/src/main/java/org/jabref/model/database/BibDatabase.java
@@ -20,7 +20,6 @@
 
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
-import javafx.collections.ObservableSet;
 
 import org.jabref.logic.bibtex.FieldWriter;
 import org.jabref.model.database.event.EntriesAddedEvent;
@@ -30,7 +29,6 @@
 import org.jabref.model.entry.Month;
 import org.jabref.model.entry.event.EntriesEventSource;
 import org.jabref.model.entry.event.EntryChangedEvent;
-import org.jabref.model.entry.event.FieldAddedOrRemovedEvent;
 import org.jabref.model.entry.event.FieldChangedEvent;
 import org.jabref.model.entry.field.Field;
 import org.jabref.model.entry.field.FieldFactory;
@@ -54,8 +52,6 @@ public class BibDatabase {
      * State attributes
      */
     private final ObservableList<BibEntry> entries = FXCollections.synchronizedObservableList(FXCollections.observableArrayList(BibEntry::getObservables));
-
-    private final ObservableSet<Field> visibleFields = FXCollections.observableSet();
     private Map<String, BibtexString> bibtexStrings = new ConcurrentHashMap<>();
 
     private final EventBus eventBus = new EventBus();
@@ -140,8 +136,13 @@ public ObservableList<BibEntry> getEntries() {
      *
      * @return set of fieldnames, that are visible
      */
-    public ObservableSet<Field> getAllVisibleFields() {
-        return visibleFields;
+    public Set<Field> getAllVisibleFields() {
+        Set<Field> allFields = new TreeSet<>(Comparator.comparing(Field::getName));
+        for (BibEntry e : getEntries()) {
+            allFields.addAll(e.getFields());
+        }
+        return allFields.stream().filter(field -> !FieldFactory.isInternalField(field))
+                        .collect(Collectors.toSet());
     }
 
     /**
@@ -213,8 +214,6 @@ public synchronized void insertEntries(List<BibEntry> newEntries, EntriesEventSo
             eventBus.post(new EntriesAddedEvent(newEntries, newEntries.get(0), eventSource));
         }
         entries.addAll(newEntries);
-
-        updateVisibleFields();
     }
 
     public synchronized void removeEntry(BibEntry bibEntry) {
@@ -252,7 +251,6 @@ public synchronized void removeEntries(List<BibEntry> toBeDeleted, EntriesEventS
         boolean anyRemoved = entries.removeIf(entry -> ids.contains(entry.getId()));
         if (anyRemoved) {
             eventBus.post(new EntriesRemovedEvent(toBeDeleted, eventSource));
-            updateVisibleFields();
         }
     }
 
@@ -586,30 +584,6 @@ private void relayEntryChangeEvent(FieldChangedEvent event) {
         eventBus.post(event);
     }
 
-    @Subscribe
-    private void listen(FieldAddedOrRemovedEvent event) {
-        // When a field is removed from an entry we can't tell if it's
-        // still present in other entries, and thus we can't remove it
-        // from the set of visible fields. However, when a new field is added
-        // to any entry, we can simply add it to the set because we're
-        // going to add it whether other entries have it or not
-        boolean isAdded = visibleFields.add(event.getField());
-        if (!isAdded) {
-            updateVisibleFields();
-        }
-    }
-
-    private void updateVisibleFields() {
-        visibleFields.clear();
-        Set<Field> allFields = new TreeSet<>(Comparator.comparing(Field::getName));
-        for (BibEntry e : getEntries()) {
-            allFields.addAll(e.getFields());
-        }
-        visibleFields.addAll(allFields.stream().filter(field -> !FieldFactory.isInternalField(field))
-                             .filter(field -> StringUtil.isNotBlank(field.getName()))
-                                     .collect(Collectors.toSet()));
-    }
-
     public Optional<BibEntry> getReferencedEntry(BibEntry entry) {
         return entry.getField(StandardField.CROSSREF).flatMap(this::getEntryByCitationKey);
     }