Produce smaller diff in FilterTableLineEditor

2 files changed, 62 insertions, 9 deletions

diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditor.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditor.java
index a9954200f8a..2d77cd32632 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditor.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditor.java
@@ -6,7 +6,6 @@ import com.yahoo.vespa.hosted.node.admin.task.util.file.LineEdit;
 import com.yahoo.vespa.hosted.node.admin.task.util.file.LineEditor;
 import com.yahoo.vespa.hosted.node.admin.task.util.network.IPVersion;
 
-import java.util.LinkedList;
 import java.util.List;
 
 /**
@@ -16,10 +15,11 @@ import java.util.List;
  */
 class FilterTableLineEditor implements LineEditor {
 
-    private final LinkedList<String> wantedRules;
+    private final List<String> wantedRules;
+    private int position = 0;
 
     private FilterTableLineEditor(List<String> wantedRules) {
-        this.wantedRules = new LinkedList<>(wantedRules);
+        this.wantedRules = List.copyOf(wantedRules);
     }
 
     static FilterTableLineEditor from(Acl acl, IPVersion ipVersion) {
@@ -29,15 +29,33 @@ class FilterTableLineEditor implements LineEditor {
 
     @Override
     public LineEdit edit(String line) {
-        // We have already added all the lines we wanted, remove the remainer
-        if (wantedRules.isEmpty()) return LineEdit.remove();
-
-        String wantedRule = wantedRules.pop();
-        return wantedRule.equals(line) ? LineEdit.none() : LineEdit.replaceWith(wantedRule);
+        int index = indexOf(wantedRules, line, position);
+        // Unwanted rule, remove
+        if (index < 0) return LineEdit.remove();
+
+        // Wanted rule at the expected position, no diff
+        if (index == position) {
+            position++;
+            return LineEdit.none();
+        }
+
+        // Insert the rules between position and index before index
+        List<String> toInsert = wantedRules.subList(position, index);
+        position = ++index;
+        return LineEdit.insertBefore(toInsert);
     }
 
     @Override
     public List<String> onComplete() {
-        return this.wantedRules;
+        return position == wantedRules.size() ? List.of() : wantedRules.subList(position, wantedRules.size());
+    }
+
+    private static <T> int indexOf(List<T> list, T value, int startPos) {
+        for (int i = startPos; i < list.size(); i++) {
+            if (value.equals(list.get(i)))
+                return i;
+        }
+
+        return -1;
     }
 }
diff --git a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditorTest.java b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditorTest.java
index 192422492c8..495c1318b71 100644
--- a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditorTest.java
+++ b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/maintenance/acl/FilterTableLineEditorTest.java
@@ -6,6 +6,7 @@ import com.yahoo.vespa.hosted.node.admin.task.util.file.Editor;
 import com.yahoo.vespa.hosted.node.admin.task.util.network.IPVersion;
 import org.junit.Test;
 
+import java.util.ArrayList;
 import java.util.List;
 
 import static org.junit.Assert.assertEquals;
@@ -37,6 +38,25 @@ public class FilterTableLineEditorTest {
                 "-A INPUT -j REJECT --reject-with icmp6-port-unreachable");
     }
 
+    @Test
+    public void produces_minimal_diff_simple() {
+        assertFilterTableDiff(List.of(2, 5, 3, 6, 1, 4), List.of(2, 5, 6, 1, 4),
+                "Patching file table:\n" +
+                "--A INPUT -s 2001::3/128 -j ACCEPT\n");
+    }
+
+    @Test
+    public void produces_minimal_diff_complex() {
+        assertFilterTableDiff(List.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), List.of(5, 11, 6, 3, 10, 4, 8, 12),
+                "Patching file table:\n" +
+                "--A INPUT -s 2001::1/128 -j ACCEPT\n" +
+                "--A INPUT -s 2001::2/128 -j ACCEPT\n" +
+                "+-A INPUT -s 2001::11/128 -j ACCEPT\n" +
+                "+-A INPUT -s 2001::12/128 -j ACCEPT\n" +
+                "--A INPUT -s 2001::7/128 -j ACCEPT\n" +
+                "--A INPUT -s 2001::9/128 -j ACCEPT\n");
+    }
+
     private static void assertFilterTableLineEditorResult(
             Acl acl, IPVersion ipVersion, String currentFilterTable, String expectedRestoreFileContent) {
         FilterTableLineEditor filterLineEditor = FilterTableLineEditor.from(acl, ipVersion);
@@ -47,4 +67,19 @@ public class FilterTableLineEditorTest {
                 filterLineEditor);
         editor.edit(m -> {});
     }
+
+    private static void assertFilterTableDiff(List<Integer> currentIpSuffix, List<Integer> wantedIpSuffix, String diff) {
+        Acl.Builder currentAcl = new Acl.Builder();
+        currentIpSuffix.forEach(i -> currentAcl.withTrustedNode("host" + i, "2001::" + i));
+        List<String> currentTable = new ArrayList<>();
+
+        Acl.Builder wantedAcl = new Acl.Builder();
+        wantedIpSuffix.forEach(i -> wantedAcl.withTrustedNode("host" + i, "2001::" + i));
+
+        new Editor("table", List::of, currentTable::addAll, FilterTableLineEditor.from(currentAcl.build(), IPVersion.IPv6))
+                .edit(log -> {});
+
+        new Editor("table", () -> currentTable, result -> {}, FilterTableLineEditor.from(wantedAcl.build(), IPVersion.IPv6))
+                .edit(log -> assertEquals(diff, log));
+    }
 }
\ No newline at end of file