Treat empty loc groups as valid

I've decided to reverse my decision in
e3e0094b43.

If you treat empty loc groups as valid, some OSRS caches do have 100%
valid keys. Being able to pick these out in the list of caches will be
useful.

Signed-off-by: Graham <gpe@openrs2.org>

archive/src/main/kotlin/org/openrs2/archive/key/KeyExporter.kt

@@ -15,30 +15,40 @@ public class KeyExporter @Inject constructor(
         val allKeys: Long,
         val validKeys: Long,
         val encryptedGroups: Long,
-        val validGroups: Long
+        val validGroups: Long,
+        val emptyGroups: Long
     ) {
         val validKeysFraction: Double = if (allKeys == 0L) {
             1.0
         } else {
             validKeys.toDouble() / allKeys
         }
+
         val validGroupsFraction: Double = if (encryptedGroups == 0L) {
             1.0
         } else {
             validGroups.toDouble() / encryptedGroups
         }
+
+        val emptyGroupsFraction: Double = if (encryptedGroups == 0L) {
+            1.0
+        } else {
+            emptyGroups.toDouble() / encryptedGroups
+        }
     }
 
     public suspend fun count(): Stats {
         return database.execute { connection ->
             val encryptedGroups: Long
             val validGroups: Long
+            val emptyGroups: Long
 
             connection.prepareStatement(
                 """
                 SELECT
                     COUNT(*),
-                    COUNT(*) FILTER (WHERE c.key_id IS NOT NULL)
+                    COUNT(*) FILTER (WHERE c.key_id IS NOT NULL),
+                    COUNT(*) FILTER (WHERE c.key_id IS NULL AND c.empty_loc)
                 FROM containers c
                 WHERE c.encrypted
             """.trimIndent()
@@ -48,6 +58,7 @@ public class KeyExporter @Inject constructor(
 
                     encryptedGroups = rows.getLong(1)
                     validGroups = rows.getLong(2)
+                    emptyGroups = rows.getLong(3)
                 }
             }
 
@@ -65,7 +76,7 @@ public class KeyExporter @Inject constructor(
 
                     val allKeys = rows.getLong(1)
                     val validKeys = rows.getLong(2)
-                    Stats(allKeys, validKeys, encryptedGroups, validGroups)
+                    Stats(allKeys, validKeys, encryptedGroups, validGroups, emptyGroups)
                 }
             }
         }

archive/src/main/resources/org/openrs2/archive/migrations/V1__init.sql

@@ -238,7 +238,7 @@ LEFT JOIN (
         i.master_index_id,
         COUNT(*) FILTER (WHERE c.id IS NOT NULL) AS valid_groups,
         COUNT(*) AS groups,
-        COUNT(*) FILTER (WHERE c.key_id IS NOT NULL) AS valid_keys,
+        COUNT(*) FILTER (WHERE c.encrypted AND (c.key_id IS NOT NULL OR c.empty_loc)) AS valid_keys,
         COUNT(*) FILTER (WHERE c.encrypted) AS keys,
         SUM(length(c.data)) FILTER (WHERE c.id IS NOT NULL) AS size
     FROM resolved_indexes i

archive/src/main/resources/org/openrs2/archive/templates/caches/index.html

@@ -21,7 +21,7 @@
 							<th>Source(s)</th>
 							<th>Indexes</th>
 							<th>Groups</th>
-							<th>Keys</th>
+							<th>Keys<sup><a href="#empty-locs">1</a></sup></th>
 							<th>Links</th>
 						</tr>
 					</thead>
@@ -95,6 +95,18 @@
 					</tbody>
 				</table>
 			</div>
+			<p>
+				<sup id="empty-locs">1</sup> Map squares in the middle of the
+				sea are unreachable by normal players, making it impossible to
+				obtain the keys for their loc groups. However, the loc groups
+				for these map squares are empty. As XTEA does not hide the
+				length of the compressed data, this service infers which
+				encrypted loc groups are empty and includes them in the number
+				of valid keys, regardless of whether the key is known or not.
+				After downloading a cache from this service, a cache editor may
+				be used to replace the empty encrypted loc groups with
+				unencrypted replacements.
+			</p>
 		</main>
 	</body>
 </html>

archive/src/main/resources/org/openrs2/archive/templates/caches/show.html

@@ -59,7 +59,7 @@
 					</td>
 				</tr>
 				<tr class="thead-dark">
-					<th>Keys</th>
+					<th>Keys<sup><a href="/caches#empty-locs">1</a></sup></th>
 					<td th:class="${cache.stats}? (${cache.stats.allKeysValid}? 'table-success' : 'table-warning')"
 					    th:text="${cache.stats}? ${#numbers.formatInteger(cache.stats.validKeys, 1, 'COMMA')} + ' / ' + ${#numbers.formatInteger(cache.stats.keys, 1, 'COMMA')} + ' (' + ${#numbers.formatPercent(cache.stats.validKeysFraction, 1, 2)} + ')' : 'Calculating...'">
 						Calculating...

archive/src/main/resources/org/openrs2/archive/templates/keys/index.html

@@ -27,7 +27,11 @@
 				<strong
 					th:text="${#numbers.formatInteger(stats.validGroups, 1, 'COMMA')} + ' (' + ${#numbers.formatPercent(stats.validGroupsFraction, 1, 2)} + ')'">0</strong>
 				have a validated key. This is equal to the total number of
-				validated keys if and only if keys are not re-used.
+				validated keys if and only if keys are not re-used. A further
+				<strong
+					th:text="${#numbers.formatInteger(stats.emptyGroups, 1, 'COMMA')} + ' (' + ${#numbers.formatPercent(stats.emptyGroupsFraction, 1, 2)} + ')'">0</strong>
+				groups do not have a validated key, but are empty and can be
+				replaced with an unencrypted equivalent with a cache editor.
 			</p>
 
 			<h2>Download</h2>