feat: allow to decode keys

For certain CF we can register decoder functions which allow to decode the keys and print them correctly.
Already done for DEFAULT and KEY

backend/src/main/kotlin/io/zell/zdb/state/ColumnFamilyKeyDecoder.kt

@@ -0,0 +1,39 @@
+package io.zell.zdb.state
+
+import io.camunda.zeebe.db.impl.DbLong
+import io.camunda.zeebe.db.impl.DbString
+import io.camunda.zeebe.db.impl.ZeebeDbConstants
+import io.camunda.zeebe.protocol.ZbColumnFamilies
+import org.agrona.concurrent.UnsafeBuffer
+import java.util.*
+
+typealias Decoder = (ByteArray) -> String
+class ColumnFamilyKeyDecoder {
+
+
+    var cfDecoders: EnumMap<ZbColumnFamilies, Decoder> = EnumMap(ZbColumnFamilies::class.java)
+
+        init {
+            cfDecoders[ZbColumnFamilies.DEFAULT] = ::dbStringToStringDecoder
+            cfDecoders[ZbColumnFamilies.KEY] = ::dbStringToStringDecoder
+        }
+
+    fun decodeColumnFamilyKey(cf: ZbColumnFamilies, key: ByteArray) : String {
+        val function = cfDecoders[cf]
+        return function?.let {
+            function(key)
+        } ?: HexFormat.ofDelimiter(" ").formatHex(key)
+    }
+
+    private fun dbLongToStringDecoder(bytes : ByteArray) : String {
+        val dbLong = DbLong()
+        dbLong.wrap(UnsafeBuffer(bytes), Long.SIZE_BYTES, bytes.size)
+        return dbLong.value.toString()
+    }
+
+    private fun dbStringToStringDecoder(bytes : ByteArray) : String {
+        val dbString = DbString()
+        dbString.wrap(UnsafeBuffer(bytes), Long.SIZE_BYTES, bytes.size)
+        return dbString.toString()
+    }
+}

backend/src/main/kotlin/io/zell/zdb/state/Experimental.kt

@@ -30,25 +30,25 @@ import java.util.*
 class Experimental(private var rocksDb: RocksDB) {
         constructor(statePath: Path) : this(OptimisticTransactionDB.openReadOnly(statePath.toString()))
 
-
     fun interface Visitor {
-        fun visit(cf: ZbColumnFamilies, key: ByteArray, value: ByteArray)
+        fun visit(cf: ZbColumnFamilies, key: String, value: ByteArray)
     }
 
     fun interface JsonVisitor {
-        fun visit(cf: ZbColumnFamilies, key: ByteArray, valueJson: String)
+        fun visit(cf: ZbColumnFamilies, key: String, valueJson: String)
     }
 
     fun visitDB(visitor: Visitor) {
-       rocksDb.newIterator(rocksDb.defaultColumnFamily, ReadOptions()).use {
+        val columnFamilyKeyDecoder = ColumnFamilyKeyDecoder()
+        rocksDb.newIterator(rocksDb.defaultColumnFamily, ReadOptions()).use {
            it.seekToFirst()
            while (it.isValid) {
                val key: ByteArray = it.key()
                val value: ByteArray = it.value()
                val unsafeBuffer = UnsafeBuffer(key)
                val enumValue = unsafeBuffer.getLong(0, ZeebeDbConstants.ZB_DB_BYTE_ORDER)
                val cf = ZbColumnFamilies.values()[enumValue.toInt()]
-               visitor.visit(cf, key, value)
+               visitor.visit(cf, columnFamilyKeyDecoder.decodeColumnFamilyKey(cf, key), value)
                it.next()
            }
        }

backend/src/test/kotlin/ZeebeStateTest.java

@@ -143,18 +143,36 @@ public void shouldCreateStatsForCompleteState() {
   public void shouldVisitValuesAsJson() {
     // given
     final var experimental = new Experimental(ZeebePaths.Companion.getRuntimePath(tempDir, "1"));
-    final var incidentMap = new HashMap<String, String>();
+    HashMap<ZbColumnFamilies, HashMap<String, String>> columnFamiliesMap = new HashMap<>();
     Experimental.JsonVisitor jsonVisitor = (cf, k, v) -> {
-      if (cf == ZbColumnFamilies.INCIDENTS) {
-        incidentMap.put(new String(k), v);
-      }
+      final var cfMap = columnFamiliesMap.computeIfAbsent(cf, (columnFamily) -> new HashMap<>());
+      cfMap.put(k, v);
     };
 
     // when
     experimental.visitDBWithJsonValues(jsonVisitor);
 
     // then
-    assertThat(incidentMap).containsValue("{\"incidentRecord\":{\"errorType\":\"IO_MAPPING_ERROR\",\"errorMessage\":\"failed to evaluate expression '{bar:foo}': no variable found for name 'foo'\",\"bpmnProcessId\":\"process\",\"processDefinitionKey\":2251799813685249,\"processInstanceKey\":2251799813685251,\"elementId\":\"incidentTask\",\"elementInstanceKey\":2251799813685260,\"jobKey\":-1,\"variableScopeKey\":2251799813685260}}");
+    assertThat(columnFamiliesMap.get(ZbColumnFamilies.INCIDENTS)).containsValue("{\"incidentRecord\":{\"errorType\":\"IO_MAPPING_ERROR\",\"errorMessage\":\"failed to evaluate expression '{bar:foo}': no variable found for name 'foo'\",\"bpmnProcessId\":\"process\",\"processDefinitionKey\":2251799813685249,\"processInstanceKey\":2251799813685251,\"elementId\":\"incidentTask\",\"elementInstanceKey\":2251799813685260,\"jobKey\":-1,\"variableScopeKey\":2251799813685260}}");
+    assertThat(columnFamiliesMap.get(ZbColumnFamilies.INCIDENT_PROCESS_INSTANCES)).containsValue("{\"key\":2251799813685263}");
+  }
+
+  @Test
+  public void shouldDecodeKeyIfPossible() {
+    // given
+    final var experimental = new Experimental(ZeebePaths.Companion.getRuntimePath(tempDir, "1"));
+    HashMap<ZbColumnFamilies, HashMap<String, String>> columnFamiliesMap = new HashMap<>();
+    Experimental.JsonVisitor jsonVisitor = (cf, k, v) -> {
+      final var cfMap = columnFamiliesMap.computeIfAbsent(cf, (columnFamily) -> new HashMap<>());
+      cfMap.put(k, v);
+    };
+
+    // when
+    experimental.visitDBWithJsonValues(jsonVisitor);
+
+    // then
+    assertThat(columnFamiliesMap.get(ZbColumnFamilies.DEFAULT)).containsKey("LAST_PROCESSED_EVENT_KEY");
+    assertThat(columnFamiliesMap.get(ZbColumnFamilies.KEY)).containsKey("latestKey");
   }
 
   @Test

cli/src/main/java/io/zell/zdb/StateCommand.java

@@ -71,7 +71,7 @@ public int list(
             }
             System.out.printf(
                 "\n{\"cf\":\"%s\",\"key\":\"%s\",\"value\":%s}",
-                cf, HexFormat.ofDelimiter(" ").formatHex(key), valueJson);
+                cf, key, valueJson);
           }
         }));
     System.out.print("]}");