[indexes] skip useless byte[] allocation/copy

+ directly use byte[] subrange instead of its copy

GitOrigin-RevId: be7ea5c8763e69afa1410171856bb0389f34d434

platform/util/src/com/intellij/util/concurrency/propagation.kt

@@ -268,6 +268,7 @@ internal fun capturePropagationContext(r: Runnable, forceUseContextJob : Boolean
   }
   val (childContext, childContinuation) =
     if (forceUseContextJob) createChildContextWithContextJob(r.toString())
+    //TODO: do we really need .toString() here? It allocates ~6 Gb during indexing
     else createChildContext(r.toString())
   command = ContextRunnable(true, childContext, command)
   if (childContinuation != null) {

platform/util/storages/src/com/intellij/platform/util/io/storages/DataExternalizerEx.java

@@ -117,6 +117,14 @@ public interface DataExternalizerEx<T> {
     return new ByteArrayWriter(bytes, 0, bytes.length);
   }
 
+  static KnownSizeRecordWriter fromBytes(@NotNull ByteArraySequence bytes) {
+    return new ByteArrayWriter(
+      bytes.getInternalBuffer(),
+      bytes.getOffset(),
+      bytes.getLength()
+    );
+  }
+
   static KnownSizeRecordWriter fromBytes(byte @NotNull [] bytes,
                                          int offset,
                                          int length) {
@@ -161,7 +169,7 @@ public interface DataExternalizerEx<T> {
 
     @Override
     public String toString() {
-      return "ByteArrayWriter[" + IOUtil.toHexString(Arrays.copyOfRange(bytes, startingOffset, startingOffset+length)) + "]";
+      return "ByteArrayWriter[" + IOUtil.toHexString(Arrays.copyOfRange(bytes, startingOffset, startingOffset + length)) + "]";
     }
   }
 }