int searchStartIndex(long startOffset) {
            IndexAndCount indexAndCount = offsetIndexMap.get(startOffset);
            if (indexAndCount != null) {
                unmap(startOffset, indexAndCount);
                return indexAndCount.index;
            } else {
                // slow path
                StreamRecordBatchList search = new StreamRecordBatchList(records);
                return search.search(startOffset);
            }
        }
Merge the right block to the left block
s3stream/src/main/java/com/automq/stream/s3/cache/LogCache.java