N1ql query result parsing has poor performance for big document

The environment :

• couchbase server 4.6
• java client

on the same machine (dev), plenty of ram, SSD disk, 4 cores

Simple bucket with only 2 (heavy) documents.
Simple query select b.* FROM thebucket b

Execute the query in the couchbase admin : 120 ms
the same query with the java client : 12 seconds
the thread doing the computation is using a core at 100%

the document is huge and badly designed but that's not the point
the performances should be nearly the same between java and the admin console.

After investigation the performance bottleneck is in QueryHandler#parseQueryRows > ByteBufJsonHelper#findSectionClosingPosition
Looks like data in being appended to a buffer but the scan with forEachByte is always done from the beginning of the buffer.