Memory Mapped file segment / always appending

[Johannes Lichtenberger]

Hi,

as I'm always appending data to the end of a file. I came up with the idea
to always map a segment in chunks of Integer.MAX, that is the segment
always get's closed and a new segment gets created with twice the size (for
reading/writing). When I'm closing the writer I'm simply truncating the
file(s) to the real length.

However, I just saw that it's horribly slow for a lot of small writes. That
is I'm always creating a read/write page reader, and closing it again after
a write. However, truncating a lot of unused space, over and over again is
a real problem. I've attached a flame graph from YourKit showing that half
of the time over a large amount of CPU samples is spend with truncating.

Any ideas, how to improve performance?

The packe is this and very small:

https://github.com/sirixdb/sirix/tree/master/bundles/sirix-core/src/main/java/org/sirix/io/memorymapped

kind regards
Johannes