io.Copy usually allocates a 32kB buffer, and due to the large
number of files processed by tar-split, this shows up in Go profiles
as a very large alloc_space total.
It doesn't seem to actually be a measurable problem in any way,
but we can allocate the buffer only once per tar-split creation,
at no additional cost to existing allocations, so let's do so,
and remove the distraction.
Signed-off-by: Miloslav Trmač <mitr@redhat.com>
When the entry name is not UTF-8, for example ISO-8859-1, then store the
raw bytes.
To accommodate this, we will have getters and setters for the entry's
name now. Since this most heavily affects the json marshalling, we'll
double check the sanity of the name before storing it in the JSONPacker.
It uses slightly less memory and more understandable.
Benchmar results:
benchmark old ns/op new ns/op delta
BenchmarkPutter-4 57272 52375 -8.55%
benchmark old allocs new allocs delta
BenchmarkPutter-4 21 19 -9.52%
benchmark old bytes new bytes delta
BenchmarkPutter-4 19416 13336 -31.31%
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
