Instead of using SetOutput(ioutil.Discard), which means
that Printf is still called for every debug message,
use a simple and fast boolean check.
Streaming write performance improves from 86 to 93 MB/s.
Another 3x performance boost for applications that walk the
directory tree.
Excerpt from performance.txt:
VERSION UNTAR LS RM
v0.4 48 1.5 5
v0.5-rc1 56 7 19
v0.5-rc1-1 54 4.1 9
v0.5-rc1-2 45 1.7 3.4 <---- THIS VERSION
Move all the intelligence into the new file address_translation.go.
That the calculations were spread out too much became apparent when adding
the file header. This should make the code much easier to modify in the
future.
Format: [ "Version" uint16 big endian ] [ "Id" 16 random bytes ]
Quoting SECURITY.md:
* Every file has a header that contains a 16-byte random *file id*
* Each block uses the file id and its block number as GCM *authentication data*
* This means the position of the blocks is protected as well. The blocks
can not be reordered or copied between different files without
causing an decryption error.
