SHA-1 prototype¶

directory : source:/prototypes/01_SHA1

Goals¶

• Compute the SHA-1 of each part of a given file.
• Compute the SHA-1 of a stream.
• Find the fastest way to compute SHA1, should be at least 40 MB/s.

Speed measures against sha1sum¶

file : 01.wmv : 17'639'245 byte ~ 17Mo (buffered)
Each measurement is pre-runned once to put the file in cache.

sha1sum from GNU coreutils (Reference)¶

speed : 57 MB/s

<gburri@overnux:~/code/lang/haskell/SHA1$> time sha1sum < 01.wmv
3aec84601612e8c604ac01971e0ecd9d536dbead  -

real    0m0.301s
user    0m0.276s
sys     0m0.020s

QCryptographicHash (release -O2)¶

speed : 49 MB/s

<flynux:~/code/projects/aybabtu/prototypes/01_SHA1 $> time ./qt_sha1 all 01.wmv 
3aec84601612e8c604ac01971e0ecd9d536dbead

real    0m0.340s
user    0m0.324s
sys     0m0.016s

Speed measures against Linus's sha1¶

file : test.bin : 754'856'284 byte ~ 720Mo (buffered)
Each measurement is pre-runned once to put the file in cache.

Linus's sha1¶

Debug mode¶

Speed : 69.3 MB/s

$ time ./debug/01_SHA1.exe all ~/data.bin
ca6fa5e8eeb976193f81a01bf67e4bbf3f07357f

real    0m10.383s
user    0m0.015s
sys     0m0.000s

Release mode (-02)¶

Speed : 165.1 MB/s

$ time ./release/01_SHA1.exe all ~/data.bin
ca6fa5e8eeb976193f81a01bf67e4bbf3f07357f

real    0m4.360s
user    0m0.000s
sys     0m0.015s

QCryptographicHash¶

Debug mode¶

Speed :21 MB/s

$ time ./debug/01_SHA1.exe all ~/data.bin
ca6fa5e8eeb976193f81a01bf67e4bbf3f07357f

real    0m34.223s
user    0m0.015s
sys     0m0.000s

Release mode (-02)¶

Speed : 164.4 MB/s

$ time ./release/01_SHA1.exe all ~/data.bin.mkv
ca6fa5e8eeb976193f81a01bf67e4bbf3f07357f

real    0m4.380s
user    0m0.000s
sys     0m0.015s

Conclusions¶

• The Qt implementation is fast and can be used without problem.
• The Qt implementation in debug mode is very slow, be careful.