Pull Request #41
Choose compression method basing on url
Travis CI fetches and pushes tgz archives with the name like cache-windows-1803-containers-hash--compiler-gpp.tgz but misleadingly compresses them as tbz archives.
According to https://tukaani.org/lzma/benchmarks.html 203 MB file takes 2 m 37 s to compress 32.2 s to decompress and yields 34 % compression ratio for bzip2.
The same file takes 66.9 s to compress 3.1 s to decompress and yields 37 % compression ratio for gzip.
The difference in compression/decompression time is huge and in compression ration small, so gzip should be used by default.
Rubby casher uses following line compression_flag = file.end_with?('.tbz') ? 'j' : 'z' to determine compression method.