Hi there! I am working on a very large code base, and build performance issues made me look at the maven-resolver source code. In terms of File usages, there are a lot of InputStreams being copied around using ByteBuffer, instead of using FileChannel.transferTo. Affected classes are DefaultFileProcessor, ChecksumCalculator, WagonTransporter, AbstractTransporter and potentially more. Was it a conscious decision to use this pattern over the more efficient transferTo? Would you accept a PR with more modern NIO API that still works with JDK 7?
Here are the throughput results from a JMH benchmark, copying a 22MB file around using the pattern currently used in maven, and transferTo, as measured on macOS with JDK 11 on an SSD. Result "MyBenchmark.resolverCopy": 291.362 ±(99.9%) 5.443 ops/s [Average] (min, avg, max) = (276.923, 291.362, 302.911), stdev = 7.266 CI (99.9%): [285.919, 296.804] (assumes normal distribution) Result "MyBenchmark.transferTo": 325.188 ±(99.9%) 8.838 ops/s [Average] (min, avg, max) = (306.978, 325.188, 355.784), stdev = 11.799 CI (99.9%): [316.350, 334.026] (assumes normal distribution) Thanks! Stefan
