nocg: make the utility work are both a decorator and context manager In some case, the context manager version will be simpler.

stream-clone: stop getting the file size of all file in v3 The point of v3 is to do less work in the locked section. It was currently not the case. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.03 seconds this-change: 24.50 seconds (-30%)

stream: in v3, skip the "size" fast path if the entries as some unknown size We are about to prefetch size during the lock less in the v3 case. So we need to avoid trying to use that prefetched size when it is not available. See next changeset for the motivation.

perf-stream-locked-section: advertise the right version key in the help As the v3 format is still experimental, its key is "v3-exp". The help text was not pointing that out. (we also fix `perf::stream-generate` in the process)

perf-stream-locked-section: fix the call to the v3 generator That generator simply return chunks so we should not assign the return to a tuple.

perf-stream-locked-section: actually use v1 generation when requested We were fetching a v1 generator but actually using the v2 function…

branching: merge stable into default