lfs: expand the user facing documentation

streamclone: also stream caches to the client When stream clone is used over bundle2, relevant cache files are also streamed. This is expected to be a massive performance win for clone since no important cache will have to be recomputed. Some performance numbers: (All times are wall-clock times in seconds, 2 attempts per case.) # Mozilla-Central ## Clone over ssh over lan V1 streaming: 234.3 239.6 V2 streaming: 248.4 243.7 ## Clone over ssh over Internet V1 streaming: 175.5 110.9 V2 streaming: 109.1 111.0 ## Clone over HTTP over lan V1 streaming: 105.3 105.6 V2 streaming: 112.7 111.4 ## Clone over HTTP over internet V1 streaming: 105.6 114.6 V2 streaming: 226.7 225.9 ## Hg tags V1 streaming (no cache): 1.084 1.071 V2 streaming (cache): 0.312 0.325 ## Hg branches V1 streaming (no cache): 14.047 14.148 V2 streaming (with cache): 0.312 0.333 # Pypy ## Clone over ssh over internet V1 streaming: 29.4 30.1 V2 streaming: 31.2 30.1 ## Clone over http over internet V1 streaming: 29.7 29.7 V2 streaming: 75.2 72.9 (since ssh and lan are not affected, there seems to be an issue with how we read/write the http stream on connection with latency, unrelated to the format) ## Hg tags V1 streaming (no cache): 1.752 1.664 V2 streaming (with cache): 0.274 0.260 ## Hg branches V1 streaming (no cache): 4.469 4.728 V2 streaming (with cache): 0.318 0.321 # Private repository: * 500K revision revisions * 11K topological heads * 28K branch heads ## hg tags no cache: 1543.332 with cache: 4.900 ## hg branches no cache: 91.828 with cache: 2.955

caches: make 'cachetocopy' available in scmutil For more code to use this information, we need it to be more publicly available.

streamclone: add support for cloning non append-only file The phaseroots are stored in a non append-only file in the repository. We include them in the stream too. Since they are not append-only, we have to keep a copy around while we hold the lock to be able to stream them later. Since phase get exchanged within the stream we can skip requesting them independently. As a side effect, this will fixes issue5648 once the feature is enabled by default.

streamclone: tests phase exchange during stream clone We add a test dedicated to phases. As reported in issue 5648 stream from a non publishing server is currently broken (does not preserve the phase). We'll fix it with 'v2' support in the next changesets.

streamclone: add support for bundle2 based stream clone The feature put to use the various bits introduced previously. If the server supports it, the client will request its stream clone through bundle2 instead of the legacy 'stream_out' commands. The bundle2 version use the better 'v2' version of stream bundles. The 'v2' format is not finalized yet. Now that there are some code running it, we can start working on it again. Performance numbers are available at the end of this series.

pull: preindent some code Next changesets will add support for using stream cloning with bundle2. We introduce indentation change first for clarity.

pull: reorganize bundle2 argument bundling We are about to add the ability to use stream bundle with bundle2. Before doing so, we need to gather some code that will not be used in the bundle2 case. There is no behavior change within this changeset.

clone: allow bundle2's stream clone with 'server.disablefullbundle' The previous check was a bit too strict and would not recognize a get bundle not requesting changegroup.

bundle2: add support for a 'stream' parameter to 'getbundle' This parameter can be used to request a stream bundle.