+
−A new repository uses zlib storage, which doesn't need a requirement
+
−
+
−  $ hg init default
+
−  $ cd default
+
−  $ cat .hg/requires
+
−  dotencode
+
−  fncache
+
−  generaldelta
+
−  revlogv1
+
−  store
+
−  testonly-simplestore (reposimplestore !)
+
−
+
−  $ touch foo
+
−  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text to trigger compression'
+
−  $ hg debugrevlog -c | grep 0x78
+
−      0x78 (x)  :   1 (100.00%)
+
−      0x78 (x)  : 110 (100.00%)
+
−
+
−  $ cd ..
+
−
+
−Unknown compression engine to format.compression aborts
+
−
+
−  $ hg --config experimental.format.compression=unknown init unknown
+
−  abort: compression engine unknown defined by experimental.format.compression not available
+
−  (run "hg debuginstall" to list available compression engines)
+
−  [255]
+
−
+
−A requirement specifying an unknown compression engine results in bail
+
−
+
−  $ hg init unknownrequirement
+
−  $ cd unknownrequirement
+
−  $ echo exp-compression-unknown >> .hg/requires
+
−  $ hg log
+
−  abort: repository requires features unknown to this Mercurial: exp-compression-unknown!
+
−  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
+
−  [255]
+
−
+
−  $ cd ..
+
−
+
−#if zstd
+
−
+
−  $ hg --config experimental.format.compression=zstd init zstd
+
−  $ cd zstd
+
−  $ cat .hg/requires
+
−  dotencode
+
−  exp-compression-zstd
+
−  fncache
+
−  generaldelta
+
−  revlogv1
+
−  store
+
−  testonly-simplestore (reposimplestore !)
+
−
+
−  $ touch foo
+
−  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text'
+
−
+
−  $ hg debugrevlog -c | grep 0x28
+
−      0x28      :  1 (100.00%)
+
−      0x28      : 98 (100.00%)
+
−
+
−  $ cd ..
+
−
+
−Specifying a new format.compression on an existing repo won't introduce data
+
−with that engine or a requirement
+
−
+
−  $ cd default
+
−  $ touch bar
+
−  $ hg --config experimental.format.compression=zstd -q commit -A -m 'add bar with a lot of repeated repeated repeated text'
+
−
+
−  $ cat .hg/requires
+
−  dotencode
+
−  fncache
+
−  generaldelta
+
−  revlogv1
+
−  store
+
−  testonly-simplestore (reposimplestore !)
+
−
+
−  $ hg debugrevlog -c | grep 0x78
+
−      0x78 (x)  :   2 (100.00%)
+
−      0x78 (x)  : 199 (100.00%)
+
−
+
−#endif