rust-nodemap: automatically use the rust index for persistent nodemap

The persistent nodemap requires the rust index to be used to provides any gains.
So we automatically enable it for revlog using the persistent nodemap. We keep
it off for other revset because now that the rust revlog fully initialise the
nodemap using it everywhere introduce a fairly significant regression (eg: hg
diff moving from 0.8s to 2.3s on mozilla-try)

Differential Revision: https://phab.mercurial-scm.org/D8164

mercurial/revlog.py

@@ -618,12 +618,19 b' class revlog(object):'
             and NodemapRevlogIO is not None
         )
 
+        use_rust_index = False
+        if rustrevlog is not None:
+            if self.nodemap_file is not None:
+                use_rust_index = True
+            else:
+                use_rust_index = self.opener.options.get(b'rust.index')
+
         self._io = revlogio()
         if self.version == REVLOGV0:
             self._io = revlogoldio()
         elif devel_nodemap:
             self._io = NodemapRevlogIO()
-        elif rustrevlog is not None and self.opener.options.get(b'rust.index'):
+        elif use_rust_index:
             self._io = rustrevlogio()
         try:
             d = self._io.parseindex(indexdata, self._inline)

tests/test-persistent-nodemap.t

@@ -2,7 +2,6 b''
 Test the persistent on-disk nodemap
 ===================================
 
-
   $ hg init test-repo
   $ cd test-repo
   $ cat << EOF >> .hg/hgrc
@@ -26,6 +25,35 b' Simple lookup works'
   $ hg log -r "$ANYNODE" --template '{rev}\n'
   5000
 
+
+#if rust
+
+  $ f --sha256 .hg/store/00changelog-*.nd
+  .hg/store/00changelog-????????????????.nd: sha256=1e38e9ffaa45cad13f15c1a9880ad606f4241e8beea2f61b4d5365abadfb55f6 (glob)
+  $ hg debugnodemap --dump-new | f --sha256 --size
+  size=122880, sha256=1e38e9ffaa45cad13f15c1a9880ad606f4241e8beea2f61b4d5365abadfb55f6
+  $ hg debugnodemap --dump-disk | f --sha256 --bytes=256 --hexdump --size
+  size=122880, sha256=1e38e9ffaa45cad13f15c1a9880ad606f4241e8beea2f61b4d5365abadfb55f6
+  0000: 00 00 00 76 00 00 01 65 00 00 00 95 00 00 01 34 |...v...e.......4|
+  0010: 00 00 00 19 00 00 01 69 00 00 00 ab 00 00 00 4b |.......i.......K|
+  0020: 00 00 00 07 00 00 01 4c 00 00 00 f8 00 00 00 8f |.......L........|
+  0030: 00 00 00 c0 00 00 00 a7 00 00 00 89 00 00 01 46 |...............F|
+  0040: 00 00 00 92 00 00 01 bc 00 00 00 71 00 00 00 ac |...........q....|
+  0050: 00 00 00 af 00 00 00 b4 00 00 00 34 00 00 01 ca |...........4....|
+  0060: 00 00 00 23 00 00 01 45 00 00 00 2d 00 00 00 b2 |...#...E...-....|
+  0070: 00 00 00 56 00 00 01 0f 00 00 00 4e 00 00 02 4c |...V.......N...L|
+  0080: 00 00 00 e7 00 00 00 cd 00 00 01 5b 00 00 00 78 |...........[...x|
+  0090: 00 00 00 e3 00 00 01 8e 00 00 00 4f 00 00 00 b1 |...........O....|
+  00a0: 00 00 00 30 00 00 00 11 00 00 00 25 00 00 00 d2 |...0.......%....|
+  00b0: 00 00 00 ec 00 00 00 69 00 00 01 2b 00 00 01 2e |.......i...+....|
+  00c0: 00 00 00 aa 00 00 00 15 00 00 00 3a 00 00 01 4e |...........:...N|
+  00d0: 00 00 00 4d 00 00 00 9d 00 00 00 8e 00 00 00 a4 |...M............|
+  00e0: 00 00 00 c3 00 00 00 eb 00 00 00 29 00 00 00 ad |...........)....|
+  00f0: 00 00 01 3a 00 00 01 32 00 00 00 04 00 00 00 53 |...:...2.......S|
+
+
+#else
+
   $ f --sha256 .hg/store/00changelog-*.nd
   .hg/store/00changelog-????????????????.nd: sha256=b961925120e1c9bc345c199b2cc442abc477029fdece37ef9d99cbe59c0558b7 (glob)
   $ hg debugnodemap --dump-new | f --sha256 --size
@@ -48,6 +76,9 b' Simple lookup works'
   00d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
   00e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
   00f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
+
+#endif
+
   $ hg debugnodemap --check
   revision in index:   5001
   revision in nodemap: 5001
@@ -60,19 +91,20 b' add a new commit'
   $ hg add foo
   $ hg ci -m 'foo'
 
-#if pure
+#if no-pure no-rust
+  $ hg debugnodemap --metadata
+  uid: ???????????????? (glob)
+  tip-rev: 5001
+  data-length: 122880
+  data-unused: 0
+#else
   $ hg debugnodemap --metadata
   uid: ???????????????? (glob)
   tip-rev: 5001
   data-length: 123072
   data-unused: 192
-#else
-  $ hg debugnodemap --metadata
-  uid: ???????????????? (glob)
-  tip-rev: 5001
-  data-length: 122880
-  data-unused: 0
 #endif
+
   $ f --size .hg/store/00changelog.n
   .hg/store/00changelog.n: size=42
 
@@ -81,11 +113,16 b' add a new commit'
 #if pure
   $ f --sha256 .hg/store/00changelog-*.nd --size
   .hg/store/00changelog-????????????????.nd: size=123072, sha256=136472751566c8198ff09e306a7d2f9bd18bd32298d614752b73da4d6df23340 (glob)
+#endif
 
-#else
+#if rust
+  $ f --sha256 .hg/store/00changelog-*.nd --size
+  .hg/store/00changelog-????????????????.nd: size=123072, sha256=ccc8a43310ace13812fcc648683e259346754ef934c12dd238cf9b7fadfe9a4b (glob)
+#endif
+
+#if no-pure no-rust
   $ f --sha256 .hg/store/00changelog-*.nd --size
   .hg/store/00changelog-????????????????.nd: size=122880, sha256=bfafebd751c4f6d116a76a37a1dee2a251747affe7efbcc4f4842ccc746d4db9 (glob)
-
 #endif
 
   $ hg debugnodemap --check
@@ -115,8 +152,17 b' Test code path without mmap'
   data-unused: 384
   $ f --sha256 .hg/store/00changelog-*.nd --size
   .hg/store/00changelog-????????????????.nd: size=123328, sha256=10d26e9776b6596af0f89143a54eba8cc581e929c38242a02a7b0760698c6c70 (glob)
-
-#else
+#endif
+#if rust
+  $ hg debugnodemap --metadata
+  uid: ???????????????? (glob)
+  tip-rev: 5002
+  data-length: 123328
+  data-unused: 384
+  $ f --sha256 .hg/store/00changelog-*.nd --size
+  .hg/store/00changelog-????????????????.nd: size=123328, sha256=081eec9eb6708f2bf085d939b4c97bc0b6762bc8336bc4b93838f7fffa1516bf (glob)
+#endif
+#if no-pure no-rust
   $ hg debugnodemap --metadata
   uid: ???????????????? (glob)
   tip-rev: 5002