debug-delta-find: add a --source option

This will help us to understand the delta-find operation in different
situations.

mercurial/debugcommands.py

@@ -59,6 +59,7 b' from . import ('
     localrepo,
     lock as lockmod,
     logcmdutil,
+    mdiff,
     mergestate as mergestatemod,
     metadata,
     obsolete,
@@ -990,17 +991,29 b' def debugdeltachain(ui, repo, file_=None'
 
 @command(
     b'debug-delta-find',
-    cmdutil.debugrevlogopts + cmdutil.formatteropts,
+    cmdutil.debugrevlogopts
+    + cmdutil.formatteropts
+    + [
+        (
+            b'',
+            b'source',
+            b'full',
+            _(b'input data feed to the process (full, storage, p1, p2, prev)'),
+        ),
+    ],
     _(b'-c|-m|FILE REV'),
     optionalrepo=True,
 )
-def debugdeltafind(ui, repo, arg_1, arg_2=None, **opts):
+def debugdeltafind(ui, repo, arg_1, arg_2=None, source=b'full', **opts):
     """display the computation to get to a valid delta for storing REV
 
     This command will replay the process used to find the "best" delta to store
     a revision and display information about all the steps used to get to that
     result.
 
+    By default, the process is fed with a the full-text for the revision. This
+    can be controlled with the --source flag.
+
     The revision use the revision number of the target storage (not changelog
     revision number).
 
@@ -1028,11 +1041,31 b' def debugdeltafind(ui, repo, arg_1, arg_'
     p1r, p2r = revlog.parentrevs(rev)
     p1 = revlog.node(p1r)
     p2 = revlog.node(p2r)
-    btext = [revlog.revision(rev)]
+    full_text = revlog.revision(rev)
+    btext = [full_text]
     textlen = len(btext[0])
     cachedelta = None
     flags = revlog.flags(rev)
 
+    if source != b'full':
+        if source == b'storage':
+            base_rev = revlog.deltaparent(rev)
+        elif source == b'p1':
+            base_rev = p1r
+        elif source == b'p2':
+            base_rev = p2r
+        elif source == b'prev':
+            base_rev = rev - 1
+        else:
+            raise error.InputError(b"invalid --source value: %s" % source)
+
+        if base_rev != nullrev:
+            base_text = revlog.revision(base_rev)
+            delta = mdiff.textdiff(base_text, full_text)
+
+            cachedelta = (base_rev, delta)
+            btext = [None]
+
     revinfo = revlogutils.revisioninfo(
         node,
         p1,

tests/test-completion.t

@@ -268,7 +268,7 b' Show all commands + options'
   config: untrusted, exp-all-known, edit, local, source, shared, non-shared, global, template
   continue: dry-run
   copy: forget, after, at-rev, force, include, exclude, dry-run
-  debug-delta-find: changelog, manifest, dir, template
+  debug-delta-find: changelog, manifest, dir, template, source
   debug-repair-issue6528: to-report, from-report, paranoid, dry-run
   debug-revlog-index: changelog, manifest, dir, template
   debugancestor: 

tests/test-sparse-revlog.t

@@ -191,4 +191,156 b' Test `debug-delta-find`'
   DBG-DELTAS-SEARCH:     DELTA: length=49132 (BAD)
   DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=3 try-count=3 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)
 
+  $ cat << EOF >>.hg/hgrc
+  > [storage]
+  > revlog.optimize-delta-parent-choice = no
+  > revlog.reuse-external-delta = yes
+  > EOF
+
+  $ hg debug-delta-find SPARSE-REVLOG-TEST-FILE 4971 --quiet
+  DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=3 try-count=3 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)
+  $ hg debug-delta-find SPARSE-REVLOG-TEST-FILE 4971 --source full
+  DBG-DELTAS-SEARCH: SEARCH rev=4971
+  DBG-DELTAS-SEARCH: ROUND #1 - 2 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4962
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=18296
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=30377
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=16872 (BAD)
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4971
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=19179
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     TOO-HIGH
+  DBG-DELTAS-SEARCH: ROUND #2 - 1 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4930
+  DBG-DELTAS-SEARCH:     type=snapshot-3
+  DBG-DELTAS-SEARCH:     size=39228
+  DBG-DELTAS-SEARCH:     base=4799
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=33050
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=19179 (GOOD)
+  DBG-DELTAS-SEARCH: ROUND #3 - 1 candidates - refine-down
+  DBG-DELTAS-SEARCH:   CONTENDER: rev=4930 - length=19179
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4799
+  DBG-DELTAS-SEARCH:     type=snapshot-2
+  DBG-DELTAS-SEARCH:     size=50213
+  DBG-DELTAS-SEARCH:     base=4623
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=82661
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=49132 (BAD)
+  DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=3 try-count=3 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)
+  $ hg debug-delta-find SPARSE-REVLOG-TEST-FILE 4971 --source storage
+  DBG-DELTAS-SEARCH: SEARCH rev=4971
+  DBG-DELTAS-SEARCH: ROUND #1 - 1 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4930
+  DBG-DELTAS-SEARCH:     type=snapshot-3
+  DBG-DELTAS-SEARCH:     size=39228
+  DBG-DELTAS-SEARCH:     base=4799
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=33050
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=19179 (GOOD)
+  DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=1 try-count=1 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)
+  $ hg debug-delta-find SPARSE-REVLOG-TEST-FILE 4971 --source p1
+  DBG-DELTAS-SEARCH: SEARCH rev=4971
+  DBG-DELTAS-SEARCH: ROUND #1 - 2 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4962
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=18296
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=30377
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=16872 (BAD)
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4971
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=19179
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     TOO-HIGH
+  DBG-DELTAS-SEARCH: ROUND #2 - 1 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4930
+  DBG-DELTAS-SEARCH:     type=snapshot-3
+  DBG-DELTAS-SEARCH:     size=39228
+  DBG-DELTAS-SEARCH:     base=4799
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=33050
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=19179 (GOOD)
+  DBG-DELTAS-SEARCH: ROUND #3 - 1 candidates - refine-down
+  DBG-DELTAS-SEARCH:   CONTENDER: rev=4930 - length=19179
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4799
+  DBG-DELTAS-SEARCH:     type=snapshot-2
+  DBG-DELTAS-SEARCH:     size=50213
+  DBG-DELTAS-SEARCH:     base=4623
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=82661
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=49132 (BAD)
+  DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=3 try-count=3 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)
+  $ hg debug-delta-find SPARSE-REVLOG-TEST-FILE 4971 --source p2
+  DBG-DELTAS-SEARCH: SEARCH rev=4971
+  DBG-DELTAS-SEARCH: ROUND #1 - 2 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4962
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=18296
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=30377
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=16872 (BAD)
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4971
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=19179
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     TOO-HIGH
+  DBG-DELTAS-SEARCH: ROUND #2 - 1 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4930
+  DBG-DELTAS-SEARCH:     type=snapshot-3
+  DBG-DELTAS-SEARCH:     size=39228
+  DBG-DELTAS-SEARCH:     base=4799
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=33050
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=19179 (GOOD)
+  DBG-DELTAS-SEARCH: ROUND #3 - 1 candidates - refine-down
+  DBG-DELTAS-SEARCH:   CONTENDER: rev=4930 - length=19179
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4799
+  DBG-DELTAS-SEARCH:     type=snapshot-2
+  DBG-DELTAS-SEARCH:     size=50213
+  DBG-DELTAS-SEARCH:     base=4623
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=82661
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=49132 (BAD)
+  DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=3 try-count=3 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)
+  $ hg debug-delta-find SPARSE-REVLOG-TEST-FILE 4971 --source prev
+  DBG-DELTAS-SEARCH: SEARCH rev=4971
+  DBG-DELTAS-SEARCH: ROUND #1 - 2 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4962
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=18296
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=30377
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=16872 (BAD)
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4971
+  DBG-DELTAS-SEARCH:     type=snapshot-4
+  DBG-DELTAS-SEARCH:     size=19179
+  DBG-DELTAS-SEARCH:     base=4930
+  DBG-DELTAS-SEARCH:     TOO-HIGH
+  DBG-DELTAS-SEARCH: ROUND #2 - 1 candidates - search-down
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4930
+  DBG-DELTAS-SEARCH:     type=snapshot-3
+  DBG-DELTAS-SEARCH:     size=39228
+  DBG-DELTAS-SEARCH:     base=4799
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=33050
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=19179 (GOOD)
+  DBG-DELTAS-SEARCH: ROUND #3 - 1 candidates - refine-down
+  DBG-DELTAS-SEARCH:   CONTENDER: rev=4930 - length=19179
+  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4799
+  DBG-DELTAS-SEARCH:     type=snapshot-2
+  DBG-DELTAS-SEARCH:     size=50213
+  DBG-DELTAS-SEARCH:     base=4623
+  DBG-DELTAS-SEARCH:     uncompressed-delta-size=82661
+  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)
+  DBG-DELTAS-SEARCH:     DELTA: length=49132 (BAD)
+  DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=3 try-count=3 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)
+
   $ cd ..