revlog: refactor delta chain computation into own function
This code is already written in multiple locations.
While this code needs to be fast and extracting it to its own function
adds overhead, code paths reading delta chains typically read,
decompress, and do binary patching on revlog data from the delta chain.
This other work (especially zlib decompression) almost certainly
accounts for a lot more time than the overhead of introducing a Python
function call. So I'm not worried about the performance impact of this
change.
Set up a repo
$ cat <<EOF >> $HGRCPATH
> [ui]
> interactive = true
> [extensions]
> record =
> EOF
$ hg init a
$ cd a
Record help
$ hg record -h
hg record [OPTION]... [FILE]...
interactively select changes to commit
If a list of files is omitted, all changes reported by "hg status" will be
candidates for recording.
See "hg help dates" for a list of formats valid for -d/--date.
You will be prompted for whether to record changes to each modified file,
and for files with multiple changes, for each change to use. For each
query, the following responses are possible:
y - record this change
n - skip this change
e - edit this change manually
s - skip remaining changes to this file
f - record remaining changes to this file
d - done, skip remaining changes and files
a - record all changes to all remaining files
q - quit, recording no changes
? - display help
This command is not available when committing a merge.
options ([+] can be repeated):
-A --addremove mark new/missing files as added/removed before
committing
--close-branch mark a branch head as closed
--amend amend the parent of the working directory
-s --secret use the secret phase for committing
-e --edit invoke editor on commit messages
-I --include PATTERN [+] include names matching the given patterns
-X --exclude PATTERN [+] exclude names matching the given patterns
-m --message TEXT use text as commit message
-l --logfile FILE read commit message from file
-d --date DATE record the specified date as commit date
-u --user USER record the specified user as committer
-S --subrepos recurse into subrepositories
-w --ignore-all-space ignore white space when comparing lines
-b --ignore-space-change ignore changes in the amount of white space
-B --ignore-blank-lines ignore changes whose lines are all blank
(some details hidden, use --verbose to show complete help)
Select no files
$ touch empty-rw
$ hg add empty-rw
$ hg record empty-rw<<EOF
> n
> EOF
diff --git a/empty-rw b/empty-rw
new file mode 100644
examine changes to 'empty-rw'? [Ynesfdaq?] n
no changes to record
$ hg tip -p
changeset: -1:000000000000
tag: tip
user:
date: Thu Jan 01 00:00:00 1970 +0000