AddCommand: ability to switch off renormalization

JGit's AddCommand always renormalizes tracked files. C git does so only
on git add --renormalize. Especially for git add . and the JGit
equivalent git.add().addFilepattern(".").call() this can make a big
difference if there are many files, or large files.

Add a "renormalize" option to AddCommand. To maintain compatibility with
existing uses, this option is "true" by default, and the behavior of
AddCommand is as it has always been in JGit.

If set to "false", use an IndexDiffFilter (in addition to a path filter,
if any). This skips any unchanged files (that are not racily clean) from
content checks. Note that changes in CRLF settings or in filters will be
ignored for such files if renormalize == false.

Add the "--renormalize" option to the Add command in the JGit command
line program. For the command-line program, the default is as in C git:
renormalize is off by default and enabled only if the option is given.
Note that --renormalize implies --update in the command line program, as
in C git. In AddCommand, the two settings are independent.

Additionally, avoid opening input streams unnecessarily in
WorkingTreeIterator.getEntryContentLength() and fix some bogus
indentation.

Add a simple test that adds 1000 files of 10kB in 10 directories twice
and that fails if the second invocation (without any changes) with
renormalize=false is not significantly faster.

Locally, I observe for that second invocation

* git.add().addFilepattern(".").call()                        ~660ms
* git.add().addFilepattern(".").setRenormalize(false).call()   ~16ms

Bug: 494323
Change-Id: I30f9d518563fa55d7058a48c27c425f3b60aeb4c
Signed-off-by: Thomas Wolf <twolf@apache.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties b/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
index 7b81af59bc..9e82c82137 100644
--- a/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
+++ b/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
@@ -255,6 +255,7 @@ unsupportedOperation=Unsupported operation: {0}
 untrackedFiles=Untracked files:
 updating=Updating {0}..{1}
 usage_Abbrev=Instead of using the default number of hexadecimal digits (which will vary according to the number of objects in the repository with a default of 7) of the abbreviated object name, use <n> digits, or as many digits as needed to form a unique object name. An <n> of 0 will suppress long format, only showing the closest tag.
+usage_addRenormalize=Apply the "clean" process freshly to tracked files to forcibly add them again to the index. This implies -u.
 usage_Aggressive=This option will cause gc to more aggressively optimize the repository at the expense of taking much more time
 usage_AlwaysFallback=Show uniquely abbreviated commit object as fallback
 usage_bareClone=Make a bare Git repository. That is, instead of creating [DIRECTORY] and placing the administrative files in [DIRECTORY]/.git, make the [DIRECTORY] itself the $GIT_DIR.
@@ -452,7 +453,7 @@ usage_resetMixed=Resets the index but not the working tree
 usage_runLfsStore=Run LFS Store in a given directory
 usage_S3NoSslVerify=Skip verification of Amazon server certificate and hostname
 usage_setTheGitRepositoryToOperateOn=set the git repository to operate on
-usage_shallowExclude=Deepen or shorten the history of a shallow repository to exclude commits reachable from a specified remote branch or tag. 
+usage_shallowExclude=Deepen or shorten the history of a shallow repository to exclude commits reachable from a specified remote branch or tag.
 usage_shallowSince=Deepen or shorten the history of a shallow repository to include all reachable commits after <date>.
 usage_show=Display one commit
 usage_showRefNamesMatchingCommits=Show ref names matching commits