* js/rename:
Implemented file path based tie breaking to exact rename detection
Added more test cases for RenameDetector
Added very small optimization to exact rename detection
Fixed Misleading Javadoc
Added file path similarity to scoring metric in rename detection
Fixed potential div by zero bug
Added file size based rename detection optimization
Create FileHeader from DiffEntry
log: Implement --follow
Cache the diff configuration section
log: Add whitespace ignore options
Format submodule links during differences
Redo DiffFormatter API to be easier to use
log, diff: Add rename detection support
Implement similarity based rename detection
Added a preliminary version of rename detection
Refactored code out of FileHeader to facilitate rename detection
A programming error using the Inflater API led to an infinite
loop within IndexPack, caused by the Inflater returning 0 from
the inflate() method, but it didn't want more input. This happens
when it has reached the end of the stream, or has reached a spot
asking for an external dictionary. Such a case is a failure for us,
and we should abort out.
Thanks to Alex for pointing out that we had 3 implementations of
the inflate rountine, which should be consolidated into one and
use a switch to determine where to load data from.
Bug: 317416
Change-Id: I34120482375b687ea36ed9154002d77047e94b1f
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
During the exact rename detection phase in RenameDetector, ties were
resolved on a first-found basis. I added support for file path based
tie breaking during that phase. Basically, there are four situations
that have to be handled:
One add matching one delete:
In this simple case, we pair them as a rename.
One add matching many deletes:
Find the delete whos path matches the add the closest, and
pair them as a rename.
Many adds matching one delete:
Similar to the above case, we find the add that matches the
delete the closest, and pair them as a rename. The other adds
are marked as copies of the delete.
Many adds matching many deletes:
Build a scoring matrix similar to the one used for content-
based matching, scoring instead by file path. Some of the
utility functions in SimilarityRenameDetector are used in
this case, as we use the same encoding scheme. Once the
matrix is built, scan it for the best matches, marking them
as renames. The rest are marked as copies.
I don't particularly like the idea of using utility functions right
out of SimilarityRenameDetector, but it works for the moment. A later
commit will likely refactor this into a common utility class, as well
as bringing exact rename detection out of RenameDetector and into a
separate class, much like SimilarityRenameDetector.
Change-Id: I1fb08390aebdcbf20d049aecf402a36506e55611
Added possibility to compare the current entry of a WorkingTreeIterator
to a given DirCacheEntry. This is done to detect whether an entry
in the index is dirty or not. 'Dirty' means that the file in the working tree
is different from what's in the index. Merge algorithms will make use of
this to detect conflicts.
Change-Id: I3ff847f4bf392553dcbd6ee236c6ca32a13eedeb
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
When the path is prefixed with ~ the URI parser thought about this
as /~. Strip the / if the next character is the tilde.
Bug: 307017
Change-Id: I58203e5617956b46d83e8987d1f8042beddffac3
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
The new Add command adds files to the Git Index.
It uses the DirCache to access the git index. It
works also in case of an existing conflict.
Fileglobs (e.g. *.c) are not yet supported.
The new Add command does add ignored files because
there is no gitignore support in jgit yet.
Bug: 318440
Change-Id: If16fdd4443e46b27361c2a18ed8f51668af5d9ff
Signed-off-by: Stefan Lay <stefan.lay@sap.com>
After refactoring ReadTreeTest the tests failed for filesystems
with coarse modification time granularity. This is fixed by
explicitly telling the repo to reread the index after we build
a new index.
Additionally the test testDirectoryFileSimple was simplified
by using buildTree() instead of misusing GitIndex to construct
trees.
Change-Id: I20d2f097491e4cc8c657a696beabc7026b485017
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
This patch adds ignore compatibility to jgit. It encompasses
exclude files as well as .gitignore. Uses TreeWalk and
FileTreeIterator to find nodes and parses .gitignore
files when required. The patch includes a simple cache that
can be used to save results and avoid excessive gitignore
parsing.
CQ: 4302
Bug: 303925
Change-Id: Iebd7e5bb534accca4bf00d25bbc1f561d7cad11b
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>
Signed-off-by: Stefan Lay <stefan.lay@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
I added test cases to cover the majority of the code. It's not 100%
coverage yet, but the remaining bits are small.
Change-Id: Ib534c8e94b13358b8b22cf54e2ff84132bae6d14
Optimized a small loop in findExactRenames. The loop would go through
all the items in a list of DiffEntries even after it already found
what it was looking for. I made it break out of the loop as soon as
a good match was found.
Change-Id: I28741e0c49ce52d8008930a87cd1db7037700a61
The javadoc for the setRenameLimit method in RenameDetector said
that you could only have limits in the range (0,100), implying
that 0 and 100 were illegal inputs. The code, however, allowed 0 and
100. I changed the javadoc to say that the range [0,100] was legal.
I also documented the IllegalArgumentException that is thrown if the
limit is outside that range.
Change-Id: I916838f254859f6f0e1516bb55b8e7dc87e57dc2
The scoring method was not taking into account the similarity of
the file paths and file names. I changed the metric so that it is 99%
based on content (which used to be 100% of the old metric), and 1%
based on path similarity. Of that 1%, half (.5% of the total final
score) is based on the actual file names (e.g. "foo.java"), and half
on the directory (e.g. "src/com/foo/bar/").
Change-Id: I94f0c23bf6413c491b10d5625f6ad7d2ecfb4def
The scoring logic in SimilarityIndex was dividing by the max file
size. If both files are empty, this would cause a div by zero
error. This case cannot currently happen, since two empty files
would have the same SHA1, and would therefore be caught in the
earlier SHA1 based detection pass. Still, if this logic eventually
gets separated from that pass, a div by zero error would occur.
I changed the logic to instead consider two empty files to have a
similarity score of 100.
Change-Id: Ic08e18a066b8fef25bb5e7c62418106a8cee762a
Prior to this change, files that were very different in size (enough
so that they could not have enough in common to be detected as
renames) were still having their scores calculated. I added an
optimization to skip such files. For example, if the rename detection
threshold is 60%, the larger file is 200kb, and the smaller file is
50kb, the pair cannot be counted as a rename since they cannot
possibly share 60% of their content in common. (200*.6=120, 120>50)
Change-Id: Icd8315412d5de6292839778e7cea7fe6f061b0fc
C Git allows this and it is quite handy.
Change-Id: I1d0238b43fca931ad2079649fb7b431e2815c351
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Added support for converting DiffEntrys to FileHeaders. FileHeaders
are DiffEntrys with a buffer containing the diff output as well as
a list of HunkHeaders. The HunkHeaders contain EditLists. The
createFileHeader(DiffEntry) method in DiffFormatter performs a Myers
Diff on the files refered to by the DiffEntry, then puts the returned
EditList into a single HunkHeader, which is then put into the
FileHeader to be returned. It also generates the appropriate diff
header an puts it into the FileHeader's buffer. The rest of the diff
output, which would normally be parsed to generate the HunkHeaders,
is not generated. In fact, the purpose of this method is to avoid
the costly diff output generation and parsing normally required to
create a FileHeader.
Change-Id: I7d8b18c0f6c85e3d02ad58995d3d231e69af5887
ReadTreeTest was hardcoded to test WorkDirCheckout. Since we want
alternative checkout implementations (especially DirCacheCheckout)
this class has been refactored so that the tests can be reused
to test other implementations
The following changes have been done:
- abstract methods for checkout and prescanTwoTrees have been
introduced. Parameters are only the two trees. As index we
will implicitly use the current index of the repo.
- whenever tests needed a manipulated index before checkout
and prescanTwoTrees it was ensured that the correct index was
persisted (before we could use not-persisted instantiations of GitIndex
passed as parameters to checkout, prescanTwoTrees
- abstract methods for getting updated, conflicting, removed entries
resulting from the last checkout, prescanTwoTrees have been introduced
- an implementation for all these abstract methods using WorkDirCheckout
has been added
- method to assert a certain state of the index and the working tree has
been added
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Change-Id: Icf177cf8043487169a32ddd72b6f8f9246a433f7
There were some small errors which made it
difficult to read the JavaDoc.
Change-Id: Ib3b34353465162adebaca3514d596d0edf5aea51
Signed-off-by: Stefan Lay <stefan.lay@sap.com>
We want to get rid of these APIs, because they don't perform as well
as DirCache/TreeWalk, or don't offer nearly as many features.
Bug: 319145
Change-Id: I2b28f9cddc36482e1ad42d53e86e9d6461ba3bfc
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
NB.decodeInt32(info, base + 4) already returns nanoseconds.
Therefore it must not be divided by 1000000.
Change-Id: Ie8f5c4a03f984d98935dccedc2b1ba4457094899
Signed-off-by: Stefan Lay <stefan.lay@sap.com>
The FollowFilter can be installed on a RevWalk to cause the path
to be updated through rename detection when the affected file is
found to be added to the project.
The filter works reasonably well, for example we can follow the
history of the fsck command in git-core:
$ jgit log --name-status --follow builtin/fsck.c | grep ^R
R100 builtin-fsck.c builtin/fsck.c
R099 fsck.c builtin-fsck.c
R099 fsck-objects.c fsck.c
R099 fsck-cache.c fsck-objects.c
Change-Id: I4017bcfd150126aa342fdd423a688493ca660a1f
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
This way we don't have to reparse for the rename limit every time
we create a new rename detector for a repository.
Change-Id: I669d031690b85ef4da5e39189be7173fb773fc56
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Similar to what we did with diff, implement whitespace ignore options
for log too. This requires us to define some means of creating any
RawText object type at will inside of DiffFormatter, so we define a
new factory interface to construct RawText instances on demand.
Unfortunately we have to copy the entire block of common options.
args4j only processes the options/arguments on the one command class
and Java doesn't support multiple inheritance.
Change-Id: Ia16cd3a11b850fffae9fbe7b721d7e43f1d0e8a5
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Instead of crashing, output a submodule link with the simple
"Subproject commit $fullid\n" syntax used by C Git.
Change-Id: Iae8646941683fb19b73fb038217d2e3bf5f77fa9
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Passing around the OutputStream and the Repository is crazy. Instead
put the stream in the constructor, since this formatter exists only to
output to the stream, and put the repository as a member variable that
can be optionally set.
Change-Id: I2bad012fee7f40dc1346700ebd19f1e048982878
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Implement rename detection in the command line diff and log commands.
Also support --name-status, -p and -U flags, as these can be quite
useful to view more detail.
All of the Git patch file formatting code is now moved over to the
DiffFormatter class. This permits us to reuse it in any context,
including inside of IDEs.
Change-Id: I687ccba34e18105a07e0a439d2181c323209d96c
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Content similarity based rename detection is performed only after
a linear time detection is performed using exact content match on
the ObjectIds. Any names which were paired up during that exact
match phase are excluded from the inexact similarity based rename,
which reduces the space that must be considered.
During rename detection two entries cannot be marked as a rename
if they are different types of files. This prevents a symlink from
being renamed to a regular file, even if their blob content appears
to be similar, or is identical.
Efficiently comparing two files is performed by building up two
hash indexes and hashing lines or short blocks from each file,
counting the number of bytes that each line or block represents.
Instead of using a standard java.util.HashMap, we use a custom
open hashing scheme similiar to what we use in ObjecIdSubclassMap.
This permits us to have a very light-weight hash, with very little
memory overhead per cell stored.
As we only need two ints per record in the map (line/block key and
number of bytes), we collapse them into a single long inside of
a long array, making very efficient use of available memory when
we create the index table. We only need object headers for the
index structure itself, and the index table, but not per-cell.
This offers a massive space savings over using java.util.HashMap.
The score calculation is done by approximating how many bytes are
the same between the two inputs (which for a delta would be how much
is copied from the base into the result). The score is derived by
dividing the approximate number of bytes in common into the length
of the larger of the two input files.
Right now the SimilarityIndex table should average about 1/2 full,
which means we waste about 50% of our memory on empty entries
after we are done indexing a file and sort the table's contents.
If memory becomes an issue we could discard the table and copy all
records over to a new array that is properly sized.
Building the index requires O(M + N log N) time, where M is the
size of the input file in bytes, and N is the number of unique
lines/blocks in the file. The N log N time constraint comes
from the sort of the index table that is necessary to perform
linear time matching against another SimilarityIndex created for
a different file.
To actually perform the rename detection, a SxD matrix is created,
placing the sources (aka deletions) along one dimension and the
destinations (aka additions) along the other. A simple O(S x D)
loop examines every cell in this matrix.
A SimilarityIndex is built along the row and reused for each
column compare along that row, avoiding the costly index rebuild
at the row level. A future improvement would be to load a smaller
square matrix into SimilarityIndexes and process everything in that
sub-matrix before discarding the column dimension and moving down
to the next sub-matrix block along that same grid of rows.
An optional ProgressMonitor is permitted to be passed in, allowing
applications to see the progress of the detector as it works through
the matrix cells. This provides some indication of current status
for very long running renames.
The default line/block hash function used by the SimilarityIndex
may not be optimal, and may produce too many collisions. It is
borrowed from RawText's hash, which is used to quickly skip out of
a longer equality test if two lines have different hash functions.
We may need to refine this hash in the future, in order to minimize
the number of collisions we get on common source files.
Based on a handful of test commits in JGit (especially my own
recent rename repository refactoring series), this rename detector
produces output that is very close to C Git. The content similarity
scores are sometimes off by 1%, which is most probably caused by
our SimilarityIndex type using a different hash function than C
Git uses when it computes the delta size between any two objects
in the rename matrix.
Bug: 318504
Change-Id: I11dff969e8a2e4cf252636d857d2113053bdd9dc
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
We used our LICENSE file to describe both the license of the package,
and also the header template that should appear at the start of
all Java files we create. This creates a confusing situation for
readers who just want to consume the package, because our file
header template starts off in the middle of a sentence.
Move our template header to a separate file, and reformat the text
of the license to be something more readable by a person reviewing
the project's terms of use.
Change-Id: If318e64c06683ea14e0240914c2d057c9199ce98
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
JGit does not currently do rename detection during diffs. I added
a class that, given a TreeWalk to iterate over, can output a list
of DiffEntry's for that TreeWalk, taking into account renames. This
class only detects renames by SHA1's. More complex rename detection,
along the lines of what C Git does will be added later.
Change-Id: I93606ce15da70df6660651ec322ea50718dd7c04
Refactored a superclass out of FileHeader called DiffEntry that holds
the more general data from FileHeader that is useful in rename
detection (old/new Ids, modes, names, as well as changeType and
score). FileHeader is now a DiffEntry that adds Hunks, parsing
abilities, etc.
Change-Id: I8398728cd218f8c6e98f7a4a7f2f342391d865e4
It is possible that StreamCopyThread will not flush everything
from it's src to it's dst. In most cases StreamCopyThread works
like this:
in loop:
n = src.read(buf);
dst.write(buf, 0, n);
and when we want to flush, we interrupt() StreamCopyThread and it
flushes everything it wrote to dst.
The problem is that our interrupt() could interrupt reading. In this
case we will flush everything we wrote to dst, but not everything
we wrote to src.
Change-Id: Ifaf4d8be87535c7364dd59b217dfc631460018ff
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Added a check in Diff to ensure that files that are most likely
not text are not line-by-line diffed. Files are determined to be
binary by checking the first 8000 bytes for a null character. This
is a similar heuristic to what C Git uses.
Change-Id: I2b6f05674c88d89b3f549a5db483f850f7f46c26
Added code to support ignoring leading, trailing, and changed
whitespace when performing a diff operation. I also added command
line options to Diff to enable the various whitespace ignoring
methods. These match the flags for git diff.
Change-Id: Ie56301aafad59ee3f0fe5de62719f5023cd702c8
JGit did not have support for skipping whitespace when comparing
lines in RawText objects. I added a subclass of RawText that skips
whitespace in its equals and hashCode methods. I used a subclass
rather than adding functionality into RawText so that performance
would not be impacted by extra logic.
This class only supports ignoring all whitespace. Others will follow
that allow other forms of whitespace ignoring.
Change-Id: Ic2f79e85215e48d3fd53ec1b4ad13373dd183a4a
Under smart HTTP the biDirectionalPipe flag is false, and we return
back immediately at this point in the negotiation process. There is
no need to flush the stream to the client, the request is over and
it will be automatically flushed out by the higher level servlet
that invoked us. Avoiding flush here allows us to only use flush
after a progress message is sent during pack generation.
Change-Id: Id0c8b7e95e3be6ca4c1b479e096bed6b0283b828
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
This simplifies the PackIndex code, which is trying to quickly copy
an existing ObjectId into a MutableObjectId. Rather than having
the PackIndex violate the ObjectId's internals, expose a copy from
function similar to the other ones for copying from raw byte arrays
or hex formatted strings.
Change-Id: I142635cbece54af2ab83c58477961ce925dc8255
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Storage systems can use these implementations to compare a passed
AnyObjectId with a stored representation of an ObjectId in the
canonical network byte order format. This can be useful to do a
binary search, or just linear scan, over an encoded storage file.
Change-Id: I8c72993c4f4c6e98d599ac2c9867453752f25fd2
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
An implementation might prefer to use the RefList type here, and
RefList is part of our public API. Expose the constructor so callers
who have a RefList can take advantage of the existing sorting.
Change-Id: I545867f85aa2c479d2d610024ebbe318144709c8
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
When we finally move RefDirectory to the new storage.file package,
its associated RefDirectoryUpdate will need visiblity to this
constructor in order to initialize itself. This is true of any
other repository implementation, so make it protected rather than
package level visible.
Change-Id: If838aec9baeb80ee2f12dcbca717657c725a9242
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Repository implementations outside of .lib need to be able to
create these events and deliver them to listening application code.
Expose and document the constructors so that they are visible when
we move FileRepository into storage.file.FileRepository.
Change-Id: I7fb6e8f4f5fdab683c5ebb5267673aa6d5b560bb
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Shawn O. Pearce
Jeff Schumacher
Christian Halstrick
Robin Rosenberg
Stefan Lay
Charley Wang
Matthias Sohn
Dmitry Neverov