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Shawn O. Pearce ab697ff18b Create new RefList and RefMap utility types
These types can be used by RefDatabase implementations to manage
the collection.

A RefList stores items sorted by their name, and is an immutable
type using copy-on-write semantics to perform modifications to
the collection.  Binary search is used to locate an existing item
by name, or to locate the proper insertion position if an item does
not exist.

A RefMap can merge up to 3 RefList collections at once during its
entry iteration, allowing items in the resolved or loose RefList
to override items by the same name in the packed RefList.

The RefMap's goal is O(log N) lookup time, and O(N) iteration time,
which is suitable for returning from a RefDatabase.  By relying on
the immutable RefList we might be able to make map construction
nearly constant, making Repository.getAllRefs() an inexpensive
operation if the caches are current.  Since modification is not
common, changes require up to O(N + log N) time to copy the internal
list and collapse or expand the list's array.  As most changes
are made to the loose collection and not the packed collection,
in practice most changes would require less than the full O(N)
time, due to a significantly smaller N in the loose list.

Almost complete test coverage is included in the corresponding
unit tests.  A handful of methods on RefMap are not tested in this
change, as writing the proper test depends on a future refactoring
of how the Ref class represents symbolic reference names.

Change-Id: Ic2095274000336556f719edd75a5c5dd6dd1d857
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2010-01-22 16:27:30 -08:00
org.eclipse.jgit Create new RefList and RefMap utility types 2010-01-22 16:27:30 -08:00
org.eclipse.jgit-feature Partial revert "Switch build to Apache Felix maven-bundle-plugin" 2010-01-10 15:59:03 +01:00
org.eclipse.jgit.console Finish removing Apache Felix maven-bundle-plugin 2010-01-12 11:46:55 -08:00
org.eclipse.jgit.http.server server side: smart fetch over HTTP 2010-01-12 12:01:28 -08:00
org.eclipse.jgit.http.test Add JUnit tests for HTTP transport 2010-01-12 12:30:42 -08:00
org.eclipse.jgit.junit Add JUnit tests for HTTP transport 2010-01-12 12:30:42 -08:00
org.eclipse.jgit.pgm Finish removing Apache Felix maven-bundle-plugin 2010-01-12 11:46:55 -08:00
org.eclipse.jgit.test Create new RefList and RefMap utility types 2010-01-22 16:27:30 -08:00
org.eclipse.jgit.ui Finish removing Apache Felix maven-bundle-plugin 2010-01-12 11:46:55 -08:00
tools Switch build to Apache Felix maven-bundle-plugin 2009-12-28 15:59:14 -08:00
.gitattributes Initial JGit contribution to eclipse.org 2009-09-29 16:47:03 -07:00
LICENSE Initial JGit contribution to eclipse.org 2009-09-29 16:47:03 -07:00
README Initial JGit contribution to eclipse.org 2009-09-29 16:47:03 -07:00
SUBMITTING_PATCHES Correcting explanation of EDL 2009-10-28 14:12:07 +01:00
pom.xml Add JUnit tests for HTTP transport 2010-01-12 12:30:42 -08:00

README

            == Java GIT ==

This package is licensed under the BSD.

  org.eclipse.jgit/

    A pure Java library capable of being run standalone, with no
    additional support libraries.  Some JUnit tests are provided
    to exercise the library.  The library provides functions to
    read and write a GIT formatted repository.

    All portions of jgit are covered by the BSD.  Absolutely no GPL,
    LGPL or EPL contributions are accepted within this package.

  org.eclipse.jgit.test/
    Unit tests for org.eclipse.jgit and the same licensing rules.

            == WARNINGS / CAVEATS              ==

- Symbolic links are not supported because java does not support it.
  Such links could be damaged.

- Only the timestamp of the index is used by jgit check if  the index
  is dirty.

- Don't try the library with a JDK other than 1.6 (Java 6) unless you
  are prepared to investigate problems yourself. JDK 1.5.0_11 and later
  Java 5 versions *may* work. Earlier versions do not. JDK 1.4 is *not*
  supported. Apple's Java 1.5.0_07 is reported to work acceptably. We
  have no information about other vendors. Please report your findings
  if you try.

- CRLF conversion is never performed. On Windows you should thereforc
  make sure your projects and workspaces are configured to save files
  with Unix (LF) line endings.

            == Package Features                ==

  org.eclipse.jgit/

    * Read loose and packed commits, trees, blobs, including
      deltafied objects.

    * Read objects from shared repositories

    * Write loose commits, trees, blobs.

    * Write blobs from local files or Java InputStreams.

    * Read blobs as Java InputStreams.

    * Copy trees to local directory, or local directory to a tree.

    * Lazily loads objects as necessary.

    * Read and write .git/config files.

    * Create a new repository.

    * Read and write refs, including walking through symrefs.

    * Read, update and write the Git index.

    * Checkout in dirty working directory if trivial.

    * Walk the history from a given set of commits looking for commits
      introducing changes in files under a specified path.

    * Object transport
      Fetch via ssh, git, http, Amazon S3 and bundles.
      Push via ssh, git and Amazon S3. JGit does not yet deltify
      the pushed packs so they may be a lot larger than C Git packs.

  org.eclipse.jgit.pgm/

    * Assorted set of command line utilities. Mostly for ad-hoc testing of jgit
      log, glog, fetch etc.

            == Missing Features                ==

There are a lot of missing features. You need the real Git for this.
For some operations it may just be the preferred solution also. There
are not just a command line, there is e.g. git-gui that makes committing
partial files simple.

- Merging. 

- Repacking.

- Generate a GIT format patch.

- Apply a GIT format patch.

- Documentation. :-)

- gitattributes support
  In particular CRLF conversion is not implemented. Files are treated
  as byte sequences.

- submodule support
  Submodules are not supported or even recognized.

            == Support                         ==

  Post question, comments or patches to the git@vger.kernel.org mailing list.


            == Contributing                    ==

  See SUBMITTING_PATCHES in this directory. However, feedback and bug reports
  are also contributions.


            == About GIT                       ==

More information about GIT, its repository format, and the canonical
C based implementation can be obtained from the GIT websites:

  http://git.or.cz/
  http://www.kernel.org/pub/software/scm/git/
  http://www.kernel.org/pub/software/scm/git/docs/