Class BaseDirCacheEditor

java.lang.Object
org.eclipse.jgit.dircache.BaseDirCacheEditor
Direct Known Subclasses:
DirCacheBuilder, DirCacheEditor

abstract class BaseDirCacheEditor extends Object
Generic update/editing support for DirCache.

The different update strategies extend this class to provide their own unique services to applications.

  • Field Details

    • cache

      protected DirCache cache
      The cache instance this editor updates during finish().
    • entries

      protected DirCacheEntry[] entries
      Entry table this builder will eventually replace into cache.

      Use fastAdd(DirCacheEntry) or fastKeep(int, int) to make additions to this table. The table is automatically expanded if it is too small for a new addition.

      Typically the entries in here are sorted by their path names, just like they are in the DirCache instance.

    • entryCnt

      protected int entryCnt
      Total number of valid entries in entries.
  • Constructor Details

    • BaseDirCacheEditor

      protected BaseDirCacheEditor(DirCache dc, int ecnt)
      Construct a new editor.
      Parameters:
      dc - the cache this editor will eventually update.
      ecnt - estimated number of entries the editor will have upon completion. This sizes the initial entry table.
  • Method Details

    • getDirCache

      public DirCache getDirCache()
      Get the DirCache
      Returns:
      the cache we will update on finish().
    • fastAdd

      protected void fastAdd(DirCacheEntry newEntry)
      Append one entry into the resulting entry list.

      The entry is placed at the end of the entry list. The caller is responsible for making sure the final table is correctly sorted.

      The entries table is automatically expanded if there is insufficient space for the new addition.

      Parameters:
      newEntry - the new entry to add.
    • fastKeep

      protected void fastKeep(int pos, int cnt)
      Add a range of existing entries from the destination cache.

      The entries are placed at the end of the entry list, preserving their current order. The caller is responsible for making sure the final table is correctly sorted.

      This method copies from the destination cache, which has not yet been updated with this editor's new table. So all offsets into the destination cache are not affected by any updates that may be currently taking place in this editor.

      The entries table is automatically expanded if there is insufficient space for the new additions.

      Parameters:
      pos - first entry to copy from the destination cache.
      cnt - number of entries to copy.
    • finish

      public abstract void finish()
      Finish this builder and update the destination DirCache.

      When this method completes this builder instance is no longer usable by the calling application. A new builder must be created to make additional changes to the index entries.

      After completion the DirCache returned by getDirCache() will contain all modifications.

      Note to implementors: Make sure entries is fully sorted then invoke replace() to update the DirCache with the new table.

    • replace

      protected void replace()
      Update the DirCache with the contents of entries.

      This method should be invoked only during an implementation of finish(), and only after entries is sorted.

    • checkNameConflicts

      private void checkNameConflicts()
    • lastSlash

      private static int lastSlash(byte[] path)
    • nextSlash

      private static int nextSlash(byte[] b, int p)
    • startsWith

      private static boolean startsWith(byte[] a, byte[] b, int n)
    • commit

      public boolean commit() throws IOException
      Finish, write, commit this change, and release the index lock.

      If this method fails (returns false) the lock is still released.

      This is a utility method for applications as the finish-write-commit pattern is very common after using a builder to update entries.

      Returns:
      true if the commit was successful and the file contains the new data; false if the commit failed and the file remains with the old data.
      Throws:
      IllegalStateException - the lock is not held.
      IOException - the output file could not be created. The caller no longer holds the lock.