mirrors/jgit - jgit - source @ dussan.org

1927 Commits

Tree: 95d311f888

Author	SHA1	Message	Date
Robin Rosenberg	95d311f888	Move JGitText to an internal package Change-Id: I763590a45d75f00a09097ab6f89581a3bbd3c797	12 years ago
Shawn O. Pearce	b88b693a3d	Fix broken HistogramDiff HistogramDiff failed on cases where the initial element for the LCS was actually very common (e.g. has 20 occurrences), and the first element of the inserted region after the LCS was also common but had fewer occurrences (e.g. 10), while the LCS also contained a unique element (1 occurrence). This happens often in Java source code. The initial element for the LCS might be the empty line ("\n"), and the inserted but common element might be "\t/\n", with the LCS being a large span of lines that contains unique method declarations. Even though "/" occurs less often than the empty line its not a better LCS if the LCS we already have contains a unique element. The logic in HistogramDiff would normally have worked fine, except I tried to optimize scanning of B by making tryLongestCommonSequence return the end of the region when there are matching elements found in A. This allows us to skip over the current LCS region, as it has already been examined, but caused us to fail to identify an element that had a lower occurrence count within the region. The solution used here is to trade space-for-time by keeping a table of A positions to their occurrence counts. This allows the matching logic to always use the smallest count for this region, even if the smallest count doesn't appear on the initial element. The new unit test testEdit_LcsContainsUnique() verifies this new behavior works as expected. Bug: 328895 Change-Id: Id170783b891f645b6a8cf6f133c6682b8de40aaf Signed-off-by: Shawn O. Pearce <spearce@spearce.org>	13 years ago
Shawn O. Pearce	33ae28b482	Correct typo in HistogramDiffIndex Javadoc Change-Id: I8bd2e81fcc14aa86919c504f1d0001944dea50b2 Signed-off-by: Shawn O. Pearce <spearce@spearce.org>	13 years ago
Shawn O. Pearce	b533a72934	Implement HistogramDiff HistogramDiff is an alternative implementation of patience diff, performing a search over all matching locations and picking the longest common subsequence that has the lowest occurrence count. If there are unique common elements, its behavior is identical to that of patience diff. Actual performance on real-world source files usually beats MyersDiff, sometimes by a factor of 3, especially for complex comparators that ignore whitespace. Change-Id: I1806cd708087e36d144fb824a0e5ab7cdd579d73 Signed-off-by: Shawn O. Pearce <spearce@spearce.org>	13 years ago

4 Commits (95d311f8886f42f31a4475f84aa23c6345ab7059)