@matheusbsbs / matheus-bagliano / commits / 04ae00062d

line-log: free diff queue when processing non-merge commits

When processing a non-merge commit, the line-level log first asks the tree-diff machinery whether any of the files in the given line ranges were modified between the current commit and its parent, and if some of them were, then it loads the contents of those files from both commits to see whether their line ranges were modified and/or need to be adjusted. Alas, it doesn't free() the diff queue holding the results of that query and the contents of those files once its done. This can add up to a substantial amount of leaked memory, especially when the file in question is big and is frequently modified: a user reported "Out of memory, malloc failed" errors with a 2MB text file that was modified ~2800 times [1] (I estimate the leak would use up almost 11GB memory in that case). Free that diff queue to plug this memory leak. However, instead of simply open-coding the necessary three lines, add them as a helper function to the diff API, because it will be useful elsewhere as well. [1] https://public-inbox.org/git/CAFOPqVXz2XwzX8vGU7wLuqb2ZuwTuOFAzBLRM_QPk+NJa=eC-g@mail.gmail.com/ Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>

SZEDER Gábor committed Nov 2, 2022 at 23:01 UTC 04ae00062d2ec301828e8df9931817be4b2f8653

3 files changed +9

diff.c

@@ -5773,6 +5773,13 @@ void diff_free_filepair(struct diff_filepair *p)

5773 free(p);

5774 }

5775

5776 +void diff_free_queue(struct diff_queue_struct *q)

5777 +{

5778 + for (int i = 0; i < q->nr; i++)

5779 + diff_free_filepair(q->queue[i]);

5780 + free(q->queue);

5781 +}

5782 +

5783 const char *diff_aligned_abbrev(const struct object_id *oid, int len)

5784 {

5785 int abblen;

diffcore.h

@@ -162,6 +162,7 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *,

162 struct diff_filespec *,

163 struct diff_filespec *);

164 void diff_q(struct diff_queue_struct *, struct diff_filepair *);

165 +void diff_free_queue(struct diff_queue_struct *q);

166

167 /* dir_rename_relevance: the reason we want rename information for a dir */

168 enum dir_rename_relevance {

line-log.c

@@ -1195,6 +1195,7 @@ static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *c

1195 if (parent)

1196 add_line_range(rev, parent, parent_range);

1197 free_line_log_data(parent_range);

1198 + diff_free_queue(&queue);

1199 return changed;

1200 }

1201