Mercurial > hg-stable
changeset 5452:82b4ff3abbcd
bdiff: tweaks for large files
- adjust the common line threshold to .1%
this speeds up a delta of 7M lines of source from 10m to 40s
- adjust the scaling of the hash array down a bit as it was raising the peak
memory usage significantly
| author | Matt Mackall <mpm@selenic.com> |
|---|---|
| date | Thu, 11 Oct 2007 00:46:56 -0500 |
| parents | 0a43875677b1 |
| children | 9d77f2b47eb7 |
| files | mercurial/bdiff.c |
| diffstat | 1 files changed, 7 insertions(+), 7 deletions(-) [+] |
line wrap: on
line diff
--- a/mercurial/bdiff.c Thu Oct 11 00:46:54 2007 -0500 +++ b/mercurial/bdiff.c Thu Oct 11 00:46:56 2007 -0500 @@ -106,19 +106,19 @@ static int equatelines(struct line *a, int an, struct line *b, int bn) { - int i, j, buckets = 1, t; - int scale = 32; - struct pos *h; + int i, j, buckets = 1, t, scale; + struct pos *h = NULL; /* build a hash table of the next highest power of 2 */ while (buckets < bn + 1) buckets *= 2; /* try to allocate a large hash table to avoid collisions */ - do { - scale /= 2; + for (scale = 4; scale; scale /= 2) { h = (struct pos *)malloc(scale * buckets * sizeof(struct pos)); - } while (!h && scale != 1); + if (h) + break; + } if (!h) return 0; @@ -147,7 +147,7 @@ } /* compute popularity threshold */ - t = (bn >= 200) ? bn / 100 : bn + 1; + t = (bn >= 4000) ? bn / 1000 : bn + 1; /* match items in a to their equivalence class in b */ for (i = 0; i < an; i++) {