fill_blame_origin() is a convenient place to store data that we will use
throughout the lifetime of a blame_origin. Some heuristics for
ignoring commits during a blame session can make use of this storage.
In particular, we will calculate a fingerprint for each line of a file
for blame_origins involved in an ignored commit.
In this commit, we only calculate the line_starts, reusing the existing
code from the scoreboard's line_starts. In an upcoming commit, we will
actually compute the fingerprints.
This feature will be used when we attempt to pass blame entries to
parents when we "ignore" a commit. Most uses of fill_blame_origin()
will not require this feature, hence the flag parameter. Multiple calls
to fill_blame_origin() are idempotent, and any of them can request the
creation of the fingerprints structure.
Suggested-by: Michael Platings <michael@xxxxxxxxx>
Signed-off-by: Barret Rhoden <brho@xxxxxxxxxx>
---
blame.c | 95 +++++++++++++++++++++++++++++++++++++++------------------
blame.h | 2 ++
2 files changed, 67 insertions(+), 30 deletions(-)
diff --git a/blame.c b/blame.c
index a98ae00e2cfc..a42dff80b1a5 100644
--- a/blame.c
+++ b/blame.c
@@ -311,12 +311,63 @@ static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
}
+static const char *get_next_line(const char *start, const char *end)
+{
+ const char *nl = memchr(start, '\n', end - start);
+
+ return nl ? nl + 1 : end;
+}
+
+static int find_line_starts(int **line_starts, const char *buf,
+ unsigned long len)
+{
+ const char *end = buf + len;
+ const char *p;
+ int *lineno;
+ int num = 0;
+
+ for (p = buf; p < end; p = get_next_line(p, end))
+ num++;
+
+ ALLOC_ARRAY(*line_starts, num + 1);
+ lineno = *line_starts;
+
+ for (p = buf; p < end; p = get_next_line(p, end))
+ *lineno++ = p - buf;
+
+ *lineno = len;
+
+ return num;
+}
+
+static void fill_origin_fingerprints(struct blame_origin *o, mmfile_t *file)
+{
+ int *line_starts;
+
+ if (o->fingerprints)
+ return;
+ o->num_lines = find_line_starts(&line_starts, o->file.ptr,
+ o->file.size);
+ /* TODO: Will fill in fingerprints in a future commit */
+ o->fingerprints = xcalloc(sizeof(struct fingerprint), o->num_lines);
+ free(line_starts);
+}
+
+static void drop_origin_fingerprints(struct blame_origin *o)
+{
+ if (o->fingerprints) {
+ o->num_lines = 0;
+ FREE_AND_NULL(o->fingerprints);
+ }
+}
+
/*
* Given an origin, prepare mmfile_t structure to be used by the
* diff machinery
*/
static void fill_origin_blob(struct diff_options *opt,
- struct blame_origin *o, mmfile_t *file, int *num_read_blob)
+ struct blame_origin *o, mmfile_t *file,
+ int *num_read_blob, int fill_fingerprints)
{
if (!o->file.ptr) {
enum object_type type;
@@ -340,11 +391,14 @@ static void fill_origin_blob(struct diff_options *opt,
}
else
*file = o->file;
+ if (fill_fingerprints)
+ fill_origin_fingerprints(o, file);
}
static void drop_origin_blob(struct blame_origin *o)
{
FREE_AND_NULL(o->file.ptr);
+ drop_origin_fingerprints(o);
}
/*
@@ -1136,8 +1190,10 @@ static void pass_blame_to_parent(struct blame_scoreboard *sb,
d.ignore_diffs = ignore_diffs;
d.dstq = &newdest; d.srcq = &target->suspects;
- fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
- fill_origin_blob(&sb->revs->diffopt, target, &file_o, &sb->num_read_blob);
+ fill_origin_blob(&sb->revs->diffopt, parent, &file_p,
+ &sb->num_read_blob, ignore_diffs);
+ fill_origin_blob(&sb->revs->diffopt, target, &file_o,
+ &sb->num_read_blob, ignore_diffs);
sb->num_get_patch++;
if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
@@ -1348,7 +1404,8 @@ static void find_move_in_parent(struct blame_scoreboard *sb,
if (!unblamed)
return; /* nothing remains for this target */
- fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
+ fill_origin_blob(&sb->revs->diffopt, parent, &file_p,
+ &sb->num_read_blob, 0);
if (!file_p.ptr)
return;
@@ -1477,7 +1534,8 @@ static void find_copy_in_parent(struct blame_scoreboard *sb,
norigin = get_origin(parent, p->one->path);
oidcpy(&norigin->blob_oid, &p->one->oid);
norigin->mode = p->one->mode;
- fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, &sb->num_read_blob);
+ fill_origin_blob(&sb->revs->diffopt, norigin, &file_p,
+ &sb->num_read_blob, 0);
if (!file_p.ptr)
continue;
@@ -1816,37 +1874,14 @@ void assign_blame(struct blame_scoreboard *sb, int opt)
}
}
-static const char *get_next_line(const char *start, const char *end)
-{
- const char *nl = memchr(start, '\n', end - start);
- return nl ? nl + 1 : end;
-}
-
/*
* To allow quick access to the contents of nth line in the
* final image, prepare an index in the scoreboard.
*/
static int prepare_lines(struct blame_scoreboard *sb)
{
- const char *buf = sb->final_buf;
- unsigned long len = sb->final_buf_size;
- const char *end = buf + len;
- const char *p;
- int *lineno;
- int num = 0;
-
- for (p = buf; p < end; p = get_next_line(p, end))
- num++;
-
- ALLOC_ARRAY(sb->lineno, num + 1);
- lineno = sb->lineno;
-
- for (p = buf; p < end; p = get_next_line(p, end))
- *lineno++ = p - buf;
-
- *lineno = len;
-
- sb->num_lines = num;
+ sb->num_lines = find_line_starts(&sb->lineno, sb->final_buf,
+ sb->final_buf_size);
return sb->num_lines;
}
diff --git a/blame.h b/blame.h
index 53df8b4c5b3f..5dd877bb78fc 100644
--- a/blame.h
+++ b/blame.h
@@ -51,6 +51,8 @@ struct blame_origin {
*/
struct blame_entry *suspects;
mmfile_t file;
+ int num_lines;
+ void *fingerprints;
struct object_id blob_oid;
unsigned mode;
/* guilty gets set when shipping any suspects to the final
--
2.21.0.392.gf8f6787159e-goog
