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git/line-log.c
Derrick Stolee f32dde8c12 line-log: integrate with changed-path Bloom filters 
The previous changes to the line-log machinery focused on making the
first result appear faster. This was achieved by no longer walking the
entire commit history before returning the early results. There is still
another way to improve the performance: walk most commits much faster.
Let's use the changed-path Bloom filters to reduce time spent computing
diffs.

Since the line-log computation requires opening blobs and checking the
content-diff, there is still a lot of necessary computation that cannot
be replaced with changed-path Bloom filters. The part that we can reduce
is most effective when checking the history of a file that is deep in
several directories and those directories are modified frequently. In
this case, the computation to check if a commit is TREESAME to its first
parent takes a large fraction of the time. That is ripe for improvement
with changed-path Bloom filters.

We must ensure that prepare_to_use_bloom_filters() is called in
revision.c so that the bloom_filter_settings are loaded into the struct
rev_info from the commit-graph. Of course, some cases are still
forbidden, but in the line-log case the pathspec is provided in a
different way than normal.

Since multiple paths and segments could be requested, we compute the
struct bloom_key data dynamically during the commit walk. This could
likely be improved, but adds code complexity that is not valuable at
this time.

There are two cases to care about: merge commits and "ordinary" commits.
Merge commits have multiple parents, but if we are TREESAME to our first
parent in every range, then pass the blame for all ranges to the first
parent. Ordinary commits have the same condition, but each is done
slightly differently in the process_ranges_[merge|ordinary]_commit()
methods. By checking if the changed-path Bloom filter can guarantee
TREESAME, we can avoid that tree-diff cost. If the filter says "probably
changed", then we need to run the tree-diff and then the blob-diff if
there was a real edit.

The Linux kernel repository is a good testing ground for the performance
improvements claimed here. There are two different cases to test. The
first is the "entire history" case, where we output the entire history
to /dev/null to see how long it would take to compute the full line-log
history. The second is the "first result" case, where we find how long
it takes to show the first value, which is an indicator of how quickly a
user would see responses when waiting at a terminal.

To test, I selected the paths that were changed most frequently in the
top 10,000 commits using this command (stolen from StackOverflow [1]):

	git log --pretty=format: --name-only -n 10000 | sort | \
		uniq -c | sort -rg | head -10

which results in

    121 MAINTAINERS
     63 fs/namei.c
     60 arch/x86/kvm/cpuid.c
     59 fs/io_uring.c
     58 arch/x86/kvm/vmx/vmx.c
     51 arch/x86/kvm/x86.c
     45 arch/x86/kvm/svm.c
     42 fs/btrfs/disk-io.c
     42 Documentation/scsi/index.rst

(along with a bogus first result). It appears that the path
arch/x86/kvm/svm.c was renamed, so we ignore that entry. This leaves the
following results for the real command time:

|                              | Entire History  | First Result    |
| Path                         | Before | After  | Before | After  |
|------------------------------|--------|--------|--------|--------|
| MAINTAINERS                  | 4.26 s | 3.87 s | 0.41 s | 0.39 s |
| fs/namei.c                   | 1.99 s | 0.99 s | 0.42 s | 0.21 s |
| arch/x86/kvm/cpuid.c         | 5.28 s | 1.12 s | 0.16 s | 0.09 s |
| fs/io_uring.c                | 4.34 s | 0.99 s | 0.94 s | 0.27 s |
| arch/x86/kvm/vmx/vmx.c       | 5.01 s | 1.34 s | 0.21 s | 0.12 s |
| arch/x86/kvm/x86.c           | 2.24 s | 1.18 s | 0.21 s | 0.14 s |
| fs/btrfs/disk-io.c           | 1.82 s | 1.01 s | 0.06 s | 0.05 s |
| Documentation/scsi/index.rst | 3.30 s | 0.89 s | 1.46 s | 0.03 s |

It is worth noting that the least speedup comes for the MAINTAINERS file
which is

 * edited frequently,
 * low in the directory heirarchy, and
 * quite a large file.

All of those points lead to spending more time doing the blob diff and
less time doing the tree diff. Still, we see some improvement in that
case and significant improvement in other cases. A 2-4x speedup is
likely the more typical case as opposed to the small 5% change for that
file.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-11 09:33:56 -07:00

1327 lines
33 KiB
C
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#include "git-compat-util.h"
#include "line-range.h"
#include "cache.h"
#include "tag.h"
#include "blob.h"
#include "tree.h"
#include "diff.h"
#include "commit.h"
#include "decorate.h"
#include "revision.h"
#include "xdiff-interface.h"
#include "strbuf.h"
#include "log-tree.h"
#include "graph.h"
#include "userdiff.h"
#include "line-log.h"
#include "argv-array.h"
#include "bloom.h"
static void range_set_grow(struct range_set *rs, size_t extra)
{
ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
}
/* Either initialization would be fine */
#define RANGE_SET_INIT {0}
void range_set_init(struct range_set *rs, size_t prealloc)
{
rs->alloc = rs->nr = 0;
rs->ranges = NULL;
if (prealloc)
range_set_grow(rs, prealloc);
}
void range_set_release(struct range_set *rs)
{
FREE_AND_NULL(rs->ranges);
rs->alloc = rs->nr = 0;
}
/* dst must be uninitialized! */
static void range_set_copy(struct range_set *dst, struct range_set *src)
{
range_set_init(dst, src->nr);
COPY_ARRAY(dst->ranges, src->ranges, src->nr);
dst->nr = src->nr;
}
static void range_set_move(struct range_set *dst, struct range_set *src)
{
range_set_release(dst);
dst->ranges = src->ranges;
dst->nr = src->nr;
dst->alloc = src->alloc;
src->ranges = NULL;
src->alloc = src->nr = 0;
}
/* tack on a _new_ range _at the end_ */
void range_set_append_unsafe(struct range_set *rs, long a, long b)
{
assert(a <= b);
range_set_grow(rs, 1);
rs->ranges[rs->nr].start = a;
rs->ranges[rs->nr].end = b;
rs->nr++;
}
void range_set_append(struct range_set *rs, long a, long b)
{
assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
range_set_append_unsafe(rs, a, b);
}
static int range_cmp(const void *_r, const void *_s)
{
const struct range *r = _r;
const struct range *s = _s;
/* this could be simply 'return r.start-s.start', but for the types */
if (r->start == s->start)
return 0;
if (r->start < s->start)
return -1;
return 1;
}
/*
* Check that the ranges are non-empty, sorted and non-overlapping
*/
static void range_set_check_invariants(struct range_set *rs)
{
unsigned int i;
if (!rs)
return;
if (rs->nr)
assert(rs->ranges[0].start < rs->ranges[0].end);
for (i = 1; i < rs->nr; i++) {
assert(rs->ranges[i-1].end < rs->ranges[i].start);
assert(rs->ranges[i].start < rs->ranges[i].end);
}
}
/*
* In-place pass of sorting and merging the ranges in the range set,
* to establish the invariants when we get the ranges from the user
*/
void sort_and_merge_range_set(struct range_set *rs)
{
unsigned int i;
unsigned int o = 0; /* output cursor */
QSORT(rs->ranges, rs->nr, range_cmp);
for (i = 0; i < rs->nr; i++) {
if (rs->ranges[i].start == rs->ranges[i].end)
continue;
if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
if (rs->ranges[o-1].end < rs->ranges[i].end)
rs->ranges[o-1].end = rs->ranges[i].end;
} else {
rs->ranges[o].start = rs->ranges[i].start;
rs->ranges[o].end = rs->ranges[i].end;
o++;
}
}
assert(o <= rs->nr);
rs->nr = o;
range_set_check_invariants(rs);
}
/*
* Union of range sets (i.e., sets of line numbers). Used to merge
* them when searches meet at a common ancestor.
*
* This is also where the ranges are consolidated into canonical form:
* overlapping and adjacent ranges are merged, and empty ranges are
* removed.
*/
static void range_set_union(struct range_set *out,
struct range_set *a, struct range_set *b)
{
unsigned int i = 0, j = 0;
struct range *ra = a->ranges;
struct range *rb = b->ranges;
/* cannot make an alias of out->ranges: it may change during grow */
assert(out->nr == 0);
while (i < a->nr || j < b->nr) {
struct range *new_range;
if (i < a->nr && j < b->nr) {
if (ra[i].start < rb[j].start)
new_range = &ra[i++];
else if (ra[i].start > rb[j].start)
new_range = &rb[j++];
else if (ra[i].end < rb[j].end)
new_range = &ra[i++];
else
new_range = &rb[j++];
} else if (i < a->nr) /* b exhausted */
new_range = &ra[i++];
else /* a exhausted */
new_range = &rb[j++];
if (new_range->start == new_range->end)
; /* empty range */
else if (!out->nr || out->ranges[out->nr-1].end < new_range->start) {
range_set_grow(out, 1);
out->ranges[out->nr].start = new_range->start;
out->ranges[out->nr].end = new_range->end;
out->nr++;
} else if (out->ranges[out->nr-1].end < new_range->end) {
out->ranges[out->nr-1].end = new_range->end;
}
}
}
/*
* Difference of range sets (out = a \ b). Pass the "interesting"
* ranges as 'a' and the target side of the diff as 'b': it removes
* the ranges for which the commit is responsible.
*/
static void range_set_difference(struct range_set *out,
struct range_set *a, struct range_set *b)
{
unsigned int i, j = 0;
for (i = 0; i < a->nr; i++) {
long start = a->ranges[i].start;
long end = a->ranges[i].end;
while (start < end) {
while (j < b->nr && start >= b->ranges[j].end)
/*
* a: |-------
* b: ------|
*/
j++;
if (j >= b->nr || end < b->ranges[j].start) {
/*
* b exhausted, or
* a: ----|
* b: |----
*/
range_set_append(out, start, end);
break;
}
if (start >= b->ranges[j].start) {
/*
* a: |--????
* b: |------|
*/
start = b->ranges[j].end;
} else if (end > b->ranges[j].start) {
/*
* a: |-----|
* b: |--?????
*/
if (start < b->ranges[j].start)
range_set_append(out, start, b->ranges[j].start);
start = b->ranges[j].end;
}
}
}
}
static void diff_ranges_init(struct diff_ranges *diff)
{
range_set_init(&diff->parent, 0);
range_set_init(&diff->target, 0);
}
static void diff_ranges_release(struct diff_ranges *diff)
{
range_set_release(&diff->parent);
range_set_release(&diff->target);
}
static void line_log_data_init(struct line_log_data *r)
{
memset(r, 0, sizeof(struct line_log_data));
range_set_init(&r->ranges, 0);
}
static void line_log_data_clear(struct line_log_data *r)
{
range_set_release(&r->ranges);
if (r->pair)
diff_free_filepair(r->pair);
}
static void free_line_log_data(struct line_log_data *r)
{
while (r) {
struct line_log_data *next = r->next;
line_log_data_clear(r);
free(r);
r = next;
}
}
static struct line_log_data *
search_line_log_data(struct line_log_data *list, const char *path,
struct line_log_data **insertion_point)
{
struct line_log_data *p = list;
if (insertion_point)
*insertion_point = NULL;
while (p) {
int cmp = strcmp(p->path, path);
if (!cmp)
return p;
if (insertion_point && cmp < 0)
*insertion_point = p;
p = p->next;
}
return NULL;
}
/*
* Note: takes ownership of 'path', which happens to be what the only
* caller needs.
*/
static void line_log_data_insert(struct line_log_data **list,
char *path,
long begin, long end)
{
struct line_log_data *ip;
struct line_log_data *p = search_line_log_data(*list, path, &ip);
if (p) {
range_set_append_unsafe(&p->ranges, begin, end);
free(path);
return;
}
p = xcalloc(1, sizeof(struct line_log_data));
p->path = path;
range_set_append(&p->ranges, begin, end);
if (ip) {
p->next = ip->next;
ip->next = p;
} else {
p->next = *list;
*list = p;
}
}
struct collect_diff_cbdata {
struct diff_ranges *diff;
};
static int collect_diff_cb(long start_a, long count_a,
long start_b, long count_b,
void *data)
{
struct collect_diff_cbdata *d = data;
if (count_a >= 0)
range_set_append(&d->diff->parent, start_a, start_a + count_a);
if (count_b >= 0)
range_set_append(&d->diff->target, start_b, start_b + count_b);
return 0;
}
static int collect_diff(mmfile_t *parent, mmfile_t *target, struct diff_ranges *out)
{
struct collect_diff_cbdata cbdata = {NULL};
xpparam_t xpp;
xdemitconf_t xecfg;
xdemitcb_t ecb;
memset(&xpp, 0, sizeof(xpp));
memset(&xecfg, 0, sizeof(xecfg));
xecfg.ctxlen = xecfg.interhunkctxlen = 0;
cbdata.diff = out;
xecfg.hunk_func = collect_diff_cb;
memset(&ecb, 0, sizeof(ecb));
ecb.priv = &cbdata;
return xdi_diff(parent, target, &xpp, &xecfg, &ecb);
}
/*
* These are handy for debugging. Removing them with #if 0 silences
* the "unused function" warning.
*/
#if 0
static void dump_range_set(struct range_set *rs, const char *desc)
{
int i;
printf("range set %s (%d items):\n", desc, rs->nr);
for (i = 0; i < rs->nr; i++)
printf("\t[%ld,%ld]\n", rs->ranges[i].start, rs->ranges[i].end);
}
static void dump_line_log_data(struct line_log_data *r)
{
char buf[4096];
while (r) {
snprintf(buf, 4096, "file %s\n", r->path);
dump_range_set(&r->ranges, buf);
r = r->next;
}
}
static void dump_diff_ranges(struct diff_ranges *diff, const char *desc)
{
int i;
assert(diff->parent.nr == diff->target.nr);
printf("diff ranges %s (%d items):\n", desc, diff->parent.nr);
printf("\tparent\ttarget\n");
for (i = 0; i < diff->parent.nr; i++) {
printf("\t[%ld,%ld]\t[%ld,%ld]\n",
diff->parent.ranges[i].start,
diff->parent.ranges[i].end,
diff->target.ranges[i].start,
diff->target.ranges[i].end);
}
}
#endif
static int ranges_overlap(struct range *a, struct range *b)
{
return !(a->end <= b->start || b->end <= a->start);
}
/*
* Given a diff and the set of interesting ranges, determine all hunks
* of the diff which touch (overlap) at least one of the interesting
* ranges in the target.
*/
static void diff_ranges_filter_touched(struct diff_ranges *out,
struct diff_ranges *diff,
struct range_set *rs)
{
unsigned int i, j = 0;
assert(out->target.nr == 0);
for (i = 0; i < diff->target.nr; i++) {
while (diff->target.ranges[i].start > rs->ranges[j].end) {
j++;
if (j == rs->nr)
return;
}
if (ranges_overlap(&diff->target.ranges[i], &rs->ranges[j])) {
range_set_append(&out->parent,
diff->parent.ranges[i].start,
diff->parent.ranges[i].end);
range_set_append(&out->target,
diff->target.ranges[i].start,
diff->target.ranges[i].end);
}
}
}
/*
* Adjust the line counts in 'rs' to account for the lines
* added/removed in the diff.
*/
static void range_set_shift_diff(struct range_set *out,
struct range_set *rs,
struct diff_ranges *diff)
{
unsigned int i, j = 0;
long offset = 0;
struct range *src = rs->ranges;
struct range *target = diff->target.ranges;
struct range *parent = diff->parent.ranges;
for (i = 0; i < rs->nr; i++) {
while (j < diff->target.nr && src[i].start >= target[j].start) {
offset += (parent[j].end-parent[j].start)
- (target[j].end-target[j].start);
j++;
}
range_set_append(out, src[i].start+offset, src[i].end+offset);
}
}
/*
* Given a diff and the set of interesting ranges, map the ranges
* across the diff. That is: observe that the target commit takes
* blame for all the + (target-side) ranges. So for every pair of
* ranges in the diff that was touched, we remove the latter and add
* its parent side.
*/
static void range_set_map_across_diff(struct range_set *out,
struct range_set *rs,
struct diff_ranges *diff,
struct diff_ranges **touched_out)
{
struct diff_ranges *touched = xmalloc(sizeof(*touched));
struct range_set tmp1 = RANGE_SET_INIT;
struct range_set tmp2 = RANGE_SET_INIT;
diff_ranges_init(touched);
diff_ranges_filter_touched(touched, diff, rs);
range_set_difference(&tmp1, rs, &touched->target);
range_set_shift_diff(&tmp2, &tmp1, diff);
range_set_union(out, &tmp2, &touched->parent);
range_set_release(&tmp1);
range_set_release(&tmp2);
*touched_out = touched;
}
static struct commit *check_single_commit(struct rev_info *revs)
{
struct object *commit = NULL;
int found = -1;
int i;
for (i = 0; i < revs->pending.nr; i++) {
struct object *obj = revs->pending.objects[i].item;
if (obj->flags & UNINTERESTING)
continue;
obj = deref_tag(revs->repo, obj, NULL, 0);
if (obj->type != OBJ_COMMIT)
die("Non commit %s?", revs->pending.objects[i].name);
if (commit)
die("More than one commit to dig from: %s and %s?",
revs->pending.objects[i].name,
revs->pending.objects[found].name);
commit = obj;
found = i;
}
if (!commit)
die("No commit specified?");
return (struct commit *) commit;
}
static void fill_blob_sha1(struct repository *r, struct commit *commit,
struct diff_filespec *spec)
{
unsigned short mode;
struct object_id oid;
if (get_tree_entry(r, &commit->object.oid, spec->path, &oid, &mode))
die("There is no path %s in the commit", spec->path);
fill_filespec(spec, &oid, 1, mode);
return;
}
static void fill_line_ends(struct repository *r,
struct diff_filespec *spec,
long *lines,
unsigned long **line_ends)
{
int num = 0, size = 50;
long cur = 0;
unsigned long *ends = NULL;
char *data = NULL;
if (diff_populate_filespec(r, spec, 0))
die("Cannot read blob %s", oid_to_hex(&spec->oid));
ALLOC_ARRAY(ends, size);
ends[cur++] = 0;
data = spec->data;
while (num < spec->size) {
if (data[num] == '\n' || num == spec->size - 1) {
ALLOC_GROW(ends, (cur + 1), size);
ends[cur++] = num;
}
num++;
}
/* shrink the array to fit the elements */
REALLOC_ARRAY(ends, cur);
*lines = cur-1;
*line_ends = ends;
}
struct nth_line_cb {
struct diff_filespec *spec;
long lines;
unsigned long *line_ends;
};
static const char *nth_line(void *data, long line)
{
struct nth_line_cb *d = data;
assert(d && line <= d->lines);
assert(d->spec && d->spec->data);
if (line == 0)
return (char *)d->spec->data;
else
return (char *)d->spec->data + d->line_ends[line] + 1;
}
static struct line_log_data *
parse_lines(struct repository *r, struct commit *commit,
const char *prefix, struct string_list *args)
{
long lines = 0;
unsigned long *ends = NULL;
struct nth_line_cb cb_data;
struct string_list_item *item;
struct line_log_data *ranges = NULL;
struct line_log_data *p;
for_each_string_list_item(item, args) {
const char *name_part, *range_part;
char *full_name;
struct diff_filespec *spec;
long begin = 0, end = 0;
long anchor;
name_part = skip_range_arg(item->string, r->index);
if (!name_part || *name_part != ':' || !name_part[1])
die("-L argument not 'start,end:file' or ':funcname:file': %s",
item->string);
range_part = xstrndup(item->string, name_part - item->string);
name_part++;
full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
name_part);
spec = alloc_filespec(full_name);
fill_blob_sha1(r, commit, spec);
fill_line_ends(r, spec, &lines, &ends);
cb_data.spec = spec;
cb_data.lines = lines;
cb_data.line_ends = ends;
p = search_line_log_data(ranges, full_name, NULL);
if (p && p->ranges.nr)
anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
else
anchor = 1;
if (parse_range_arg(range_part, nth_line, &cb_data,
lines, anchor, &begin, &end,
full_name, r->index))
die("malformed -L argument '%s'", range_part);
if ((!lines && (begin || end)) || lines < begin)
die("file %s has only %lu lines", name_part, lines);
if (begin < 1)
begin = 1;
if (end < 1 || lines < end)
end = lines;
begin--;
line_log_data_insert(&ranges, full_name, begin, end);
free_filespec(spec);
FREE_AND_NULL(ends);
}
for (p = ranges; p; p = p->next)
sort_and_merge_range_set(&p->ranges);
return ranges;
}
static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
{
struct line_log_data *ret = xmalloc(sizeof(*ret));
assert(r);
line_log_data_init(ret);
range_set_copy(&ret->ranges, &r->ranges);
ret->path = xstrdup(r->path);
return ret;
}
static struct line_log_data *
line_log_data_copy(struct line_log_data *r)
{
struct line_log_data *ret = NULL;
struct line_log_data *tmp = NULL, *prev = NULL;
assert(r);
ret = tmp = prev = line_log_data_copy_one(r);
r = r->next;
while (r) {
tmp = line_log_data_copy_one(r);
prev->next = tmp;
prev = tmp;
r = r->next;
}
return ret;
}
/* merge two range sets across files */
static struct line_log_data *line_log_data_merge(struct line_log_data *a,
struct line_log_data *b)
{
struct line_log_data *head = NULL, **pp = &head;
while (a || b) {
struct line_log_data *src;
struct line_log_data *src2 = NULL;
struct line_log_data *d;
int cmp;
if (!a)
cmp = 1;
else if (!b)
cmp = -1;
else
cmp = strcmp(a->path, b->path);
if (cmp < 0) {
src = a;
a = a->next;
} else if (cmp == 0) {
src = a;
a = a->next;
src2 = b;
b = b->next;
} else {
src = b;
b = b->next;
}
d = xmalloc(sizeof(struct line_log_data));
line_log_data_init(d);
d->path = xstrdup(src->path);
*pp = d;
pp = &d->next;
if (src2)
range_set_union(&d->ranges, &src->ranges, &src2->ranges);
else
range_set_copy(&d->ranges, &src->ranges);
}
return head;
}
static void add_line_range(struct rev_info *revs, struct commit *commit,
struct line_log_data *range)
{
struct line_log_data *old_line = NULL;
struct line_log_data *new_line = NULL;
old_line = lookup_decoration(&revs->line_log_data, &commit->object);
if (old_line && range) {
new_line = line_log_data_merge(old_line, range);
free_line_log_data(old_line);
} else if (range)
new_line = line_log_data_copy(range);
if (new_line)
add_decoration(&revs->line_log_data, &commit->object, new_line);
}
static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
{
struct line_log_data *r;
r = lookup_decoration(&revs->line_log_data, &commit->object);
if (!r)
return;
free_line_log_data(r);
add_decoration(&revs->line_log_data, &commit->object, NULL);
}
static struct line_log_data *lookup_line_range(struct rev_info *revs,
struct commit *commit)
{
struct line_log_data *ret = NULL;
struct line_log_data *d;
ret = lookup_decoration(&revs->line_log_data, &commit->object);
for (d = ret; d; d = d->next)
range_set_check_invariants(&d->ranges);
return ret;
}
static int same_paths_in_pathspec_and_range(struct pathspec *pathspec,
struct line_log_data *range)
{
int i;
struct line_log_data *r;
for (i = 0, r = range; i < pathspec->nr && r; i++, r = r->next)
if (strcmp(pathspec->items[i].match, r->path))
return 0;
if (i < pathspec->nr || r)
/* different number of pathspec items and ranges */
return 0;
return 1;
}
static void parse_pathspec_from_ranges(struct pathspec *pathspec,
struct line_log_data *range)
{
struct line_log_data *r;
struct argv_array array = ARGV_ARRAY_INIT;
const char **paths;
for (r = range; r; r = r->next)
argv_array_push(&array, r->path);
paths = argv_array_detach(&array);
parse_pathspec(pathspec, 0, PATHSPEC_PREFER_FULL, "", paths);
/* strings are now owned by pathspec */
free(paths);
}
void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
{
struct commit *commit = NULL;
struct line_log_data *range;
commit = check_single_commit(rev);
range = parse_lines(rev->diffopt.repo, commit, prefix, args);
add_line_range(rev, commit, range);
parse_pathspec_from_ranges(&rev->diffopt.pathspec, range);
}
static void move_diff_queue(struct diff_queue_struct *dst,
struct diff_queue_struct *src)
{
assert(src != dst);
memcpy(dst, src, sizeof(struct diff_queue_struct));
DIFF_QUEUE_CLEAR(src);
}
static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
{
int i;
struct diff_queue_struct outq;
DIFF_QUEUE_CLEAR(&outq);
for (i = 0; i < diff_queued_diff.nr; i++) {
struct diff_filepair *p = diff_queued_diff.queue[i];
struct line_log_data *rg = NULL;
if (!DIFF_FILE_VALID(p->two)) {
if (keep_deletions)
diff_q(&outq, p);
else
diff_free_filepair(p);
continue;
}
for (rg = range; rg; rg = rg->next) {
if (!strcmp(rg->path, p->two->path))
break;
}
if (rg)
diff_q(&outq, p);
else
diff_free_filepair(p);
}
free(diff_queued_diff.queue);
diff_queued_diff = outq;
}
static inline int diff_might_be_rename(void)
{
int i;
for (i = 0; i < diff_queued_diff.nr; i++)
if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
/* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
/* diff_queued_diff.queue[i]->two->path); */
return 1;
}
return 0;
}
static void queue_diffs(struct line_log_data *range,
struct diff_options *opt,
struct diff_queue_struct *queue,
struct commit *commit, struct commit *parent)
{
struct object_id *tree_oid, *parent_tree_oid;
assert(commit);
tree_oid = get_commit_tree_oid(commit);
parent_tree_oid = parent ? get_commit_tree_oid(parent) : NULL;
if (opt->detect_rename &&
!same_paths_in_pathspec_and_range(&opt->pathspec, range)) {
clear_pathspec(&opt->pathspec);
parse_pathspec_from_ranges(&opt->pathspec, range);
}
DIFF_QUEUE_CLEAR(&diff_queued_diff);
diff_tree_oid(parent_tree_oid, tree_oid, "", opt);
if (opt->detect_rename && diff_might_be_rename()) {
/* must look at the full tree diff to detect renames */
clear_pathspec(&opt->pathspec);
DIFF_QUEUE_CLEAR(&diff_queued_diff);
diff_tree_oid(parent_tree_oid, tree_oid, "", opt);
filter_diffs_for_paths(range, 1);
diffcore_std(opt);
filter_diffs_for_paths(range, 0);
}
move_diff_queue(queue, &diff_queued_diff);
}
static char *get_nth_line(long line, unsigned long *ends, void *data)
{
if (line == 0)
return (char *)data;
else
return (char *)data + ends[line] + 1;
}
static void print_line(const char *prefix, char first,
long line, unsigned long *ends, void *data,
const char *color, const char *reset, FILE *file)
{
char *begin = get_nth_line(line, ends, data);
char *end = get_nth_line(line+1, ends, data);
int had_nl = 0;
if (end > begin && end[-1] == '\n') {
end--;
had_nl = 1;
}
fputs(prefix, file);
fputs(color, file);
putc(first, file);
fwrite(begin, 1, end-begin, file);
fputs(reset, file);
putc('\n', file);
if (!had_nl)
fputs("\\ No newline at end of file\n", file);
}
static char *output_prefix(struct diff_options *opt)
{
char *prefix = "";
if (opt->output_prefix) {
struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
prefix = sb->buf;
}
return prefix;
}
static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
{
unsigned int i, j = 0;
long p_lines, t_lines;
unsigned long *p_ends = NULL, *t_ends = NULL;
struct diff_filepair *pair = range->pair;
struct diff_ranges *diff = &range->diff;
struct diff_options *opt = &rev->diffopt;
char *prefix = output_prefix(opt);
const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
if (!pair || !diff)
return;
if (pair->one->oid_valid)
fill_line_ends(rev->diffopt.repo, pair->one, &p_lines, &p_ends);
fill_line_ends(rev->diffopt.repo, pair->two, &t_lines, &t_ends);
fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
pair->one->oid_valid ? "a/" : "",
pair->one->oid_valid ? pair->one->path : "/dev/null",
c_reset);
fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
for (i = 0; i < range->ranges.nr; i++) {
long p_start, p_end;
long t_start = range->ranges.ranges[i].start;
long t_end = range->ranges.ranges[i].end;
long t_cur = t_start;
unsigned int j_last;
while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
j++;
if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
continue;
/* Scan ahead to determine the last diff that falls in this range */
j_last = j;
while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
j_last++;
if (j_last > j)
j_last--;
/*
* Compute parent hunk headers: we know that the diff
* has the correct line numbers (but not all hunks).
* So it suffices to shift the start/end according to
* the line numbers of the first/last hunk(s) that
* fall in this range.
*/
if (t_start < diff->target.ranges[j].start)
p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
else
p_start = diff->parent.ranges[j].start;
if (t_end > diff->target.ranges[j_last].end)
p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
else
p_end = diff->parent.ranges[j_last].end;
if (!p_start && !p_end) {
p_start = -1;
p_end = -1;
}
/* Now output a diff hunk for this range */
fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
prefix, c_frag,
p_start+1, p_end-p_start, t_start+1, t_end-t_start,
c_reset);
while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
int k;
for (; t_cur < diff->target.ranges[j].start; t_cur++)
print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
c_context, c_reset, opt->file);
for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
print_line(prefix, '-', k, p_ends, pair->one->data,
c_old, c_reset, opt->file);
for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
print_line(prefix, '+', t_cur, t_ends, pair->two->data,
c_new, c_reset, opt->file);
j++;
}
for (; t_cur < t_end; t_cur++)
print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
c_context, c_reset, opt->file);
}
free(p_ends);
free(t_ends);
}
/*
* NEEDSWORK: manually building a diff here is not the Right
* Thing(tm). log -L should be built into the diff pipeline.
*/
static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
{
fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
while (range) {
dump_diff_hacky_one(rev, range);
range = range->next;
}
}
/*
* Unlike most other functions, this destructively operates on
* 'range'.
*/
static int process_diff_filepair(struct rev_info *rev,
struct diff_filepair *pair,
struct line_log_data *range,
struct diff_ranges **diff_out)
{
struct line_log_data *rg = range;
struct range_set tmp;
struct diff_ranges diff;
mmfile_t file_parent, file_target;
assert(pair->two->path);
while (rg) {
assert(rg->path);
if (!strcmp(rg->path, pair->two->path))
break;
rg = rg->next;
}
if (!rg)
return 0;
if (rg->ranges.nr == 0)
return 0;
assert(pair->two->oid_valid);
diff_populate_filespec(rev->diffopt.repo, pair->two, 0);
file_target.ptr = pair->two->data;
file_target.size = pair->two->size;
if (pair->one->oid_valid) {
diff_populate_filespec(rev->diffopt.repo, pair->one, 0);
file_parent.ptr = pair->one->data;
file_parent.size = pair->one->size;
} else {
file_parent.ptr = "";
file_parent.size = 0;
}
diff_ranges_init(&diff);
if (collect_diff(&file_parent, &file_target, &diff))
die("unable to generate diff for %s", pair->one->path);
/* NEEDSWORK should apply some heuristics to prevent mismatches */
free(rg->path);
rg->path = xstrdup(pair->one->path);
range_set_init(&tmp, 0);
range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
range_set_release(&rg->ranges);
range_set_move(&rg->ranges, &tmp);
diff_ranges_release(&diff);
return ((*diff_out)->parent.nr > 0);
}
static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
{
struct diff_filepair *new_filepair = xmalloc(sizeof(struct diff_filepair));
new_filepair->one = pair->one;
new_filepair->two = pair->two;
new_filepair->one->count++;
new_filepair->two->count++;
return new_filepair;
}
static void free_diffqueues(int n, struct diff_queue_struct *dq)
{
int i, j;
for (i = 0; i < n; i++)
for (j = 0; j < dq[i].nr; j++)
diff_free_filepair(dq[i].queue[j]);
free(dq);
}
static int process_all_files(struct line_log_data **range_out,
struct rev_info *rev,
struct diff_queue_struct *queue,
struct line_log_data *range)
{
int i, changed = 0;
*range_out = line_log_data_copy(range);
for (i = 0; i < queue->nr; i++) {
struct diff_ranges *pairdiff = NULL;
struct diff_filepair *pair = queue->queue[i];
if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
/*
* Store away the diff for later output. We
* tuck it in the ranges we got as _input_,
* since that's the commit that caused the
* diff.
*
* NEEDSWORK not enough when we get around to
* doing something interesting with merges;
* currently each invocation on a merge parent
* trashes the previous one's diff.
*
* NEEDSWORK tramples over data structures not owned here
*/
struct line_log_data *rg = range;
changed++;
while (rg && strcmp(rg->path, pair->two->path))
rg = rg->next;
assert(rg);
rg->pair = diff_filepair_dup(queue->queue[i]);
memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
}
free(pairdiff);
}
return changed;
}
int line_log_print(struct rev_info *rev, struct commit *commit)
{
show_log(rev);
if (!(rev->diffopt.output_format & DIFF_FORMAT_NO_OUTPUT)) {
struct line_log_data *range = lookup_line_range(rev, commit);
dump_diff_hacky(rev, range);
}
return 1;
}
static int bloom_filter_check(struct rev_info *rev,
struct commit *commit,
struct line_log_data *range)
{
struct bloom_filter *filter;
struct bloom_key key;
int result = 0;
if (!commit->parents)
return 1;
if (!rev->bloom_filter_settings ||
!(filter = get_bloom_filter(rev->repo, commit, 0)))
return 1;
if (!range)
return 0;
while (!result && range) {
fill_bloom_key(range->path, strlen(range->path), &key, rev->bloom_filter_settings);
if (bloom_filter_contains(filter, &key, rev->bloom_filter_settings))
result = 1;
clear_bloom_key(&key);
range = range->next;
}
return result;
}
static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
struct line_log_data *range)
{
struct commit *parent = NULL;
struct diff_queue_struct queue;
struct line_log_data *parent_range;
int changed;
if (commit->parents)
parent = commit->parents->item;
queue_diffs(range, &rev->diffopt, &queue, commit, parent);
changed = process_all_files(&parent_range, rev, &queue, range);
if (parent)
add_line_range(rev, parent, parent_range);
free_line_log_data(parent_range);
return changed;
}
static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
struct line_log_data *range)
{
struct diff_queue_struct *diffqueues;
struct line_log_data **cand;
struct commit **parents;
struct commit_list *p;
int i;
int nparents = commit_list_count(commit->parents);
if (nparents > 1 && rev->first_parent_only)
nparents = 1;
ALLOC_ARRAY(diffqueues, nparents);
ALLOC_ARRAY(cand, nparents);
ALLOC_ARRAY(parents, nparents);
p = commit->parents;
for (i = 0; i < nparents; i++) {
parents[i] = p->item;
p = p->next;
queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
}
for (i = 0; i < nparents; i++) {
int changed;
cand[i] = NULL;
changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
if (!changed) {
/*
* This parent can take all the blame, so we
* don't follow any other path in history
*/
add_line_range(rev, parents[i], cand[i]);
clear_commit_line_range(rev, commit);
commit_list_append(parents[i], &commit->parents);
free(parents);
free(cand);
free_diffqueues(nparents, diffqueues);
/* NEEDSWORK leaking like a sieve */
return 0;
}
}
/*
* No single parent took the blame. We add the candidates
* from the above loop to the parents.
*/
for (i = 0; i < nparents; i++) {
add_line_range(rev, parents[i], cand[i]);
}
clear_commit_line_range(rev, commit);
free(parents);
free(cand);
free_diffqueues(nparents, diffqueues);
return 1;
/* NEEDSWORK evil merge detection stuff */
/* NEEDSWORK leaking like a sieve */
}
int line_log_process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
{
struct line_log_data *range = lookup_line_range(rev, commit);
int changed = 0;
if (range) {
if (commit->parents && !bloom_filter_check(rev, commit, range)) {
struct line_log_data *prange = line_log_data_copy(range);
add_line_range(rev, commit->parents->item, prange);
clear_commit_line_range(rev, commit);
} else if (!commit->parents || !commit->parents->next)
changed = process_ranges_ordinary_commit(rev, commit, range);
else
changed = process_ranges_merge_commit(rev, commit, range);
}
if (!changed)
commit->object.flags |= TREESAME;
return changed;
}
static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
{
for (;;) {
struct commit *p = *pp;
if (p->parents && p->parents->next)
return rewrite_one_ok;
if (p->object.flags & UNINTERESTING)
return rewrite_one_ok;
if (!(p->object.flags & TREESAME))
return rewrite_one_ok;
if (!p->parents)
return rewrite_one_noparents;
*pp = p->parents->item;
}
}
int line_log_filter(struct rev_info *rev)
{
struct commit *commit;
struct commit_list *list = rev->commits;
struct commit_list *out = NULL, **pp = &out;
while (list) {
struct commit_list *to_free = NULL;
commit = list->item;
if (line_log_process_ranges_arbitrary_commit(rev, commit)) {
*pp = list;
pp = &list->next;
} else
to_free = list;
list = list->next;
free(to_free);
}
*pp = NULL;
for (list = out; list; list = list->next)
rewrite_parents(rev, list->item, line_log_rewrite_one);
rev->commits = out;
return 0;
}
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