git/range-diff.c
Elijah Newren b19315d8ab Use new HASHMAP_INIT macro to simplify hashmap initialization
Now that hashamp has lazy initialization and a HASHMAP_INIT macro,
hashmaps allocated on the stack can be initialized without a call to
hashmap_init() and in some cases makes the code a bit shorter.  Convert
some callsites over to take advantage of this.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 12:55:27 -08:00

567 lines
15 KiB
C

#include "cache.h"
#include "range-diff.h"
#include "string-list.h"
#include "run-command.h"
#include "strvec.h"
#include "hashmap.h"
#include "xdiff-interface.h"
#include "linear-assignment.h"
#include "diffcore.h"
#include "commit.h"
#include "pretty.h"
#include "userdiff.h"
#include "apply.h"
struct patch_util {
/* For the search for an exact match */
struct hashmap_entry e;
const char *diff, *patch;
int i, shown;
int diffsize;
size_t diff_offset;
/* the index of the matching item in the other branch, or -1 */
int matching;
struct object_id oid;
};
static size_t find_end_of_line(char *buffer, unsigned long size)
{
char *eol = memchr(buffer, '\n', size);
if (!eol)
return size;
*eol = '\0';
return eol + 1 - buffer;
}
/*
* Reads the patches into a string list, with the `util` field being populated
* as struct object_id (will need to be free()d).
*/
static int read_patches(const char *range, struct string_list *list,
const struct strvec *other_arg)
{
struct child_process cp = CHILD_PROCESS_INIT;
struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
struct patch_util *util = NULL;
int in_header = 1;
char *line, *current_filename = NULL;
int offset, len;
size_t size;
strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
"--reverse", "--date-order", "--decorate=no",
"--no-prefix",
/*
* Choose indicators that are not used anywhere
* else in diffs, but still look reasonable
* (e.g. will not be confusing when debugging)
*/
"--output-indicator-new=>",
"--output-indicator-old=<",
"--output-indicator-context=#",
"--no-abbrev-commit",
"--pretty=medium",
"--notes",
NULL);
if (other_arg)
strvec_pushv(&cp.args, other_arg->v);
strvec_push(&cp.args, range);
cp.out = -1;
cp.no_stdin = 1;
cp.git_cmd = 1;
if (start_command(&cp))
return error_errno(_("could not start `log`"));
if (strbuf_read(&contents, cp.out, 0) < 0) {
error_errno(_("could not read `log` output"));
finish_command(&cp);
return -1;
}
line = contents.buf;
size = contents.len;
for (offset = 0; size > 0; offset += len, size -= len, line += len) {
const char *p;
len = find_end_of_line(line, size);
line[len - 1] = '\0';
if (skip_prefix(line, "commit ", &p)) {
if (util) {
string_list_append(list, buf.buf)->util = util;
strbuf_reset(&buf);
}
util = xcalloc(sizeof(*util), 1);
if (get_oid(p, &util->oid)) {
error(_("could not parse commit '%s'"), p);
free(util);
string_list_clear(list, 1);
strbuf_release(&buf);
strbuf_release(&contents);
finish_command(&cp);
return -1;
}
util->matching = -1;
in_header = 1;
continue;
}
if (!util) {
error(_("could not parse first line of `log` output: "
"did not start with 'commit ': '%s'"),
line);
string_list_clear(list, 1);
strbuf_release(&buf);
strbuf_release(&contents);
finish_command(&cp);
return -1;
}
if (starts_with(line, "diff --git")) {
struct patch patch = { 0 };
struct strbuf root = STRBUF_INIT;
int linenr = 0;
int orig_len;
in_header = 0;
strbuf_addch(&buf, '\n');
if (!util->diff_offset)
util->diff_offset = buf.len;
line[len - 1] = '\n';
orig_len = len;
len = parse_git_diff_header(&root, &linenr, 0, line,
len, size, &patch);
if (len < 0)
die(_("could not parse git header '%.*s'"),
orig_len, line);
strbuf_addstr(&buf, " ## ");
if (patch.is_new > 0)
strbuf_addf(&buf, "%s (new)", patch.new_name);
else if (patch.is_delete > 0)
strbuf_addf(&buf, "%s (deleted)", patch.old_name);
else if (patch.is_rename)
strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
else
strbuf_addstr(&buf, patch.new_name);
free(current_filename);
if (patch.is_delete > 0)
current_filename = xstrdup(patch.old_name);
else
current_filename = xstrdup(patch.new_name);
if (patch.new_mode && patch.old_mode &&
patch.old_mode != patch.new_mode)
strbuf_addf(&buf, " (mode change %06o => %06o)",
patch.old_mode, patch.new_mode);
strbuf_addstr(&buf, " ##");
} else if (in_header) {
if (starts_with(line, "Author: ")) {
strbuf_addstr(&buf, " ## Metadata ##\n");
strbuf_addstr(&buf, line);
strbuf_addstr(&buf, "\n\n");
strbuf_addstr(&buf, " ## Commit message ##\n");
} else if (starts_with(line, "Notes") &&
line[strlen(line) - 1] == ':') {
strbuf_addstr(&buf, "\n\n");
/* strip the trailing colon */
strbuf_addf(&buf, " ## %.*s ##\n",
(int)(strlen(line) - 1), line);
} else if (starts_with(line, " ")) {
p = line + len - 2;
while (isspace(*p) && p >= line)
p--;
strbuf_add(&buf, line, p - line + 1);
strbuf_addch(&buf, '\n');
}
continue;
} else if (skip_prefix(line, "@@ ", &p)) {
p = strstr(p, "@@");
strbuf_addstr(&buf, "@@");
if (current_filename && p[2])
strbuf_addf(&buf, " %s:", current_filename);
if (p)
strbuf_addstr(&buf, p + 2);
} else if (!line[0])
/*
* A completely blank (not ' \n', which is context)
* line is not valid in a diff. We skip it
* silently, because this neatly handles the blank
* separator line between commits in git-log
* output.
*/
continue;
else if (line[0] == '>') {
strbuf_addch(&buf, '+');
strbuf_addstr(&buf, line + 1);
} else if (line[0] == '<') {
strbuf_addch(&buf, '-');
strbuf_addstr(&buf, line + 1);
} else if (line[0] == '#') {
strbuf_addch(&buf, ' ');
strbuf_addstr(&buf, line + 1);
} else {
strbuf_addch(&buf, ' ');
strbuf_addstr(&buf, line);
}
strbuf_addch(&buf, '\n');
util->diffsize++;
}
strbuf_release(&contents);
if (util)
string_list_append(list, buf.buf)->util = util;
strbuf_release(&buf);
free(current_filename);
if (finish_command(&cp))
return -1;
return 0;
}
static int patch_util_cmp(const void *dummy, const struct patch_util *a,
const struct patch_util *b, const char *keydata)
{
return strcmp(a->diff, keydata ? keydata : b->diff);
}
static void find_exact_matches(struct string_list *a, struct string_list *b)
{
struct hashmap map = HASHMAP_INIT((hashmap_cmp_fn)patch_util_cmp, NULL);
int i;
/* First, add the patches of a to a hash map */
for (i = 0; i < a->nr; i++) {
struct patch_util *util = a->items[i].util;
util->i = i;
util->patch = a->items[i].string;
util->diff = util->patch + util->diff_offset;
hashmap_entry_init(&util->e, strhash(util->diff));
hashmap_add(&map, &util->e);
}
/* Now try to find exact matches in b */
for (i = 0; i < b->nr; i++) {
struct patch_util *util = b->items[i].util, *other;
util->i = i;
util->patch = b->items[i].string;
util->diff = util->patch + util->diff_offset;
hashmap_entry_init(&util->e, strhash(util->diff));
other = hashmap_remove_entry(&map, util, e, NULL);
if (other) {
if (other->matching >= 0)
BUG("already assigned!");
other->matching = i;
util->matching = other->i;
}
}
hashmap_clear(&map);
}
static void diffsize_consume(void *data, char *line, unsigned long len)
{
(*(int *)data)++;
}
static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
const char *funcline, long funclen)
{
diffsize_consume(data, NULL, 0);
}
static int diffsize(const char *a, const char *b)
{
xpparam_t pp = { 0 };
xdemitconf_t cfg = { 0 };
mmfile_t mf1, mf2;
int count = 0;
mf1.ptr = (char *)a;
mf1.size = strlen(a);
mf2.ptr = (char *)b;
mf2.size = strlen(b);
cfg.ctxlen = 3;
if (!xdi_diff_outf(&mf1, &mf2,
diffsize_hunk, diffsize_consume, &count,
&pp, &cfg))
return count;
error(_("failed to generate diff"));
return COST_MAX;
}
static void get_correspondences(struct string_list *a, struct string_list *b,
int creation_factor)
{
int n = a->nr + b->nr;
int *cost, c, *a2b, *b2a;
int i, j;
ALLOC_ARRAY(cost, st_mult(n, n));
ALLOC_ARRAY(a2b, n);
ALLOC_ARRAY(b2a, n);
for (i = 0; i < a->nr; i++) {
struct patch_util *a_util = a->items[i].util;
for (j = 0; j < b->nr; j++) {
struct patch_util *b_util = b->items[j].util;
if (a_util->matching == j)
c = 0;
else if (a_util->matching < 0 && b_util->matching < 0)
c = diffsize(a_util->diff, b_util->diff);
else
c = COST_MAX;
cost[i + n * j] = c;
}
c = a_util->matching < 0 ?
a_util->diffsize * creation_factor / 100 : COST_MAX;
for (j = b->nr; j < n; j++)
cost[i + n * j] = c;
}
for (j = 0; j < b->nr; j++) {
struct patch_util *util = b->items[j].util;
c = util->matching < 0 ?
util->diffsize * creation_factor / 100 : COST_MAX;
for (i = a->nr; i < n; i++)
cost[i + n * j] = c;
}
for (i = a->nr; i < n; i++)
for (j = b->nr; j < n; j++)
cost[i + n * j] = 0;
compute_assignment(n, n, cost, a2b, b2a);
for (i = 0; i < a->nr; i++)
if (a2b[i] >= 0 && a2b[i] < b->nr) {
struct patch_util *a_util = a->items[i].util;
struct patch_util *b_util = b->items[a2b[i]].util;
a_util->matching = a2b[i];
b_util->matching = i;
}
free(cost);
free(a2b);
free(b2a);
}
static void output_pair_header(struct diff_options *diffopt,
int patch_no_width,
struct strbuf *buf,
struct strbuf *dashes,
struct patch_util *a_util,
struct patch_util *b_util)
{
struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
struct commit *commit;
char status;
const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
const char *color;
if (!dashes->len)
strbuf_addchars(dashes, '-',
strlen(find_unique_abbrev(oid,
DEFAULT_ABBREV)));
if (!b_util) {
color = color_old;
status = '<';
} else if (!a_util) {
color = color_new;
status = '>';
} else if (strcmp(a_util->patch, b_util->patch)) {
color = color_commit;
status = '!';
} else {
color = color_commit;
status = '=';
}
strbuf_reset(buf);
strbuf_addstr(buf, status == '!' ? color_old : color);
if (!a_util)
strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
else
strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
if (status == '!')
strbuf_addf(buf, "%s%s", color_reset, color);
strbuf_addch(buf, status);
if (status == '!')
strbuf_addf(buf, "%s%s", color_reset, color_new);
if (!b_util)
strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
else
strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
commit = lookup_commit_reference(the_repository, oid);
if (commit) {
if (status == '!')
strbuf_addf(buf, "%s%s", color_reset, color);
strbuf_addch(buf, ' ');
pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
}
strbuf_addf(buf, "%s\n", color_reset);
fwrite(buf->buf, buf->len, 1, diffopt->file);
}
static struct userdiff_driver section_headers = {
.funcname = { "^ ## (.*) ##$\n"
"^.?@@ (.*)$", REG_EXTENDED }
};
static struct diff_filespec *get_filespec(const char *name, const char *p)
{
struct diff_filespec *spec = alloc_filespec(name);
fill_filespec(spec, &null_oid, 0, 0100644);
spec->data = (char *)p;
spec->size = strlen(p);
spec->should_munmap = 0;
spec->is_stdin = 1;
spec->driver = &section_headers;
return spec;
}
static void patch_diff(const char *a, const char *b,
struct diff_options *diffopt)
{
diff_queue(&diff_queued_diff,
get_filespec("a", a), get_filespec("b", b));
diffcore_std(diffopt);
diff_flush(diffopt);
}
static void output(struct string_list *a, struct string_list *b,
struct diff_options *diffopt)
{
struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
int i = 0, j = 0;
/*
* We assume the user is really more interested in the second argument
* ("newer" version). To that end, we print the output in the order of
* the RHS (the `b` parameter). To put the LHS (the `a` parameter)
* commits that are no longer in the RHS into a good place, we place
* them once we have shown all of their predecessors in the LHS.
*/
while (i < a->nr || j < b->nr) {
struct patch_util *a_util, *b_util;
a_util = i < a->nr ? a->items[i].util : NULL;
b_util = j < b->nr ? b->items[j].util : NULL;
/* Skip all the already-shown commits from the LHS. */
while (i < a->nr && a_util->shown)
a_util = ++i < a->nr ? a->items[i].util : NULL;
/* Show unmatched LHS commit whose predecessors were shown. */
if (i < a->nr && a_util->matching < 0) {
output_pair_header(diffopt, patch_no_width,
&buf, &dashes, a_util, NULL);
i++;
continue;
}
/* Show unmatched RHS commits. */
while (j < b->nr && b_util->matching < 0) {
output_pair_header(diffopt, patch_no_width,
&buf, &dashes, NULL, b_util);
b_util = ++j < b->nr ? b->items[j].util : NULL;
}
/* Show matching LHS/RHS pair. */
if (j < b->nr) {
a_util = a->items[b_util->matching].util;
output_pair_header(diffopt, patch_no_width,
&buf, &dashes, a_util, b_util);
if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
patch_diff(a->items[b_util->matching].string,
b->items[j].string, diffopt);
a_util->shown = 1;
j++;
}
}
strbuf_release(&buf);
strbuf_release(&dashes);
}
static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
{
return data;
}
int show_range_diff(const char *range1, const char *range2,
int creation_factor, int dual_color,
const struct diff_options *diffopt,
const struct strvec *other_arg)
{
int res = 0;
struct string_list branch1 = STRING_LIST_INIT_DUP;
struct string_list branch2 = STRING_LIST_INIT_DUP;
if (read_patches(range1, &branch1, other_arg))
res = error(_("could not parse log for '%s'"), range1);
if (!res && read_patches(range2, &branch2, other_arg))
res = error(_("could not parse log for '%s'"), range2);
if (!res) {
struct diff_options opts;
struct strbuf indent = STRBUF_INIT;
if (diffopt)
memcpy(&opts, diffopt, sizeof(opts));
else
diff_setup(&opts);
if (!opts.output_format)
opts.output_format = DIFF_FORMAT_PATCH;
opts.flags.suppress_diff_headers = 1;
opts.flags.dual_color_diffed_diffs = dual_color;
opts.flags.suppress_hunk_header_line_count = 1;
opts.output_prefix = output_prefix_cb;
strbuf_addstr(&indent, " ");
opts.output_prefix_data = &indent;
diff_setup_done(&opts);
find_exact_matches(&branch1, &branch2);
get_correspondences(&branch1, &branch2, creation_factor);
output(&branch1, &branch2, &opts);
strbuf_release(&indent);
}
string_list_clear(&branch1, 1);
string_list_clear(&branch2, 1);
return res;
}