[thirdparty/git.git] / range-diff.c

#include "cache.h"
#include "range-diff.h"
#include "string-list.h"
#include "run-command.h"
#include "argv-array.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)
{
	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;

	argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
			"--reverse", "--date-order", "--decorate=no",
			/*
			 * 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", range,
			NULL);
	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 (starts_with(line, "diff --git")) {
			struct patch patch = { 0 };
			struct strbuf root = STRBUF_INIT;
			int linenr = 0;

			in_header = 0;
			strbuf_addch(&buf, '\n');
			if (!util->diff_offset)
				util->diff_offset = buf.len;
			line[len - 1] = '\n';
			len = parse_git_diff_header(&root, &linenr, 1, line,
						    len, size, &patch);
			if (len < 0)
				die(_("could not parse git header '%.*s'"), (int)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, "    ")) {
				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;
	int i;

	hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);

	/* 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, strhash(util->diff));
		hashmap_add(&map, util);
	}

	/* 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, strhash(util->diff));
		other = hashmap_remove(&map, util, NULL);
		if (other) {
			if (other->matching >= 0)
				BUG("already assigned!");

			other->matching = i;
			util->matching = other->i;
		}
	}

	hashmap_free(&map, 0);
}

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,
		    struct diff_options *diffopt)
{
	int res = 0;

	struct string_list branch1 = STRING_LIST_INIT_DUP;
	struct string_list branch2 = STRING_LIST_INIT_DUP;

	if (read_patches(range1, &branch1))
		res = error(_("could not parse log for '%s'"), range1);
	if (!res && read_patches(range2, &branch2))
		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;
}
Commit	Line	Data
d9c66f0b JS	1	#include "cache.h"
	2	#include "range-diff.h"
	3	#include "string-list.h"
	4	#include "run-command.h"
	5	#include "argv-array.h"
	6	#include "hashmap.h"
	7	#include "xdiff-interface.h"
	8	#include "linear-assignment.h"
c8c5e43a	9	#include "diffcore.h"
eb0be38c JS	10	#include "commit.h"
eb0be38c JS	11	#include "pretty.h"
4eba1fe6	12	#include "userdiff.h"
b66885a3	13	#include "apply.h"
d9c66f0b JS	14
	15	struct patch_util {
	16	/* For the search for an exact match */
	17	struct hashmap_entry e;
	18	const char diff, patch;
	19
9dc46e02	20	int i, shown;
d9c66f0b JS	21	int diffsize;
	22	size_t diff_offset;
	23	/* the index of the matching item in the other branch, or -1 */
	24	int matching;
	25	struct object_id oid;
	26	};
	27
44b67cb6 TG	28	static size_t find_end_of_line(char *buffer, unsigned long size)
	29	{
	30	char *eol = memchr(buffer, '\n', size);
	31
	32	if (!eol)
	33	return size;
	34
	35	*eol = '\0';
	36	return eol + 1 - buffer;
	37	}
	38
d9c66f0b JS	39	/*
	40	* Reads the patches into a string list, with the `util` field being populated
	41	* as struct object_id (will need to be free()d).
	42	*/
	43	static int read_patches(const char range, struct string_list list)
	44	{
	45	struct child_process cp = CHILD_PROCESS_INIT;
44b67cb6	46	struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
d9c66f0b JS	47	struct patch_util *util = NULL;
d9c66f0b JS	48	int in_header = 1;
444e0969	49	char line, current_filename = NULL;
44b67cb6 TG	50	int offset, len;
44b67cb6 TG	51	size_t size;
d9c66f0b JS	52
	53	argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
	54	"--reverse", "--date-order", "--decorate=no",
8d5ccb59 SB	55	/*
	56	* Choose indicators that are not used anywhere
	57	* else in diffs, but still look reasonable
	58	* (e.g. will not be confusing when debugging)
	59	*/
	60	"--output-indicator-new=>",
	61	"--output-indicator-old=<",
	62	"--output-indicator-context=#",
d9c66f0b JS	63	"--no-abbrev-commit", range,
	64	NULL);
	65	cp.out = -1;
	66	cp.no_stdin = 1;
	67	cp.git_cmd = 1;
	68
	69	if (start_command(&cp))
	70	return error_errno(_("could not start `log`"));
44b67cb6	71	if (strbuf_read(&contents, cp.out, 0) < 0) {
d9c66f0b JS	72	error_errno(_("could not read `log` output"));
	73	finish_command(&cp);
	74	return -1;
	75	}
	76
44b67cb6 TG	77	line = contents.buf;
	78	size = contents.len;
	79	for (offset = 0; size > 0; offset += len, size -= len, line += len) {
d9c66f0b JS	80	const char *p;
d9c66f0b JS	81
44b67cb6 TG	82	len = find_end_of_line(line, size);
	83	line[len - 1] = '\0';
	84	if (skip_prefix(line, "commit ", &p)) {
d9c66f0b JS	85	if (util) {
	86	string_list_append(list, buf.buf)->util = util;
	87	strbuf_reset(&buf);
	88	}
	89	util = xcalloc(sizeof(*util), 1);
	90	if (get_oid(p, &util->oid)) {
	91	error(_("could not parse commit '%s'"), p);
	92	free(util);
	93	string_list_clear(list, 1);
	94	strbuf_release(&buf);
44b67cb6	95	strbuf_release(&contents);
d9c66f0b JS	96	finish_command(&cp);
	97	return -1;
	98	}
	99	util->matching = -1;
	100	in_header = 1;
	101	continue;
	102	}
	103
44b67cb6	104	if (starts_with(line, "diff --git")) {
b66885a3 TG	105	struct patch patch = { 0 };
	106	struct strbuf root = STRBUF_INIT;
	107	int linenr = 0;
	108
d9c66f0b JS	109	in_header = 0;
	110	strbuf_addch(&buf, '\n');
	111	if (!util->diff_offset)
	112	util->diff_offset = buf.len;
b66885a3 TG	113	line[len - 1] = '\n';
	114	len = parse_git_diff_header(&root, &linenr, 1, line,
	115	len, size, &patch);
	116	if (len < 0)
	117	die(_("could not parse git header '%.*s'"), (int)len, line);
	118	strbuf_addstr(&buf, " ## ");
	119	if (patch.is_new > 0)
	120	strbuf_addf(&buf, "%s (new)", patch.new_name);
	121	else if (patch.is_delete > 0)
	122	strbuf_addf(&buf, "%s (deleted)", patch.old_name);
	123	else if (patch.is_rename)
	124	strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
	125	else
	126	strbuf_addstr(&buf, patch.new_name);
	127
444e0969 TG	128	free(current_filename);
	129	if (patch.is_delete > 0)
	130	current_filename = xstrdup(patch.old_name);
	131	else
	132	current_filename = xstrdup(patch.new_name);
	133
b66885a3 TG	134	if (patch.new_mode && patch.old_mode &&
	135	patch.old_mode != patch.new_mode)
	136	strbuf_addf(&buf, " (mode change %06o => %06o)",
	137	patch.old_mode, patch.new_mode);
	138
	139	strbuf_addstr(&buf, " ##");
d9c66f0b	140	} else if (in_header) {
44b67cb6	141	if (starts_with(line, "Author: ")) {
499352c2	142	strbuf_addstr(&buf, " ## Metadata ##\n");
44b67cb6	143	strbuf_addstr(&buf, line);
d9c66f0b	144	strbuf_addstr(&buf, "\n\n");
499352c2	145	strbuf_addstr(&buf, " ## Commit message ##\n");
44b67cb6 TG	146	} else if (starts_with(line, " ")) {
	147	p = line + len - 2;
	148	while (isspace(*p) && p >= line)
	149	p--;
	150	strbuf_add(&buf, line, p - line + 1);
d9c66f0b JS	151	strbuf_addch(&buf, '\n');
	152	}
	153	continue;
e1db2630 TG	154	} else if (skip_prefix(line, "@@ ", &p)) {
e1db2630 TG	155	p = strstr(p, "@@");
444e0969 TG	156	strbuf_addstr(&buf, "@@");
	157	if (current_filename && p[2])
	158	strbuf_addf(&buf, " %s:", current_filename);
	159	if (p)
	160	strbuf_addstr(&buf, p + 2);
b66885a3	161	} else if (!line[0])
d9c66f0b JS	162	/*
	163	* A completely blank (not ' \n', which is context)
	164	* line is not valid in a diff. We skip it
	165	* silently, because this neatly handles the blank
	166	* separator line between commits in git-log
	167	* output.
d9c66f0b JS	168	*/
d9c66f0b JS	169	continue;
44b67cb6	170	else if (line[0] == '>') {
8d5ccb59	171	strbuf_addch(&buf, '+');
44b67cb6 TG	172	strbuf_addstr(&buf, line + 1);
44b67cb6 TG	173	} else if (line[0] == '<') {
8d5ccb59	174	strbuf_addch(&buf, '-');
44b67cb6 TG	175	strbuf_addstr(&buf, line + 1);
44b67cb6 TG	176	} else if (line[0] == '#') {
8d5ccb59	177	strbuf_addch(&buf, ' ');
44b67cb6	178	strbuf_addstr(&buf, line + 1);
8d5ccb59	179	} else {
2543a641	180	strbuf_addch(&buf, ' ');
44b67cb6	181	strbuf_addstr(&buf, line);
8d5ccb59	182	}
d9c66f0b JS	183
	184	strbuf_addch(&buf, '\n');
	185	util->diffsize++;
	186	}
44b67cb6	187	strbuf_release(&contents);
d9c66f0b JS	188
	189	if (util)
	190	string_list_append(list, buf.buf)->util = util;
	191	strbuf_release(&buf);
444e0969	192	free(current_filename);
d9c66f0b JS	193
	194	if (finish_command(&cp))
	195	return -1;
	196
	197	return 0;
	198	}
	199
	200	static int patch_util_cmp(const void dummy, const struct patch_util a,
1ca69225	201	const struct patch_util b, const char keydata)
d9c66f0b JS	202	{
	203	return strcmp(a->diff, keydata ? keydata : b->diff);
	204	}
	205
	206	static void find_exact_matches(struct string_list a, struct string_list b)
	207	{
	208	struct hashmap map;
	209	int i;
	210
	211	hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);
	212
	213	/* First, add the patches of a to a hash map */
	214	for (i = 0; i < a->nr; i++) {
	215	struct patch_util *util = a->items[i].util;
	216
	217	util->i = i;
	218	util->patch = a->items[i].string;
	219	util->diff = util->patch + util->diff_offset;
	220	hashmap_entry_init(util, strhash(util->diff));
	221	hashmap_add(&map, util);
	222	}
	223
	224	/* Now try to find exact matches in b */
	225	for (i = 0; i < b->nr; i++) {
	226	struct patch_util util = b->items[i].util, other;
	227
	228	util->i = i;
	229	util->patch = b->items[i].string;
	230	util->diff = util->patch + util->diff_offset;
	231	hashmap_entry_init(util, strhash(util->diff));
	232	other = hashmap_remove(&map, util, NULL);
	233	if (other) {
	234	if (other->matching >= 0)
	235	BUG("already assigned!");
	236
	237	other->matching = i;
	238	util->matching = other->i;
	239	}
	240	}
	241
	242	hashmap_free(&map, 0);
	243	}
	244
	245	static void diffsize_consume(void data, char line, unsigned long len)
	246	{
	247	((int )data)++;
	248	}
	249
d2eb8093 JK	250	static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
	251	const char *funcline, long funclen)
	252	{
	253	diffsize_consume(data, NULL, 0);
	254	}
	255
d9c66f0b JS	256	static int diffsize(const char a, const char b)
	257	{
	258	xpparam_t pp = { 0 };
	259	xdemitconf_t cfg = { 0 };
	260	mmfile_t mf1, mf2;
	261	int count = 0;
	262
	263	mf1.ptr = (char *)a;
	264	mf1.size = strlen(a);
	265	mf2.ptr = (char *)b;
	266	mf2.size = strlen(b);
	267
	268	cfg.ctxlen = 3;
d2eb8093 JK	269	if (!xdi_diff_outf(&mf1, &mf2,
	270	diffsize_hunk, diffsize_consume, &count,
	271	&pp, &cfg))
d9c66f0b JS	272	return count;
	273
	274	error(_("failed to generate diff"));
	275	return COST_MAX;
	276	}
	277
	278	static void get_correspondences(struct string_list a, struct string_list b,
	279	int creation_factor)
	280	{
	281	int n = a->nr + b->nr;
	282	int cost, c, a2b, *b2a;
	283	int i, j;
	284
	285	ALLOC_ARRAY(cost, st_mult(n, n));
	286	ALLOC_ARRAY(a2b, n);
	287	ALLOC_ARRAY(b2a, n);
	288
	289	for (i = 0; i < a->nr; i++) {
	290	struct patch_util *a_util = a->items[i].util;
	291
	292	for (j = 0; j < b->nr; j++) {
	293	struct patch_util *b_util = b->items[j].util;
	294
	295	if (a_util->matching == j)
	296	c = 0;
	297	else if (a_util->matching < 0 && b_util->matching < 0)
	298	c = diffsize(a_util->diff, b_util->diff);
	299	else
	300	c = COST_MAX;
	301	cost[i + n * j] = c;
	302	}
	303
	304	c = a_util->matching < 0 ?
	305	a_util->diffsize * creation_factor / 100 : COST_MAX;
	306	for (j = b->nr; j < n; j++)
	307	cost[i + n * j] = c;
	308	}
	309
	310	for (j = 0; j < b->nr; j++) {
	311	struct patch_util *util = b->items[j].util;
	312
	313	c = util->matching < 0 ?
	314	util->diffsize * creation_factor / 100 : COST_MAX;
	315	for (i = a->nr; i < n; i++)
	316	cost[i + n * j] = c;
	317	}
	318
	319	for (i = a->nr; i < n; i++)
	320	for (j = b->nr; j < n; j++)
	321	cost[i + n * j] = 0;
	322
	323	compute_assignment(n, n, cost, a2b, b2a);
	324
	325	for (i = 0; i < a->nr; i++)
	326	if (a2b[i] >= 0 && a2b[i] < b->nr) {
	327	struct patch_util *a_util = a->items[i].util;
	328	struct patch_util *b_util = b->items[a2b[i]].util;
	329
	330	a_util->matching = a2b[i];
	331	b_util->matching = i;
	332	}
	333
	334	free(cost);
	335	free(a2b);
336	free(b2a);
337	}
338
faa1df86	339	static void output_pair_header(struct diff_options *diffopt,
d1f87a2d	340	int patch_no_width,
faa1df86	341	struct strbuf *buf,
eb0be38c JS	342	struct strbuf *dashes,
	343	struct patch_util *a_util,
	344	struct patch_util *b_util)
d9c66f0b	345	{
eb0be38c JS	346	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
eb0be38c JS	347	struct commit *commit;
faa1df86 JS	348	char status;
	349	const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
	350	const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
	351	const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
	352	const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
	353	const char *color;
eb0be38c JS	354
	355	if (!dashes->len)
	356	strbuf_addchars(dashes, '-',
	357	strlen(find_unique_abbrev(oid,
	358	DEFAULT_ABBREV)));
	359
faa1df86 JS	360	if (!b_util) {
	361	color = color_old;
	362	status = '<';
	363	} else if (!a_util) {
	364	color = color_new;
	365	status = '>';
	366	} else if (strcmp(a_util->patch, b_util->patch)) {
	367	color = color_commit;
	368	status = '!';
	369	} else {
	370	color = color_commit;
	371	status = '=';
	372	}
	373
eb0be38c	374	strbuf_reset(buf);
faa1df86	375	strbuf_addstr(buf, status == '!' ? color_old : color);
eb0be38c	376	if (!a_util)
d1f87a2d	377	strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
eb0be38c	378	else
d1f87a2d	379	strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
eb0be38c JS	380	find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
eb0be38c JS	381
faa1df86 JS	382	if (status == '!')
	383	strbuf_addf(buf, "%s%s", color_reset, color);
	384	strbuf_addch(buf, status);
	385	if (status == '!')
	386	strbuf_addf(buf, "%s%s", color_reset, color_new);
eb0be38c JS	387
eb0be38c JS	388	if (!b_util)
d1f87a2d	389	strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
eb0be38c	390	else
d1f87a2d	391	strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
eb0be38c JS	392	find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
	393
	394	commit = lookup_commit_reference(the_repository, oid);
	395	if (commit) {
faa1df86 JS	396	if (status == '!')
	397	strbuf_addf(buf, "%s%s", color_reset, color);
	398
eb0be38c JS	399	strbuf_addch(buf, ' ');
	400	pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
	401	}
faa1df86	402	strbuf_addf(buf, "%s\n", color_reset);
eb0be38c	403
87f1b2d4	404	fwrite(buf->buf, buf->len, 1, diffopt->file);
d9c66f0b JS	405	}
d9c66f0b JS	406
499352c2 TG	407	static struct userdiff_driver section_headers = {
	408	.funcname = { "^ ## (.*) ##$\n"
	409	"^.?@@ (.*)$", REG_EXTENDED }
4eba1fe6 JS	410	};
4eba1fe6 JS	411
c8c5e43a JS	412	static struct diff_filespec get_filespec(const char name, const char *p)
	413	{
	414	struct diff_filespec *spec = alloc_filespec(name);
	415
0e573e8f	416	fill_filespec(spec, &null_oid, 0, 0100644);
c8c5e43a JS	417	spec->data = (char *)p;
	418	spec->size = strlen(p);
	419	spec->should_munmap = 0;
	420	spec->is_stdin = 1;
499352c2	421	spec->driver = &section_headers;
c8c5e43a JS	422
	423	return spec;
	424	}
	425
	426	static void patch_diff(const char a, const char b,
1ca69225	427	struct diff_options *diffopt)
c8c5e43a JS	428	{
	429	diff_queue(&diff_queued_diff,
	430	get_filespec("a", a), get_filespec("b", b));
	431
	432	diffcore_std(diffopt);
	433	diff_flush(diffopt);
	434	}
	435
	436	static void output(struct string_list a, struct string_list b,
	437	struct diff_options *diffopt)
d9c66f0b	438	{
eb0be38c	439	struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
d1f87a2d	440	int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
9dc46e02 JS	441	int i = 0, j = 0;
	442
	443	/*
	444	* We assume the user is really more interested in the second argument
	445	* ("newer" version). To that end, we print the output in the order of
	446	* the RHS (the `b` parameter). To put the LHS (the `a` parameter)
	447	* commits that are no longer in the RHS into a good place, we place
	448	* them once we have shown all of their predecessors in the LHS.
	449	*/
	450
	451	while (i < a->nr \|\| j < b->nr) {
	452	struct patch_util a_util, b_util;
	453	a_util = i < a->nr ? a->items[i].util : NULL;
	454	b_util = j < b->nr ? b->items[j].util : NULL;
	455
	456	/* Skip all the already-shown commits from the LHS. */
	457	while (i < a->nr && a_util->shown)
	458	a_util = ++i < a->nr ? a->items[i].util : NULL;
	459
	460	/* Show unmatched LHS commit whose predecessors were shown. */
	461	if (i < a->nr && a_util->matching < 0) {
d1f87a2d	462	output_pair_header(diffopt, patch_no_width,
faa1df86	463	&buf, &dashes, a_util, NULL);
9dc46e02 JS	464	i++;
	465	continue;
	466	}
d9c66f0b	467
9dc46e02 JS	468	/* Show unmatched RHS commits. */
9dc46e02 JS	469	while (j < b->nr && b_util->matching < 0) {
d1f87a2d	470	output_pair_header(diffopt, patch_no_width,
faa1df86	471	&buf, &dashes, NULL, b_util);
9dc46e02	472	b_util = ++j < b->nr ? b->items[j].util : NULL;
d9c66f0b	473	}
d9c66f0b	474
9dc46e02 JS	475	/* Show matching LHS/RHS pair. */
	476	if (j < b->nr) {
	477	a_util = a->items[b_util->matching].util;
d1f87a2d	478	output_pair_header(diffopt, patch_no_width,
faa1df86	479	&buf, &dashes, a_util, b_util);
c8c5e43a JS	480	if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
	481	patch_diff(a->items[b_util->matching].string,
	482	b->items[j].string, diffopt);
9dc46e02 JS	483	a_util->shown = 1;
	484	j++;
	485	}
d9c66f0b	486	}
eb0be38c JS	487	strbuf_release(&buf);
eb0be38c JS	488	strbuf_release(&dashes);
d9c66f0b JS	489	}
d9c66f0b JS	490
73a834e9 ES	491	static struct strbuf output_prefix_cb(struct diff_options opt, void *data)
	492	{
	493	return data;
	494	}
	495
d9c66f0b	496	int show_range_diff(const char range1, const char range2,
73a834e9 ES	497	int creation_factor, int dual_color,
73a834e9 ES	498	struct diff_options *diffopt)
d9c66f0b JS	499	{
	500	int res = 0;
	501
	502	struct string_list branch1 = STRING_LIST_INIT_DUP;
	503	struct string_list branch2 = STRING_LIST_INIT_DUP;
	504
	505	if (read_patches(range1, &branch1))
	506	res = error(_("could not parse log for '%s'"), range1);
	507	if (!res && read_patches(range2, &branch2))
	508	res = error(_("could not parse log for '%s'"), range2);
	509
	510	if (!res) {
73a834e9 ES	511	struct diff_options opts;
	512	struct strbuf indent = STRBUF_INIT;
	513
d8981c3f JH	514	if (diffopt)
	515	memcpy(&opts, diffopt, sizeof(opts));
	516	else
	517	diff_setup(&opts);
	518
a48e12ef ÆAB	519	if (!opts.output_format)
a48e12ef ÆAB	520	opts.output_format = DIFF_FORMAT_PATCH;
73a834e9 ES	521	opts.flags.suppress_diff_headers = 1;
73a834e9 ES	522	opts.flags.dual_color_diffed_diffs = dual_color;
430be36e	523	opts.flags.suppress_hunk_header_line_count = 1;
73a834e9 ES	524	opts.output_prefix = output_prefix_cb;
	525	strbuf_addstr(&indent, " ");
	526	opts.output_prefix_data = &indent;
	527	diff_setup_done(&opts);
	528
d9c66f0b JS	529	find_exact_matches(&branch1, &branch2);
d9c66f0b JS	530	get_correspondences(&branch1, &branch2, creation_factor);
73a834e9 ES	531	output(&branch1, &branch2, &opts);
	532
	533	strbuf_release(&indent);
d9c66f0b JS	534	}
	535
	536	string_list_clear(&branch1, 1);
	537	string_list_clear(&branch2, 1);
	538
	539	return res;
	540	}