[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->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, NULL,
					struct patch_util,
					e /* member name */);
		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;
d22245a2	220	hashmap_entry_init(&util->e, strhash(util->diff));
b94e5c1d	221	hashmap_add(&map, &util->e);
d9c66f0b JS	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;
d22245a2	231	hashmap_entry_init(&util->e, strhash(util->diff));
8a973d0b EW	232	other = hashmap_remove_entry(&map, util, NULL,
	233	struct patch_util,
	234	e /* member name */);
d9c66f0b JS	235	if (other) {
	236	if (other->matching >= 0)
	237	BUG("already assigned!");
	238
	239	other->matching = i;
	240	util->matching = other->i;
	241	}
	242	}
	243
	244	hashmap_free(&map, 0);
	245	}
	246
	247	static void diffsize_consume(void data, char line, unsigned long len)
	248	{
	249	((int )data)++;
	250	}
	251
d2eb8093 JK	252	static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
	253	const char *funcline, long funclen)
	254	{
	255	diffsize_consume(data, NULL, 0);
	256	}
	257
d9c66f0b JS	258	static int diffsize(const char a, const char b)
	259	{
	260	xpparam_t pp = { 0 };
	261	xdemitconf_t cfg = { 0 };
	262	mmfile_t mf1, mf2;
	263	int count = 0;
	264
	265	mf1.ptr = (char *)a;
	266	mf1.size = strlen(a);
	267	mf2.ptr = (char *)b;
	268	mf2.size = strlen(b);
	269
	270	cfg.ctxlen = 3;
d2eb8093 JK	271	if (!xdi_diff_outf(&mf1, &mf2,
	272	diffsize_hunk, diffsize_consume, &count,
	273	&pp, &cfg))
d9c66f0b JS	274	return count;
	275
	276	error(_("failed to generate diff"));
	277	return COST_MAX;
	278	}
	279
	280	static void get_correspondences(struct string_list a, struct string_list b,
	281	int creation_factor)
	282	{
	283	int n = a->nr + b->nr;
	284	int cost, c, a2b, *b2a;
	285	int i, j;
	286
	287	ALLOC_ARRAY(cost, st_mult(n, n));
	288	ALLOC_ARRAY(a2b, n);
	289	ALLOC_ARRAY(b2a, n);
	290
	291	for (i = 0; i < a->nr; i++) {
	292	struct patch_util *a_util = a->items[i].util;
	293
	294	for (j = 0; j < b->nr; j++) {
	295	struct patch_util *b_util = b->items[j].util;
	296
	297	if (a_util->matching == j)
	298	c = 0;
	299	else if (a_util->matching < 0 && b_util->matching < 0)
	300	c = diffsize(a_util->diff, b_util->diff);
	301	else
	302	c = COST_MAX;
	303	cost[i + n * j] = c;
	304	}
	305
	306	c = a_util->matching < 0 ?
	307	a_util->diffsize * creation_factor / 100 : COST_MAX;
	308	for (j = b->nr; j < n; j++)
	309	cost[i + n * j] = c;
	310	}
	311
	312	for (j = 0; j < b->nr; j++) {
	313	struct patch_util *util = b->items[j].util;
	314
	315	c = util->matching < 0 ?
	316	util->diffsize * creation_factor / 100 : COST_MAX;
	317	for (i = a->nr; i < n; i++)
	318	cost[i + n * j] = c;
	319	}
	320
	321	for (i = a->nr; i < n; i++)
	322	for (j = b->nr; j < n; j++)
	323	cost[i + n * j] = 0;
	324
	325	compute_assignment(n, n, cost, a2b, b2a);
	326
	327	for (i = 0; i < a->nr; i++)
	328	if (a2b[i] >= 0 && a2b[i] < b->nr) {
	329	struct patch_util *a_util = a->items[i].util;
	330	struct patch_util *b_util = b->items[a2b[i]].util;
	331
	332	a_util->matching = a2b[i];
	333	b_util->matching = i;
	334	}
	335
	336	free(cost);
	337	free(a2b);
338	free(b2a);
339	}
340
faa1df86	341	static void output_pair_header(struct diff_options *diffopt,
d1f87a2d	342	int patch_no_width,
faa1df86	343	struct strbuf *buf,
eb0be38c JS	344	struct strbuf *dashes,
	345	struct patch_util *a_util,
	346	struct patch_util *b_util)
d9c66f0b	347	{
eb0be38c JS	348	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
eb0be38c JS	349	struct commit *commit;
faa1df86 JS	350	char status;
	351	const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
	352	const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
	353	const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
	354	const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
	355	const char *color;
eb0be38c JS	356
	357	if (!dashes->len)
	358	strbuf_addchars(dashes, '-',
	359	strlen(find_unique_abbrev(oid,
	360	DEFAULT_ABBREV)));
	361
faa1df86 JS	362	if (!b_util) {
	363	color = color_old;
	364	status = '<';
	365	} else if (!a_util) {
	366	color = color_new;
	367	status = '>';
	368	} else if (strcmp(a_util->patch, b_util->patch)) {
	369	color = color_commit;
	370	status = '!';
	371	} else {
	372	color = color_commit;
	373	status = '=';
	374	}
	375
eb0be38c	376	strbuf_reset(buf);
faa1df86	377	strbuf_addstr(buf, status == '!' ? color_old : color);
eb0be38c	378	if (!a_util)
d1f87a2d	379	strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
eb0be38c	380	else
d1f87a2d	381	strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
eb0be38c JS	382	find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
eb0be38c JS	383
faa1df86 JS	384	if (status == '!')
	385	strbuf_addf(buf, "%s%s", color_reset, color);
	386	strbuf_addch(buf, status);
	387	if (status == '!')
	388	strbuf_addf(buf, "%s%s", color_reset, color_new);
eb0be38c JS	389
eb0be38c JS	390	if (!b_util)
d1f87a2d	391	strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
eb0be38c	392	else
d1f87a2d	393	strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
eb0be38c JS	394	find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
	395
	396	commit = lookup_commit_reference(the_repository, oid);
	397	if (commit) {
faa1df86 JS	398	if (status == '!')
	399	strbuf_addf(buf, "%s%s", color_reset, color);
	400
eb0be38c JS	401	strbuf_addch(buf, ' ');
	402	pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
	403	}
faa1df86	404	strbuf_addf(buf, "%s\n", color_reset);
eb0be38c	405
87f1b2d4	406	fwrite(buf->buf, buf->len, 1, diffopt->file);
d9c66f0b JS	407	}
d9c66f0b JS	408
499352c2 TG	409	static struct userdiff_driver section_headers = {
	410	.funcname = { "^ ## (.*) ##$\n"
	411	"^.?@@ (.*)$", REG_EXTENDED }
4eba1fe6 JS	412	};
4eba1fe6 JS	413
c8c5e43a JS	414	static struct diff_filespec get_filespec(const char name, const char *p)
	415	{
	416	struct diff_filespec *spec = alloc_filespec(name);
	417
0e573e8f	418	fill_filespec(spec, &null_oid, 0, 0100644);
c8c5e43a JS	419	spec->data = (char *)p;
	420	spec->size = strlen(p);
	421	spec->should_munmap = 0;
	422	spec->is_stdin = 1;
499352c2	423	spec->driver = &section_headers;
c8c5e43a JS	424
	425	return spec;
	426	}
	427
	428	static void patch_diff(const char a, const char b,
1ca69225	429	struct diff_options *diffopt)
c8c5e43a JS	430	{
	431	diff_queue(&diff_queued_diff,
	432	get_filespec("a", a), get_filespec("b", b));
	433
	434	diffcore_std(diffopt);
	435	diff_flush(diffopt);
	436	}
	437
	438	static void output(struct string_list a, struct string_list b,
	439	struct diff_options *diffopt)
d9c66f0b	440	{
eb0be38c	441	struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
d1f87a2d	442	int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
9dc46e02 JS	443	int i = 0, j = 0;
	444
	445	/*
	446	* We assume the user is really more interested in the second argument
	447	* ("newer" version). To that end, we print the output in the order of
	448	* the RHS (the `b` parameter). To put the LHS (the `a` parameter)
	449	* commits that are no longer in the RHS into a good place, we place
	450	* them once we have shown all of their predecessors in the LHS.
	451	*/
	452
	453	while (i < a->nr \|\| j < b->nr) {
	454	struct patch_util a_util, b_util;
	455	a_util = i < a->nr ? a->items[i].util : NULL;
	456	b_util = j < b->nr ? b->items[j].util : NULL;
	457
	458	/* Skip all the already-shown commits from the LHS. */
	459	while (i < a->nr && a_util->shown)
	460	a_util = ++i < a->nr ? a->items[i].util : NULL;
	461
	462	/* Show unmatched LHS commit whose predecessors were shown. */
	463	if (i < a->nr && a_util->matching < 0) {
d1f87a2d	464	output_pair_header(diffopt, patch_no_width,
faa1df86	465	&buf, &dashes, a_util, NULL);
9dc46e02 JS	466	i++;
	467	continue;
	468	}
d9c66f0b	469
9dc46e02 JS	470	/* Show unmatched RHS commits. */
9dc46e02 JS	471	while (j < b->nr && b_util->matching < 0) {
d1f87a2d	472	output_pair_header(diffopt, patch_no_width,
faa1df86	473	&buf, &dashes, NULL, b_util);
9dc46e02	474	b_util = ++j < b->nr ? b->items[j].util : NULL;
d9c66f0b	475	}
d9c66f0b	476
9dc46e02 JS	477	/* Show matching LHS/RHS pair. */
	478	if (j < b->nr) {
	479	a_util = a->items[b_util->matching].util;
d1f87a2d	480	output_pair_header(diffopt, patch_no_width,
faa1df86	481	&buf, &dashes, a_util, b_util);
c8c5e43a JS	482	if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
	483	patch_diff(a->items[b_util->matching].string,
	484	b->items[j].string, diffopt);
9dc46e02 JS	485	a_util->shown = 1;
	486	j++;
	487	}
d9c66f0b	488	}
eb0be38c JS	489	strbuf_release(&buf);
eb0be38c JS	490	strbuf_release(&dashes);
d9c66f0b JS	491	}
d9c66f0b JS	492
73a834e9 ES	493	static struct strbuf output_prefix_cb(struct diff_options opt, void *data)
	494	{
	495	return data;
	496	}
	497
d9c66f0b	498	int show_range_diff(const char range1, const char range2,
73a834e9 ES	499	int creation_factor, int dual_color,
73a834e9 ES	500	struct diff_options *diffopt)
d9c66f0b JS	501	{
	502	int res = 0;
	503
	504	struct string_list branch1 = STRING_LIST_INIT_DUP;
	505	struct string_list branch2 = STRING_LIST_INIT_DUP;
	506
	507	if (read_patches(range1, &branch1))
	508	res = error(_("could not parse log for '%s'"), range1);
	509	if (!res && read_patches(range2, &branch2))
	510	res = error(_("could not parse log for '%s'"), range2);
	511
	512	if (!res) {
73a834e9 ES	513	struct diff_options opts;
	514	struct strbuf indent = STRBUF_INIT;
	515
d8981c3f JH	516	if (diffopt)
	517	memcpy(&opts, diffopt, sizeof(opts));
	518	else
	519	diff_setup(&opts);
	520
a48e12ef ÆAB	521	if (!opts.output_format)
a48e12ef ÆAB	522	opts.output_format = DIFF_FORMAT_PATCH;
73a834e9 ES	523	opts.flags.suppress_diff_headers = 1;
73a834e9 ES	524	opts.flags.dual_color_diffed_diffs = dual_color;
430be36e	525	opts.flags.suppress_hunk_header_line_count = 1;
73a834e9 ES	526	opts.output_prefix = output_prefix_cb;
	527	strbuf_addstr(&indent, " ");
	528	opts.output_prefix_data = &indent;
	529	diff_setup_done(&opts);
	530
d9c66f0b JS	531	find_exact_matches(&branch1, &branch2);
d9c66f0b JS	532	get_correspondences(&branch1, &branch2, creation_factor);
73a834e9 ES	533	output(&branch1, &branch2, &opts);
	534
	535	strbuf_release(&indent);
d9c66f0b JS	536	}
	537
	538	string_list_clear(&branch1, 1);
	539	string_list_clear(&branch2, 1);
	540
	541	return res;
	542	}