[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,
			const struct argv_array *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;

	argv_array_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",
			NULL);
	if (other_arg)
		argv_array_pushv(&cp.args, other_arg->argv);
	argv_array_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 (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, 0, 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, "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;
	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, e, NULL);
		if (other) {
			if (other->matching >= 0)
				BUG("already assigned!");

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

	hashmap_free(&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 argv_array *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;
}
Commit	Line	Data
	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"
	9	#include "diffcore.h"
	10	#include "commit.h"
	11	#include "pretty.h"
	12	#include "userdiff.h"
	13	#include "apply.h"
	14
	15	struct patch_util {
	16	/* For the search for an exact match */
	17	struct hashmap_entry e;
	18	const char diff, patch;
	19
	20	int i, shown;
	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
	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
	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	const struct argv_array *other_arg)
	45	{
	46	struct child_process cp = CHILD_PROCESS_INIT;
	47	struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
	48	struct patch_util *util = NULL;
	49	int in_header = 1;
	50	char line, current_filename = NULL;
	51	int offset, len;
	52	size_t size;
	53
	54	argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
	55	"--reverse", "--date-order", "--decorate=no",
	56	"--no-prefix",
	57	/*
	58	* Choose indicators that are not used anywhere
	59	* else in diffs, but still look reasonable
	60	* (e.g. will not be confusing when debugging)
	61	*/
	62	"--output-indicator-new=>",
	63	"--output-indicator-old=<",
	64	"--output-indicator-context=#",
	65	"--no-abbrev-commit",
	66	NULL);
	67	if (other_arg)
	68	argv_array_pushv(&cp.args, other_arg->argv);
	69	argv_array_push(&cp.args, range);
	70	cp.out = -1;
	71	cp.no_stdin = 1;
	72	cp.git_cmd = 1;
	73
	74	if (start_command(&cp))
	75	return error_errno(_("could not start `log`"));
	76	if (strbuf_read(&contents, cp.out, 0) < 0) {
	77	error_errno(_("could not read `log` output"));
	78	finish_command(&cp);
	79	return -1;
	80	}
	81
	82	line = contents.buf;
	83	size = contents.len;
	84	for (offset = 0; size > 0; offset += len, size -= len, line += len) {
	85	const char *p;
	86
	87	len = find_end_of_line(line, size);
	88	line[len - 1] = '\0';
	89	if (skip_prefix(line, "commit ", &p)) {
	90	if (util) {
	91	string_list_append(list, buf.buf)->util = util;
	92	strbuf_reset(&buf);
	93	}
	94	util = xcalloc(sizeof(*util), 1);
	95	if (get_oid(p, &util->oid)) {
	96	error(_("could not parse commit '%s'"), p);
	97	free(util);
	98	string_list_clear(list, 1);
	99	strbuf_release(&buf);
	100	strbuf_release(&contents);
	101	finish_command(&cp);
	102	return -1;
	103	}
	104	util->matching = -1;
	105	in_header = 1;
	106	continue;
	107	}
	108
	109	if (starts_with(line, "diff --git")) {
	110	struct patch patch = { 0 };
	111	struct strbuf root = STRBUF_INIT;
	112	int linenr = 0;
	113
	114	in_header = 0;
	115	strbuf_addch(&buf, '\n');
	116	if (!util->diff_offset)
	117	util->diff_offset = buf.len;
	118	line[len - 1] = '\n';
	119	len = parse_git_diff_header(&root, &linenr, 0, line,
	120	len, size, &patch);
	121	if (len < 0)
	122	die(_("could not parse git header '%.*s'"), (int)len, line);
	123	strbuf_addstr(&buf, " ## ");
	124	if (patch.is_new > 0)
	125	strbuf_addf(&buf, "%s (new)", patch.new_name);
	126	else if (patch.is_delete > 0)
	127	strbuf_addf(&buf, "%s (deleted)", patch.old_name);
	128	else if (patch.is_rename)
	129	strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
	130	else
	131	strbuf_addstr(&buf, patch.new_name);
	132
	133	free(current_filename);
	134	if (patch.is_delete > 0)
	135	current_filename = xstrdup(patch.old_name);
	136	else
	137	current_filename = xstrdup(patch.new_name);
	138
	139	if (patch.new_mode && patch.old_mode &&
	140	patch.old_mode != patch.new_mode)
	141	strbuf_addf(&buf, " (mode change %06o => %06o)",
	142	patch.old_mode, patch.new_mode);
	143
	144	strbuf_addstr(&buf, " ##");
	145	} else if (in_header) {
	146	if (starts_with(line, "Author: ")) {
	147	strbuf_addstr(&buf, " ## Metadata ##\n");
	148	strbuf_addstr(&buf, line);
	149	strbuf_addstr(&buf, "\n\n");
	150	strbuf_addstr(&buf, " ## Commit message ##\n");
	151	} else if (starts_with(line, "Notes") &&
	152	line[strlen(line) - 1] == ':') {
	153	strbuf_addstr(&buf, "\n\n");
	154	/* strip the trailing colon */
	155	strbuf_addf(&buf, " ## %.*s ##\n",
	156	(int)(strlen(line) - 1), line);
	157	} else if (starts_with(line, " ")) {
	158	p = line + len - 2;
	159	while (isspace(*p) && p >= line)
	160	p--;
	161	strbuf_add(&buf, line, p - line + 1);
	162	strbuf_addch(&buf, '\n');
	163	}
	164	continue;
	165	} else if (skip_prefix(line, "@@ ", &p)) {
	166	p = strstr(p, "@@");
	167	strbuf_addstr(&buf, "@@");
	168	if (current_filename && p[2])
	169	strbuf_addf(&buf, " %s:", current_filename);
	170	if (p)
	171	strbuf_addstr(&buf, p + 2);
	172	} else if (!line[0])
	173	/*
	174	* A completely blank (not ' \n', which is context)
	175	* line is not valid in a diff. We skip it
	176	* silently, because this neatly handles the blank
	177	* separator line between commits in git-log
	178	* output.
	179	*/
	180	continue;
	181	else if (line[0] == '>') {
	182	strbuf_addch(&buf, '+');
	183	strbuf_addstr(&buf, line + 1);
	184	} else if (line[0] == '<') {
	185	strbuf_addch(&buf, '-');
	186	strbuf_addstr(&buf, line + 1);
	187	} else if (line[0] == '#') {
	188	strbuf_addch(&buf, ' ');
	189	strbuf_addstr(&buf, line + 1);
	190	} else {
	191	strbuf_addch(&buf, ' ');
	192	strbuf_addstr(&buf, line);
	193	}
	194
	195	strbuf_addch(&buf, '\n');
	196	util->diffsize++;
	197	}
	198	strbuf_release(&contents);
	199
	200	if (util)
	201	string_list_append(list, buf.buf)->util = util;
	202	strbuf_release(&buf);
	203	free(current_filename);
	204
	205	if (finish_command(&cp))
	206	return -1;
	207
	208	return 0;
	209	}
	210
	211	static int patch_util_cmp(const void dummy, const struct patch_util a,
	212	const struct patch_util b, const char keydata)
	213	{
	214	return strcmp(a->diff, keydata ? keydata : b->diff);
	215	}
	216
	217	static void find_exact_matches(struct string_list a, struct string_list b)
	218	{
	219	struct hashmap map;
	220	int i;
	221
	222	hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);
	223
	224	/* First, add the patches of a to a hash map */
	225	for (i = 0; i < a->nr; i++) {
	226	struct patch_util *util = a->items[i].util;
	227
	228	util->i = i;
	229	util->patch = a->items[i].string;
	230	util->diff = util->patch + util->diff_offset;
	231	hashmap_entry_init(&util->e, strhash(util->diff));
	232	hashmap_add(&map, &util->e);
	233	}
	234
	235	/* Now try to find exact matches in b */
	236	for (i = 0; i < b->nr; i++) {
	237	struct patch_util util = b->items[i].util, other;
	238
	239	util->i = i;
	240	util->patch = b->items[i].string;
	241	util->diff = util->patch + util->diff_offset;
	242	hashmap_entry_init(&util->e, strhash(util->diff));
	243	other = hashmap_remove_entry(&map, util, e, NULL);
	244	if (other) {
	245	if (other->matching >= 0)
	246	BUG("already assigned!");
	247
	248	other->matching = i;
	249	util->matching = other->i;
	250	}
	251	}
	252
	253	hashmap_free(&map);
	254	}
	255
	256	static void diffsize_consume(void data, char line, unsigned long len)
	257	{
	258	((int )data)++;
	259	}
	260
	261	static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
	262	const char *funcline, long funclen)
	263	{
	264	diffsize_consume(data, NULL, 0);
	265	}
	266
	267	static int diffsize(const char a, const char b)
	268	{
	269	xpparam_t pp = { 0 };
	270	xdemitconf_t cfg = { 0 };
	271	mmfile_t mf1, mf2;
	272	int count = 0;
	273
	274	mf1.ptr = (char *)a;
	275	mf1.size = strlen(a);
	276	mf2.ptr = (char *)b;
	277	mf2.size = strlen(b);
	278
	279	cfg.ctxlen = 3;
	280	if (!xdi_diff_outf(&mf1, &mf2,
	281	diffsize_hunk, diffsize_consume, &count,
	282	&pp, &cfg))
	283	return count;
	284
	285	error(_("failed to generate diff"));
	286	return COST_MAX;
	287	}
	288
	289	static void get_correspondences(struct string_list a, struct string_list b,
	290	int creation_factor)
	291	{
	292	int n = a->nr + b->nr;
	293	int cost, c, a2b, *b2a;
	294	int i, j;
	295
	296	ALLOC_ARRAY(cost, st_mult(n, n));
	297	ALLOC_ARRAY(a2b, n);
	298	ALLOC_ARRAY(b2a, n);
	299
	300	for (i = 0; i < a->nr; i++) {
	301	struct patch_util *a_util = a->items[i].util;
	302
	303	for (j = 0; j < b->nr; j++) {
	304	struct patch_util *b_util = b->items[j].util;
	305
	306	if (a_util->matching == j)
	307	c = 0;
	308	else if (a_util->matching < 0 && b_util->matching < 0)
	309	c = diffsize(a_util->diff, b_util->diff);
	310	else
	311	c = COST_MAX;
	312	cost[i + n * j] = c;
	313	}
	314
	315	c = a_util->matching < 0 ?
	316	a_util->diffsize * creation_factor / 100 : COST_MAX;
	317	for (j = b->nr; j < n; j++)
	318	cost[i + n * j] = c;
	319	}
	320
	321	for (j = 0; j < b->nr; j++) {
	322	struct patch_util *util = b->items[j].util;
	323
	324	c = util->matching < 0 ?
	325	util->diffsize * creation_factor / 100 : COST_MAX;
	326	for (i = a->nr; i < n; i++)
	327	cost[i + n * j] = c;
	328	}
	329
	330	for (i = a->nr; i < n; i++)
	331	for (j = b->nr; j < n; j++)
	332	cost[i + n * j] = 0;
	333
	334	compute_assignment(n, n, cost, a2b, b2a);
	335
	336	for (i = 0; i < a->nr; i++)
	337	if (a2b[i] >= 0 && a2b[i] < b->nr) {
	338	struct patch_util *a_util = a->items[i].util;
	339	struct patch_util *b_util = b->items[a2b[i]].util;
	340
	341	a_util->matching = a2b[i];
	342	b_util->matching = i;
	343	}
	344
	345	free(cost);
	346	free(a2b);
	347	free(b2a);
	348	}
	349
	350	static void output_pair_header(struct diff_options *diffopt,
	351	int patch_no_width,
	352	struct strbuf *buf,
	353	struct strbuf *dashes,
	354	struct patch_util *a_util,
	355	struct patch_util *b_util)
	356	{
	357	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
	358	struct commit *commit;
	359	char status;
	360	const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
	361	const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
	362	const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
	363	const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
	364	const char *color;
	365
	366	if (!dashes->len)
	367	strbuf_addchars(dashes, '-',
	368	strlen(find_unique_abbrev(oid,
	369	DEFAULT_ABBREV)));
	370
	371	if (!b_util) {
	372	color = color_old;
	373	status = '<';
	374	} else if (!a_util) {
	375	color = color_new;
	376	status = '>';
	377	} else if (strcmp(a_util->patch, b_util->patch)) {
	378	color = color_commit;
	379	status = '!';
	380	} else {
	381	color = color_commit;
	382	status = '=';
	383	}
	384
	385	strbuf_reset(buf);
	386	strbuf_addstr(buf, status == '!' ? color_old : color);
	387	if (!a_util)
	388	strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
	389	else
	390	strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
	391	find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
	392
	393	if (status == '!')
	394	strbuf_addf(buf, "%s%s", color_reset, color);
	395	strbuf_addch(buf, status);
	396	if (status == '!')
	397	strbuf_addf(buf, "%s%s", color_reset, color_new);
	398
	399	if (!b_util)
	400	strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
	401	else
	402	strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
	403	find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
	404
	405	commit = lookup_commit_reference(the_repository, oid);
	406	if (commit) {
	407	if (status == '!')
	408	strbuf_addf(buf, "%s%s", color_reset, color);
	409
	410	strbuf_addch(buf, ' ');
	411	pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
	412	}
	413	strbuf_addf(buf, "%s\n", color_reset);
	414
	415	fwrite(buf->buf, buf->len, 1, diffopt->file);
	416	}
	417
	418	static struct userdiff_driver section_headers = {
	419	.funcname = { "^ ## (.*) ##$\n"
	420	"^.?@@ (.*)$", REG_EXTENDED }
	421	};
	422
	423	static struct diff_filespec get_filespec(const char name, const char *p)
	424	{
	425	struct diff_filespec *spec = alloc_filespec(name);
	426
	427	fill_filespec(spec, &null_oid, 0, 0100644);
	428	spec->data = (char *)p;
	429	spec->size = strlen(p);
	430	spec->should_munmap = 0;
	431	spec->is_stdin = 1;
	432	spec->driver = &section_headers;
	433
	434	return spec;
	435	}
	436
	437	static void patch_diff(const char a, const char b,
	438	struct diff_options *diffopt)
	439	{
	440	diff_queue(&diff_queued_diff,
	441	get_filespec("a", a), get_filespec("b", b));
	442
	443	diffcore_std(diffopt);
	444	diff_flush(diffopt);
	445	}
	446
	447	static void output(struct string_list a, struct string_list b,
	448	struct diff_options *diffopt)
	449	{
	450	struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
	451	int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
	452	int i = 0, j = 0;
	453
	454	/*
	455	* We assume the user is really more interested in the second argument
	456	* ("newer" version). To that end, we print the output in the order of
	457	* the RHS (the `b` parameter). To put the LHS (the `a` parameter)
	458	* commits that are no longer in the RHS into a good place, we place
	459	* them once we have shown all of their predecessors in the LHS.
	460	*/
	461
	462	while (i < a->nr \|\| j < b->nr) {
	463	struct patch_util a_util, b_util;
	464	a_util = i < a->nr ? a->items[i].util : NULL;
	465	b_util = j < b->nr ? b->items[j].util : NULL;
	466
	467	/* Skip all the already-shown commits from the LHS. */
	468	while (i < a->nr && a_util->shown)
	469	a_util = ++i < a->nr ? a->items[i].util : NULL;
	470
	471	/* Show unmatched LHS commit whose predecessors were shown. */
	472	if (i < a->nr && a_util->matching < 0) {
	473	output_pair_header(diffopt, patch_no_width,
	474	&buf, &dashes, a_util, NULL);
	475	i++;
	476	continue;
	477	}
	478
	479	/* Show unmatched RHS commits. */
	480	while (j < b->nr && b_util->matching < 0) {
	481	output_pair_header(diffopt, patch_no_width,
	482	&buf, &dashes, NULL, b_util);
	483	b_util = ++j < b->nr ? b->items[j].util : NULL;
	484	}
	485
	486	/* Show matching LHS/RHS pair. */
	487	if (j < b->nr) {
	488	a_util = a->items[b_util->matching].util;
	489	output_pair_header(diffopt, patch_no_width,
	490	&buf, &dashes, a_util, b_util);
	491	if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
	492	patch_diff(a->items[b_util->matching].string,
	493	b->items[j].string, diffopt);
	494	a_util->shown = 1;
	495	j++;
	496	}
	497	}
	498	strbuf_release(&buf);
	499	strbuf_release(&dashes);
	500	}
	501
	502	static struct strbuf output_prefix_cb(struct diff_options opt, void *data)
	503	{
	504	return data;
	505	}
	506
	507	int show_range_diff(const char range1, const char range2,
	508	int creation_factor, int dual_color,
	509	const struct diff_options *diffopt,
	510	const struct argv_array *other_arg)
	511	{
	512	int res = 0;
	513
	514	struct string_list branch1 = STRING_LIST_INIT_DUP;
	515	struct string_list branch2 = STRING_LIST_INIT_DUP;
	516
	517	if (read_patches(range1, &branch1, other_arg))
	518	res = error(_("could not parse log for '%s'"), range1);
	519	if (!res && read_patches(range2, &branch2, other_arg))
	520	res = error(_("could not parse log for '%s'"), range2);
	521
	522	if (!res) {
	523	struct diff_options opts;
	524	struct strbuf indent = STRBUF_INIT;
	525
	526	if (diffopt)
	527	memcpy(&opts, diffopt, sizeof(opts));
	528	else
	529	diff_setup(&opts);
	530
	531	if (!opts.output_format)
	532	opts.output_format = DIFF_FORMAT_PATCH;
	533	opts.flags.suppress_diff_headers = 1;
	534	opts.flags.dual_color_diffed_diffs = dual_color;
	535	opts.flags.suppress_hunk_header_line_count = 1;
	536	opts.output_prefix = output_prefix_cb;
	537	strbuf_addstr(&indent, " ");
	538	opts.output_prefix_data = &indent;
	539	diff_setup_done(&opts);
	540
	541	find_exact_matches(&branch1, &branch2);
	542	get_correspondences(&branch1, &branch2, creation_factor);
	543	output(&branch1, &branch2, &opts);
	544
	545	strbuf_release(&indent);
	546	}
	547
	548	string_list_clear(&branch1, 1);
	549	string_list_clear(&branch2, 1);
	550
	551	return res;
	552	}