[PATCH v3 09/13] print the line log

[Bo Yang <struggleyb.nku@gmail.com>]

'struct line_chunk' is used to make sure each file is scaned
only once when printing the lines. We trace the line number and
the start position of intermediate line in this struct.
Two helper functions from diff.c are used to generate the
consistent format of diff meta info.

Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
---
 line.c |  245 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 245 insertions(+), 0 deletions(-)

diff --git a/line.c b/line.c
index e1af2f6..8813376 100644
--- a/line.c
+++ b/line.c
@@ -951,3 +951,248 @@ static void assign_parents_range(struct rev_info *rev, struct commit *commit)
 	}
 }
 
+struct line_chunk {
+	int lone, ltwo;
+	const char *one, *two;
+	const char *one_end, *two_end;
+	struct diff_line_range *range;
+};
+
+static void flush_lines(struct diff_options *opt, const char **ptr, const char *end,
+		int slno, int elno, int *lno, const char *color, const char heading)
+{
+	const char *p = *ptr;
+	struct strbuf buf = STRBUF_INIT;
+	const char *reset;
+
+	if (strcmp(color, ""))
+		reset = "";
+	else
+		reset = diff_get_color_opt(opt, DIFF_RESET);
+
+	strbuf_addf(&buf, "%s%c", color, heading);
+	while (*ptr < end && *lno < slno) {
+		if (**ptr == '\n') {
+			(*lno)++;
+			if (*lno == slno) {
+				(*ptr)++;
+				break;
+			}
+		}
+		(*ptr)++;
+	}
+	assert(*ptr <= end);
+	p = *ptr;
+
+	/*
+	 * todo: when --graph landed on master, this should be changed
+	 * a little.
+	 */
+	while (*ptr < end && *lno <= elno) {
+		if (**ptr == '\n') {
+			fprintf(opt->file, "%s", buf.buf);
+			if (*ptr - p) {
+				fwrite(p, *ptr - p, 1, opt->file);
+			}
+			fprintf(opt->file, "%s\n", reset);
+			p = *ptr + 1;
+			(*lno)++;
+		}
+		(*ptr)++;
+	}
+	if (*lno <= elno) {
+		fprintf(opt->file, "%s", buf.buf);
+		if (*ptr - p) {
+			fwrite(p, *ptr - p, 1, opt->file);
+		}
+		fprintf(opt->file, "%s\n", reset);
+	}
+	strbuf_release(&buf);
+}
+
+static void diff_flush_range(struct diff_options *opt, struct line_chunk *chunk,
+		struct range *range)
+{
+	struct print_pair *pair = &range->pair;
+	const char *old = diff_get_color_opt(opt, DIFF_FILE_OLD);
+	const char *new = diff_get_color_opt(opt, DIFF_FILE_NEW);
+	int i, cur = range->start;
+
+	for (i = 0; i < pair->nr; i++) {
+		struct print_range *pr = pair->ranges + i;
+		if (cur < pr->start)
+			flush_lines(opt, &chunk->two, chunk->two_end,
+				cur, pr->start - 1, &chunk->ltwo, "", ' ');
+
+		if (!pr->line_added)
+			flush_lines(opt, &chunk->one, chunk->one_end,
+				pr->pstart, pr->pend, &chunk->lone, old, '-');
+		flush_lines(opt, &chunk->two, chunk->two_end,
+			pr->start, pr->end, &chunk->ltwo, new, '+');
+
+		cur = pr->end + 1;
+	}
+
+	if (cur <= range->end) {
+		flush_lines(opt, &chunk->two, chunk->two_end,
+			cur, range->end, &chunk->ltwo, "", ' ');
+	}
+}
+
+static void diff_flush_chunks(struct diff_options *opt, struct line_chunk *chunk)
+{
+	struct diff_line_range *range = chunk->range;
+	const char *set = diff_get_color_opt(opt, DIFF_FRAGINFO);
+	const char *reset = diff_get_color_opt(opt, DIFF_RESET);
+	int i;
+
+	for (i = 0; i < range->nr; i++) {
+		struct range *r = range->ranges + i;
+		long lenp = r->pend - r->pstart + 1, pstart = r->pstart;
+		long len = r->end - r->start + 1;
+		if (pstart == 0)
+			lenp = 0;
+
+		fprintf(opt->file, "%s@@ -%ld,%ld +%ld,%ld @@%s\n",
+			set, pstart, lenp, r->start, len, reset);
+
+		diff_flush_range(opt, chunk, r);
+	}
+}
+
+static void diff_flush_filepair(struct rev_info *rev, struct diff_line_range *range)
+{
+	struct diff_options *opt = &rev->diffopt;
+	struct diff_filespec *one = range->prev, *two = range->spec;
+	struct diff_filepair p = {one, two, range->status, 0};
+	struct strbuf header = STRBUF_INIT, meta = STRBUF_INIT;
+	const char *a_prefix, *b_prefix;
+	const char *name_a, *name_b, *a_one, *b_two;
+	const char *lbl[2];
+	const char *set = diff_get_color_opt(opt, DIFF_METAINFO);
+	const char *reset = diff_get_color_opt(opt, DIFF_RESET);
+	struct line_chunk chunk;
+	int must_show_header;
+
+	/*
+	 * the ranges that touch no different file, in this case
+	 * the line number will not change, and of course we have
+	 * no sensible rang->pair since there is no diff run.
+	 */
+	if (one == NULL) {
+		return;
+	}
+
+	if (range->status == DIFF_STATUS_DELETED)
+		die("We are following an nonexistent file, interesting!");
+
+	name_a  = one->path;
+	name_b = two->path;
+	fill_metainfo(&meta, name_a, name_b, one, two, opt, &p, &must_show_header,
+			DIFF_OPT_TST(opt, COLOR_DIFF));
+
+	diff_set_mnemonic_prefix(opt, "a/", "b/");
+	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
+		a_prefix = opt->b_prefix;
+		b_prefix = opt->a_prefix;
+	} else {
+		a_prefix = opt->a_prefix;
+		b_prefix = opt->b_prefix;
+	}
+
+	name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
+	name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
+
+	a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
+	b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
+	lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
+	lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
+	strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
+	if (lbl[0][0] == '/') {
+		strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
+	} else if (lbl[1][0] == '/') {
+		strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
+	} else if (one->mode != two->mode) {
+			strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
+			strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
+	}
+
+	fprintf(opt->file, "%s%s", header.buf, meta.buf);
+	strbuf_release(&meta);
+	strbuf_release(&header);
+	fprintf(opt->file, "%s--- %s%s\n", set, lbl[0], reset);
+	fprintf(opt->file, "%s+++ %s%s\n", set, lbl[1], reset);
+	free((void *)a_one);
+	free((void *)b_two);
+
+	chunk.one = one->data;
+	chunk.one_end = one->data + one->size;
+	chunk.lone = 1;
+	chunk.two = two->data;
+	chunk.two_end = two->data + two->size;
+	chunk.ltwo = 1;
+	chunk.range = range;
+	diff_flush_chunks(&rev->diffopt, &chunk);
+}
+
+#define EVIL_MERGE_STR "nontrivial merge found"
+static void flush_nontrivial_merge(struct rev_info *rev, struct diff_line_range *range)
+{
+	struct diff_options *opt = &rev->diffopt;
+	const char *reset = diff_get_color_opt(opt, DIFF_RESET);
+	const char *frag = diff_get_color_opt(opt, DIFF_FRAGINFO);
+	const char *meta = diff_get_color_opt(opt, DIFF_METAINFO);
+	const char *new = diff_get_color_opt(opt, DIFF_FILE_NEW);
+
+	fprintf(opt->file, "%s%s%s\n", meta, EVIL_MERGE_STR, reset);
+
+	while (range) {
+		if (range->nr) {
+			fprintf(opt->file, "%s%s%s\n\n", meta, range->spec->path, reset);
+			int lno = 1;
+			const char *ptr = range->spec->data;
+			const char *end = range->spec->data + range->spec->size;
+			int i = 0;
+			for (; i < range->nr; i++) {
+				struct range *r = range->ranges + i;
+				fprintf(opt->file, "%s@@ %ld,%ld @@%s\n", frag, r->start,
+					r->end - r->start + 1, reset);
+				flush_lines(opt, &ptr, end, r->start, r->end,
+					&lno, new, ' ');
+			}
+			fprintf(opt->file, "\n");
+		}
+		range = range->next;
+	}
+}
+
+static void line_log_flush(struct rev_info *rev, struct commit *c)
+{
+	struct diff_line_range *range = lookup_line_range(rev, c);
+	struct diff_line_range *nontrivial = lookup_decoration(&rev->nontrivial_merge, &c->object);
+	struct log_info log;
+
+	if (range == NULL)
+		return;
+
+	log.commit = c;
+	log.parent = NULL;
+	rev->loginfo = &log;
+	show_log(rev);
+	rev->loginfo = NULL;
+	/*
+	 * Add a new line after each commit message, of course we should
+	 * add --graph alignment later when the patches comes to master.
+	 */
+	fprintf(rev->diffopt.file, "\n");
+
+	if (c->object.flags & EVIL_MERGE)
+		return flush_nontrivial_merge(rev, nontrivial);
+
+	while (range) {
+		if (range->diff)
+			diff_flush_filepair(rev, range);
+		range = range->next;
+	}
+}
+
-- 
1.7.0.2.273.gc2413.dirty