Add a 'stats' page to each repo

This new page, which is disabled by default, can be used to print some
statistics about the number of commits per period in the repository,
where period can be either weeks, months, quarters or years.

The function can be activated globally by setting 'enable-stats=1' in
cgitrc and disabled for individual repos by setting 'repo.enable-stats=0'.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 380 insertions, 0 deletions

diff --git a/ui-stats.c b/ui-stats.c
new file mode 100644
index 0000000..9150840
--- /dev/null
+++ b/ui-stats.c
@@ -0,0 +1,380 @@
+#include "cgit.h"
+#include "html.h"
+#include <string-list.h>
+
+#define MONTHS 6
+
+struct Period {
+	const char code;
+	const char *name;
+	int max_periods;
+	int count;
+
+	/* Convert a tm value to the first day in the period */
+	void (*trunc)(struct tm *tm);
+
+	/* Update tm value to start of next/previous period */
+	void (*dec)(struct tm *tm);
+	void (*inc)(struct tm *tm);
+
+	/* Pretty-print a tm value */
+	char *(*pretty)(struct tm *tm);
+};
+
+struct authorstat {
+	long total;
+	struct string_list list;
+};
+
+#define DAY_SECS (60 * 60 * 24)
+#define WEEK_SECS (DAY_SECS * 7)
+
+static void trunc_week(struct tm *tm)
+{
+	time_t t = timegm(tm);
+	t -= ((tm->tm_wday + 6) % 7) * DAY_SECS;
+	gmtime_r(&t, tm);	
+}
+
+static void dec_week(struct tm *tm)
+{
+	time_t t = timegm(tm);
+	t -= WEEK_SECS;
+	gmtime_r(&t, tm);	
+}
+
+static void inc_week(struct tm *tm)
+{
+	time_t t = timegm(tm);
+	t += WEEK_SECS;
+	gmtime_r(&t, tm);	
+}
+
+static char *pretty_week(struct tm *tm)
+{
+	static char buf[10];
+
+	strftime(buf, sizeof(buf), "W%V %G", tm);
+	return buf;
+}
+
+static void trunc_month(struct tm *tm)
+{
+	tm->tm_mday = 1;
+}
+
+static void dec_month(struct tm *tm)
+{
+	tm->tm_mon--;
+	if (tm->tm_mon < 0) {
+		tm->tm_year--;
+		tm->tm_mon = 11;
+	}
+}
+
+static void inc_month(struct tm *tm)
+{
+	tm->tm_mon++;
+	if (tm->tm_mon > 11) {
+		tm->tm_year++;
+		tm->tm_mon = 0;
+	}
+}
+
+static char *pretty_month(struct tm *tm)
+{
+	static const char *months[] = {
+		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+	};
+	return fmt("%s %d", months[tm->tm_mon], tm->tm_year + 1900);
+}
+
+static void trunc_quarter(struct tm *tm)
+{
+	trunc_month(tm);
+	while(tm->tm_mon % 3 != 0)
+		dec_month(tm);
+}
+
+static void dec_quarter(struct tm *tm)
+{
+	dec_month(tm);
+	dec_month(tm);
+	dec_month(tm);
+}
+
+static void inc_quarter(struct tm *tm)
+{
+	inc_month(tm);
+	inc_month(tm);
+	inc_month(tm);
+}
+
+static char *pretty_quarter(struct tm *tm)
+{
+	return fmt("Q%d %d", tm->tm_mon / 3 + 1, tm->tm_year + 1900);
+}
+
+static void trunc_year(struct tm *tm)
+{
+	trunc_month(tm);
+	tm->tm_mon = 0;
+}
+
+static void dec_year(struct tm *tm)
+{
+	tm->tm_year--;
+}
+
+static void inc_year(struct tm *tm)
+{
+	tm->tm_year++;
+}
+
+static char *pretty_year(struct tm *tm)
+{
+	return fmt("%d", tm->tm_year + 1900);
+}
+
+struct Period periods[] = {
+	{'w', "week", 12, 4, trunc_week, dec_week, inc_week, pretty_week},
+	{'m', "month", 12, 4, trunc_month, dec_month, inc_month, pretty_month},
+	{'q', "quarter", 12, 4, trunc_quarter, dec_quarter, inc_quarter, pretty_quarter},
+	{'y', "year", 12, 4, trunc_year, dec_year, inc_year, pretty_year},
+};
+
+static void add_commit(struct string_list *authors, struct commit *commit,
+	struct Period *period)
+{
+	struct commitinfo *info;
+	struct string_list_item *author, *item;
+	struct authorstat *authorstat;
+	struct string_list *items;
+	char *tmp;
+	struct tm *date;
+	time_t t;
+
+	info = cgit_parse_commit(commit);
+	tmp = xstrdup(info->author);
+	author = string_list_insert(tmp, authors);
+	if (!author->util)
+		author->util = xcalloc(1, sizeof(struct authorstat));
+	else
+		free(tmp);
+	authorstat = author->util;
+	items = &authorstat->list;
+	t = info->committer_date;
+	date = gmtime(&t);
+	period->trunc(date);
+	tmp = xstrdup(period->pretty(date));
+	item = string_list_insert(tmp, items);
+	if (item->util)
+		free(tmp);
+	item->util++;
+	authorstat->total++;
+	cgit_free_commitinfo(info);
+}
+
+static int cmp_total_commits(const void *a1, const void *a2)
+{
+	const struct string_list_item *i1 = a1;
+	const struct string_list_item *i2 = a2;
+	const struct authorstat *auth1 = i1->util;
+	const struct authorstat *auth2 = i2->util;
+
+	return auth2->total - auth1->total;
+}
+
+/* Walk the commit DAG and collect number of commits per author per
+ * timeperiod into a nested string_list collection.
+ */
+struct string_list collect_stats(struct cgit_context *ctx,
+	struct Period *period)
+{
+	struct string_list authors;
+	struct rev_info rev;
+	struct commit *commit;
+	const char *argv[] = {NULL, ctx->qry.head, NULL, NULL};
+	time_t now;
+	long i;
+	struct tm *tm;
+	char tmp[11];
+
+	time(&now);
+	tm = gmtime(&now);
+	period->trunc(tm);
+	for (i = 1; i < period->count; i++)
+		period->dec(tm);
+	strftime(tmp, sizeof(tmp), "%Y-%m-%d", tm);
+	argv[2] = xstrdup(fmt("--since=%s", tmp));
+	init_revisions(&rev, NULL);
+	rev.abbrev = DEFAULT_ABBREV;
+	rev.commit_format = CMIT_FMT_DEFAULT;
+	rev.no_merges = 1;
+	rev.verbose_header = 1;
+	rev.show_root_diff = 0;
+	setup_revisions(3, argv, &rev, NULL);
+	prepare_revision_walk(&rev);
+	memset(&authors, 0, sizeof(authors));
+	while ((commit = get_revision(&rev)) != NULL) {
+		add_commit(&authors, commit, period);
+		free(commit->buffer);
+		free_commit_list(commit->parents);
+	}
+	return authors;
+}
+
+void print_combined_authorrow(struct string_list *authors, int from, int to,
+	const char *name, const char *leftclass, const char *centerclass,
+	const char *rightclass, struct Period *period)
+{
+	struct string_list_item *author;
+	struct authorstat *authorstat;
+	struct string_list *items;
+	struct string_list_item *date;
+	time_t now;
+	long i, j, total, subtotal;
+	struct tm *tm;
+	char *tmp;
+
+	time(&now);
+	tm = gmtime(&now);
+	period->trunc(tm);
+	for (i = 1; i < period->count; i++)
+		period->dec(tm);
+
+	total = 0;
+	htmlf("<tr><td class='%s'>%s</td>", leftclass,
+		fmt(name, to - from + 1));
+	for (j = 0; j < period->count; j++) {
+		tmp = period->pretty(tm);
+		period->inc(tm);
+		subtotal = 0;
+		for (i = from; i <= to; i++) {
+			author = &authors->items[i];
+			authorstat = author->util;
+			items = &authorstat->list;
+			date = string_list_lookup(tmp, items);
+			if (date)
+				subtotal += (size_t)date->util;
+		}
+		htmlf("<td class='%s'>%d</td>", centerclass, subtotal);
+		total += subtotal;
+	}
+	htmlf("<td class='%s'>%d</td></tr>", rightclass, total);
+}
+
+void print_authors(struct string_list *authors, int top, struct Period *period)
+{
+	struct string_list_item *author;
+	struct authorstat *authorstat;
+	struct string_list *items;
+	struct string_list_item *date;
+	time_t now;
+	long i, j, total;
+	struct tm *tm;
+	char *tmp;
+
+	time(&now);
+	tm = gmtime(&now);
+	period->trunc(tm);
+	for (i = 1; i < period->count; i++)
+		period->dec(tm);
+
+	html("<table class='stats'><tr><th>Author</th>");
+	for (j = 0; j < period->count; j++) {
+		tmp = period->pretty(tm);
+		htmlf("<th>%s</th>", tmp);
+		period->inc(tm);
+	}
+	html("<th>Total</th></tr>\n");
+
+	if (top <= 0 || top > authors->nr)
+		top = authors->nr;
+
+	for (i = 0; i < top; i++) {
+		author = &authors->items[i];
+		html("<tr><td class='left'>");
+		html_txt(author->string);
+		html("</td>");
+		authorstat = author->util;
+		items = &authorstat->list;
+		total = 0;
+		for (j = 0; j < period->count; j++)
+			period->dec(tm);
+		for (j = 0; j < period->count; j++) {
+			tmp = period->pretty(tm);
+			period->inc(tm);
+			date = string_list_lookup(tmp, items);
+			if (!date)
+				html("<td>0</td>");
+			else {
+				htmlf("<td>%d</td>", date->util);
+				total += (size_t)date->util;
+			}
+		}
+		htmlf("<td class='sum'>%d</td></tr>", total);
+	}
+
+	if (top < authors->nr)
+		print_combined_authorrow(authors, top, authors->nr - 1,
+			"Others (%d)", "left", "", "sum", period);
+
+	print_combined_authorrow(authors, 0, authors->nr - 1, "Total",
+		"total", "sum", "sum", period);
+	html("</table>");
+}
+
+/* Create a sorted string_list with one entry per author. The util-field
+ * for each author is another string_list which is used to calculate the
+ * number of commits per time-interval.
+ */
+void cgit_show_stats(struct cgit_context *ctx)
+{
+	struct string_list authors;
+	struct Period *period;
+	int top, i;
+
+	period = &periods[0];
+	if (ctx->qry.period) {
+		for (i = 0; i < sizeof(periods) / sizeof(periods[0]); i++)
+			if (periods[i].code == ctx->qry.period[0]) {
+				period = &periods[i];
+				break;
+			}
+	}
+	authors = collect_stats(ctx, period);
+	qsort(authors.items, authors.nr, sizeof(struct string_list_item),
+		cmp_total_commits);
+
+	top = ctx->qry.ofs;
+	if (!top)
+		top = 10;
+	htmlf("<h2>Commits per author per %s</h2>", period->name);
+
+	html("<form method='get' action='.' style='float: right; text-align: right;'>");
+	if (strcmp(ctx->qry.head, ctx->repo->defbranch))
+		htmlf("<input type='hidden' name='h' value='%s'/>", ctx->qry.head);
+	html("Period: ");
+	html("<select name='period' onchange='this.form.submit();'>");
+	for (i = 0; i < sizeof(periods) / sizeof(periods[0]); i++)
+		htmlf("<option value='%c'%s>%s</option>",
+			periods[i].code,
+			period == &periods[i] ? " selected" : "",
+			periods[i].name);
+	html("</select><br/><br/>");
+	html("Authors: ");
+	html("");
+	html("<select name='ofs' onchange='this.form.submit();'>");
+	htmlf("<option value='10'%s>10</option>", top == 10 ? " selected" : "");
+	htmlf("<option value='25'%s>25</option>", top == 25 ? " selected" : "");
+	htmlf("<option value='50'%s>50</option>", top == 50 ? " selected" : "");
+	htmlf("<option value='100'%s>100</option>", top == 100 ? " selected" : "");
+	htmlf("<option value='-1'%s>All</option>", top == -1 ? " selected" : "");
+	html("</select>");
+	html("<noscript>&nbsp;&nbsp;<input type='submit' value='Reload'/></noscript>");
+	html("</form>");
+	print_authors(&authors, top, period);
+}
+