Merge branch 'lh/stats'

Conflicts:
	cgit.c
	cgit.css
	cgit.h
	ui-tree.c

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

12 files changed, 569 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index 7793c0b..a52285e 100644
--- a/Makefile
+++ b/Makefile
@@ -90,6 +90,7 @@ OBJECTS += ui-refs.o
 OBJECTS += ui-repolist.o
 OBJECTS += ui-shared.o
 OBJECTS += ui-snapshot.o
+OBJECTS += ui-stats.o
 OBJECTS += ui-summary.o
 OBJECTS += ui-tag.o
 OBJECTS += ui-tree.o
diff --git a/cgit.c b/cgit.c
index f35f605..608cab6 100644
--- a/cgit.c
+++ b/cgit.c
@@ -12,6 +12,7 @@
 #include "configfile.h"
 #include "html.h"
 #include "ui-shared.h"
+#include "ui-stats.h"
 #include "scan-tree.h"
 
 const char *cgit_version = CGIT_VERSION;
@@ -54,6 +55,8 @@ void config_cb(const char *name, const char *value)
 		ctx.cfg.enable_log_filecount = atoi(value);
 	else if (!strcmp(name, "enable-log-linecount"))
 		ctx.cfg.enable_log_linecount = atoi(value);
+	else if (!strcmp(name, "max-stats"))
+		ctx.cfg.max_stats = cgit_find_stats_period(value, NULL);
 	else if (!strcmp(name, "cache-size"))
 		ctx.cfg.cache_size = atoi(value);
 	else if (!strcmp(name, "cache-root"))
@@ -112,6 +115,8 @@ void config_cb(const char *name, const char *value)
 		ctx.repo->enable_log_filecount = ctx.cfg.enable_log_filecount * atoi(value);
 	else if (ctx.repo && !strcmp(name, "repo.enable-log-linecount"))
 		ctx.repo->enable_log_linecount = ctx.cfg.enable_log_linecount * atoi(value);
+	else if (ctx.repo && !strcmp(name, "repo.max-stats"))
+		ctx.repo->max_stats = cgit_find_stats_period(value, NULL);
 	else if (ctx.repo && !strcmp(name, "repo.module-link"))
 		ctx.repo->module_link= xstrdup(value);
 	else if (ctx.repo && !strcmp(name, "repo.readme") && value != NULL) {
@@ -158,6 +163,8 @@ static void querystring_cb(const char *name, const char *value)
 		ctx.qry.sort = xstrdup(value);
 	} else if (!strcmp(name, "showmsg")) {
 		ctx.qry.showmsg = atoi(value);
+	} else if (!strcmp(name, "period")) {
+		ctx.qry.period = xstrdup(value);
 	}
 }
 
@@ -181,6 +188,7 @@ static void prepare_context(struct cgit_context *ctx)
 	ctx->cfg.max_lock_attempts = 5;
 	ctx->cfg.max_msg_len = 80;
 	ctx->cfg.max_repodesc_len = 80;
+	ctx->cfg.max_stats = 0;
 	ctx->cfg.module_link = "./?repo=%s&page=commit&id=%s";
 	ctx->cfg.renamelimit = -1;
 	ctx->cfg.robots = "index, nofollow";
diff --git a/cgit.css b/cgit.css
index f19446d..e8214de 100644
--- a/cgit.css
+++ b/cgit.css
@@ -495,3 +495,79 @@ a.deco {
 	background-color: #ff8888;
 	border: solid 1px #770000;
 }
+table.stats {
+	border: solid 1px black;
+	border-collapse: collapse;
+}
+
+table.stats th {
+	text-align: left;
+	padding: 1px 0.5em;
+	background-color: #eee;
+	border: solid 1px black;
+}
+
+table.stats td {
+	text-align: right;
+	padding: 1px 0.5em;
+	border: solid 1px black;
+}
+
+table.stats td.total {
+	font-weight: bold;
+	text-align: left;
+}
+
+table.stats td.sum {
+	color: #c00;
+	font-weight: bold;
+/*	background-color: #eee; */
+}
+
+table.stats td.left {
+	text-align: left;
+}
+
+table.vgraph {
+	border-collapse: separate;
+	border: solid 1px black;
+	height: 200px;
+}
+
+table.vgraph th {
+	background-color: #eee;
+	font-weight: bold;
+	border: solid 1px white;
+	padding: 1px 0.5em;
+}
+
+table.vgraph td {
+	vertical-align: bottom;
+	padding: 0px 10px;
+}
+
+table.vgraph div.bar {
+	background-color: #eee;
+}
+
+table.hgraph {
+	border: solid 1px black;
+	width: 800px;
+}
+
+table.hgraph th {
+	background-color: #eee;
+	font-weight: bold;
+	border: solid 1px black;
+	padding: 1px 0.5em;
+}
+
+table.hgraph td {
+	vertical-align: center;
+	padding: 2px 2px;
+}
+
+table.hgraph div.bar {
+	background-color: #eee;
+	height: 1em;
+}
diff --git a/cgit.h b/cgit.h
index cb2f176..4fe94c6 100644
--- a/cgit.h
+++ b/cgit.h
@@ -61,6 +61,7 @@ struct cgit_repo {
 	int snapshots;
 	int enable_log_filecount;
 	int enable_log_linecount;
+	int max_stats;
 	time_t mtime;
 };
 
@@ -120,6 +121,7 @@ struct cgit_query {
 	char *name;
 	char *mimetype;
 	char *url;
+	char *period;
 	int   ofs;
 	int nohead;
 	char *sort;
@@ -160,6 +162,7 @@ struct cgit_config {
 	int max_lock_attempts;
 	int max_msg_len;
 	int max_repodesc_len;
+	int max_stats;
 	int nocache;
 	int renamelimit;
 	int snapshots;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index ab9ab66..09f56a6 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -129,6 +129,11 @@ max-repodesc-length
 	Specifies the maximum number of repo description characters to display
 	on the repository index page. Default value: "80".
 
+max-stats
+	Set the default maximum statistics period. Valid values are "week",
+	"month", "quarter" and "year". If unspecified, statistics are
+	disabled. Default value: none. See also: "repo.max-stats".
+
 module-link
 	Text which will be used as the formatstring for a hyperlink when a
 	submodule is printed in a directory listing. The arguments for the
@@ -218,6 +223,11 @@ repo.enable-log-linecount
 	A flag which can be used to disable the global setting
 	`enable-log-linecount'. Default value: none.
 
+repo.max-stats
+	Override the default maximum statistics period. Valid values are equal
+	to the values specified for the global "max-stats" setting. Default
+	value: none.
+
 repo.name
 	The value to show as repository name. Default value: <repo.url>.
 
@@ -276,6 +286,10 @@ favicon=/favicon.ico
 logo=/img/mylogo.png
 
 
+# Enable statistics per week, month and quarter
+max-stats=quarter
+
+
 # Set the title and heading of the repository index page
 root-title=foobar.com git repositories
 
@@ -348,6 +362,9 @@ repo.snapshots=0
 # Disable line-counts for this repo
 repo.enable-log-linecount=0
 
+# Restrict the max statistics period for this repo
+repo.max-stats=month
+
 
 BUGS
 ----
diff --git a/cmd.c b/cmd.c
index 8914fa5..cf97da7 100644
--- a/cmd.c
+++ b/cmd.c
@@ -21,6 +21,7 @@
 #include "ui-refs.h"
 #include "ui-repolist.h"
 #include "ui-snapshot.h"
+#include "ui-stats.h"
 #include "ui-summary.h"
 #include "ui-tag.h"
 #include "ui-tree.h"
@@ -108,6 +109,11 @@ static void snapshot_fn(struct cgit_context *ctx)
 			    ctx->repo->snapshots, ctx->qry.nohead);
 }
 
+static void stats_fn(struct cgit_context *ctx)
+{
+	cgit_show_stats(ctx);
+}
+
 static void summary_fn(struct cgit_context *ctx)
 {
 	cgit_print_summary();
@@ -144,6 +150,7 @@ struct cgit_cmd *cgit_get_cmd(struct cgit_context *ctx)
 		def_cmd(refs, 1, 1),
 		def_cmd(repolist, 0, 0),
 		def_cmd(snapshot, 1, 0),
+		def_cmd(stats, 1, 1),
 		def_cmd(summary, 1, 1),
 		def_cmd(tag, 1, 1),
 		def_cmd(tree, 1, 1),
diff --git a/shared.c b/shared.c
index a764c4d..578a544 100644
--- a/shared.c
+++ b/shared.c
@@ -58,6 +58,7 @@ struct cgit_repo *cgit_add_repo(const char *url)
 	ret->snapshots = ctx.cfg.snapshots;
 	ret->enable_log_filecount = ctx.cfg.enable_log_filecount;
 	ret->enable_log_linecount = ctx.cfg.enable_log_linecount;
+	ret->max_stats = ctx.cfg.max_stats;
 	ret->module_link = ctx.cfg.module_link;
 	ret->readme = NULL;
 	ret->mtime = -1;
diff --git a/ui-shared.c b/ui-shared.c
index fba1ba6..4f28512 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -369,6 +369,12 @@ void cgit_patch_link(char *name, char *title, char *class, char *head,
 	reporevlink("patch", name, title, class, head, rev, NULL);
 }
 
+void cgit_stats_link(char *name, char *title, char *class, char *head,
+		     char *path)
+{
+	reporevlink("stats", name, title, class, head, NULL, path);
+}
+
 void cgit_object_link(struct object *obj)
 {
 	char *page, *shortrev, *fullrev, *name;
@@ -557,7 +563,7 @@ int print_archive_ref(const char *refname, const unsigned char *sha1,
 	return 0;
 }
 
-void add_hidden_formfields(int incl_head, int incl_search, char *page)
+void cgit_add_hidden_formfields(int incl_head, int incl_search, char *page)
 {
 	char *url;
 
@@ -619,7 +625,7 @@ void cgit_print_pageheader(struct cgit_context *ctx)
 		cgit_summary_link(ctx->repo->name, ctx->repo->name, NULL, NULL);
 		html("</td><td class='form'>");
 		html("<form method='get' action=''>\n");
-		add_hidden_formfields(0, 1, ctx->qry.page);
+		cgit_add_hidden_formfields(0, 1, ctx->qry.page);
 		html("<select name='h' onchange='this.form.submit();'>\n");
 		for_each_branch_ref(print_branch_option, ctx->qry.head);
 		html("</select> ");
@@ -656,6 +662,9 @@ void cgit_print_pageheader(struct cgit_context *ctx)
 				 ctx->qry.head, ctx->qry.sha1);
 		cgit_diff_link("diff", NULL, hc(cmd, "diff"), ctx->qry.head,
 			       ctx->qry.sha1, ctx->qry.sha2, NULL);
+		if (ctx->repo->max_stats)
+			cgit_stats_link("stats", NULL, hc(cmd, "stats"),
+					ctx->qry.head, NULL);
 		if (ctx->repo->readme)
 			reporevlink("about", "about", NULL,
 				    hc(cmd, "about"), ctx->qry.head, NULL,
@@ -666,7 +675,7 @@ void cgit_print_pageheader(struct cgit_context *ctx)
 			html_url_path(cgit_fileurl(ctx->qry.repo, "log",
 						   ctx->qry.path, NULL));
 		html("'>\n");
-		add_hidden_formfields(1, 0, "log");
+		cgit_add_hidden_formfields(1, 0, "log");
 		html("<select name='qt'>\n");
 		html_option("grep", "log msg", ctx->qry.grep);
 		html_option("author", "author", ctx->qry.grep);
diff --git a/ui-shared.h b/ui-shared.h
index 2ab53ae..5a3821f 100644
--- a/ui-shared.h
+++ b/ui-shared.h
@@ -30,6 +30,8 @@ extern void cgit_snapshot_link(char *name, char *title, char *class,
 			       char *head, char *rev, char *archivename);
 extern void cgit_diff_link(char *name, char *title, char *class, char *head,
 			   char *new_rev, char *old_rev, char *path);
+extern void cgit_stats_link(char *name, char *title, char *class, char *head,
+			    char *path);
 extern void cgit_object_link(struct object *obj);
 
 extern void cgit_print_error(char *msg);
@@ -42,5 +44,6 @@ extern void cgit_print_pageheader(struct cgit_context *ctx);
 extern void cgit_print_filemode(unsigned short mode);
 extern void cgit_print_snapshot_links(const char *repo, const char *head,
 				      const char *hex, int snapshots);
-
+extern void cgit_add_hidden_formfields(int incl_head, int incl_search,
+				       char *page);
 #endif /* UI_SHARED_H */
diff --git a/ui-stats.c b/ui-stats.c
new file mode 100644
index 0000000..9fc06d3
--- a/dev/null
+++ b/ui-stats.c
@@ -0,0 +1,410 @@
+#include <string-list.h>
+
+#include "cgit.h"
+#include "html.h"
+#include "ui-shared.h"
+#include "ui-stats.h"
+
+#define MONTHS 6
+
+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 cgit_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},
+};
+
+/* Given a period code or name, return a period index (1, 2, 3 or 4)
+ * and update the period pointer to the correcsponding struct.
+ * If no matching code is found, return 0.
+ */
+int cgit_find_stats_period(const char *expr, struct cgit_period **period)
+{
+	int i;
+	char code = '\0';
+
+	if (!expr)
+		return 0;
+
+	if (strlen(expr) == 1)
+		code = expr[0];
+
+	for (i = 0; i < sizeof(periods) / sizeof(periods[0]); i++)
+		if (periods[i].code == code || !strcmp(periods[i].name, expr)) {
+			if (period)
+				*period = &periods[i];
+			return i+1;
+		}
+	return 0;
+}
+
+static void add_commit(struct string_list *authors, struct commit *commit,
+	struct cgit_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 cgit_period *period)
+{
+	struct string_list authors;
+	struct rev_info rev;
+	struct commit *commit;
+	const char *argv[] = {NULL, ctx->qry.head, NULL, NULL, NULL, NULL};
+	int argc = 3;
+	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));
+	if (ctx->qry.path) {
+		argv[3] = "--";
+		argv[4] = ctx->qry.path;
+		argc += 2;
+	}
+	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(argc, 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 cgit_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 cgit_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 cgit_period *period;
+	int top, i;
+	const char *code = "w";
+
+	if (ctx->qry.period)
+		code = ctx->qry.period;
+
+	i = cgit_find_stats_period(code, &period);
+	if (!i) {
+		cgit_print_error(fmt("Unknown statistics type: %c", code));
+		return;
+	}
+	if (i > ctx->repo->max_stats) {
+		cgit_print_error(fmt("Statistics type disabled: %s",
+				     period->name));
+		return;
+	}
+	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", period->name);
+	if (ctx->qry.path) {
+		html(" (path '");
+		html_txt(ctx->qry.path);
+		html("')");
+	}
+	html("</h2>");
+
+	html("<form method='get' action='' style='float: right; text-align: right;'>");
+	cgit_add_hidden_formfields(1, 0, "stats");
+	if (ctx->repo->max_stats > 1) {
+		html("Period: ");
+		html("<select name='period' onchange='this.form.submit();'>");
+		for (i = 0; i < ctx->repo->max_stats; 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);
+}
+
diff --git a/ui-stats.h b/ui-stats.h
new file mode 100644
index 0000000..4f13dba
--- a/dev/null
+++ b/ui-stats.h
@@ -0,0 +1,27 @@
+#ifndef UI_STATS_H
+#define UI_STATS_H
+
+#include "cgit.h"
+
+struct cgit_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);
+};
+
+extern int cgit_find_stats_period(const char *expr, struct cgit_period **period);
+
+extern void cgit_show_stats(struct cgit_context *ctx);
+
+#endif /* UI_STATS_H */
diff --git a/ui-tree.c b/ui-tree.c
index 9876c99..4b8e7a0 100644
--- a/ui-tree.c
+++ b/ui-tree.c
@@ -109,6 +109,9 @@ static int ls_item(const unsigned char *sha1, const char *base, int baselen,
 	html("<td>");
 	cgit_log_link("log", NULL, "button", ctx.qry.head, curr_rev,
 		      fullpath, 0, NULL, NULL, ctx.qry.showmsg);
+	if (ctx.repo->max_stats)
+		cgit_stats_link("stats", NULL, "button", ctx.qry.head,
+				fullpath);
 	html("</td></tr>\n");
 	free(name);
 	return 0;