Mercurial > dovecot > core-2.2

changeset 18292:a9952ceeac61

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stats process/plugin redesign to be more modular. The visible functionality doesn't actually change with this patch yet, but it allows other plugins/services to add their own fields to stats process. For example auth process could send auth success/failures or auth cache hits/misses.
author Timo Sirainen <tss@iki.fi>
date Thu, 05 Mar 2015 23:02:48 +0200
parents c98991820dde
children a54408ed4767
files configure.ac src/Makefile.am src/lib-dovecot/Makefile.am src/lib-stats/Makefile.am src/lib-stats/stats-parser.c src/lib-stats/stats-parser.h src/lib-stats/stats.c src/lib-stats/stats.h src/lib-storage/mail-user.c src/lib-storage/mail-user.h src/plugins/imap-stats/Makefile.am src/plugins/imap-stats/imap-stats-plugin.c src/plugins/stats/Makefile.am src/plugins/stats/mail-stats-fill.c src/plugins/stats/mail-stats.c src/plugins/stats/mail-stats.h src/plugins/stats/stats-connection.c src/plugins/stats/stats-connection.h src/plugins/stats/stats-plugin.c src/plugins/stats/stats-plugin.h src/stats/Makefile.am src/stats/client-export.c src/stats/mail-command.c src/stats/mail-domain.c src/stats/mail-domain.h src/stats/mail-ip.c src/stats/mail-ip.h src/stats/mail-server-connection.c src/stats/mail-session.c src/stats/mail-session.h src/stats/mail-stats.c src/stats/mail-stats.h src/stats/mail-user.c src/stats/mail-user.h src/stats/main.c
diffstat 35 files changed, 1164 insertions(+), 740 deletions(-) [+]
line wrap: on
line diff
--- a/configure.ac	Thu Mar 05 22:19:02 2015 +0200
+++ b/configure.ac	Thu Mar 05 23:02:48 2015 +0200
@@ -2549,7 +2549,7 @@
   LIBDOVECOT_COMPRESS='$(top_builddir)/src/lib-compression/libcompression.la'
   LIBDOVECOT_LDA='$(top_builddir)/src/lib-lda/libdovecot-lda.la'
 else
-  LIBDOVECOT_DEPS='$(top_builddir)/src/lib-master/libmaster.la $(top_builddir)/src/lib-settings/libsettings.la $(top_builddir)/src/lib-http/libhttp.la $(top_builddir)/src/lib-dict/libdict.la $(top_builddir)/src/lib-dns/libdns.la $(top_builddir)/src/lib-fs/libfs.la $(top_builddir)/src/lib-imap/libimap.la $(top_builddir)/src/lib-mail/libmail.la $(top_builddir)/src/lib-sasl/libsasl.la $(top_builddir)/src/lib-auth/libauth.la $(top_builddir)/src/lib-charset/libcharset.la $(top_builddir)/src/lib-ssl-iostream/libssl_iostream.la $(top_builddir)/src/lib-test/libtest.la $(top_builddir)/src/lib/liblib.la'
+  LIBDOVECOT_DEPS='$(top_builddir)/src/lib-master/libmaster.la $(top_builddir)/src/lib-settings/libsettings.la $(top_builddir)/src/lib-stats/libstats.la $(top_builddir)/src/lib-http/libhttp.la $(top_builddir)/src/lib-dict/libdict.la $(top_builddir)/src/lib-dns/libdns.la $(top_builddir)/src/lib-fs/libfs.la $(top_builddir)/src/lib-imap/libimap.la $(top_builddir)/src/lib-mail/libmail.la $(top_builddir)/src/lib-sasl/libsasl.la $(top_builddir)/src/lib-auth/libauth.la $(top_builddir)/src/lib-charset/libcharset.la $(top_builddir)/src/lib-ssl-iostream/libssl_iostream.la $(top_builddir)/src/lib-test/libtest.la $(top_builddir)/src/lib/liblib.la'
   LIBDOVECOT="$LIBDOVECOT_DEPS \$(LIBICONV) \$(MODULE_LIBS)"
   LIBDOVECOT_STORAGE_DEPS='$(top_builddir)/src/lib-storage/libstorage.la'
   LIBDOVECOT_LOGIN='$(top_builddir)/src/login-common/liblogin.la'
@@ -2849,6 +2849,7 @@
 src/lib-sasl/Makefile
 src/lib-settings/Makefile
 src/lib-ssl-iostream/Makefile
+src/lib-stats/Makefile
 src/lib-test/Makefile
 src/lib-storage/Makefile
 src/lib-storage/list/Makefile
--- a/src/Makefile.am	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/Makefile.am	Thu Mar 05 23:02:48 2015 +0200
@@ -9,6 +9,7 @@
 	lib-dict \
 	lib-sasl \
 	lib-ssl-iostream \
+	lib-stats \
 	lib-http \
 	lib-fs \
 	lib-mail \
--- a/src/lib-dovecot/Makefile.am	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/lib-dovecot/Makefile.am	Thu Mar 05 23:02:48 2015 +0200
@@ -3,6 +3,7 @@
 	../lib-master/libmaster.la \
 	../lib-fs/libfs.la \
 	../lib-settings/libsettings.la \
+	../lib-stats/libstats.la \
 	../lib-http/libhttp.la \
 	../lib-dict/libdict.la \
 	../lib-imap/libimap.la \
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib-stats/Makefile.am	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,15 @@
+noinst_LTLIBRARIES = libstats.la
+
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/src/lib
+
+libstats_la_SOURCES = \
+	stats.c \
+	stats-parser.c
+
+headers = \
+	stats.h \
+	stats-parser.h
+
+pkginc_libdir = $(pkgincludedir)
+pkginc_lib_HEADERS = $(headers)
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib-stats/stats-parser.c	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,180 @@
+/* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "str.h"
+#include "time-util.h"
+#include "stats-parser.h"
+
+#define USECS_PER_SEC 1000000
+
+static bool stats_diff_timeval(struct timeval *dest,
+			       const struct timeval *src1,
+			       const struct timeval *src2)
+{
+	long long diff_usecs;
+
+	diff_usecs = timeval_diff_usecs(src2, src1);
+	if (diff_usecs < 0)
+		return FALSE;
+	dest->tv_sec = diff_usecs / USECS_PER_SEC;
+	dest->tv_usec = diff_usecs % USECS_PER_SEC;
+	return TRUE;
+}
+
+static bool
+stats_diff_uint32(uint32_t *dest, const uint32_t *src1, const uint32_t *src2)
+{
+	if (*src1 > *src2)
+		return FALSE;
+	*dest = *src2 - *src1;
+	return TRUE;
+}
+
+static bool
+stats_diff_uint64(uint64_t *dest, const uint64_t *src1, const uint64_t *src2)
+{
+	if (*src1 > *src2)
+		return FALSE;
+	*dest = *src2 - *src1;
+	return TRUE;
+}
+
+bool stats_parser_diff(const struct stats_parser_field *fields,
+		       unsigned int fields_count,
+		       const struct stats *stats1, const struct stats *stats2,
+		       struct stats *diff_stats_r, const char **error_r)
+{
+	unsigned int i;
+
+	for (i = 0; i < fields_count; i++) {
+		unsigned int offset = fields[i].offset;
+		void *dest = PTR_OFFSET(diff_stats_r, offset);
+		const void *src1 = CONST_PTR_OFFSET(stats1, offset);
+		const void *src2 = CONST_PTR_OFFSET(stats2, offset);
+
+		switch (fields[i].type) {
+		case STATS_PARSER_TYPE_UINT:
+			switch (fields[i].size) {
+			case sizeof(uint32_t):
+				if (!stats_diff_uint32(dest, src1, src2)) {
+					*error_r = t_strdup_printf("%s %u < %u",
+						fields[i].name,
+						*(const uint32_t *)src2,
+						*(const uint32_t *)src1);
+					return FALSE;
+				}
+				break;
+			case sizeof(uint64_t):
+				if (!stats_diff_uint64(dest, src1, src2)) {
+					const uint64_t *n1 = src1, *n2 = src2;
+
+					*error_r = t_strdup_printf("%s %llu < %llu",
+						fields[i].name,
+						(unsigned long long)*n2,
+						(unsigned long long)*n1);
+					return FALSE;
+				}
+				break;
+			default:
+				i_unreached();
+			}
+			break;
+		case STATS_PARSER_TYPE_TIMEVAL:
+			if (!stats_diff_timeval(dest, src1, src2)) {
+				const struct timeval *tv1 = src1, *tv2 = src2;
+
+				*error_r = t_strdup_printf("%s %ld.%d < %ld.%d",
+					fields[i].name,
+					(long)tv2->tv_sec, (int)tv2->tv_usec,
+					(long)tv1->tv_sec, (int)tv1->tv_usec);
+				return FALSE;
+			}
+			break;
+		}
+	}
+	return TRUE;
+}
+
+static void stats_timeval_add(struct timeval *dest, const struct timeval *src)
+{
+	dest->tv_sec += src->tv_sec;
+	dest->tv_usec += src->tv_usec;
+	if (dest->tv_usec > USECS_PER_SEC) {
+		dest->tv_usec -= USECS_PER_SEC;
+		dest->tv_sec++;
+	}
+}
+
+void stats_parser_add(const struct stats_parser_field *fields,
+		      unsigned int fields_count,
+		      struct stats *dest, const struct stats *src)
+{
+	unsigned int i;
+
+	for (i = 0; i < fields_count; i++) {
+		unsigned int offset = fields[i].offset;
+		void *f_dest = PTR_OFFSET(dest, offset);
+		const void *f_src = CONST_PTR_OFFSET(src, offset);
+
+		switch (fields[i].type) {
+		case STATS_PARSER_TYPE_UINT:
+			switch (fields[i].size) {
+			case sizeof(uint32_t): {
+				uint32_t *n_dest = f_dest;
+				const uint32_t *n_src = f_src;
+
+				*n_dest += *n_src;
+				break;
+			}
+			case sizeof(uint64_t): {
+				uint64_t *n_dest = f_dest;
+				const uint64_t *n_src = f_src;
+
+				*n_dest += *n_src;
+				break;
+			}
+			default:
+				i_unreached();
+			}
+			break;
+		case STATS_PARSER_TYPE_TIMEVAL:
+			stats_timeval_add(f_dest, f_src);
+			break;
+		}
+	}
+}
+
+void stats_parser_value(string_t *str,
+			const struct stats_parser_field *field,
+			const void *data)
+{
+	const void *ptr = CONST_PTR_OFFSET(data, field->offset);
+
+	switch (field->type) {
+	case STATS_PARSER_TYPE_UINT:
+		switch (field->size) {
+		case sizeof(uint32_t): {
+			const uint32_t *n = ptr;
+
+			str_printfa(str, "%u", *n);
+			break;
+		}
+		case sizeof(uint64_t): {
+			const uint64_t *n = ptr;
+
+			str_printfa(str, "%llu", (unsigned long long)*n);
+			break;
+		}
+		default:
+			i_unreached();
+		}
+		break;
+	case STATS_PARSER_TYPE_TIMEVAL: {
+		const struct timeval *tv = ptr;
+
+		str_printfa(str, "%lu.%u", (unsigned long)tv->tv_sec,
+			    (unsigned int)tv->tv_usec);
+		break;
+	}
+	}
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib-stats/stats-parser.h	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,29 @@
+#ifndef STATS_PARSER_H
+#define STATS_PARSER_H
+
+struct stats;
+
+enum stats_parser_type {
+	STATS_PARSER_TYPE_UINT,
+	STATS_PARSER_TYPE_TIMEVAL
+};
+
+struct stats_parser_field {
+	const char *name;
+	unsigned int offset;
+	unsigned int size;
+	enum stats_parser_type type;
+};
+
+bool stats_parser_diff(const struct stats_parser_field *fields,
+		       unsigned int fields_count,
+		       const struct stats *stats1, const struct stats *stats2,
+		       struct stats *diff_stats_r, const char **error_r);
+void stats_parser_add(const struct stats_parser_field *fields,
+		      unsigned int fields_count,
+		      struct stats *dest, const struct stats *src);
+void stats_parser_value(string_t *str,
+			const struct stats_parser_field *field,
+			const void *data);
+
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib-stats/stats.c	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,220 @@
+/* Copyright (c) 2015 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "array.h"
+#include "stats.h"
+
+struct stats_item {
+	struct stats_vfuncs v;
+	size_t pos;
+};
+
+static ARRAY(struct stats_item *) stats_items = ARRAY_INIT;
+static unsigned int stats_total_size = 0;
+static bool stats_allocated = FALSE;
+
+struct stats_item *stats_register(const struct stats_vfuncs *vfuncs)
+{
+	struct stats_item *item;
+
+	if (stats_allocated)
+		i_panic("stats_register() called after stats_alloc_size() was already called - this will break existing allocations");
+
+	if (!array_is_created(&stats_items))
+		i_array_init(&stats_items, 8);
+
+	item = i_new(struct stats_item, 1);
+	item->v = *vfuncs;
+	item->pos = stats_total_size;
+	array_append(&stats_items, &item, 1);
+
+	stats_total_size += vfuncs->alloc_size();
+	return item;
+}
+
+static bool stats_item_find(struct stats_item *item, unsigned int *idx_r)
+{
+	struct stats_item *const *itemp;
+
+	array_foreach(&stats_items, itemp) {
+		if (*itemp == item) {
+			*idx_r = array_foreach_idx(&stats_items, itemp);
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+static struct stats_item *stats_item_find_by_name(const char *name)
+{
+	struct stats_item *const *itemp;
+
+	array_foreach(&stats_items, itemp) {
+		if (strcmp((*itemp)->v.short_name, name) == 0)
+			return *itemp;
+	}
+	return NULL;
+}
+
+void stats_unregister(struct stats_item **_item)
+{
+	struct stats_item *item = *_item;
+	unsigned int idx;
+
+	*_item = NULL;
+
+	if (!stats_item_find(item, &idx))
+		i_unreached();
+	array_delete(&stats_items, idx, 1);
+
+	i_free(item);
+	if (array_count(&stats_items) == 0)
+		array_free(&stats_items);
+}
+
+struct stats *stats_alloc(pool_t pool)
+{
+	return p_malloc(pool, stats_alloc_size());
+}
+
+size_t stats_alloc_size(void)
+{
+	stats_allocated = TRUE;
+	return stats_total_size;
+}
+
+void stats_copy(struct stats *dest, const struct stats *src)
+{
+	memcpy(dest, src, stats_total_size);
+}
+
+unsigned int stats_field_count(void)
+{
+	struct stats_item *const *itemp;
+	unsigned int count = 0;
+
+	array_foreach(&stats_items, itemp)
+		count += (*itemp)->v.field_count();
+	return count;
+}
+
+const char *stats_field_name(unsigned int n)
+{
+	struct stats_item *const *itemp;
+	unsigned int i = 0, count;
+
+	array_foreach(&stats_items, itemp) {
+		count = (*itemp)->v.field_count();
+		if (i + count > n)
+			return (*itemp)->v.field_name(n - i);
+		i += count;
+	}
+	i_unreached();
+}
+
+void stats_field_value(string_t *str, const struct stats *stats,
+		       unsigned int n)
+{
+	struct stats_item *const *itemp;
+	unsigned int i = 0, count;
+
+	array_foreach(&stats_items, itemp) {
+		count = (*itemp)->v.field_count();
+		if (i + count > n) {
+			const void *item_stats
+				= CONST_PTR_OFFSET(stats, (*itemp)->pos);
+			(*itemp)->v.field_value(str, item_stats, n - i);
+			return;
+		}
+		i += count;
+	}
+	i_unreached();
+}
+
+bool stats_diff(const struct stats *stats1, const struct stats *stats2,
+		struct stats *diff_stats_r, const char **error_r)
+{
+	struct stats_item *const *itemp;
+	bool ret = TRUE;
+
+	array_foreach(&stats_items, itemp) {
+		if (!(*itemp)->v.diff(CONST_PTR_OFFSET(stats1, (*itemp)->pos),
+				      CONST_PTR_OFFSET(stats2, (*itemp)->pos),
+				      PTR_OFFSET(diff_stats_r, (*itemp)->pos),
+				      error_r))
+			ret = FALSE;
+	}
+	return ret;
+}
+
+void stats_add(struct stats *dest, const struct stats *src)
+{
+	struct stats_item *const *itemp;
+
+	array_foreach(&stats_items, itemp) {
+		(*itemp)->v.add(PTR_OFFSET(dest, (*itemp)->pos),
+				CONST_PTR_OFFSET(src, (*itemp)->pos));
+	}
+}
+
+bool stats_have_changed(const struct stats *prev, const struct stats *cur)
+{
+	struct stats_item *const *itemp;
+
+	array_foreach(&stats_items, itemp) {
+		if ((*itemp)->v.have_changed(CONST_PTR_OFFSET(prev, (*itemp)->pos),
+					     CONST_PTR_OFFSET(cur, (*itemp)->pos)))
+			return TRUE;
+	}
+	return FALSE;
+}
+
+void stats_export(buffer_t *buf, const struct stats *stats)
+{
+	struct stats_item *const *itemp;
+
+	array_foreach(&stats_items, itemp) {
+		buffer_append(buf, (*itemp)->v.short_name,
+			      strlen((*itemp)->v.short_name)+1);
+		(*itemp)->v.export(buf, CONST_PTR_OFFSET(stats, (*itemp)->pos));
+	}
+}
+
+bool stats_import(const unsigned char *data, size_t size,
+		  const struct stats *old_stats, struct stats *stats,
+		  const char **error_r)
+{
+	struct stats_item *item;
+	const unsigned char *p;
+	size_t pos;
+
+	memcpy(stats, old_stats, stats_total_size);
+	while (size > 0) {
+		const char *next_name = (const void *)data;
+
+		p = memchr(data, '\0', size);
+		if (p == NULL) {
+			*error_r = "Expected name, but NUL is missing";
+			return -1;
+		}
+		item = stats_item_find_by_name(next_name);
+		if (item == NULL) {
+			*error_r = t_strdup_printf("Unknown stats name: '%s'", next_name);
+			return -1;
+		}
+		size -= (p+1) - data;
+		data = p+1;
+		if (!item->v.import(data, size, &pos,
+				    PTR_OFFSET(stats, item->pos), error_r))
+			return FALSE;
+		i_assert(pos <= size);
+		data += pos;
+		size -= pos;
+	}
+	return TRUE;
+}
+
+void *stats_fill_ptr(struct stats *stats, struct stats_item *item)
+{
+	return PTR_OFFSET(stats, item->pos);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib-stats/stats.h	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,69 @@
+#ifndef STATS_H
+#define STATS_H
+
+struct stats;
+struct stats_item;
+
+struct stats_vfuncs {
+	const char *short_name;
+
+	size_t (*alloc_size)(void);
+	unsigned int (*field_count)(void);
+	const char *(*field_name)(unsigned int n);
+	void (*field_value)(string_t *str, const struct stats *stats,
+			    unsigned int n);
+
+	bool (*diff)(const struct stats *stats1, const struct stats *stats2,
+		     struct stats *diff_stats_r, const char **error_r);
+	void (*add)(struct stats *dest, const struct stats *src);
+	bool (*have_changed)(const struct stats *prev, const struct stats *cur);
+
+	void (*export)(buffer_t *buf, const struct stats *stats);
+	bool (*import)(const unsigned char *data, size_t size, size_t *pos_r,
+		       struct stats *stats, const char **error_r);
+};
+
+struct stats_item *stats_register(const struct stats_vfuncs *vfuncs);
+void stats_unregister(struct stats_item **item);
+
+/* Allocate struct stats from a given pool. */
+struct stats *stats_alloc(pool_t pool);
+/* Returns the number of bytes allocated to stats. */
+size_t stats_alloc_size(void);
+/* Copy all stats from src to dest. */
+void stats_copy(struct stats *dest, const struct stats *src);
+
+/* Returns the number of stats fields. */
+unsigned int stats_field_count(void);
+/* Returns the name of a stats field (exported to doveadm). */
+const char *stats_field_name(unsigned int n);
+/* Returns the value of a stats field as a string (exported to doveadm). */
+void stats_field_value(string_t *str, const struct stats *stats,
+		       unsigned int n);
+
+/* Return diff_stats_r->field = stats2->field - stats1->field.
+   diff1 is supposed to have smaller values than diff2. Returns TRUE if this
+   is so, FALSE if not */
+bool stats_diff(const struct stats *stats1, const struct stats *stats2,
+		struct stats *diff_stats_r, const char **error_r);
+/* dest->field += src->field */
+void stats_add(struct stats *dest, const struct stats *src);
+/* Returns TRUE if any fields have changed in cur since prev in a way that
+   a plugin should send the updated statistics to the stats process. Not all
+   fields necessarily require sending an update. */
+bool stats_have_changed(const struct stats *prev, const struct stats *cur);
+
+/* Export stats into a buffer in binary format. */
+void stats_export(buffer_t *buf, const struct stats *stats);
+/* Import stats from a buffer. The buffer doesn't need to contain an update to
+   all the stats items - old_stats are used for that item in such case.
+   Currently it's not allowed to have unknown items in the buffer. */
+bool stats_import(const unsigned char *data, size_t size,
+		  const struct stats *old_stats, struct stats *stats,
+		  const char **error_r);
+/* Return a pointer to stats where the specified item starts. The returned
+   pointer can be used to fill up the item-specific stats (up to its
+   alloc_size() number of bytes). */
+void *stats_fill_ptr(struct stats *stats, struct stats_item *item);
+
+#endif
--- a/src/lib-storage/mail-user.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/lib-storage/mail-user.c	Thu Mar 05 23:02:48 2015 +0200
@@ -40,6 +40,11 @@
 		mountpoint_list_deinit(&user->mountpoints);
 }
 
+static void mail_user_stats_fill_base(struct mail_user *user ATTR_UNUSED,
+				      struct stats *stats ATTR_UNUSED)
+{
+}
+
 struct mail_user *mail_user_alloc(const char *username,
 				  const struct setting_parser_info *set_info,
 				  const struct mail_user_settings *set)
@@ -68,6 +73,7 @@
 		i_panic("Settings check unexpectedly failed: %s", error);
 
 	user->v.deinit = mail_user_deinit_base;
+	user->v.stats_fill = mail_user_stats_fill_base;
 	p_array_init(&user->module_contexts, user->pool, 5);
 	return user;
 }
@@ -556,3 +562,8 @@
 	ssl_set->ca_dir = mail_set->ssl_client_ca_dir;
 	ssl_set->ca_file = mail_set->ssl_client_ca_file;
 }
+
+void mail_user_stats_fill(struct mail_user *user, struct stats *stats)
+{
+	user->v.stats_fill(user, stats);
+}
--- a/src/lib-storage/mail-user.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/lib-storage/mail-user.h	Thu Mar 05 23:02:48 2015 +0200
@@ -5,12 +5,14 @@
 #include "mail-storage-settings.h"
 
 struct module;
-struct mail_user;
+struct stats;
 struct fs_settings;
 struct ssl_iostream_settings;
+struct mail_user;
 
 struct mail_user_vfuncs {
 	void (*deinit)(struct mail_user *user);
+	void (*stats_fill)(struct mail_user *user, struct stats *stats);
 };
 
 struct mail_user {
@@ -166,4 +168,8 @@
 				struct fs_settings *fs_set,
 				struct ssl_iostream_settings *ssl_set);
 
+/* Fill statistics for user. By default there are no statistics, so stats
+   plugin must be loaded to have anything filled. */
+void mail_user_stats_fill(struct mail_user *user, struct stats *stats);
+
 #endif
--- a/src/plugins/imap-stats/Makefile.am	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/plugins/imap-stats/Makefile.am	Thu Mar 05 23:02:48 2015 +0200
@@ -1,5 +1,6 @@
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/src/lib \
+	-I$(top_srcdir)/src/lib-stats \
 	-I$(top_srcdir)/src/lib-mail \
 	-I$(top_srcdir)/src/lib-imap \
 	-I$(top_srcdir)/src/lib-index \
--- a/src/plugins/imap-stats/imap-stats-plugin.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/plugins/imap-stats/imap-stats-plugin.c	Thu Mar 05 23:02:48 2015 +0200
@@ -1,8 +1,10 @@
 /* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
 
 #include "imap-common.h"
+#include "base64.h"
 #include "str.h"
 #include "imap-commands.h"
+#include "stats.h"
 #include "stats-plugin.h"
 #include "stats-connection.h"
 #include "imap-stats-plugin.h"
@@ -15,8 +17,7 @@
 
 	unsigned int id;
 	bool continued;
-	struct mail_stats stats, pre_stats;
-	struct mailbox_transaction_stats pre_trans_stats;
+	struct stats *stats, *pre_stats;
 };
 
 static MODULE_CONTEXT_DEFINE_INIT(imap_stats_imap_module,
@@ -43,33 +44,34 @@
 	if (scmd == NULL) {
 		scmd = p_new(cmd->pool, struct stats_client_command, 1);
 		scmd->id = ++stats_cmd_id_counter;
+		scmd->stats = stats_alloc(cmd->pool);
+		scmd->pre_stats = stats_alloc(cmd->pool);
 		MODULE_CONTEXT_SET(cmd, imap_stats_imap_module, scmd);
 	}
-	mail_stats_get(suser, &scmd->pre_stats);
-	scmd->pre_trans_stats = suser->session_stats.trans_stats;
+
+	mail_user_stats_fill(cmd->client->user, scmd->pre_stats);
 }
 
 static void stats_command_post(struct client_command_context *cmd)
 {
 	struct stats_user *suser = STATS_USER_CONTEXT(cmd->client->user);
 	struct stats_client_command *scmd = IMAP_STATS_IMAP_CONTEXT(cmd);
-	struct mail_stats stats, pre_trans_stats, trans_stats;
+	struct stats *new_stats, *diff_stats;
+	const char *error;
 	unsigned int args_pos = 0, args_len = 0;
 	string_t *str;
+	buffer_t *buf;
 
 	if (scmd == NULL)
 		return;
 
-	mail_stats_get(suser, &stats);
-	mail_stats_add_diff(&scmd->stats, &scmd->pre_stats, &stats);
+	new_stats = stats_alloc(pool_datastack_create());
+	diff_stats = stats_alloc(pool_datastack_create());
 
-	/* mail_stats_get() can't see the transactions that already went
-	   away, so we'll need to use the session's stats difference */
-	memset(&pre_trans_stats, 0, sizeof(pre_trans_stats));
-	memset(&trans_stats, 0, sizeof(trans_stats));
-	pre_trans_stats.trans_stats = scmd->pre_trans_stats;
-	trans_stats.trans_stats = suser->session_stats.trans_stats;
-	mail_stats_add_diff(&scmd->stats, &pre_trans_stats, &trans_stats);
+	mail_user_stats_fill(cmd->client->user, new_stats);
+	if (!stats_diff(scmd->pre_stats, new_stats, diff_stats, &error))
+		i_error("stats: command stats shrank: %s", error);
+	stats_add(scmd->stats, diff_stats);
 
 	str = t_str_new(128);
 	str_append(str, "UPDATE-CMD\t");
@@ -91,7 +93,11 @@
 		scmd->continued = TRUE;
 	}
 
-	mail_stats_export(str, &scmd->stats);
+	buf = buffer_create_dynamic(pool_datastack_create(), 128);
+	stats_export(buf, scmd->stats);
+	str_append_c(str, '\t');
+	base64_encode(buf->data, buf->used, str);
+
 	str_append_c(str, '\n');
 
 	if (str_len(str) > PIPE_BUF) {
--- a/src/plugins/stats/Makefile.am	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/plugins/stats/Makefile.am	Thu Mar 05 23:02:48 2015 +0200
@@ -3,6 +3,7 @@
 	-I$(top_srcdir)/src/lib-settings \
 	-I$(top_srcdir)/src/lib-mail \
 	-I$(top_srcdir)/src/lib-master \
+	-I$(top_srcdir)/src/lib-stats \
 	-I$(top_srcdir)/src/lib-index \
 	-I$(top_srcdir)/src/lib-storage
 
@@ -13,9 +14,20 @@
 	lib90_stats_plugin.la
 
 lib90_stats_plugin_la_SOURCES = \
+	mail-stats.c \
+	mail-stats-fill.c \
 	stats-connection.c \
 	stats-plugin.c
 
 noinst_HEADERS = \
+	mail-stats.h \
 	stats-connection.h \
 	stats-plugin.h
+
+stats_moduledir = $(moduledir)/stats
+stats_module_LTLIBRARIES = libstats_mail.la
+
+libstats_mail_la_LDFLAGS = -module -avoid-version
+libstats_mail_la_LIBADD = mail-stats.lo $(LIBDOVECOT)
+libstats_mail_la_DEPENDENCIES = mail-stats.lo
+libstats_mail_la_SOURCES =
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plugins/stats/mail-stats-fill.c	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,130 @@
+/* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "stats-plugin.h"
+#include "mail-stats.h"
+
+#include <sys/resource.h>
+
+#define PROC_IO_PATH "/proc/self/io"
+
+static bool proc_io_disabled = FALSE;
+static int proc_io_fd = -1;
+
+static int
+process_io_buffer_parse(const char *buf, struct mail_stats *stats)
+{
+	const char *const *tmp;
+
+	tmp = t_strsplit(buf, "\n");
+	for (; *tmp != NULL; tmp++) {
+		if (strncmp(*tmp, "rchar: ", 7) == 0) {
+			if (str_to_uint64(*tmp + 7, &stats->read_bytes) < 0)
+				return -1;
+		} else if (strncmp(*tmp, "wchar: ", 7) == 0) {
+			if (str_to_uint64(*tmp + 7, &stats->write_bytes) < 0)
+				return -1;
+		} else if (strncmp(*tmp, "syscr: ", 7) == 0) {
+			if (str_to_uint32(*tmp + 7, &stats->read_count) < 0)
+				return -1;
+		} else if (strncmp(*tmp, "syscw: ", 7) == 0) {
+			if (str_to_uint32(*tmp + 7, &stats->write_count) < 0)
+				return -1;
+		}
+	}
+	return 0;
+}
+
+static int process_io_open(void)
+{
+	uid_t uid;
+
+	if (proc_io_fd != -1)
+		return proc_io_fd;
+
+	if (proc_io_disabled)
+		return -1;
+	proc_io_fd = open(PROC_IO_PATH, O_RDONLY);
+	if (proc_io_fd == -1 && errno == EACCES) {
+		/* kludge: if we're running with permissions temporarily
+		   dropped, get them temporarily back so we can open
+		   /proc/self/io. */
+		uid = geteuid();
+		if (seteuid(0) == 0) {
+			proc_io_fd = open(PROC_IO_PATH, O_RDONLY);
+			if (seteuid(uid) < 0) {
+				/* oops, this is bad */
+				i_fatal("stats: seteuid(%s) failed", dec2str(uid));
+			}
+		}
+		errno = EACCES;
+	}
+	if (proc_io_fd == -1) {
+		if (errno != ENOENT)
+			i_error("open(%s) failed: %m", PROC_IO_PATH);
+		proc_io_disabled = TRUE;
+		return -1;
+	}
+	return proc_io_fd;
+}
+
+static void process_read_io_stats(struct mail_stats *stats)
+{
+	char buf[1024];
+	int fd, ret;
+
+	if ((fd = process_io_open()) == -1)
+		return;
+
+	ret = pread(fd, buf, sizeof(buf), 0);
+	if (ret <= 0) {
+		if (ret == -1)
+			i_error("read(%s) failed: %m", PROC_IO_PATH);
+		else
+			i_error("read(%s) returned EOF", PROC_IO_PATH);
+	} else if (ret == sizeof(buf)) {
+		/* just shouldn't happen.. */
+		i_error("%s is larger than expected", PROC_IO_PATH);
+		proc_io_disabled = TRUE;
+	} else {
+		buf[ret] = '\0';
+		T_BEGIN {
+			if (process_io_buffer_parse(buf, stats) < 0) {
+				i_error("Invalid input in file %s",
+					PROC_IO_PATH);
+				proc_io_disabled = TRUE;
+			}
+		} T_END;
+	}
+}
+
+static void
+user_trans_stats_get(struct stats_user *suser, struct mail_stats *dest_r)
+{
+	struct stats_transaction_context *strans;
+
+	mail_stats_add_transaction(dest_r, &suser->finished_transaction_stats);
+	for (strans = suser->transactions; strans != NULL; strans = strans->next)
+		mail_stats_add_transaction(dest_r, &strans->trans->stats);
+}
+
+void mail_stats_fill(struct stats_user *suser, struct mail_stats *stats_r)
+{
+	struct rusage usage;
+
+	memset(stats_r, 0, sizeof(*stats_r));
+	/* cputime */
+	if (getrusage(RUSAGE_SELF, &usage) < 0)
+		memset(&usage, 0, sizeof(usage));
+	stats_r->user_cpu = usage.ru_utime;
+	stats_r->sys_cpu = usage.ru_stime;
+	stats_r->min_faults = usage.ru_minflt;
+	stats_r->maj_faults = usage.ru_majflt;
+	stats_r->vol_cs = usage.ru_nvcsw;
+	stats_r->invol_cs = usage.ru_nivcsw;
+	stats_r->disk_input = (unsigned long long)usage.ru_inblock * 512ULL;
+	stats_r->disk_output = (unsigned long long)usage.ru_oublock * 512ULL;
+	(void)gettimeofday(&stats_r->clock_time, NULL);
+	process_read_io_stats(stats_r);
+	user_trans_stats_get(suser, stats_r);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plugins/stats/mail-stats.c	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,168 @@
+/* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "time-util.h"
+#include "stats.h"
+#include "stats-parser.h"
+#include "mail-stats.h"
+
+static struct stats_parser_field mail_stats_fields[] = {
+#define E(parsename, name, type) { parsename, offsetof(struct mail_stats, name), sizeof(((struct mail_stats *)0)->name), type }
+#define EN(parsename, name) E(parsename, name, STATS_PARSER_TYPE_UINT)
+	E("user_cpu", user_cpu, STATS_PARSER_TYPE_TIMEVAL),
+	E("sys_cpu", sys_cpu, STATS_PARSER_TYPE_TIMEVAL),
+	E("clock_time", clock_time, STATS_PARSER_TYPE_TIMEVAL),
+	EN("min_faults", min_faults),
+	EN("maj_faults", maj_faults),
+	EN("vol_cs", vol_cs),
+	EN("invol_cs", invol_cs),
+	EN("disk_input", disk_input),
+	EN("disk_output", disk_output),
+
+	EN("read_count", read_count),
+	EN("read_bytes", read_bytes),
+	EN("write_count", write_count),
+	EN("write_bytes", write_bytes),
+
+	/*EN("mopen", trans_stats.open_lookup_count),
+	EN("mstat", trans_stats.stat_lookup_count),
+	EN("mfstat", trans_stats.fstat_lookup_count),*/
+	EN("mail_lookup_path", trans_lookup_path),
+	EN("mail_lookup_attr", trans_lookup_attr),
+	EN("mail_read_count", trans_files_read_count),
+	EN("mail_read_bytes", trans_files_read_bytes),
+	EN("mail_cache_hits", trans_cache_hit_count)
+};
+
+static size_t mail_stats_alloc_size(void)
+{
+	return sizeof(struct mail_stats);
+}
+
+static unsigned int mail_stats_field_count(void)
+{
+	return N_ELEMENTS(mail_stats_fields);
+}
+
+static const char *mail_stats_field_name(unsigned int n)
+{
+	i_assert(n < N_ELEMENTS(mail_stats_fields));
+
+	return mail_stats_fields[n].name;
+}
+
+static void
+mail_stats_field_value(string_t *str, const struct stats *stats,
+		       unsigned int n)
+{
+	i_assert(n < N_ELEMENTS(mail_stats_fields));
+
+	stats_parser_value(str, &mail_stats_fields[n], stats);
+}
+
+static bool
+mail_stats_diff(const struct stats *stats1, const struct stats *stats2,
+		struct stats *diff_stats_r, const char **error_r)
+{
+	return stats_parser_diff(mail_stats_fields, N_ELEMENTS(mail_stats_fields),
+				 stats1, stats2, diff_stats_r, error_r);
+}
+
+static void mail_stats_add(struct stats *dest, const struct stats *src)
+{
+	stats_parser_add(mail_stats_fields, N_ELEMENTS(mail_stats_fields),
+			 dest, src);
+}
+
+static bool
+mail_stats_have_changed(const struct stats *_prev, const struct stats *_cur)
+{
+	const struct mail_stats *prev = (const struct mail_stats *)_prev;
+	const struct mail_stats *cur = (const struct mail_stats *)_cur;
+
+	if (cur->disk_input != prev->disk_input ||
+	    cur->disk_output != prev->disk_output ||
+	    cur->trans_lookup_path != prev->trans_lookup_path ||
+	    cur->trans_lookup_attr != prev->trans_lookup_attr ||
+	    cur->trans_files_read_count != prev->trans_files_read_count ||
+	    cur->trans_files_read_bytes != prev->trans_files_read_bytes ||
+	    cur->trans_cache_hit_count != prev->trans_cache_hit_count)
+		return TRUE;
+
+	/* allow a tiny bit of changes that are caused by this
+	   timeout handling */
+	if (timeval_diff_msecs(&cur->user_cpu, &prev->user_cpu) != 0)
+		return TRUE;
+	if (timeval_diff_msecs(&cur->sys_cpu, &prev->sys_cpu) != 0)
+		return TRUE;
+
+	if (cur->maj_faults > prev->maj_faults+10)
+		return TRUE;
+	if (cur->invol_cs > prev->invol_cs+10)
+		return TRUE;
+	/* don't check for read/write count/bytes changes, since they get
+	   changed by stats checking itself */
+	return FALSE;
+}
+
+static void mail_stats_export(buffer_t *buf, const struct stats *_stats)
+{
+	const struct mail_stats *stats = (const struct mail_stats *)_stats;
+
+	buffer_append(buf, stats, sizeof(*stats));
+}
+
+static bool
+mail_stats_import(const unsigned char *data, size_t size, size_t *pos_r,
+		  struct stats *_stats, const char **error_r)
+{
+	struct mail_stats *stats = (struct mail_stats *)_stats;
+
+	if (size < sizeof(*stats)) {
+		*error_r = "mail_stats too small";
+		return FALSE;
+	}
+	memcpy(stats, data, sizeof(*stats));
+	*pos_r = sizeof(*stats);
+	return TRUE;
+}
+
+void mail_stats_add_transaction(struct mail_stats *stats,
+				const struct mailbox_transaction_stats *trans_stats)
+{
+	stats->trans_lookup_path += trans_stats->open_lookup_count;
+	stats->trans_lookup_attr += trans_stats->stat_lookup_count +
+		trans_stats->fstat_lookup_count;
+	stats->trans_files_read_count += trans_stats->files_read_count;
+	stats->trans_files_read_bytes += trans_stats->files_read_bytes;
+	stats->trans_cache_hit_count += trans_stats->cache_hit_count;
+}
+
+const struct stats_vfuncs mail_stats_vfuncs = {
+	"mail",
+	mail_stats_alloc_size,
+	mail_stats_field_count,
+	mail_stats_field_name,
+	mail_stats_field_value,
+	mail_stats_diff,
+	mail_stats_add,
+	mail_stats_have_changed,
+	mail_stats_export,
+	mail_stats_import
+};
+
+/* for the stats_mail plugin: */
+void stats_mail_init(void);
+void stats_mail_deinit(void);
+
+static struct stats_item *mail_stats_item;
+
+void stats_mail_init(void)
+{
+	mail_stats_item = stats_register(&mail_stats_vfuncs);
+}
+
+void stats_mail_deinit(void)
+{
+	stats_unregister(&mail_stats_item);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plugins/stats/mail-stats.h	Thu Mar 05 23:02:48 2015 +0200
@@ -0,0 +1,38 @@
+#ifndef MAIL_STATS_H
+#define MAIL_STATS_H
+
+#include <sys/time.h>
+#include "mail-storage-private.h"
+
+struct stats_user;
+
+struct mail_stats {
+	/* user/system CPU time used */
+	struct timeval user_cpu, sys_cpu;
+	/* clock time used (not counting the time in ioloop wait) */
+	struct timeval clock_time;
+	/* minor / major page faults */
+	uint32_t min_faults, maj_faults;
+	/* voluntary / involuntary context switches */
+	uint32_t vol_cs, invol_cs;
+	/* disk input/output bytes */
+	uint64_t disk_input, disk_output;
+	/* read()/write() syscall count and number of bytes */
+	uint32_t read_count, write_count;
+	uint64_t read_bytes, write_bytes;
+
+	/* based on struct mailbox_transaction_stats: */
+	uint32_t trans_lookup_path;
+	uint32_t trans_lookup_attr;
+	uint32_t trans_files_read_count;
+	uint64_t trans_files_read_bytes;
+	uint64_t trans_cache_hit_count;
+};
+
+extern const struct stats_vfuncs mail_stats_vfuncs;
+
+void mail_stats_fill(struct stats_user *suser, struct mail_stats *mail_stats);
+void mail_stats_add_transaction(struct mail_stats *stats,
+				const struct mailbox_transaction_stats *trans_stats);
+
+#endif
--- a/src/plugins/stats/stats-connection.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/plugins/stats/stats-connection.c	Thu Mar 05 23:02:48 2015 +0200
@@ -1,12 +1,14 @@
 /* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
 
 #include "lib.h"
+#include "base64.h"
 #include "hostpid.h"
 #include "net.h"
 #include "str.h"
 #include "strescape.h"
 #include "master-service.h"
 #include "mail-storage.h"
+#include "stats.h"
 #include "stats-plugin.h"
 #include "stats-connection.h"
 
@@ -147,15 +149,19 @@
 
 void stats_connection_send_session(struct stats_connection *conn,
 				   struct mail_user *user,
-				   const struct mail_stats *stats)
+				   const struct stats *stats)
 {
 	struct stats_user *suser = STATS_USER_CONTEXT(user);
-	string_t *str = t_str_new(128);
+	string_t *str = t_str_new(256);
+	buffer_t *buf;
+
+	buf = buffer_create_dynamic(pool_datastack_create(), 128);
+	stats_export(buf, stats);
 
 	str_append(str, "UPDATE-SESSION\t");
 	str_append(str, suser->stats_session_id);
-
-	mail_stats_export(str, stats);
+	str_append_c(str, '\t');
+	base64_encode(buf->data, buf->used, str);
 
 	str_append_c(str, '\n');
 	stats_connection_send(conn, str);
--- a/src/plugins/stats/stats-connection.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/plugins/stats/stats-connection.h	Thu Mar 05 23:02:48 2015 +0200
@@ -15,7 +15,7 @@
 
 void stats_connection_send_session(struct stats_connection *conn,
 				   struct mail_user *user,
-				   const struct mail_stats *stats);
+				   const struct stats *stats);
 void stats_connection_send(struct stats_connection *conn, const string_t *str);
 
 #endif
--- a/src/plugins/stats/stats-plugin.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/plugins/stats/stats-plugin.c	Thu Mar 05 23:02:48 2015 +0200
@@ -6,12 +6,11 @@
 #include "str.h"
 #include "time-util.h"
 #include "settings-parser.h"
+#include "mail-stats.h"
+#include "stats.h"
 #include "stats-connection.h"
 #include "stats-plugin.h"
 
-#include <sys/time.h>
-#include <sys/resource.h>
-
 #define STATS_CONTEXT(obj) \
 	MODULE_CONTEXT(obj, stats_storage_module)
 
@@ -20,18 +19,6 @@
 #define SESSION_STATS_FORCE_REFRESH_SECS (5*60)
 #define REFRESH_CHECK_INTERVAL 100
 #define MAIL_STATS_SOCKET_NAME "stats-mail"
-#define PROC_IO_PATH "/proc/self/io"
-
-#define USECS_PER_SEC 1000000
-
-struct stats_transaction_context {
-	union mailbox_transaction_module_context module_ctx;
-
-	struct stats_transaction_context *prev, *next;
-	struct mailbox_transaction_context *trans;
-
-	struct mailbox_transaction_stats prev_stats;
-};
 
 struct stats_storage {
 	union mail_storage_module_context module_ctx;
@@ -48,162 +35,20 @@
 
 struct stats_user_module stats_user_module =
 	MODULE_CONTEXT_INIT(&mail_user_module_register);
-static MODULE_CONTEXT_DEFINE_INIT(stats_storage_module,
-				  &mail_storage_module_register);
+struct stats_storage_module stats_storage_module =
+	MODULE_CONTEXT_INIT(&mail_storage_module_register);
 
-static bool proc_io_disabled = FALSE;
-static int proc_io_fd = -1;
-
+static struct stats_item *mail_stats_item;
 static struct stats_connection *global_stats_conn = NULL;
 static struct mail_user *stats_global_user = NULL;
 static unsigned int stats_user_count = 0;
 
 static void session_stats_refresh_timeout(struct mail_user *user);
 
-static void trans_stats_dec(struct mailbox_transaction_stats *dest,
-			    const struct mailbox_transaction_stats *src)
-{
-	dest->open_lookup_count -= src->open_lookup_count;
-	dest->stat_lookup_count -= src->stat_lookup_count;
-	dest->fstat_lookup_count -= src->fstat_lookup_count;
-	dest->files_read_count -= src->files_read_count;
-	dest->files_read_bytes -= src->files_read_bytes;
-	dest->cache_hit_count -= src->cache_hit_count;
-}
-
-static void trans_stats_add(struct mailbox_transaction_stats *dest,
-			    const struct mailbox_transaction_stats *src)
-{
-	dest->open_lookup_count += src->open_lookup_count;
-	dest->stat_lookup_count += src->stat_lookup_count;
-	dest->fstat_lookup_count += src->fstat_lookup_count;
-	dest->files_read_count += src->files_read_count;
-	dest->files_read_bytes += src->files_read_bytes;
-	dest->cache_hit_count += src->cache_hit_count;
-}
-
-static void user_trans_stats_get(struct stats_user *suser,
-				 struct mailbox_transaction_stats *dest_r)
-{
-	struct stats_transaction_context *strans;
-
-	memset(dest_r, 0, sizeof(*dest_r));
-	strans = suser->transactions;
-	for (; strans != NULL; strans = strans->next)
-		trans_stats_add(dest_r, &strans->trans->stats);
-}
-
-static int
-process_io_buffer_parse(const char *buf, struct mail_stats *stats)
-{
-	const char *const *tmp;
-
-	tmp = t_strsplit(buf, "\n");
-	for (; *tmp != NULL; tmp++) {
-		if (strncmp(*tmp, "rchar: ", 7) == 0) {
-			if (str_to_uint64(*tmp + 7, &stats->read_bytes) < 0)
-				return -1;
-		} else if (strncmp(*tmp, "wchar: ", 7) == 0) {
-			if (str_to_uint64(*tmp + 7, &stats->write_bytes) < 0)
-				return -1;
-		} else if (strncmp(*tmp, "syscr: ", 7) == 0) {
-			if (str_to_uint32(*tmp + 7, &stats->read_count) < 0)
-				return -1;
-		} else if (strncmp(*tmp, "syscw: ", 7) == 0) {
-			if (str_to_uint32(*tmp + 7, &stats->write_count) < 0)
-				return -1;
-		}
-	}
-	return 0;
-}
-
-static int process_io_open(void)
-{
-	uid_t uid;
-
-	if (proc_io_fd != -1)
-		return proc_io_fd;
-
-	if (proc_io_disabled)
-		return -1;
-	proc_io_fd = open(PROC_IO_PATH, O_RDONLY);
-	if (proc_io_fd == -1 && errno == EACCES) {
-		/* kludge: if we're running with permissions temporarily
-		   dropped, get them temporarily back so we can open
-		   /proc/self/io. */
-		uid = geteuid();
-		if (seteuid(0) == 0) {
-			proc_io_fd = open(PROC_IO_PATH, O_RDONLY);
-			if (seteuid(uid) < 0) {
-				/* oops, this is bad */
-				i_fatal("stats: seteuid(%s) failed", dec2str(uid));
-			}
-		}
-		errno = EACCES;
-	}
-	if (proc_io_fd == -1) {
-		if (errno != ENOENT)
-			i_error("open(%s) failed: %m", PROC_IO_PATH);
-		proc_io_disabled = TRUE;
-		return -1;
-	}
-	return proc_io_fd;
-}
-
-static void process_read_io_stats(struct mail_stats *stats)
-{
-	char buf[1024];
-	int fd, ret;
-
-	if ((fd = process_io_open()) == -1)
-		return;
-
-	ret = pread(fd, buf, sizeof(buf), 0);
-	if (ret <= 0) {
-		if (ret == -1)
-			i_error("read(%s) failed: %m", PROC_IO_PATH);
-		else
-			i_error("read(%s) returned EOF", PROC_IO_PATH);
-	} else if (ret == sizeof(buf)) {
-		/* just shouldn't happen.. */
-		i_error("%s is larger than expected", PROC_IO_PATH);
-		proc_io_disabled = TRUE;
-	} else {
-		buf[ret] = '\0';
-		T_BEGIN {
-			if (process_io_buffer_parse(buf, stats) < 0) {
-				i_error("Invalid input in file %s",
-					PROC_IO_PATH);
-				proc_io_disabled = TRUE;
-			}
-		} T_END;
-	}
-}
-
-void mail_stats_get(struct stats_user *suser, struct mail_stats *stats_r)
-{
-	struct rusage usage;
-
-	memset(stats_r, 0, sizeof(*stats_r));
-	/* cputime */
-	if (getrusage(RUSAGE_SELF, &usage) < 0)
-		memset(&usage, 0, sizeof(usage));
-	stats_r->user_cpu = usage.ru_utime;
-	stats_r->sys_cpu = usage.ru_stime;
-	stats_r->min_faults = usage.ru_minflt;
-	stats_r->maj_faults = usage.ru_majflt;
-	stats_r->vol_cs = usage.ru_nvcsw;
-	stats_r->invol_cs = usage.ru_nivcsw;
-	stats_r->disk_input = (unsigned long long)usage.ru_inblock * 512ULL;
-	stats_r->disk_output = (unsigned long long)usage.ru_oublock * 512ULL;
-	(void)gettimeofday(&stats_r->clock_time, NULL);
-	process_read_io_stats(stats_r);
-	user_trans_stats_get(suser, &stats_r->trans_stats);
-}
-
 static void stats_io_activate(struct mail_user *user)
 {
 	struct stats_user *suser = STATS_USER_CONTEXT(user);
+	struct mail_stats *mail_stats;
 
 	if (stats_user_count == 1) {
 		/* the first user sets the global user. the second user sets
@@ -211,121 +56,35 @@
 		   the global user again somewhere. do it here. */
 		stats_global_user = user;
 		/* skip time spent waiting in ioloop */
-		suser->pre_io_stats.clock_time = ioloop_timeval;
+		mail_stats = stats_fill_ptr(suser->pre_io_stats, mail_stats_item);
+		mail_stats->clock_time = ioloop_timeval;
 	} else {
 		i_assert(stats_global_user == NULL);
 
-		mail_stats_get(suser, &suser->pre_io_stats);
-	}
-}
-
-static void timeval_add_diff(struct timeval *dest,
-			     const struct timeval *newsrc,
-			     const struct timeval *oldsrc)
-{
-	long long usecs;
-
-	usecs = timeval_diff_usecs(newsrc, oldsrc);
-	dest->tv_sec += usecs / USECS_PER_SEC;
-	dest->tv_usec += usecs % USECS_PER_SEC;
-	if (dest->tv_usec > USECS_PER_SEC) {
-		dest->tv_usec -= USECS_PER_SEC;
-		dest->tv_sec++;
+		mail_user_stats_fill(user, suser->pre_io_stats);
 	}
 }
 
-void mail_stats_add_diff(struct mail_stats *dest,
-			 const struct mail_stats *old_stats,
-			 const struct mail_stats *new_stats)
-{
-	dest->disk_input += new_stats->disk_input - old_stats->disk_input;
-	dest->disk_output += new_stats->disk_output - old_stats->disk_output;
-	dest->min_faults += new_stats->min_faults - old_stats->min_faults;
-	dest->maj_faults += new_stats->maj_faults - old_stats->maj_faults;
-	dest->vol_cs += new_stats->vol_cs - old_stats->vol_cs;
-	dest->invol_cs += new_stats->invol_cs - old_stats->invol_cs;
-	dest->read_count += new_stats->read_count - old_stats->read_count;
-	dest->write_count += new_stats->write_count - old_stats->write_count;
-	dest->read_bytes += new_stats->read_bytes - old_stats->read_bytes;
-	dest->write_bytes += new_stats->write_bytes - old_stats->write_bytes;
-
-	timeval_add_diff(&dest->user_cpu, &new_stats->user_cpu,
-			 &old_stats->user_cpu);
-	timeval_add_diff(&dest->sys_cpu, &new_stats->sys_cpu,
-			 &old_stats->sys_cpu);
-	timeval_add_diff(&dest->clock_time, &new_stats->clock_time,
-			 &old_stats->clock_time);
-	trans_stats_dec(&dest->trans_stats, &old_stats->trans_stats);
-	trans_stats_add(&dest->trans_stats, &new_stats->trans_stats);
-}
-
-void mail_stats_export(string_t *str, const struct mail_stats *stats)
-{
-	const struct mailbox_transaction_stats *tstats = &stats->trans_stats;
-
-	str_printfa(str, "\tucpu=%ld.%ld", (long)stats->user_cpu.tv_sec,
-		    (long)stats->user_cpu.tv_usec);
-	str_printfa(str, "\tscpu=%ld.%ld", (long)stats->sys_cpu.tv_sec,
-		    (long)stats->sys_cpu.tv_usec);
-	str_printfa(str, "\ttime=%ld.%ld", (long)stats->clock_time.tv_sec,
-		    (long)stats->clock_time.tv_usec);
-	str_printfa(str, "\tminflt=%u", stats->min_faults);
-	str_printfa(str, "\tmajflt=%u", stats->maj_faults);
-	str_printfa(str, "\tvolcs=%u", stats->vol_cs);
-	str_printfa(str, "\tinvolcs=%u", stats->invol_cs);
-	str_printfa(str, "\tdiskin=%llu",
-		    (unsigned long long)stats->disk_input);
-	str_printfa(str, "\tdiskout=%llu",
-		    (unsigned long long)stats->disk_output);
-	str_printfa(str, "\trchar=%llu",
-		    (unsigned long long)stats->read_bytes);
-	str_printfa(str, "\twchar=%llu",
-		    (unsigned long long)stats->write_bytes);
-	str_printfa(str, "\tsyscr=%u", stats->read_count);
-	str_printfa(str, "\tsyscw=%u", stats->write_count);
-	str_printfa(str, "\tmlpath=%lu",
-		    tstats->open_lookup_count + tstats->stat_lookup_count);
-	str_printfa(str, "\tmlattr=%lu",
-		    tstats->fstat_lookup_count + tstats->stat_lookup_count);
-	str_printfa(str, "\tmrcount=%lu", tstats->files_read_count);
-	str_printfa(str, "\tmrbytes=%llu", tstats->files_read_bytes);
-	str_printfa(str, "\tmcache=%lu", tstats->cache_hit_count);
-}
-
 static void stats_add_session(struct mail_user *user)
 {
 	struct stats_user *suser = STATS_USER_CONTEXT(user);
-	struct mail_stats new_stats;
+	struct stats *new_stats, *diff_stats;
+	const char *error;
 
-	mail_stats_get(suser, &new_stats);
-	mail_stats_add_diff(&suser->session_stats, &suser->pre_io_stats,
-			    &new_stats);
-	suser->pre_io_stats = new_stats;
-}
+	new_stats = stats_alloc(pool_datastack_create());
+	diff_stats = stats_alloc(pool_datastack_create());
 
-static bool session_has_changed(const struct mail_stats *prev,
-				const struct mail_stats *cur)
-{
-	if (cur->disk_input != prev->disk_input ||
-	    cur->disk_output != prev->disk_output ||
-	    memcmp(&cur->trans_stats, &prev->trans_stats,
-		   sizeof(cur->trans_stats)) != 0)
-		return TRUE;
-
-	/* allow a tiny bit of changes that are caused by this
-	   timeout handling */
-	if (timeval_diff_msecs(&cur->user_cpu, &prev->user_cpu) != 0)
-		return TRUE;
-	if (timeval_diff_msecs(&cur->sys_cpu, &prev->sys_cpu) != 0)
-		return TRUE;
-
-	if (cur->maj_faults > prev->maj_faults+10)
-		return TRUE;
-	if (cur->invol_cs > prev->invol_cs+10)
-		return TRUE;
-	/* don't check for read/write count/bytes changes, since they get
-	   changed by stats checking itself */
-	return FALSE;
+	mail_user_stats_fill(user, new_stats);
+	/* we'll count new_stats-pre_io_stats and add the changes to
+	   session_stats. the new_stats can't be directly copied to
+	   session_stats because there are some fields that don't start from
+	   zero, like clock_time. (actually with stats_global_user code we're
+	   requiring that clock_time is the only such field..) */
+	if (!stats_diff(suser->pre_io_stats, new_stats, diff_stats, &error))
+		i_error("stats: session stats shrank: %s", error);
+	stats_add(suser->session_stats, diff_stats);
+	/* copying is only needed if stats_global_user=NULL */
+	stats_copy(suser->pre_io_stats, new_stats);
 }
 
 static bool
@@ -336,8 +95,8 @@
 
 	*to_next_secs_r = SESSION_STATS_FORCE_REFRESH_SECS;
 
-	if (session_has_changed(&suser->last_sent_session_stats,
-				&suser->session_stats)) {
+	if (stats_have_changed(suser->last_sent_session_stats,
+			       suser->session_stats)) {
 		*to_next_secs_r = suser->refresh_secs;
 		*changed_r = TRUE;
 		return TRUE;
@@ -372,9 +131,9 @@
 	if (session_stats_need_send(suser, now, &changed, &to_next_secs)) {
 		suser->session_sent_duplicate = !changed;
 		suser->last_session_update = now;
-		suser->last_sent_session_stats = suser->session_stats;
+		stats_copy(suser->last_sent_session_stats, suser->session_stats);
 		stats_connection_send_session(suser->stats_conn, user,
-					      &suser->session_stats);
+					      suser->session_stats);
 	}
 
 	if (suser->to_stats_timeout != NULL)
@@ -407,10 +166,18 @@
 static void stats_transaction_free(struct stats_user *suser,
 				   struct stats_transaction_context *strans)
 {
+	const struct mailbox_transaction_stats *src = &strans->trans->stats;
+	struct mailbox_transaction_stats *dest =
+		&suser->finished_transaction_stats;
+
 	DLLIST_REMOVE(&suser->transactions, strans);
 
-	trans_stats_add(&suser->session_stats.trans_stats,
-			&strans->trans->stats);
+	dest->open_lookup_count += src->open_lookup_count;
+	dest->stat_lookup_count += src->stat_lookup_count;
+	dest->fstat_lookup_count += src->fstat_lookup_count;
+	dest->files_read_count += src->files_read_count;
+	dest->files_read_bytes += src->files_read_bytes;
+	dest->cache_hit_count += src->cache_hit_count;
 	i_free(strans);
 }
 
@@ -538,6 +305,17 @@
 	}
 }
 
+static void stats_user_stats_fill(struct mail_user *user, struct stats *stats)
+{
+	struct stats_user *suser = STATS_USER_CONTEXT(user);
+	struct mail_stats *mail_stats;
+
+	mail_stats = stats_fill_ptr(stats, mail_stats_item);
+	mail_stats_fill(suser, mail_stats);
+
+	suser->module_ctx.super.stats_fill(user, stats);
+}
+
 static void stats_user_deinit(struct mail_user *user)
 {
 	struct stats_user *suser = STATS_USER_CONTEXT(user);
@@ -624,6 +402,7 @@
 	suser->module_ctx.super = *v;
 	user->vlast = &suser->module_ctx.super;
 	v->deinit = stats_user_deinit;
+	v->stats_fill = stats_user_stats_fill;
 
 	suser->refresh_secs = refresh_secs;
 	str = mail_user_plugin_getenv(user, "stats_track_cmds");
@@ -647,6 +426,10 @@
 				      stats_io_activate,
 				      stats_io_deactivate, user);
 
+	suser->pre_io_stats = stats_alloc(user->pool);
+	suser->session_stats = stats_alloc(user->pool);
+	suser->last_sent_session_stats = stats_alloc(user->pool);
+
 	MODULE_CONTEXT_SET(user, stats_user_module, suser);
 	stats_connection_connect(suser->stats_conn, user);
 }
@@ -658,6 +441,7 @@
 
 void stats_plugin_init(struct module *module)
 {
+	mail_stats_item = stats_register(&mail_stats_vfuncs);
 	mail_storage_hooks_add(module, &stats_mail_storage_hooks);
 }
 
@@ -666,4 +450,5 @@
 	if (global_stats_conn != NULL)
 		stats_connection_unref(&global_stats_conn);
 	mail_storage_hooks_remove(&stats_mail_storage_hooks);
+	stats_unregister(&mail_stats_item);
 }
--- a/src/plugins/stats/stats-plugin.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/plugins/stats/stats-plugin.h	Thu Mar 05 23:02:48 2015 +0200
@@ -5,28 +5,9 @@
 #include "mail-user.h"
 #include "mail-storage-private.h"
 
-#include <sys/time.h>
-
 #define STATS_USER_CONTEXT(obj) \
 	MODULE_CONTEXT(obj, stats_user_module)
 
-struct mail_stats {
-	/* user/system CPU time used */
-	struct timeval user_cpu, sys_cpu;
-	/* clock time used (not counting the time in ioloop wait) */
-	struct timeval clock_time;
-	/* minor / major page faults */
-	uint32_t min_faults, maj_faults;
-	/* voluntary / involuntary context switches */
-	uint32_t vol_cs, invol_cs;
-	/* disk input/output bytes */
-	uint64_t disk_input, disk_output;
-	/* read()/write() syscall count and number of bytes */
-	uint32_t read_count, write_count;
-	uint64_t read_bytes, write_bytes;
-	struct mailbox_transaction_stats trans_stats;
-};
-
 struct stats_user {
 	union mail_user_module_context module_ctx;
 
@@ -39,28 +20,34 @@
 	unsigned int refresh_check_counter;
 
 	/* current session statistics */
-	struct mail_stats session_stats;
+	struct stats *session_stats;
+	/* cumulative trans_stats for all already freed transactions. */
+	struct mailbox_transaction_stats finished_transaction_stats;
 	/* stats before calling IO callback. after IO callback this value is
 	   compared to current stats to see the difference */
-	struct mail_stats pre_io_stats;
+	struct stats *pre_io_stats;
 
 	time_t last_session_update;
 	struct timeout *to_stats_timeout;
 	/* stats that were last sent to stats server */
-	struct mail_stats last_sent_session_stats;
+	struct stats *last_sent_session_stats;
 	bool session_sent_duplicate;
 
 	/* list of all currently existing transactions for this user */
 	struct stats_transaction_context *transactions;
 };
 
-extern MODULE_CONTEXT_DEFINE(stats_user_module, &mail_user_module_register);
+struct stats_transaction_context {
+	union mailbox_transaction_module_context module_ctx;
+
+	struct stats_transaction_context *prev, *next;
+	struct mailbox_transaction_context *trans;
 
-void mail_stats_get(struct stats_user *suser, struct mail_stats *stats_r);
-void mail_stats_add_diff(struct mail_stats *dest,
-			 const struct mail_stats *old_stats,
-			 const struct mail_stats *new_stats);
-void mail_stats_export(string_t *str, const struct mail_stats *stats);
+	struct mailbox_transaction_stats prev_stats;
+};
+
+extern MODULE_CONTEXT_DEFINE(stats_user_module, &mail_user_module_register);
+extern MODULE_CONTEXT_DEFINE(stats_storage_module, &mail_storage_module_register);
 
 void stats_plugin_init(struct module *module);
 void stats_plugin_deinit(void);
--- a/src/stats/Makefile.am	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/Makefile.am	Thu Mar 05 23:02:48 2015 +0200
@@ -1,11 +1,14 @@
+stats_moduledir = $(moduledir)/stats
 pkglibexecdir = $(libexecdir)/dovecot
 
 pkglibexec_PROGRAMS = stats
 
 AM_CPPFLAGS = \
+	-DSTATS_MODULE_DIR=\""$(stats_moduledir)"\" \
 	-I$(top_srcdir)/src/lib \
 	-I$(top_srcdir)/src/lib-settings \
-	-I$(top_srcdir)/src/lib-master
+	-I$(top_srcdir)/src/lib-master \
+	-I$(top_srcdir)/src/lib-stats
 
 stats_LDADD = $(LIBDOVECOT) 
 stats_DEPENDENCIES = $(LIBDOVECOT_DEPS)
--- a/src/stats/client-export.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/client-export.c	Thu Mar 05 23:02:48 2015 +0200
@@ -96,34 +96,34 @@
 }
 
 static void
-client_export_mail_stats(string_t *str, const struct mail_stats *stats)
+client_export_stats_headers(struct client *client)
 {
-#define MAIL_STATS_HEADER "\tuser_cpu\tsys_cpu\tclock_time" \
-	"\tmin_faults\tmaj_faults\tvol_cs\tinvol_cs" \
-	"\tdisk_input\tdisk_output" \
-	"\tread_count\tread_bytes\twrite_count\twrite_bytes" \
-	"\tmail_lookup_path\tmail_lookup_attr" \
-	"\tmail_read_count\tmail_read_bytes\tmail_cache_hits\n"
+	unsigned int i, count = stats_field_count();
+	string_t *str = t_str_new(128);
+
+	i_assert(count > 0);
 
-	str_printfa(str, "\t%ld.%06u", (long)stats->user_cpu.tv_sec,
-		    (unsigned int)stats->user_cpu.tv_usec);
-	str_printfa(str, "\t%ld.%06u", (long)stats->sys_cpu.tv_sec,
-		    (unsigned int)stats->sys_cpu.tv_usec);
-	str_printfa(str, "\t%ld.%06u", (long)stats->clock_time.tv_sec,
-		    (unsigned int)stats->clock_time.tv_usec);
-	str_printfa(str, "\t%u\t%u", stats->min_faults, stats->maj_faults);
-	str_printfa(str, "\t%u\t%u", stats->vol_cs, stats->invol_cs);
-	str_printfa(str, "\t%llu\t%llu",
-		    (unsigned long long)stats->disk_input,
-		    (unsigned long long)stats->disk_output);
-	str_printfa(str, "\t%u\t%llu\t%u\t%llu",
-		    stats->read_count, (unsigned long long)stats->read_bytes,
-		    stats->write_count, (unsigned long long)stats->write_bytes);
-	str_printfa(str, "\t%u\t%u\t%u\t%llu\t%u",
-		    stats->mail_lookup_path, stats->mail_lookup_attr,
-		    stats->mail_read_count,
-		    (unsigned long long)stats->mail_read_bytes,
-		    stats->mail_cache_hits);
+	str_append(str, stats_field_name(0));
+	for (i = 1; i < count; i++) {
+		str_append_c(str, '\t');
+		str_append(str, stats_field_name(i));
+	}
+	str_append_c(str, '\n');
+	o_stream_send(client->output, str_data(str), str_len(str));
+}
+
+static void
+client_export_stats(string_t *str, const struct stats *stats)
+{
+	unsigned int i, count = stats_field_count();
+
+	i_assert(count > 0);
+
+	stats_field_value(str, stats, 0);
+	for (i = 1; i < count; i++) {
+		str_append_c(str, '\t');
+		stats_field_value(str, stats, i);
+	}
 }
 
 static bool
@@ -259,7 +259,8 @@
 
 	if (!cmd->header_sent) {
 		o_stream_nsend_str(client->output,
-			"cmd\targs\tsession\tuser\tlast_update"MAIL_STATS_HEADER);
+			"cmd\targs\tsession\tuser\tlast_update\t");
+		client_export_stats_headers(client);
 		cmd->header_sent = TRUE;
 	}
 
@@ -275,14 +276,13 @@
 		str_append_c(cmd->str, '\t');
 		str_append_tabescaped(cmd->str, command->args);
 		str_append_c(cmd->str, '\t');
-		T_BEGIN {
-			str_append(cmd->str, command->session->id);
-			str_append_c(cmd->str, '\t');
-			str_append_tabescaped(cmd->str,
-					      command->session->user->name);
-		} T_END;
+		str_append(cmd->str, command->session->id);
+		str_append_c(cmd->str, '\t');
+		str_append_tabescaped(cmd->str,
+				      command->session->user->name);
 		client_export_timeval(cmd->str, &command->last_update);
-		client_export_mail_stats(cmd->str, &command->stats);
+		str_append_c(cmd->str, '\t');
+		client_export_stats(cmd->str, command->stats);
 		str_append_c(cmd->str, '\n');
 		o_stream_nsend(client->output, str_data(cmd->str),
 			       str_len(cmd->str));
@@ -307,8 +307,8 @@
 	if (!cmd->header_sent) {
 		o_stream_nsend_str(client->output,
 			"session\tuser\tip\tservice\tpid\tconnected"
-			"\tlast_update\tnum_cmds"
-			MAIL_STATS_HEADER);
+			"\tlast_update\tnum_cmds\t");
+		client_export_stats_headers(client);
 		cmd->header_sent = TRUE;
 	}
 
@@ -319,23 +319,20 @@
 			continue;
 
 		str_truncate(cmd->str, 0);
-		T_BEGIN {
-			str_append(cmd->str, session->id);
-			str_append_c(cmd->str, '\t');
-			str_append_tabescaped(cmd->str, session->user->name);
-			str_append_c(cmd->str, '\t');
-			if (session->ip != NULL) {
-				str_append(cmd->str,
-					   net_ip2addr(&session->ip->ip));
-			}
-			str_append_c(cmd->str, '\t');
-			str_append_tabescaped(cmd->str, session->service);
+		str_append(cmd->str, session->id);
+		str_append_c(cmd->str, '\t');
+		str_append_tabescaped(cmd->str, session->user->name);
+		str_append_c(cmd->str, '\t');
+		if (session->ip != NULL) T_BEGIN {
+			str_append(cmd->str, net_ip2addr(&session->ip->ip));
 		} T_END;
+		str_append_c(cmd->str, '\t');
+		str_append_tabescaped(cmd->str, session->service);
 		str_printfa(cmd->str, "\t%ld", (long)session->pid);
 		str_printfa(cmd->str, "\t%d", !session->disconnected);
 		client_export_timeval(cmd->str, &session->last_update);
-		str_printfa(cmd->str, "\t%u", session->num_cmds);
-		client_export_mail_stats(cmd->str, &session->stats);
+		str_printfa(cmd->str, "\t%u\t", session->num_cmds);
+		client_export_stats(cmd->str, session->stats);
 		str_append_c(cmd->str, '\n');
 		o_stream_nsend(client->output, str_data(cmd->str),
 			       str_len(cmd->str));
@@ -360,7 +357,8 @@
 	if (!cmd->header_sent) {
 		o_stream_nsend_str(client->output,
 			"user\treset_timestamp\tlast_update"
-			"\tnum_logins\tnum_cmds"MAIL_STATS_HEADER);
+			"\tnum_logins\tnum_cmds\t");
+		client_export_stats_headers(client);
 		cmd->header_sent = TRUE;
 	}
 
@@ -374,9 +372,9 @@
 		str_append_tabescaped(cmd->str, user->name);
 		str_printfa(cmd->str, "\t%ld", (long)user->reset_timestamp);
 		client_export_timeval(cmd->str, &user->last_update);
-		str_printfa(cmd->str, "\t%u\t%u",
+		str_printfa(cmd->str, "\t%u\t%u\t",
 			    user->num_logins, user->num_cmds);
-		client_export_mail_stats(cmd->str, &user->stats);
+		client_export_stats(cmd->str, user->stats);
 		str_append_c(cmd->str, '\n');
 		o_stream_nsend(client->output, str_data(cmd->str),
 			       str_len(cmd->str));
@@ -401,7 +399,8 @@
 	if (!cmd->header_sent) {
 		o_stream_nsend_str(client->output,
 			"domain\treset_timestamp\tlast_update"
-			"\tnum_logins\tnum_cmds\tnum_connected_sessions"MAIL_STATS_HEADER);
+			"\tnum_logins\tnum_cmds\tnum_connected_sessions\t");
+		client_export_stats_headers(client);
 		cmd->header_sent = TRUE;
 	}
 
@@ -415,10 +414,10 @@
 		str_append_tabescaped(cmd->str, domain->name);
 		str_printfa(cmd->str, "\t%ld", (long)domain->reset_timestamp);
 		client_export_timeval(cmd->str, &domain->last_update);
-		str_printfa(cmd->str, "\t%u\t%u\t%u",
+		str_printfa(cmd->str, "\t%u\t%u\t%u\t",
 			    domain->num_logins, domain->num_cmds,
 			    domain->num_connected_sessions);
-		client_export_mail_stats(cmd->str, &domain->stats);
+		client_export_stats(cmd->str, domain->stats);
 		str_append_c(cmd->str, '\n');
 		o_stream_nsend(client->output, str_data(cmd->str),
 			       str_len(cmd->str));
@@ -443,7 +442,8 @@
 	if (!cmd->header_sent) {
 		o_stream_nsend_str(client->output,
 			"ip\treset_timestamp\tlast_update"
-			"\tnum_logins\tnum_cmds\tnum_connected_sessions"MAIL_STATS_HEADER);
+			"\tnum_logins\tnum_cmds\tnum_connected_sessions\t");
+		client_export_stats_headers(client);
 		cmd->header_sent = TRUE;
 	}
 
@@ -459,9 +459,9 @@
 		} T_END;
 		str_printfa(cmd->str, "\t%ld", (long)ip->reset_timestamp);
 		client_export_timeval(cmd->str, &ip->last_update);
-		str_printfa(cmd->str, "\t%u\t%u\t%u",
+		str_printfa(cmd->str, "\t%u\t%u\t%u\t",
 			    ip->num_logins, ip->num_cmds, ip->num_connected_sessions);
-		client_export_mail_stats(cmd->str, &ip->stats);
+		client_export_stats(cmd->str, ip->stats);
 		str_append_c(cmd->str, '\n');
 		o_stream_nsend(client->output, str_data(cmd->str),
 			       str_len(cmd->str));
@@ -485,16 +485,17 @@
 	if (!cmd->header_sent) {
 		o_stream_nsend_str(client->output,
 			"reset_timestamp\tlast_update"
-			"\tnum_logins\tnum_cmds\tnum_connected_sessions"MAIL_STATS_HEADER);
+			"\tnum_logins\tnum_cmds\tnum_connected_sessions\t");
+		client_export_stats_headers(client);
 		cmd->header_sent = TRUE;
 	}
 
 	str_truncate(cmd->str, 0);
 	str_printfa(cmd->str, "%ld", (long)g->reset_timestamp);
 	client_export_timeval(cmd->str, &g->last_update);
-	str_printfa(cmd->str, "\t%u\t%u\t%u",
+	str_printfa(cmd->str, "\t%u\t%u\t%u\t",
 		    g->num_logins, g->num_cmds, g->num_connected_sessions);
-	client_export_mail_stats(cmd->str, &g->stats);
+	client_export_stats(cmd->str, g->stats);
 	str_append_c(cmd->str, '\n');
 	o_stream_nsend(client->output, str_data(cmd->str),
 		       str_len(cmd->str));
--- a/src/stats/mail-command.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-command.c	Thu Mar 05 23:02:48 2015 +0200
@@ -1,6 +1,8 @@
 /* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
 
 #include "lib.h"
+#include "buffer.h"
+#include "base64.h"
 #include "ioloop.h"
 #include "llist.h"
 #include "global-memory.h"
@@ -45,7 +47,8 @@
 {
 	struct mail_command *cmd;
 
-	cmd = i_new(struct mail_command, 1);
+	cmd = i_malloc(sizeof(struct mail_command) + stats_alloc_size());
+	cmd->stats = (void *)(cmd + 1);
 	cmd->refcount = 1; /* unrefed at "done" */
 	cmd->session = session;
 	cmd->name = i_strdup(name);
@@ -98,13 +101,14 @@
 {
 	struct mail_session *session;
 	struct mail_command *cmd;
-	struct mail_stats stats, diff_stats;
+	struct stats *new_stats, *diff_stats;
+	buffer_t *buf;
 	const char *error;
 	unsigned int i, cmd_id;
 	bool done = FALSE, continued = FALSE;
 
-	/* <session guid> <cmd id> [d] <name> <args> [key=value ..]
-	   <session guid> <cmd id> c[d] [key=value ..] */
+	/* <session guid> <cmd id> [d] <name> <args> <stats>
+	   <session guid> <cmd id> c[d] <stats> */
 	if (str_array_length(args) < 3) {
 		*error_r = "UPDATE-CMD: Too few parameters";
 		return -1;
@@ -161,16 +165,26 @@
 		args += 3;
 		cmd->last_update = ioloop_timeval;
 	}
-	if (mail_stats_parse(args, &stats, error_r) < 0) {
-		*error_r = t_strconcat("UPDATE-CMD: ", *error_r, NULL);
+	buf = buffer_create_dynamic(pool_datastack_create(), 256);
+	if (args[0] == NULL ||
+	    base64_decode(args[0], strlen(args[0]), NULL, buf) < 0) {
+		*error_r = t_strdup_printf("UPDATE-CMD: Invalid base64 input");
 		return -1;
 	}
-	if (!mail_stats_diff(&cmd->stats, &stats, &diff_stats, &error)) {
-		*error_r = t_strconcat("UPDATE-CMD: stats shrank: ",
-				       error, NULL);
+
+	new_stats = stats_alloc(pool_datastack_create());
+	diff_stats = stats_alloc(pool_datastack_create());
+
+	if (!stats_import(buf->data, buf->used, cmd->stats, new_stats, &error)) {
+		*error_r = t_strdup_printf("UPDATE-CMD: %s", error);
 		return -1;
 	}
-	mail_stats_add(&cmd->stats, &diff_stats);
+
+	if (!stats_diff(cmd->stats, new_stats, diff_stats, &error)) {
+		*error_r = t_strdup_printf("UPDATE-CMD: stats shrank: %s", error);
+		return -1;
+	}
+	stats_add(cmd->stats, diff_stats);
 
 	if (done) {
 		cmd->id = 0;
--- a/src/stats/mail-domain.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-domain.c	Thu Mar 05 23:02:48 2015 +0200
@@ -29,7 +29,8 @@
 		return domain;
 	}
 
-	domain = i_new(struct mail_domain, 1);
+	domain = i_malloc(sizeof(struct mail_domain) + stats_alloc_size());
+	domain->stats = (void *)(domain + 1);
 	domain->name = i_strdup(name);
 	domain->reset_timestamp = ioloop_time;
 
@@ -93,10 +94,10 @@
 }
 
 void mail_domain_refresh(struct mail_domain *domain,
-			 const struct mail_stats *diff_stats)
+			 const struct stats *diff_stats)
 {
 	if (diff_stats != NULL)
-		mail_stats_add(&domain->stats, diff_stats);
+		stats_add(domain->stats, diff_stats);
 	domain->last_update = ioloop_timeval;
 	DLLIST2_REMOVE_FULL(&mail_domains_head, &mail_domains_tail, domain,
 			    sorted_prev, sorted_next);
--- a/src/stats/mail-domain.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-domain.h	Thu Mar 05 23:02:48 2015 +0200
@@ -1,7 +1,7 @@
 #ifndef MAIL_DOMAIN_H
 #define MAIL_DOMAIN_H
 
-struct mail_stats;
+struct stats;
 
 extern struct mail_domain *stable_mail_domains;
 
@@ -10,7 +10,7 @@
 void mail_domain_disconnected(struct mail_domain *domain);
 struct mail_domain *mail_domain_lookup(const char *name);
 void mail_domain_refresh(struct mail_domain *domain,
-			 const struct mail_stats *diff_stats) ATTR_NULL(2);
+			 const struct stats *diff_stats) ATTR_NULL(2);
 
 void mail_domain_ref(struct mail_domain *domain);
 void mail_domain_unref(struct mail_domain **domain);
--- a/src/stats/mail-ip.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-ip.c	Thu Mar 05 23:02:48 2015 +0200
@@ -31,7 +31,8 @@
 		return ip;
 	}
 
-	ip = i_new(struct mail_ip, 1);
+	ip = i_malloc(sizeof(struct mail_ip) + stats_alloc_size());
+	ip->stats = (void *)(ip + 1);
 	ip->ip = *ip_addr;
 	ip->reset_timestamp = ioloop_time;
 
@@ -86,10 +87,10 @@
 	i_free(ip);
 }
 
-void mail_ip_refresh(struct mail_ip *ip, const struct mail_stats *diff_stats)
+void mail_ip_refresh(struct mail_ip *ip, const struct stats *diff_stats)
 {
 	if (diff_stats != NULL)
-		mail_stats_add(&ip->stats, diff_stats);
+		stats_add(ip->stats, diff_stats);
 	ip->last_update = ioloop_timeval;
 	DLLIST2_REMOVE_FULL(&mail_ips_head, &mail_ips_tail, ip,
 			    sorted_prev, sorted_next);
--- a/src/stats/mail-ip.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-ip.h	Thu Mar 05 23:02:48 2015 +0200
@@ -6,7 +6,7 @@
 struct mail_ip *mail_ip_login(const struct ip_addr *ip_addr);
 void mail_ip_disconnected(struct mail_ip *ip);
 struct mail_ip *mail_ip_lookup(const struct ip_addr *ip_addr);
-void mail_ip_refresh(struct mail_ip *ip, const struct mail_stats *diff_stats)
+void mail_ip_refresh(struct mail_ip *ip, const struct stats *diff_stats)
 	ATTR_NULL(2);
 
 void mail_ip_ref(struct mail_ip *ip);
--- a/src/stats/mail-server-connection.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-server-connection.c	Thu Mar 05 23:02:48 2015 +0200
@@ -19,23 +19,6 @@
 	struct io *io;
 };
 
-static const char *const*
-mail_server_connection_next_line(struct mail_server_connection *conn)
-{
-	const char *line;
-	char **args;
-	unsigned int i;
-
-	line = i_stream_next_line(conn->input);
-	if (line == NULL)
-		return NULL;
-
-	args = p_strsplit(pool_datastack_create(), line, "\t");
-	for (i = 0; args[i] != NULL; i++)
-		args[i] = str_tabunescape(args[i]);
-	return (void *)args;
-}
-
 static int
 mail_server_connection_request(const char *const *args, const char **error_r)
 {
@@ -62,7 +45,7 @@
 
 static void mail_server_connection_input(struct mail_server_connection *conn)
 {
-	const char *const *args, *error;
+	const char *line, *const *args, *error;
 
 	switch (i_stream_read(conn->input)) {
 	case -2:
@@ -74,10 +57,11 @@
 		return;
 	}
 
-	while ((args = mail_server_connection_next_line(conn)) != NULL) {
+	while ((line = i_stream_next_line(conn->input)) != NULL) T_BEGIN {
+		args = t_strsplit_tabescaped(line);
 		if (mail_server_connection_request(args, &error) < 0)
 			i_error("Mail server input error: %s", error);
-	}
+	} T_END;
 }
 
 struct mail_server_connection *mail_server_connection_create(int fd)
--- a/src/stats/mail-session.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-session.c	Thu Mar 05 23:02:48 2015 +0200
@@ -1,6 +1,8 @@
 /* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
 
 #include "lib.h"
+#include "buffer.h"
+#include "base64.h"
 #include "ioloop.h"
 #include "hash.h"
 #include "llist.h"
@@ -91,7 +93,8 @@
 		*error_r = "CONNECT: Duplicate session ID";
 		return -1;
 	}
-	session = i_new(struct mail_session, 1);
+	session = i_malloc(sizeof(struct mail_session) + stats_alloc_size());
+	session->stats = (void *)(session + 1);
 	session->refcount = 1; /* unrefed at disconnect */
 	session->id = i_strdup(session_id);
 	session->service = str_table_ref(services, args[2]);
@@ -233,12 +236,12 @@
 }
 
 void mail_session_refresh(struct mail_session *session,
-			  const struct mail_stats *diff_stats)
+			  const struct stats *diff_stats)
 {
 	timeout_reset(session->to_idle);
 
 	if (diff_stats != NULL)
-		mail_stats_add(&session->stats, diff_stats);
+		stats_add(session->stats, diff_stats);
 	session->last_update = ioloop_timeval;
 	DLLIST2_REMOVE_FULL(&mail_sessions_head, &mail_sessions_tail, session,
 			    sorted_prev, sorted_next);
@@ -253,27 +256,40 @@
 int mail_session_update_parse(const char *const *args, const char **error_r)
 {
 	struct mail_session *session;
-	struct mail_stats stats, diff_stats;
+	struct stats *new_stats, *diff_stats;
+	buffer_t *buf;
 	const char *error;
 
-	/* <session id> [key=value ..] */
+	/* <session id> <stats> */
 	if (mail_session_get(args[0], &session, error_r) < 0)
 		return -1;
 
-	if (mail_stats_parse(args+1, &stats, error_r) < 0) {
-		*error_r = t_strdup_printf("UPDATE-SESSION %s %s: %s",
+	buf = buffer_create_dynamic(pool_datastack_create(), 256);
+	if (args[1] == NULL ||
+	    base64_decode(args[1], strlen(args[1]), NULL, buf) < 0) {
+		*error_r = t_strdup_printf("UPDATE-SESSION %s %s: Invalid base64 input",
 					   session->user->name,
-					   session->service, *error_r);
+					   session->service);
 		return -1;
 	}
 
-	if (!mail_stats_diff(&session->stats, &stats, &diff_stats, &error)) {
+	new_stats = stats_alloc(pool_datastack_create());
+	diff_stats = stats_alloc(pool_datastack_create());
+
+	if (!stats_import(buf->data, buf->used, session->stats, new_stats, &error)) {
+		*error_r = t_strdup_printf("UPDATE-SESSION %s %s: %s",
+					   session->user->name,
+					   session->service, error);
+		return -1;
+	}
+
+	if (!stats_diff(session->stats, new_stats, diff_stats, &error)) {
 		*error_r = t_strdup_printf("UPDATE-SESSION %s %s: stats shrank: %s",
 					   session->user->name,
 					   session->service, error);
 		return -1;
 	}
-	mail_session_refresh(session, &diff_stats);
+	mail_session_refresh(session, diff_stats);
 	return 0;
 }
 
--- a/src/stats/mail-session.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-session.h	Thu Mar 05 23:02:48 2015 +0200
@@ -1,7 +1,7 @@
 #ifndef MAIL_SESSION_H
 #define MAIL_SESSION_H
 
-struct mail_stats;
+struct stats;
 struct mail_session;
 
 extern struct mail_session *stable_mail_sessions;
@@ -19,7 +19,7 @@
 int mail_session_get(const char *guid, struct mail_session **session_r,
 		     const char **error_r);
 void mail_session_refresh(struct mail_session *session,
-			  const struct mail_stats *diff_stats) ATTR_NULL(2);
+			  const struct stats *diff_stats) ATTR_NULL(2);
 
 void mail_sessions_free_memory(void);
 void mail_sessions_init(void);
--- a/src/stats/mail-stats.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-stats.c	Thu Mar 05 23:02:48 2015 +0200
@@ -5,278 +5,17 @@
 #include "time-util.h"
 #include "mail-stats.h"
 
-enum mail_stats_type {
-	TYPE_NUM,
-	TYPE_TIMEVAL
-};
-
-static struct mail_stats_parse_map {
-	const char *name;
-	unsigned int offset;
-	unsigned int size;
-	enum mail_stats_type type;
-} parse_map[] = {
-#define E(parsename, name, type) { parsename, offsetof(struct mail_stats, name), sizeof(((struct mail_stats *)0)->name), type }
-#define EN(parsename, name) E(parsename, name, TYPE_NUM)
-	E("ucpu", user_cpu, TYPE_TIMEVAL),
-	E("scpu", sys_cpu, TYPE_TIMEVAL),
-	E("time", clock_time, TYPE_TIMEVAL),
-	EN("minflt", min_faults),
-	EN("majflt", maj_faults),
-	EN("volcs", vol_cs),
-	EN("involcs", invol_cs),
-	EN("diskin", disk_input),
-	EN("diskout", disk_output),
-
-	EN("rchar", read_bytes),
-	EN("wchar", write_bytes),
-	EN("syscr", read_count),
-	EN("syscw", write_count),
-
-	EN("mlpath", mail_lookup_path),
-	EN("mlattr", mail_lookup_attr),
-	EN("mrcount", mail_read_count),
-	EN("mrbytes", mail_read_bytes),
-	EN("mcache", mail_cache_hits)
-};
-
 struct mail_global mail_global_stats;
 
-static int mail_stats_parse_timeval(const char *value, struct timeval *tv)
-{
-	const char *p, *secs_str;
-	unsigned long secs, usecs;
-
-	p = strchr(value, '.');
-	if (p == NULL)
-		return -1;
-
-	secs_str = t_strdup_until(value, p++);
-	if (str_to_ulong(secs_str, &secs) < 0 ||
-	    str_to_ulong(p, &usecs) < 0 ||
-	    usecs > 1000000)
-		return -1;
-
-	tv->tv_sec = secs;
-	tv->tv_usec = usecs;
-	return 0;
-}
-
-static struct mail_stats_parse_map *
-parse_map_find(const char *name)
-{
-	unsigned int i;
-
-	for (i = 0; i < N_ELEMENTS(parse_map); i++) {
-		if (strcmp(parse_map[i].name, name) == 0)
-			return &parse_map[i];
-	}
-	return NULL;
-}
-
-static int
-mail_stats_parse_one(const char *key, const char *value,
-		     struct mail_stats *stats, const char **error_r)
-{
-	struct mail_stats_parse_map *map;
-	void *dest;
-
-	map = parse_map_find(key);
-	if (map == NULL)
-		return 0;
-
-	dest = PTR_OFFSET(stats, map->offset);
-	switch (map->type) {
-	case TYPE_NUM:
-		switch (map->size) {
-		case sizeof(uint32_t):
-			if (str_to_uint32(value, dest) < 0) {
-				*error_r = "invalid number";
-				return -1;
-			}
-			break;
-		case sizeof(uint64_t):
-			if (str_to_uint64(value, dest) < 0) {
-				*error_r = "invalid number";
-				return -1;
-			}
-			break;
-		default:
-			i_unreached();
-		}
-		break;
-	case TYPE_TIMEVAL:
-		if (mail_stats_parse_timeval(value, dest) < 0) {
-			*error_r = "invalid cpu parameter";
-			return -1;
-		}
-		break;
-	}
-	return 0;
-}
-
-int mail_stats_parse(const char *const *args, struct mail_stats *stats_r,
-		     const char **error_r)
-{
-	const char *p, *key, *value;
-	unsigned int i;
-
-	memset(stats_r, 0, sizeof(*stats_r));
-	for (i = 0; args[i] != NULL; i++) {
-		p = strchr(args[i], '=');
-		if (p == NULL) {
-			*error_r = "mail stats parameter missing '='";
-			return -1;
-		}
-		key = t_strdup_until(args[i], p);
-		value = p + 1;
-		if (mail_stats_parse_one(key, value, stats_r, error_r) < 0)
-			return -1;
-	}
-	return 0;
-}
-
-static bool mail_stats_diff_timeval(struct timeval *dest,
-				    const struct timeval *src1,
-				    const struct timeval *src2)
-{
-	long long diff_usecs;
-
-	diff_usecs = timeval_diff_usecs(src2, src1);
-	if (diff_usecs < 0)
-		return FALSE;
-	dest->tv_sec = diff_usecs / 1000000;
-	dest->tv_usec = diff_usecs % 1000000;
-	return TRUE;
-}
-
-static bool
-mail_stats_diff_uint32(uint32_t *dest, const uint32_t *src1,
-		       const uint32_t *src2)
-{
-	if (*src1 > *src2)
-		return FALSE;
-	*dest = *src2 - *src1;
-	return TRUE;
-}
-
-static bool
-mail_stats_diff_uint64(uint64_t *dest, const uint64_t *src1,
-		       const uint64_t *src2)
-{
-	if (*src1 > *src2)
-		return FALSE;
-	*dest = *src2 - *src1;
-	return TRUE;
-}
-
-bool mail_stats_diff(const struct mail_stats *stats1,
-		     const struct mail_stats *stats2,
-		     struct mail_stats *diff_stats_r, const char **error_r)
-{
-	unsigned int i;
-
-	memset(diff_stats_r, 0, sizeof(*diff_stats_r));
-
-	for (i = 0; i < N_ELEMENTS(parse_map); i++) {
-		unsigned int offset = parse_map[i].offset;
-		void *dest = PTR_OFFSET(diff_stats_r, offset);
-		const void *src1 = CONST_PTR_OFFSET(stats1, offset);
-		const void *src2 = CONST_PTR_OFFSET(stats2, offset);
-
-		switch (parse_map[i].type) {
-		case TYPE_NUM:
-			switch (parse_map[i].size) {
-			case sizeof(uint32_t):
-				if (!mail_stats_diff_uint32(dest, src1, src2)) {
-					*error_r = t_strdup_printf("%s %u < %u",
-						parse_map[i].name,
-						*(const uint32_t *)src2,
-						*(const uint32_t *)src1);
-					return FALSE;
-				}
-				break;
-			case sizeof(uint64_t):
-				if (!mail_stats_diff_uint64(dest, src1, src2)) {
-					const uint64_t *n1 = src1, *n2 = src2;
-
-					*error_r = t_strdup_printf("%s %llu < %llu",
-						parse_map[i].name,
-						(unsigned long long)*n2,
-						(unsigned long long)*n1);
-					return FALSE;
-				}
-				break;
-			default:
-				i_unreached();
-			}
-			break;
-		case TYPE_TIMEVAL:
-			if (!mail_stats_diff_timeval(dest, src1, src2)) {
-				const struct timeval *tv1 = src1, *tv2 = src2;
-
-				*error_r = t_strdup_printf("%s %ld.%d < %ld.%d",
-					parse_map[i].name,
-					(long)tv2->tv_sec, (int)tv2->tv_usec,
-					(long)tv1->tv_sec, (int)tv1->tv_usec);
-				return FALSE;
-			}
-			break;
-		}
-	}
-	return TRUE;
-}
-
-static void timeval_add(struct timeval *dest, const struct timeval *src)
-{
-	dest->tv_sec += src->tv_sec;
-	dest->tv_usec += src->tv_usec;
-	if (dest->tv_usec > 1000000) {
-		dest->tv_usec -= 1000000;
-		dest->tv_sec++;
-	}
-}
-
-void mail_stats_add(struct mail_stats *dest, const struct mail_stats *src)
-{
-	unsigned int i;
-
-	for (i = 0; i < N_ELEMENTS(parse_map); i++) {
-		unsigned int offset = parse_map[i].offset;
-		void *f_dest = PTR_OFFSET(dest, offset);
-		const void *f_src = CONST_PTR_OFFSET(src, offset);
-
-		switch (parse_map[i].type) {
-		case TYPE_NUM:
-			switch (parse_map[i].size) {
-			case sizeof(uint32_t): {
-				uint32_t *n_dest = f_dest;
-				const uint32_t *n_src = f_src;
-
-				*n_dest += *n_src;
-				break;
-			}
-			case sizeof(uint64_t): {
-				uint64_t *n_dest = f_dest;
-				const uint64_t *n_src = f_src;
-
-				*n_dest += *n_src;
-				break;
-			}
-			default:
-				i_unreached();
-			}
-			break;
-		case TYPE_TIMEVAL:
-			timeval_add(f_dest, f_src);
-			break;
-		}
-	}
-}
-
 void mail_global_init(void)
 {
 	mail_global_stats.reset_timestamp = ioloop_time;
+	mail_global_stats.stats = stats_alloc(default_pool);
+}
+
+void mail_global_deinit(void)
+{
+	i_free(mail_global_stats.stats);
 }
 
 void mail_global_login(void)
@@ -291,9 +30,9 @@
 	mail_global_stats.num_connected_sessions--;
 }
 
-void mail_global_refresh(const struct mail_stats *diff_stats)
+void mail_global_refresh(const struct stats *diff_stats)
 {
 	if (diff_stats != NULL)
-		mail_stats_add(&mail_global_stats.stats, diff_stats);
+		stats_add(mail_global_stats.stats, diff_stats);
 	mail_global_stats.last_update = ioloop_timeval;
 }
--- a/src/stats/mail-stats.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-stats.h	Thu Mar 05 23:02:48 2015 +0200
@@ -3,20 +3,7 @@
 
 #include "net.h"
 #include "guid.h"
-
-struct mail_stats {
-	struct timeval user_cpu, sys_cpu, clock_time;
-	uint32_t min_faults, maj_faults;
-	uint32_t vol_cs, invol_cs;
-	uint64_t disk_input, disk_output;
-
-	uint32_t read_count, write_count;
-	uint64_t read_bytes, write_bytes;
-
-	uint32_t mail_lookup_path, mail_lookup_attr, mail_read_count;
-	uint32_t mail_cache_hits;
-	uint64_t mail_read_bytes;
-};
+#include "stats.h"
 
 struct mail_command {
 	struct mail_command *stable_prev, *stable_next;
@@ -28,7 +15,7 @@
 	unsigned int id;
 
 	struct timeval last_update;
-	struct mail_stats stats;
+	struct stats *stats;
 
 	int refcount;
 };
@@ -48,7 +35,7 @@
 	struct mail_ip *ip;
 	struct timeout *to_idle;
 
-	struct mail_stats stats;
+	struct stats *stats;
 	struct timeval last_update;
 	unsigned int num_cmds;
 
@@ -67,7 +54,7 @@
 	time_t reset_timestamp;
 
 	struct timeval last_update;
-	struct mail_stats stats;
+	struct stats *stats;
 	unsigned int num_logins;
 	unsigned int num_cmds;
 
@@ -82,7 +69,7 @@
 	time_t reset_timestamp;
 
 	struct timeval last_update;
-	struct mail_stats stats;
+	struct stats *stats;
 	unsigned int num_logins;
 	unsigned int num_cmds;
 	unsigned int num_connected_sessions;
@@ -98,7 +85,7 @@
 	time_t reset_timestamp;
 
 	struct timeval last_update;
-	struct mail_stats stats;
+	struct stats *stats;
 	unsigned int num_logins;
 	unsigned int num_cmds;
 	unsigned int num_connected_sessions;
@@ -111,7 +98,7 @@
 	time_t reset_timestamp;
 
 	struct timeval last_update;
-	struct mail_stats stats;
+	struct stats *stats;
 	unsigned int num_logins;
 	unsigned int num_cmds;
 	unsigned int num_connected_sessions;
@@ -119,18 +106,11 @@
 
 extern struct mail_global mail_global_stats;
 
-int mail_stats_parse(const char *const *args, struct mail_stats *stats_r,
-		     const char **error_r);
-/* diff1 is supposed to have smaller values than diff2. Returns TRUE if this
-   is so, FALSE if not */
-bool mail_stats_diff(const struct mail_stats *stats1,
-		     const struct mail_stats *stats2,
-		     struct mail_stats *diff_stats_r, const char **error_r);
-void mail_stats_add(struct mail_stats *dest, const struct mail_stats *src);
+void mail_global_init(void);
+void mail_global_deinit(void);
 
-void mail_global_init(void);
 void mail_global_login(void);
 void mail_global_disconnected(void);
-void mail_global_refresh(const struct mail_stats *diff_stats);
+void mail_global_refresh(const struct stats *diff_stats);
 
 #endif
--- a/src/stats/mail-user.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-user.c	Thu Mar 05 23:02:48 2015 +0200
@@ -39,7 +39,8 @@
 	else
 		domain = "";
 
-	user = i_new(struct mail_user, 1);
+	user = i_malloc(sizeof(struct mail_user) + stats_alloc_size());
+	user->stats = (void *)(user + 1);
 	user->name = i_strdup(username);
 	user->reset_timestamp = ioloop_time;
 	user->domain = mail_domain_login_create(domain);
@@ -104,10 +105,10 @@
 }
 
 void mail_user_refresh(struct mail_user *user,
-		       const struct mail_stats *diff_stats)
+		       const struct stats *diff_stats)
 {
 	if (diff_stats != NULL)
-		mail_stats_add(&user->stats, diff_stats);
+		stats_add(user->stats, diff_stats);
 	user->last_update = ioloop_timeval;
 	DLLIST2_REMOVE_FULL(&mail_users_head, &mail_users_tail, user,
 			    sorted_prev, sorted_next);
--- a/src/stats/mail-user.h	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/mail-user.h	Thu Mar 05 23:02:48 2015 +0200
@@ -1,7 +1,7 @@
 #ifndef MAIL_USER_H
 #define MAIL_USER_H
 
-struct mail_stats;
+struct stats;
 
 extern struct mail_user *stable_mail_users;
 
@@ -10,7 +10,7 @@
 struct mail_user *mail_user_lookup(const char *username);
 
 void mail_user_refresh(struct mail_user *user,
-		       const struct mail_stats *diff_stats) ATTR_NULL(2);
+		       const struct stats *diff_stats) ATTR_NULL(2);
 
 void mail_user_ref(struct mail_user *user);
 void mail_user_unref(struct mail_user **user);
--- a/src/stats/main.c	Thu Mar 05 22:19:02 2015 +0200
+++ b/src/stats/main.c	Thu Mar 05 23:02:48 2015 +0200
@@ -1,6 +1,7 @@
 /* Copyright (c) 2011-2015 Dovecot authors, see the included COPYING file */
 
 #include "lib.h"
+#include "module-dir.h"
 #include "restrict-access.h"
 #include "master-service.h"
 #include "master-service-settings.h"
@@ -16,6 +17,7 @@
 #include "client.h"
 
 static struct mail_server_connection *mail_server_conn = NULL;
+static struct module *modules = NULL;
 
 static void client_connected(struct master_service_connection *conn)
 {
@@ -31,6 +33,21 @@
 	master_service_client_connection_accept(conn);
 }
 
+static void main_preinit(void)
+{
+	struct module_dir_load_settings mod_set;
+
+	memset(&mod_set, 0, sizeof(mod_set));
+	mod_set.abi_version = DOVECOT_ABI_VERSION;
+	mod_set.require_init_funcs = TRUE;
+
+	modules = module_dir_load(STATS_MODULE_DIR, NULL, &mod_set);
+	module_dir_init(modules);
+
+	restrict_access_by_env(NULL, FALSE);
+	restrict_access_allow_coredumps(TRUE);
+}
+
 int main(int argc, char *argv[])
 {
 	const struct setting_parser_info *set_roots[] = {
@@ -52,8 +69,7 @@
 		i_fatal("Error reading configuration: %s", error);
 	master_service_init_log(master_service, "stats: ");
 
-	restrict_access_by_env(NULL, FALSE);
-	restrict_access_allow_coredumps(TRUE);
+	main_preinit();
 
 	sets = master_service_settings_get_others(master_service);
 	stats_settings = sets[0];
@@ -74,10 +90,12 @@
 	mail_users_deinit();
 	mail_domains_deinit();
 	mail_ips_deinit();
+	mail_global_deinit();
 
 	if (mail_server_conn != NULL)
 		mail_server_connection_destroy(&mail_server_conn);
 
+	module_dir_unload(&modules);
 	i_assert(global_used_memory == 0);
 	master_service_deinit(&master_service);
         return 0;