Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1764 insertions, 0 deletions

diff --git a/src/lib/lib-event.c b/src/lib/lib-event.c
new file mode 100644
index 0000000..87db436
--- /dev/null
+++ b/src/lib/lib-event.c
@@ -0,0 +1,1764 @@
+/* Copyright (c) 2017-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "lib-event-private.h"
+#include "event-filter.h"
+#include "array.h"
+#include "llist.h"
+#include "time-util.h"
+#include "str.h"
+#include "strescape.h"
+#include "ioloop-private.h"
+
+#include <ctype.h>
+
+enum event_code {
+	EVENT_CODE_ALWAYS_LOG_SOURCE	= 'a',
+	EVENT_CODE_CATEGORY		= 'c',
+	EVENT_CODE_TV_LAST_SENT		= 'l',
+	EVENT_CODE_SENDING_NAME		= 'n',
+	EVENT_CODE_SOURCE		= 's',
+
+	EVENT_CODE_FIELD_INTMAX		= 'I',
+	EVENT_CODE_FIELD_STR		= 'S',
+	EVENT_CODE_FIELD_TIMEVAL	= 'T',
+	EVENT_CODE_FIELD_STRLIST	= 'L',
+};
+
+/* Internal event category state.
+
+   Each (unique) event category maps to one internal category.  (I.e., if
+   two places attempt to register the same category, they will share the
+   internal state.)
+
+   This is required in order to support multiple registrations of the same
+   category.  Currently, the only situation in which this occurs is the
+   stats process receiving categories from other processes and also using
+   the same categories internally.
+
+   During registration, we look up the internal state based on the new
+   category's name.  If found, we use it after sanity checking that the two
+   are identical (i.e., they both have the same name and parent).  If not
+   found, we allocate a new internal state and use it.
+
+   We stash a pointer to the internal state in struct event_category (the
+   "internal" member).  As a result, all category structs for the same
+   category point to the same internal state. */
+struct event_internal_category {
+	/* More than one category can be represented by the internal state.
+	   To give consumers a unique but consistent category pointer, we
+	   return a pointer to this 'represetative' category structure.
+	   Because we allocated it, we know that it will live exactly as
+	   long as we need it to. */
+	struct event_category representative;
+
+	struct event_internal_category *parent;
+	char *name;
+	int refcount;
+};
+
+struct event_reason {
+	struct event *event;
+};
+
+extern struct event_passthrough event_passthrough_vfuncs;
+
+static struct event *events = NULL;
+static struct event *current_global_event = NULL;
+static struct event *event_last_passthrough = NULL;
+static ARRAY(event_callback_t *) event_handlers;
+static ARRAY(event_category_callback_t *) event_category_callbacks;
+static ARRAY(struct event_internal_category *) event_registered_categories_internal;
+static ARRAY(struct event_category *) event_registered_categories_representative;
+static ARRAY(struct event *) global_event_stack;
+static uint64_t event_id_counter = 0;
+
+static void get_self_rusage(struct rusage *ru_r)
+{
+	if (getrusage(RUSAGE_SELF, ru_r) < 0)
+		i_fatal("getrusage() failed: %m");
+}
+
+static struct event *
+event_create_internal(struct event *parent, const char *source_filename,
+		      unsigned int source_linenum);
+static struct event_internal_category *
+event_category_find_internal(const char *name);
+
+static struct event *last_passthrough_event(void)
+{
+	i_assert(event_last_passthrough != NULL);
+	return event_last_passthrough;
+}
+
+static void event_copy_parent_defaults(struct event *event,
+				       const struct event *parent)
+{
+	event->always_log_source = parent->always_log_source;
+	event->passthrough = parent->passthrough;
+	event->min_log_level = parent->min_log_level;
+	event->forced_debug = parent->forced_debug;
+}
+
+static bool
+event_find_category(const struct event *event,
+		    const struct event_category *category);
+
+static void event_set_changed(struct event *event)
+{
+	event->change_id++;
+	/* It's unlikely that change_id will ever wrap, but lets be safe
+	   anyway. */
+	if (event->change_id == 0 ||
+	    event->change_id == event->sent_to_stats_id)
+		event->change_id++;
+}
+
+static bool
+event_call_callbacks(struct event *event, enum event_callback_type type,
+		     struct failure_context *ctx, const char *fmt, va_list args)
+{
+	event_callback_t *callback;
+
+	array_foreach_elem(&event_handlers, callback) {
+		bool ret;
+
+		T_BEGIN {
+			ret = callback(event, type, ctx, fmt, args);
+		} T_END;
+		if (!ret) {
+			/* event sending was stopped */
+			return FALSE;
+		}
+	}
+	return TRUE;
+}
+
+static void
+event_call_callbacks_noargs(struct event *event,
+			    enum event_callback_type type, ...)
+{
+	va_list args;
+
+	/* the args are empty and not used for anything, but there doesn't seem
+	   to be any nice and standard way of passing an initialized va_list
+	   as a parameter without va_start(). */
+	va_start(args, type);
+	(void)event_call_callbacks(event, type, NULL, NULL, args);
+	va_end(args);
+}
+
+void event_copy_categories(struct event *to, struct event *from)
+{
+	unsigned int cat_count;
+	struct event_category *const *categories =
+		event_get_categories(from, &cat_count);
+	for (unsigned int i = 1; i <= cat_count; i++)
+		event_add_category(to, categories[cat_count-i]);
+}
+
+void event_copy_fields(struct event *to, struct event *from)
+{
+	const struct event_field *fld;
+	unsigned int count;
+	const char *const *values;
+
+	if (!array_is_created(&from->fields))
+		return;
+	array_foreach(&from->fields, fld) {
+		switch (fld->value_type) {
+		case EVENT_FIELD_VALUE_TYPE_STR:
+			event_add_str(to, fld->key, fld->value.str);
+			break;
+		case EVENT_FIELD_VALUE_TYPE_INTMAX:
+			event_add_int(to, fld->key, fld->value.intmax);
+			break;
+		case EVENT_FIELD_VALUE_TYPE_TIMEVAL:
+			event_add_timeval(to, fld->key, &fld->value.timeval);
+			break;
+		case EVENT_FIELD_VALUE_TYPE_STRLIST:
+			values = array_get(&fld->value.strlist, &count);
+			for (unsigned int i = 0; i < count; i++)
+				event_strlist_append(to, fld->key, values[i]);
+			break;
+		default:
+			break;
+		}
+	}
+}
+
+bool event_has_all_categories(struct event *event, const struct event *other)
+{
+	struct event_category **cat;
+	if (!array_is_created(&other->categories))
+		return TRUE;
+	if (!array_is_created(&event->categories))
+		return FALSE;
+	array_foreach_modifiable(&other->categories, cat) {
+		if (!event_find_category(event, *cat))
+			return FALSE;
+	}
+	return TRUE;
+}
+
+bool event_has_all_fields(struct event *event, const struct event *other)
+{
+	struct event_field *fld;
+	if (!array_is_created(&other->fields))
+		return TRUE;
+	array_foreach_modifiable(&other->fields, fld) {
+		if (event_find_field_nonrecursive(event, fld->key) == NULL)
+			return FALSE;
+	}
+	return TRUE;
+}
+
+struct event *event_dup(const struct event *source)
+{
+	struct event *ret =
+		event_create_internal(source->parent, source->source_filename,
+				      source->source_linenum);
+	string_t *str = t_str_new(256);
+	const char *err;
+	event_export(source, str);
+	if (!event_import(ret, str_c(str), &err))
+		i_panic("event_import(%s) failed: %s", str_c(str), err);
+	ret->tv_created_ioloop = source->tv_created_ioloop;
+	return ret;
+}
+
+/*
+ * Copy the source's categories and fields recursively.
+ *
+ * We recurse to the parent before copying this event's data because we may
+ * be overriding a field.
+ */
+static void event_flatten_recurse(struct event *dst, struct event *src,
+				  struct event *limit)
+{
+	if (src->parent != limit)
+		event_flatten_recurse(dst, src->parent, limit);
+
+	event_copy_categories(dst, src);
+	event_copy_fields(dst, src);
+}
+
+struct event *event_flatten(struct event *src)
+{
+	struct event *dst;
+
+	/* If we don't have a parent or a global event,
+	   we have nothing to flatten. */
+	if (src->parent == NULL && current_global_event == NULL)
+		return event_ref(src);
+
+	/* We have to flatten the event. */
+
+	dst = event_create_internal(NULL, src->source_filename,
+				    src->source_linenum);
+	dst = event_set_name(dst, src->sending_name);
+
+	if (current_global_event != NULL)
+		event_flatten_recurse(dst, current_global_event, NULL);
+	event_flatten_recurse(dst, src, NULL);
+
+	dst->tv_created_ioloop = src->tv_created_ioloop;
+	dst->tv_created = src->tv_created;
+	dst->tv_last_sent = src->tv_last_sent;
+
+	return dst;
+}
+
+static inline void replace_parent_ref(struct event *event, struct event *new)
+{
+	if (event->parent == new)
+		return; /* no-op */
+
+	if (new != NULL)
+		event_ref(new);
+
+	event_unref(&event->parent);
+
+	event->parent = new;
+}
+
+/*
+ * Minimize the event and its ancestry.
+ *
+ * In general, the chain of parents starting from this event can be divided
+ * up into four consecutive ranges:
+ *
+ *  1. the event itself
+ *  2. a range of events that should be flattened into the event itself
+ *  3. a range of trivial (i.e., no categories or fields) events that should
+ *     be skipped
+ *  4. the rest of the chain
+ *
+ * Except for the first range, the event itself, the remaining ranges can
+ * have zero events.
+ *
+ * As the names of these ranges imply, we want to flatten certain parts of
+ * the ancestry, skip other parts of the ancestry and leave the remainder
+ * untouched.
+ *
+ * For example, suppose that we have an event (A) with ancestors forming the
+ * following graph:
+ *
+ *	A -> B -> C -> D -> E -> F
+ *
+ * Further, suppose that B, C, and F contain some categories or fields but
+ * have not yet been sent to an external process that knows how to reference
+ * previously encountered events, and D contains no fields or categories of
+ * its own (but it inherits some from E and F).
+ *
+ * We can define the 4 ranges:
+ *
+ *	A:     the event
+ *	B-C:   flattening
+ *	D:     skipping
+ *	E-end: the rest
+ *
+ * The output would therefore be:
+ *
+ *	G -> E -> F
+ *
+ * where G contains the fields and categories of A, B, and C (and trivially
+ * D beacuse D was empty).
+ *
+ * Note that even though F has not yet been sent out, we send it now because
+ * it is part of the "rest" range.
+ *
+ * TODO: We could likely apply this function recursively on the "rest"
+ * range, but further investigation is required to determine whether it is
+ * worth it.
+ */
+struct event *event_minimize(struct event *event)
+{
+	struct event *flatten_bound;
+	struct event *skip_bound;
+	struct event *new_event;
+	struct event *cur;
+
+	if (event->parent == NULL)
+		return event_ref(event);
+
+	/* find the bound for field/category flattening */
+	flatten_bound = NULL;
+	for (cur = event->parent; cur != NULL; cur = cur->parent) {
+		if (cur->sent_to_stats_id == 0 &&
+		    timeval_cmp(&cur->tv_created_ioloop,
+				&event->tv_created_ioloop) == 0)
+			continue;
+
+		flatten_bound = cur;
+		break;
+	}
+
+	/* continue to find the bound for empty event skipping */
+	skip_bound = NULL;
+	for (; cur != NULL; cur = cur->parent) {
+		if (cur->sent_to_stats_id == 0 &&
+		    (!array_is_created(&cur->fields) ||
+		     array_is_empty(&cur->fields)) &&
+		    (!array_is_created(&cur->categories) ||
+		     array_is_empty(&cur->categories)))
+			continue;
+
+		skip_bound = cur;
+		break;
+	}
+
+	/* fast path - no flattening and no skipping to do */
+	if ((event->parent == flatten_bound) &&
+	    (event->parent == skip_bound))
+		return event_ref(event);
+
+	new_event = event_dup(event);
+
+	/* flatten */
+	event_flatten_recurse(new_event, event, flatten_bound);
+	replace_parent_ref(new_event, flatten_bound);
+
+	/* skip */
+	replace_parent_ref(new_event, skip_bound);
+
+	return new_event;
+}
+
+static struct event *
+event_create_internal(struct event *parent, const char *source_filename,
+		      unsigned int source_linenum)
+{
+	struct event *event;
+	pool_t pool = pool_alloconly_create(MEMPOOL_GROWING"event", 1024);
+
+	event = p_new(pool, struct event, 1);
+	event->refcount = 1;
+	event->id = ++event_id_counter;
+	event->pool = pool;
+	event->tv_created_ioloop = ioloop_timeval;
+	event->min_log_level = LOG_TYPE_INFO;
+	i_gettimeofday(&event->tv_created);
+	event->source_filename = p_strdup(pool, source_filename);
+	event->source_linenum = source_linenum;
+	event->change_id = 1;
+	if (parent != NULL) {
+		event->parent = parent;
+		event_ref(event->parent);
+		event_copy_parent_defaults(event, parent);
+	}
+	DLLIST_PREPEND(&events, event);
+	return event;
+}
+
+#undef event_create
+struct event *event_create(struct event *parent, const char *source_filename,
+			   unsigned int source_linenum)
+{
+	struct event *event;
+
+	event = event_create_internal(parent, source_filename, source_linenum);
+	(void)event_call_callbacks_noargs(event, EVENT_CALLBACK_TYPE_CREATE);
+	return event;
+}
+
+#undef event_create_passthrough
+struct event_passthrough *
+event_create_passthrough(struct event *parent, const char *source_filename,
+			 unsigned int source_linenum)
+{
+	if (!parent->passthrough) {
+		if (event_last_passthrough != NULL) {
+			/* API is being used in a wrong or dangerous way */
+			i_panic("Can't create multiple passthrough events - "
+				"finish the earlier with ->event()");
+		}
+		struct event *event =
+			event_create(parent, source_filename, source_linenum);
+		event->passthrough = TRUE;
+		/* This event only intends to extend the parent event.
+		   Use the parent's creation timestamp. */
+		event->tv_created_ioloop = parent->tv_created_ioloop;
+		event->tv_created = parent->tv_created;
+		memcpy(&event->ru_last, &parent->ru_last, sizeof(parent->ru_last));
+		event_last_passthrough = event;
+	} else {
+		event_last_passthrough = parent;
+	}
+	return &event_passthrough_vfuncs;
+}
+
+struct event *event_ref(struct event *event)
+{
+	i_assert(event->refcount > 0);
+
+	event->refcount++;
+	return event;
+}
+
+void event_unref(struct event **_event)
+{
+	struct event *event = *_event;
+
+	if (event == NULL)
+		return;
+	*_event = NULL;
+
+	i_assert(event->refcount > 0);
+	if (--event->refcount > 0)
+		return;
+	i_assert(event != current_global_event);
+
+	event_call_callbacks_noargs(event, EVENT_CALLBACK_TYPE_FREE);
+
+	if (event_last_passthrough == event)
+		event_last_passthrough = NULL;
+	if (event->log_prefix_from_system_pool)
+		i_free(event->log_prefix);
+	i_free(event->sending_name);
+	event_unref(&event->parent);
+
+	DLLIST_REMOVE(&events, event);
+	pool_unref(&event->pool);
+}
+
+struct event *events_get_head(void)
+{
+	return events;
+}
+
+struct event *event_push_global(struct event *event)
+{
+	i_assert(event != NULL);
+
+	if (current_global_event != NULL) {
+		if (!array_is_created(&global_event_stack))
+			i_array_init(&global_event_stack, 4);
+		array_push_back(&global_event_stack, &current_global_event);
+	}
+	current_global_event = event;
+	return event;
+}
+
+struct event *event_pop_global(struct event *event)
+{
+	i_assert(event != NULL);
+	i_assert(event == current_global_event);
+	/* If the active context's root event is popped, we'll assert-crash
+	   later on when deactivating the context and the root event no longer
+	   exists. */
+	i_assert(event != io_loop_get_active_global_root());
+
+	if (!array_is_created(&global_event_stack) ||
+	    array_count(&global_event_stack) == 0)
+		current_global_event = NULL;
+	else {
+		unsigned int event_count;
+		struct event *const *events =
+			array_get(&global_event_stack, &event_count);
+
+		i_assert(event_count > 0);
+		current_global_event = events[event_count-1];
+		array_delete(&global_event_stack, event_count-1, 1);
+	}
+	return current_global_event;
+}
+
+struct event *event_get_global(void)
+{
+	return current_global_event;
+}
+
+#undef event_reason_begin
+struct event_reason *
+event_reason_begin(const char *reason_code, const char *source_filename,
+		   unsigned int source_linenum)
+{
+	struct event_reason *reason;
+
+	reason = i_new(struct event_reason, 1);
+	reason->event = event_create(event_get_global(),
+				     source_filename, source_linenum);
+	event_strlist_append(reason->event, EVENT_REASON_CODE, reason_code);
+	event_push_global(reason->event);
+	return reason;
+}
+
+void event_reason_end(struct event_reason **_reason)
+{
+	struct event_reason *reason = *_reason;
+
+	if (reason == NULL)
+		return;
+	event_pop_global(reason->event);
+	/* This event was created only for global use. It shouldn't be
+	   permanently stored anywhere. This assert could help catch bugs. */
+	i_assert(reason->event->refcount == 1);
+	event_unref(&reason->event);
+	i_free(reason);
+}
+
+const char *event_reason_code(const char *module, const char *name)
+{
+	return event_reason_code_prefix(module, "", name);
+}
+
+static bool event_reason_code_module_validate(const char *module)
+{
+	const char *p;
+
+	for (p = module; *p != '\0'; p++) {
+		if (*p == ' ' || *p == '-' || *p == ':')
+			return FALSE;
+		if (i_isupper(*p))
+			return FALSE;
+	}
+	return TRUE;
+}
+
+const char *event_reason_code_prefix(const char *module,
+				     const char *name_prefix, const char *name)
+{
+	const char *p;
+
+	i_assert(module[0] != '\0');
+	i_assert(name[0] != '\0');
+
+	if (!event_reason_code_module_validate(module)) {
+		i_panic("event_reason_code_prefix(): "
+			"Invalid module '%s'", module);
+	}
+	if (!event_reason_code_module_validate(name_prefix)) {
+		i_panic("event_reason_code_prefix(): "
+			"Invalid name_prefix '%s'", name_prefix);
+	}
+
+	string_t *str = t_str_new(strlen(module) + 1 +
+				  strlen(name_prefix) + strlen(name));
+	str_append(str, module);
+	str_append_c(str, ':');
+	str_append(str, name_prefix);
+
+	for (p = name; *p != '\0'; p++) {
+		switch (*p) {
+		case ' ':
+		case '-':
+			str_append_c(str, '_');
+			break;
+		case ':':
+			i_panic("event_reason_code_prefix(): "
+				"name has ':' (%s, %s%s)",
+				module, name_prefix, name);
+		default:
+			str_append_c(str, i_tolower(*p));
+			break;
+		}
+	}
+	return str_c(str);
+}
+
+static struct event *
+event_set_log_prefix(struct event *event, const char *prefix, bool append)
+{
+	event->log_prefix_callback = NULL;
+	event->log_prefix_callback_context = NULL;
+	if (event->log_prefix == NULL) {
+		/* allocate the first log prefix from the pool */
+		event->log_prefix = p_strdup(event->pool, prefix);
+	} else {
+		/* log prefix is being updated multiple times -
+		   switch to system pool so we don't keep leaking memory */
+		if (event->log_prefix_from_system_pool)
+			i_free(event->log_prefix);
+		else
+			event->log_prefix_from_system_pool = TRUE;
+		event->log_prefix = i_strdup(prefix);
+	}
+	event->log_prefix_replace = !append;
+	return event;
+}
+
+struct event *
+event_set_append_log_prefix(struct event *event, const char *prefix)
+{
+	return event_set_log_prefix(event, prefix, TRUE);
+}
+
+struct event *event_replace_log_prefix(struct event *event, const char *prefix)
+{
+	return event_set_log_prefix(event, prefix, FALSE);
+}
+
+struct event *
+event_drop_parent_log_prefixes(struct event *event, unsigned int count)
+{
+	event->log_prefixes_dropped = count;
+	return event;
+}
+
+#undef event_set_log_prefix_callback
+struct event *
+event_set_log_prefix_callback(struct event *event,
+			      bool replace,
+			      event_log_prefix_callback_t *callback,
+			      void *context)
+{
+	if (event->log_prefix_from_system_pool)
+		i_free(event->log_prefix);
+	else
+		event->log_prefix = NULL;
+	event->log_prefix_replace = replace;
+	event->log_prefix_callback = callback;
+	event->log_prefix_callback_context = context;
+	return event;
+}
+
+#undef event_set_log_message_callback
+struct event *
+event_set_log_message_callback(struct event *event,
+			       event_log_message_callback_t *callback,
+			       void *context)
+{
+	event->log_message_callback = callback;
+	event->log_message_callback_context = context;
+	return event;
+}
+
+struct event *
+event_set_name(struct event *event, const char *name)
+{
+	i_free(event->sending_name);
+	event->sending_name = i_strdup(name);
+	return event;
+}
+
+struct event *
+event_set_source(struct event *event, const char *filename,
+		 unsigned int linenum, bool literal_fname)
+{
+	if (strcmp(event->source_filename, filename) != 0) {
+		event->source_filename = literal_fname ? filename :
+			p_strdup(event->pool, filename);
+	}
+	event->source_linenum = linenum;
+	return event;
+}
+
+struct event *event_set_always_log_source(struct event *event)
+{
+	event->always_log_source = TRUE;
+	return event;
+}
+
+struct event *event_set_min_log_level(struct event *event, enum log_type level)
+{
+	event->min_log_level = level;
+	event_recalculate_debug_level(event);
+	return event;
+}
+
+enum log_type event_get_min_log_level(const struct event *event)
+{
+	return event->min_log_level;
+}
+
+struct event *event_set_ptr(struct event *event, const char *key, void *value)
+{
+	struct event_pointer *p;
+
+	if (!array_is_created(&event->pointers))
+		p_array_init(&event->pointers, event->pool, 4);
+	else {
+		/* replace existing pointer if the key already exists */
+		array_foreach_modifiable(&event->pointers, p) {
+			if (strcmp(p->key, key) == 0) {
+				p->value = value;
+				return event;
+			}
+		}
+	}
+	p = array_append_space(&event->pointers);
+	p->key = p_strdup(event->pool, key);
+	p->value = value;
+	return event;
+}
+
+void *event_get_ptr(const struct event *event, const char *key)
+{
+	const struct event_pointer *p;
+
+	if (!array_is_created(&event->pointers))
+		return NULL;
+	array_foreach(&event->pointers, p) {
+		if (strcmp(p->key, key) == 0)
+			return p->value;
+	}
+	return NULL;
+}
+
+struct event_category *event_category_find_registered(const char *name)
+{
+	struct event_category *cat;
+
+	array_foreach_elem(&event_registered_categories_representative, cat) {
+		if (strcmp(cat->name, name) == 0)
+			return cat;
+	}
+	return NULL;
+}
+
+static struct event_internal_category *
+event_category_find_internal(const char *name)
+{
+	struct event_internal_category *internal;
+
+	array_foreach_elem(&event_registered_categories_internal, internal) {
+		if (strcmp(internal->name, name) == 0)
+			return internal;
+	}
+
+	return NULL;
+}
+
+struct event_category *const *
+event_get_registered_categories(unsigned int *count_r)
+{
+	return array_get(&event_registered_categories_representative, count_r);
+}
+
+static void
+event_category_add_to_array(struct event_internal_category *internal)
+{
+	struct event_category *representative = &internal->representative;
+
+	array_push_back(&event_registered_categories_internal, &internal);
+	array_push_back(&event_registered_categories_representative,
+			&representative);
+}
+
+static struct event_category *
+event_category_register(struct event_category *category)
+{
+	struct event_internal_category *internal = category->internal;
+	event_category_callback_t *callback;
+	bool allocated;
+
+	if (internal != NULL)
+		return &internal->representative; /* case 2 - see below */
+
+	/* register parent categories first */
+	if (category->parent != NULL)
+		(void) event_category_register(category->parent);
+
+	/* There are four cases we need to handle:
+
+	   1) a new category is registered
+	   2) same category struct is re-registered - already handled above
+	      internal NULL check
+	   3) different category struct is registered, but it is identical
+	      to the previously registered one
+	   4) different category struct is registered, and it is different
+	      from the previously registered one - a programming error */
+	internal = event_category_find_internal(category->name);
+	if (internal == NULL) {
+		/* case 1: first time we saw this name - allocate new */
+		internal = i_new(struct event_internal_category, 1);
+		if (category->parent != NULL)
+			internal->parent = category->parent->internal;
+		internal->name = i_strdup(category->name);
+		internal->refcount = 1;
+		internal->representative.name = internal->name;
+		internal->representative.parent = category->parent;
+		internal->representative.internal = internal;
+
+		event_category_add_to_array(internal);
+
+		allocated = TRUE;
+	} else {
+		/* case 3 or 4: someone registered this name before - share */
+		if ((category->parent != NULL) &&
+		    (internal->parent != category->parent->internal)) {
+			/* case 4 */
+			struct event_internal_category *other =
+				category->parent->internal;
+
+			i_panic("event category parent mismatch detected: "
+				"category %p internal %p (%s), "
+				"internal parent %p (%s), public parent %p (%s)",
+				category, internal, internal->name,
+				internal->parent, internal->parent->name,
+				other, other->name);
+		}
+
+		internal->refcount++;
+
+		allocated = FALSE;
+	}
+
+	category->internal = internal;
+
+	if (!allocated) {
+		/* not the first registration of this category */
+		return &internal->representative;
+	}
+
+	array_foreach_elem(&event_category_callbacks, callback) T_BEGIN {
+		callback(&internal->representative);
+	} T_END;
+
+	return &internal->representative;
+}
+
+static bool
+event_find_category(const struct event *event,
+		    const struct event_category *category)
+{
+	struct event_internal_category *internal = category->internal;
+	struct event_category *cat;
+
+	/* make sure we're always looking for a representative */
+	i_assert(category == &internal->representative);
+
+	array_foreach_elem(&event->categories, cat) {
+		if (cat == category)
+			return TRUE;
+	}
+	return FALSE;
+}
+
+struct event *
+event_add_categories(struct event *event,
+		     struct event_category *const *categories)
+{
+	struct event_category *representative;
+
+	if (!array_is_created(&event->categories))
+		p_array_init(&event->categories, event->pool, 4);
+
+	for (unsigned int i = 0; categories[i] != NULL; i++) {
+		representative = event_category_register(categories[i]);
+		if (!event_find_category(event, representative))
+			array_push_back(&event->categories, &representative);
+	}
+	event_set_changed(event);
+	event_recalculate_debug_level(event);
+	return event;
+}
+
+struct event *
+event_add_category(struct event *event, struct event_category *category)
+{
+	struct event_category *const categories[] = { category, NULL };
+	return event_add_categories(event, categories);
+}
+
+struct event_field *
+event_find_field_nonrecursive(const struct event *event, const char *key)
+{
+	struct event_field *field;
+
+	if (!array_is_created(&event->fields))
+		return NULL;
+
+	array_foreach_modifiable(&event->fields, field) {
+		if (strcmp(field->key, key) == 0)
+			return field;
+	}
+	return NULL;
+}
+
+const struct event_field *
+event_find_field_recursive(const struct event *event, const char *key)
+{
+	const struct event_field *field;
+
+	do {
+		if ((field = event_find_field_nonrecursive(event, key)) != NULL)
+			return field;
+		event = event->parent;
+	} while (event != NULL);
+
+	/* check also the global event and its parents */
+	event = event_get_global();
+	while (event != NULL) {
+		if ((field = event_find_field_nonrecursive(event, key)) != NULL)
+			return field;
+		event = event->parent;
+	}
+	return NULL;
+}
+
+static void
+event_get_recursive_strlist(const struct event *event, pool_t pool,
+			    const char *key, ARRAY_TYPE(const_string) *dest)
+{
+	const struct event_field *field;
+	const char *str;
+
+	if (event == NULL)
+		return;
+
+	field = event_find_field_nonrecursive(event, key);
+	if (field != NULL) {
+		if (field->value_type != EVENT_FIELD_VALUE_TYPE_STRLIST) {
+			/* Value type unexpectedly changed. Stop recursing. */
+			return;
+		}
+		array_foreach_elem(&field->value.strlist, str) {
+			if (array_lsearch(dest, &str, i_strcmp_p) == NULL) {
+				if (pool != NULL)
+					str = p_strdup(pool, str);
+				array_push_back(dest, &str);
+			}
+		}
+	}
+	event_get_recursive_strlist(event->parent, pool, key, dest);
+}
+
+const char *
+event_find_field_recursive_str(const struct event *event, const char *key)
+{
+	const struct event_field *field;
+
+	field = event_find_field_recursive(event, key);
+	if (field == NULL)
+		return NULL;
+
+	switch (field->value_type) {
+	case EVENT_FIELD_VALUE_TYPE_STR:
+		return field->value.str;
+	case EVENT_FIELD_VALUE_TYPE_INTMAX:
+		return dec2str(field->value.intmax);
+	case EVENT_FIELD_VALUE_TYPE_TIMEVAL:
+		return t_strdup_printf("%"PRIdTIME_T".%u",
+			field->value.timeval.tv_sec,
+			(unsigned int)field->value.timeval.tv_usec);
+	case EVENT_FIELD_VALUE_TYPE_STRLIST: {
+		ARRAY_TYPE(const_string) list;
+		t_array_init(&list, 8);
+		/* This is a bit different, because it needs to be merging
+		   all of the parent events' and global events' lists
+		   together. */
+		event_get_recursive_strlist(event, NULL, key, &list);
+		event_get_recursive_strlist(event_get_global(), NULL,
+					    key, &list);
+		return t_array_const_string_join(&list, ",");
+	}
+	}
+	i_unreached();
+}
+
+static struct event_field *
+event_get_field(struct event *event, const char *key, bool clear)
+{
+	struct event_field *field;
+
+	field = event_find_field_nonrecursive(event, key);
+	if (field == NULL) {
+		if (!array_is_created(&event->fields))
+			p_array_init(&event->fields, event->pool, 8);
+		field = array_append_space(&event->fields);
+		field->key = p_strdup(event->pool, key);
+	} else if (clear) {
+		i_zero(&field->value);
+	}
+	event_set_changed(event);
+	return field;
+}
+
+struct event *
+event_add_str(struct event *event, const char *key, const char *value)
+{
+	struct event_field *field;
+
+	if (value == NULL) {
+		/* silently ignoring is perhaps better than assert-crashing? */
+		return event;
+	}
+
+	field = event_get_field(event, key, TRUE);
+	field->value_type = EVENT_FIELD_VALUE_TYPE_STR;
+	field->value.str = p_strdup(event->pool, value);
+	return event;
+}
+
+struct event *
+event_strlist_append(struct event *event, const char *key, const char *value)
+{
+	struct event_field *field = event_get_field(event, key, FALSE);
+
+	if (field->value_type != EVENT_FIELD_VALUE_TYPE_STRLIST)
+		i_zero(&field->value);
+	field->value_type = EVENT_FIELD_VALUE_TYPE_STRLIST;
+
+	if (!array_is_created(&field->value.strlist))
+		p_array_init(&field->value.strlist, event->pool, 1);
+
+	/* lets not add empty values there though */
+	if (value == NULL)
+		return event;
+
+	const char *str = p_strdup(event->pool, value);
+	if (array_lsearch(&field->value.strlist, &str, i_strcmp_p) == NULL)
+		array_push_back(&field->value.strlist, &str);
+	return event;
+}
+
+struct event *
+event_strlist_replace(struct event *event, const char *key,
+		      const char *const *values, unsigned int count)
+{
+	struct event_field *field = event_get_field(event, key, TRUE);
+	field->value_type = EVENT_FIELD_VALUE_TYPE_STRLIST;
+
+	for (unsigned int i = 0; i < count; i++)
+		event_strlist_append(event, key, values[i]);
+	return event;
+}
+
+struct event *
+event_strlist_copy_recursive(struct event *dest, const struct event *src,
+			     const char *key)
+{
+	event_strlist_append(dest, key, NULL);
+	struct event_field *field = event_get_field(dest, key, FALSE);
+	i_assert(field != NULL);
+	event_get_recursive_strlist(src, dest->pool, key,
+				    &field->value.strlist);
+	return dest;
+}
+
+struct event *
+event_add_int(struct event *event, const char *key, intmax_t num)
+{
+	struct event_field *field;
+
+	field = event_get_field(event, key, TRUE);
+	field->value_type = EVENT_FIELD_VALUE_TYPE_INTMAX;
+	field->value.intmax = num;
+	return event;
+}
+
+struct event *
+event_add_int_nonzero(struct event *event, const char *key, intmax_t num)
+{
+	if (num != 0)
+		return event_add_int(event, key, num);
+	return event;
+}
+
+struct event *
+event_inc_int(struct event *event, const char *key, intmax_t num)
+{
+	struct event_field *field;
+
+	field = event_find_field_nonrecursive(event, key);
+	if (field == NULL || field->value_type != EVENT_FIELD_VALUE_TYPE_INTMAX)
+		return event_add_int(event, key, num);
+
+	field->value.intmax += num;
+	event_set_changed(event);
+	return event;
+}
+
+struct event *
+event_add_timeval(struct event *event, const char *key,
+		  const struct timeval *tv)
+{
+	struct event_field *field;
+
+	field = event_get_field(event, key, TRUE);
+	field->value_type = EVENT_FIELD_VALUE_TYPE_TIMEVAL;
+	field->value.timeval = *tv;
+	return event;
+}
+
+struct event *
+event_add_fields(struct event *event,
+		 const struct event_add_field *fields)
+{
+	for (unsigned int i = 0; fields[i].key != NULL; i++) {
+		if (fields[i].value != NULL)
+			event_add_str(event, fields[i].key, fields[i].value);
+		else if (fields[i].value_timeval.tv_sec != 0) {
+			event_add_timeval(event, fields[i].key,
+					  &fields[i].value_timeval);
+		} else {
+			event_add_int(event, fields[i].key,
+				      fields[i].value_intmax);
+		}
+	}
+	return event;
+}
+
+void event_field_clear(struct event *event, const char *key)
+{
+	event_add_str(event, key, "");
+}
+
+struct event *event_get_parent(const struct event *event)
+{
+	return event->parent;
+}
+
+void event_get_create_time(const struct event *event, struct timeval *tv_r)
+{
+	*tv_r = event->tv_created;
+}
+
+bool event_get_last_send_time(const struct event *event, struct timeval *tv_r)
+{
+	*tv_r = event->tv_last_sent;
+	return tv_r->tv_sec != 0;
+}
+
+void event_get_last_duration(const struct event *event,
+			     uintmax_t *duration_usecs_r)
+{
+	if (event->tv_last_sent.tv_sec == 0) {
+		*duration_usecs_r = 0;
+		return;
+	}
+	long long diff = timeval_diff_usecs(&event->tv_last_sent,
+					    &event->tv_created);
+	i_assert(diff >= 0);
+	*duration_usecs_r = diff;
+}
+
+const struct event_field *
+event_get_fields(const struct event *event, unsigned int *count_r)
+{
+	if (!array_is_created(&event->fields)) {
+		*count_r = 0;
+		return NULL;
+	}
+	return array_get(&event->fields, count_r);
+}
+
+struct event_category *const *
+event_get_categories(const struct event *event, unsigned int *count_r)
+{
+	if (!array_is_created(&event->categories)) {
+		*count_r = 0;
+		return NULL;
+	}
+	return array_get(&event->categories, count_r);
+}
+
+void event_send(struct event *event, struct failure_context *ctx,
+		const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	event_vsend(event, ctx, fmt, args);
+	va_end(args);
+}
+
+void event_vsend(struct event *event, struct failure_context *ctx,
+		 const char *fmt, va_list args)
+{
+	i_gettimeofday(&event->tv_last_sent);
+
+	/* Skip adding user_cpu_usecs if not enabled. */
+	if (event->ru_last.ru_utime.tv_sec != 0 ||
+	    event->ru_last.ru_utime.tv_usec != 0) {
+		struct rusage ru_current;
+		get_self_rusage(&ru_current);
+		long long udiff = timeval_diff_usecs(&ru_current.ru_utime,
+						     &event->ru_last.ru_utime);
+		event_add_int(event, "user_cpu_usecs", udiff > 0 ? udiff : 0);
+	}
+	if (event_call_callbacks(event, EVENT_CALLBACK_TYPE_SEND,
+				 ctx, fmt, args)) {
+		if (ctx->type != LOG_TYPE_DEBUG ||
+		    event->sending_debug_log)
+			i_log_typev(ctx, fmt, args);
+	}
+	event_send_abort(event);
+}
+
+void event_send_abort(struct event *event)
+{
+	/* if the event is sent again, it needs a new name */
+	i_free(event->sending_name);
+	if (event->passthrough)
+		event_unref(&event);
+}
+
+static void
+event_export_field_value(string_t *dest, const struct event_field *field)
+{
+	switch (field->value_type) {
+	case EVENT_FIELD_VALUE_TYPE_STR:
+		str_append_c(dest, EVENT_CODE_FIELD_STR);
+		str_append_tabescaped(dest, field->key);
+		str_append_c(dest, '\t');
+		str_append_tabescaped(dest, field->value.str);
+		break;
+	case EVENT_FIELD_VALUE_TYPE_INTMAX:
+		str_append_c(dest, EVENT_CODE_FIELD_INTMAX);
+		str_append_tabescaped(dest, field->key);
+		str_printfa(dest, "\t%jd", field->value.intmax);
+		break;
+	case EVENT_FIELD_VALUE_TYPE_TIMEVAL:
+		str_append_c(dest, EVENT_CODE_FIELD_TIMEVAL);
+		str_append_tabescaped(dest, field->key);
+		str_printfa(dest, "\t%"PRIdTIME_T"\t%u",
+			    field->value.timeval.tv_sec,
+			    (unsigned int)field->value.timeval.tv_usec);
+		break;
+	case EVENT_FIELD_VALUE_TYPE_STRLIST: {
+		unsigned int count;
+		const char *const *strlist =
+			array_get(&field->value.strlist, &count);
+		str_append_c(dest, EVENT_CODE_FIELD_STRLIST);
+		str_append_tabescaped(dest, field->key);
+		str_printfa(dest, "\t%u", count);
+		for (unsigned int i = 0; i < count; i++) {
+			str_append_c(dest, '\t');
+			str_append_tabescaped(dest, strlist[i]);
+		}
+	}
+	}
+}
+
+void event_export(const struct event *event, string_t *dest)
+{
+	/* required fields: */
+	str_printfa(dest, "%"PRIdTIME_T"\t%u",
+		    event->tv_created.tv_sec,
+		    (unsigned int)event->tv_created.tv_usec);
+
+	/* optional fields: */
+	if (event->source_filename != NULL) {
+		str_append_c(dest, '\t');
+		str_append_c(dest, EVENT_CODE_SOURCE);
+		str_append_tabescaped(dest, event->source_filename);
+		str_printfa(dest, "\t%u", event->source_linenum);
+	}
+	if (event->always_log_source) {
+		str_append_c(dest, '\t');
+		str_append_c(dest, EVENT_CODE_ALWAYS_LOG_SOURCE);
+	}
+	if (event->tv_last_sent.tv_sec != 0) {
+		str_printfa(dest, "\t%c%"PRIdTIME_T"\t%u",
+			    EVENT_CODE_TV_LAST_SENT,
+			    event->tv_last_sent.tv_sec,
+			    (unsigned int)event->tv_last_sent.tv_usec);
+	}
+	if (event->sending_name != NULL) {
+		str_append_c(dest, '\t');
+		str_append_c(dest, EVENT_CODE_SENDING_NAME);
+		str_append_tabescaped(dest, event->sending_name);
+	}
+
+	if (array_is_created(&event->categories)) {
+		struct event_category *cat;
+		array_foreach_elem(&event->categories, cat) {
+			str_append_c(dest, '\t');
+			str_append_c(dest, EVENT_CODE_CATEGORY);
+			str_append_tabescaped(dest, cat->name);
+		}
+	}
+
+	if (array_is_created(&event->fields)) {
+		const struct event_field *field;
+		array_foreach(&event->fields, field) {
+			str_append_c(dest, '\t');
+			event_export_field_value(dest, field);
+		}
+	}
+}
+
+bool event_import(struct event *event, const char *str, const char **error_r)
+{
+	return event_import_unescaped(event, t_strsplit_tabescaped(str),
+				      error_r);
+}
+
+static bool event_import_tv(const char *arg_secs, const char *arg_usecs,
+			    struct timeval *tv_r, const char **error_r)
+{
+	unsigned int usecs;
+
+	if (str_to_time(arg_secs, &tv_r->tv_sec) < 0) {
+		*error_r = "Invalid timeval seconds parameter";
+		return FALSE;
+	}
+
+	if (arg_usecs == NULL) {
+		*error_r = "Timeval missing microseconds parameter";
+		return FALSE;
+	}
+	if (str_to_uint(arg_usecs, &usecs) < 0 || usecs >= 1000000) {
+		*error_r = "Invalid timeval microseconds parameter";
+		return FALSE;
+	}
+	tv_r->tv_usec = usecs;
+	return TRUE;
+}
+
+static bool
+event_import_strlist(struct event *event, struct event_field *field,
+		     const char *const **_args, const char **error_r)
+{
+	const char *const *args = *_args;
+	unsigned int count, i;
+
+	field->value_type = EVENT_FIELD_VALUE_TYPE_STRLIST;
+	if (str_to_uint(args[0], &count) < 0) {
+		*error_r = t_strdup_printf("Field '%s' has invalid count: '%s'",
+					   field->key, args[0]);
+		return FALSE;
+	}
+	p_array_init(&field->value.strlist, event->pool, count);
+	for (i = 1; i <= count && args[i] != NULL; i++) {
+		const char *str = p_strdup(event->pool, args[i]);
+		array_push_back(&field->value.strlist, &str);
+	}
+	if (i < count) {
+		*error_r = t_strdup_printf("Field '%s' has too few values",
+					   field->key);
+		return FALSE;
+	}
+	*_args += count;
+	return TRUE;
+}
+
+static bool
+event_import_field(struct event *event, enum event_code code, const char *arg,
+		   const char *const **_args, const char **error_r)
+{
+	const char *const *args = *_args;
+	const char *error;
+
+	if (*arg == '\0') {
+		*error_r = "Field name is missing";
+		return FALSE;
+	}
+	struct event_field *field = event_get_field(event, arg, TRUE);
+	if (args[0] == NULL) {
+		*error_r = "Field value is missing";
+		return FALSE;
+	}
+	switch (code) {
+	case EVENT_CODE_FIELD_INTMAX:
+		field->value_type = EVENT_FIELD_VALUE_TYPE_INTMAX;
+		if (str_to_intmax(*args, &field->value.intmax) < 0) {
+			*error_r = t_strdup_printf(
+				"Invalid field value '%s' number for '%s'",
+				*args, field->key);
+			return FALSE;
+		}
+		break;
+	case EVENT_CODE_FIELD_STR:
+		if (field->value_type == EVENT_FIELD_VALUE_TYPE_STR &&
+		    null_strcmp(field->value.str, *args) == 0) {
+			/* already identical value */
+			break;
+		}
+		field->value_type = EVENT_FIELD_VALUE_TYPE_STR;
+		field->value.str = p_strdup(event->pool, *args);
+		break;
+	case EVENT_CODE_FIELD_TIMEVAL:
+		field->value_type = EVENT_FIELD_VALUE_TYPE_TIMEVAL;
+		if (!event_import_tv(args[0], args[1],
+				     &field->value.timeval, &error)) {
+			*error_r = t_strdup_printf("Field '%s' value '%s': %s",
+						   field->key, args[1], error);
+			return FALSE;
+		}
+		args++;
+		break;
+	case EVENT_CODE_FIELD_STRLIST:
+		if (!event_import_strlist(event, field, &args, error_r))
+			return FALSE;
+		break;
+	default:
+		i_unreached();
+	}
+	*_args = args;
+	return TRUE;
+}
+
+
+static bool
+event_import_arg(struct event *event, const char *const **_args,
+		 const char **error_r)
+{
+	const char *const *args = *_args;
+	const char *error, *arg = *args;
+	enum event_code code = arg[0];
+
+	arg++;
+	switch (code) {
+	case EVENT_CODE_ALWAYS_LOG_SOURCE:
+		event->always_log_source = TRUE;
+		break;
+	case EVENT_CODE_CATEGORY: {
+		struct event_category *category =
+			event_category_find_registered(arg);
+		if (category == NULL) {
+			*error_r = t_strdup_printf(
+				"Unregistered category: '%s'", arg);
+			return FALSE;
+		}
+		if (!array_is_created(&event->categories))
+			p_array_init(&event->categories, event->pool, 4);
+		if (!event_find_category(event, category))
+			array_push_back(&event->categories, &category);
+		break;
+	}
+	case EVENT_CODE_TV_LAST_SENT:
+		if (!event_import_tv(arg, args[1], &event->tv_last_sent,
+				     &error)) {
+			*error_r = t_strdup_printf(
+				"Invalid tv_last_sent: %s", error);
+			return FALSE;
+		}
+		args++;
+		break;
+	case EVENT_CODE_SENDING_NAME:
+		i_free(event->sending_name);
+		event->sending_name = i_strdup(arg);
+		break;
+	case EVENT_CODE_SOURCE: {
+		unsigned int linenum;
+
+		if (args[1] == NULL) {
+			*error_r = "Source line number missing";
+			return FALSE;
+		}
+		if (str_to_uint(args[1], &linenum) < 0) {
+			*error_r = "Invalid Source line number";
+			return FALSE;
+		}
+		event_set_source(event, arg, linenum, FALSE);
+		args++;
+		break;
+	}
+	case EVENT_CODE_FIELD_INTMAX:
+	case EVENT_CODE_FIELD_STR:
+	case EVENT_CODE_FIELD_STRLIST:
+	case EVENT_CODE_FIELD_TIMEVAL: {
+		args++;
+		if (!event_import_field(event, code, arg, &args, error_r))
+			return FALSE;
+		break;
+	}
+	}
+	*_args = args;
+	return TRUE;
+}
+
+bool event_import_unescaped(struct event *event, const char *const *args,
+			    const char **error_r)
+{
+	const char *error;
+
+	/* Event's create callback has already added service:<name> category.
+	   This imported event may be coming from another service process
+	   though, so clear it out. */
+	if (array_is_created(&event->categories))
+		array_clear(&event->categories);
+
+	/* required fields: */
+	if (args[0] == NULL) {
+		*error_r = "Missing required fields";
+		return FALSE;
+	}
+	if (!event_import_tv(args[0], args[1], &event->tv_created, &error)) {
+		*error_r = t_strdup_printf("Invalid tv_created: %s", error);
+		return FALSE;
+	}
+	args += 2;
+
+	/* optional fields: */
+	while (*args != NULL) {
+		if (!event_import_arg(event, &args, error_r))
+			return FALSE;
+		args++;
+	}
+	return TRUE;
+}
+
+void event_register_callback(event_callback_t *callback)
+{
+	array_push_back(&event_handlers, &callback);
+}
+
+void event_unregister_callback(event_callback_t *callback)
+{
+	event_callback_t *const *callbackp;
+
+	array_foreach(&event_handlers, callbackp) {
+		if (*callbackp == callback) {
+			unsigned int idx =
+				array_foreach_idx(&event_handlers, callbackp);
+			array_delete(&event_handlers, idx, 1);
+			return;
+		}
+	}
+	i_unreached();
+}
+
+void event_category_register_callback(event_category_callback_t *callback)
+{
+	array_push_back(&event_category_callbacks, &callback);
+}
+
+void event_category_unregister_callback(event_category_callback_t *callback)
+{
+	event_category_callback_t *const *callbackp;
+
+	array_foreach(&event_category_callbacks, callbackp) {
+		if (*callbackp == callback) {
+			unsigned int idx =
+				array_foreach_idx(&event_category_callbacks,
+						  callbackp);
+			array_delete(&event_category_callbacks, idx, 1);
+			return;
+		}
+	}
+	i_unreached();
+}
+
+static struct event_passthrough *
+event_passthrough_set_append_log_prefix(const char *prefix)
+{
+	event_set_append_log_prefix(last_passthrough_event(), prefix);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_replace_log_prefix(const char *prefix)
+{
+	event_replace_log_prefix(last_passthrough_event(), prefix);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_set_name(const char *name)
+{
+	event_set_name(last_passthrough_event(), name);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_set_source(const char *filename,
+			     unsigned int linenum, bool literal_fname)
+{
+	event_set_source(last_passthrough_event(), filename,
+			 linenum, literal_fname);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_set_always_log_source(void)
+{
+	event_set_always_log_source(last_passthrough_event());
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_add_categories(struct event_category *const *categories)
+{
+	event_add_categories(last_passthrough_event(), categories);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_add_category(struct event_category *category)
+{
+	event_add_category(last_passthrough_event(), category);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_add_fields(const struct event_add_field *fields)
+{
+	event_add_fields(last_passthrough_event(), fields);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_add_str(const char *key, const char *value)
+{
+	event_add_str(last_passthrough_event(), key, value);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_strlist_append(const char *key, const char *value)
+{
+	event_strlist_append(last_passthrough_event(), key, value);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_strlist_replace(const char *key, const char *const *values,
+				  unsigned int count)
+{
+	event_strlist_replace(last_passthrough_event(), key, values, count);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_add_int(const char *key, intmax_t num)
+{
+	event_add_int(last_passthrough_event(), key, num);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_add_int_nonzero(const char *key, intmax_t num)
+{
+	event_add_int_nonzero(last_passthrough_event(), key, num);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_add_timeval(const char *key, const struct timeval *tv)
+{
+	event_add_timeval(last_passthrough_event(), key, tv);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_inc_int(const char *key, intmax_t num)
+{
+	event_inc_int(last_passthrough_event(), key, num);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event_passthrough *
+event_passthrough_clear_field(const char *key)
+{
+	event_field_clear(last_passthrough_event(), key);
+	return &event_passthrough_vfuncs;
+}
+
+static struct event *event_passthrough_event(void)
+{
+	struct event *event = last_passthrough_event();
+	event_last_passthrough = NULL;
+	return event;
+}
+
+struct event_passthrough event_passthrough_vfuncs = {
+	.append_log_prefix = event_passthrough_set_append_log_prefix,
+	.replace_log_prefix = event_passthrough_replace_log_prefix,
+	.set_name = event_passthrough_set_name,
+	.set_source = event_passthrough_set_source,
+	.set_always_log_source = event_passthrough_set_always_log_source,
+	.add_categories = event_passthrough_add_categories,
+	.add_category = event_passthrough_add_category,
+	.add_fields = event_passthrough_add_fields,
+	.add_str = event_passthrough_add_str,
+	.add_int = event_passthrough_add_int,
+	.add_int_nonzero = event_passthrough_add_int_nonzero,
+	.add_timeval = event_passthrough_add_timeval,
+	.inc_int = event_passthrough_inc_int,
+	.strlist_append = event_passthrough_strlist_append,
+	.strlist_replace = event_passthrough_strlist_replace,
+	.clear_field = event_passthrough_clear_field,
+	.event = event_passthrough_event,
+};
+
+void event_enable_user_cpu_usecs(struct event *event)
+{
+	get_self_rusage(&event->ru_last);
+}
+
+void lib_event_init(void)
+{
+	i_array_init(&event_handlers, 4);
+	i_array_init(&event_category_callbacks, 4);
+	i_array_init(&event_registered_categories_internal, 16);
+	i_array_init(&event_registered_categories_representative, 16);
+}
+
+void lib_event_deinit(void)
+{
+	struct event_internal_category *internal;
+
+	event_unset_global_debug_log_filter();
+	event_unset_global_debug_send_filter();
+	event_unset_global_core_log_filter();
+	for (struct event *event = events; event != NULL; event = event->next) {
+		i_warning("Event %p leaked (parent=%p): %s:%u",
+			  event, event->parent,
+			  event->source_filename, event->source_linenum);
+	}
+	/* categories cannot be unregistered, so just free them here */
+	array_foreach_elem(&event_registered_categories_internal, internal) {
+		i_free(internal->name);
+		i_free(internal);
+	}
+	array_free(&event_handlers);
+	array_free(&event_category_callbacks);
+	array_free(&event_registered_categories_internal);
+	array_free(&event_registered_categories_representative);
+	array_free(&global_event_stack);
+}