--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plugins/trash/trash-plugin.c	Sat Dec 10 21:44:45 2005 +0200
@@ -0,0 +1,295 @@
+/* Copyright (C) 2005 Timo Sirainen */
+
+#include "lib.h"
+#include "array.h"
+#include "istream.h"
+#include "home-expand.h"
+#include "mail-search.h"
+#include "quota-private.h"
+#include "quota-plugin.h"
+#include "trash-plugin.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#define LOCAL_CONFIG_FILE "~/.dovecot.trash.conf"
+#define GLOBAL_CONFIG_FILE "/etc/dovecot-trash.conf"
+
+#define MAX_RETRY_COUNT 3
+
+#define TRASH_CONTEXT(obj) \
+	*((void **)array_idx_modifyable(&(obj)->quota_module_contexts, \
+					trash_quota_module_id))
+
+struct trash_quota {
+	struct quota super;
+};
+
+struct trash_mailbox {
+	const char *name;
+	int priority; /* lower number = higher priority */
+
+	struct mail_storage *storage;
+
+	/* temporarily set while cleaning: */
+	struct mailbox *box;
+	struct mailbox_transaction_context *trans;
+	struct mail_search_context *search_ctx;
+	struct mail *mail;
+
+	unsigned int mail_set:1;
+};
+
+/* defined by imap, pop3, lda */
+extern void (*hook_mail_storage_created)(struct mail_storage *storage);
+
+static void (*trash_next_hook_mail_storage_created)
+	(struct mail_storage *storage);
+static int quota_initialized;
+static unsigned int trash_quota_module_id;
+
+static pool_t config_pool;
+/* trash_boxes ordered by priority, highest first */
+static array_t ARRAY_DEFINE(trash_boxes, struct trash_mailbox);
+
+static int trash_clean_mailbox_open(struct trash_mailbox *trash)
+{
+        struct mail_search_arg search_arg;
+
+	trash->box = mailbox_open(trash->storage, trash->name, NULL,
+				  MAILBOX_OPEN_KEEP_RECENT);
+	trash->trans = mailbox_transaction_begin(trash->box, 0);
+
+	memset(&search_arg, 0, sizeof(search_arg));
+	search_arg.type = SEARCH_ALL;
+
+	trash->search_ctx =
+		mailbox_search_init(trash->trans, NULL, &search_arg, NULL);
+	trash->mail = mail_alloc(trash->trans, MAIL_FETCH_PHYSICAL_SIZE |
+				 MAIL_FETCH_RECEIVED_DATE, NULL);
+
+	return mailbox_search_next(trash->search_ctx, trash->mail);
+}
+
+static int trash_clean_mailbox_get_next(struct trash_mailbox *trash,
+					time_t *received_time_r)
+{
+	int ret;
+
+	if (!trash->mail_set) {
+		if (trash->box == NULL)
+			ret = trash_clean_mailbox_open(trash);
+		else
+			ret = mailbox_search_next(trash->search_ctx,
+						  trash->mail);
+		if (ret <= 0)
+			return ret;
+
+		trash->mail_set = TRUE;
+	}
+
+	*received_time_r = mail_get_received_date(trash->mail);
+	return 1;
+}
+
+static int trash_try_clean_mails(uint64_t size_needed)
+{
+	struct trash_mailbox *trashes;
+	unsigned int i, j, count, oldest_idx;
+	time_t oldest, received;
+	uint64_t size;
+	int ret = 0;
+
+	trashes = array_get_modifyable(&trash_boxes, &count);
+	for (i = 0; i < count; ) {
+		/* expunge oldest mails first in all trash boxes with
+		   same priority */
+		oldest_idx = count;
+		oldest = (time_t)-1;
+		for (j = i; j < count; j++) {
+			if (trashes[j].priority != trashes[j].priority)
+				break;
+
+			ret = trash_clean_mailbox_get_next(&trashes[i],
+							   &received);
+			if (ret < 0)
+				goto __err;
+			if (ret > 0) {
+				if (oldest == (time_t)-1 ||
+				    received < oldest) {
+					oldest = received;
+					oldest_idx = j;
+				}
+			}
+		}
+
+		if (oldest_idx < count) {
+			if (mail_expunge(trashes[oldest_idx].mail) < 0)
+				break;
+
+			size = mail_get_physical_size(trashes[oldest_idx].mail);
+			if (size >= size_needed) {
+				size_needed = 0;
+				break;
+			}
+			trashes[oldest_idx].mail_set = FALSE;
+
+			size_needed -= size;
+		} else {
+			/* find more mails from next priority's mailbox */
+			i = j;
+		}
+	}
+
+__err:
+	for (i = 0; i < count; i++) {
+		struct trash_mailbox *trash = &trashes[i];
+
+		mail_free(trash->mail);
+		trash->mail = NULL;
+
+		(void)mailbox_search_deinit(trash->search_ctx);
+		trash->search_ctx = NULL;
+
+		if (size_needed == 0) {
+			(void)mailbox_transaction_commit(trash->trans,
+				MAILBOX_SYNC_FLAG_FULL_WRITE);
+		} else {
+			/* couldn't get enough space, don't expunge anything */
+                        mailbox_transaction_rollback(trash->trans);
+		}
+		trash->trans = NULL;
+
+		mailbox_close(trash->box);
+		trash->box = NULL;
+	}
+	return size_needed == 0;
+}
+
+static int
+trash_quota_try_alloc(struct quota_transaction_context *ctx,
+		      struct mail *mail, int *too_large_r)
+{
+	struct trash_quota *tquota = TRASH_CONTEXT(quota);
+	int ret, i;
+
+	for (i = 0; ; i++) {
+		ret = tquota->super.try_alloc(ctx, mail, too_large_r);
+		if (ret != 0 || *too_large_r)
+			return ret;
+
+		if (i == MAX_RETRY_COUNT) {
+			/* trash_try_clean_mails() should have returned 0 if
+			   it couldn't get enough space, but allow retrying
+			   it a couple of times if there was some extra space
+			   that was needed.. */
+			break;
+		}
+
+		/* not enough space. try deleting some from mailbox. */
+		ret = trash_try_clean_mails(mail_get_physical_size(mail));
+		if (ret <= 0)
+			return 0;
+	}
+
+	return 0;
+}
+
+static void trash_quota_deinit(struct quota *quota)
+{
+	struct trash_quota *tquota = TRASH_CONTEXT(quota);
+	void *null = NULL;
+
+	array_idx_set(&quota->quota_module_contexts,
+		      trash_quota_module_id, &null);
+	tquota->super.deinit(quota);
+	i_free(tquota);
+}
+
+static void trash_mail_storage_created(struct mail_storage *storage)
+{
+	struct trash_quota *tquota;
+
+	if (trash_next_hook_mail_storage_created != NULL)
+		trash_next_hook_mail_storage_created(storage);
+
+	if (quota_initialized || quota == NULL)
+		return;
+
+	/* initialize here because plugins could be loaded in wrong order */
+	quota_initialized = TRUE;
+
+	tquota = i_new(struct trash_quota, 1);
+	tquota->super = *quota;
+	quota->deinit = trash_quota_deinit;
+	quota->try_alloc = trash_quota_try_alloc;
+
+	trash_quota_module_id = quota_module_id++;
+	array_idx_set(&quota->quota_module_contexts,
+		      trash_quota_module_id, &tquota);
+}
+
+static int trash_mailbox_priority_cmp(const void *p1, const void *p2)
+{
+	const struct trash_mailbox *t1 = p1, *t2 = p2;
+
+	return t1->priority - t2->priority;
+}
+
+static int read_configuration(const char *path)
+{
+	struct istream *input;
+	const char *line, *name;
+	struct trash_mailbox *trash;
+	int fd;
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1) {
+		if (errno != ENOENT)
+			i_error("open(%s) failed: %m", path);
+		return -1;
+	}
+
+	p_clear(config_pool);
+	ARRAY_CREATE(&trash_boxes, config_pool, struct trash_mailbox, 8);
+
+	input = i_stream_create_file(fd, default_pool, (size_t)-1, FALSE);
+	while ((line = i_stream_read_next_line(input)) != NULL) {
+		/* <priority> <mailbox name> */
+		name = strchr(line, ' ');
+		if (name == NULL || name[1] == '\0')
+			continue;
+
+		trash = array_append_space(&trash_boxes);
+		trash->name = p_strdup(config_pool, name+1);
+		trash->priority = atoi(t_strdup_until(line, name));
+	}
+	i_stream_unref(input);
+	(void)close(fd);
+
+	qsort(array_get_modifyable(&trash_boxes, NULL),
+	      array_count(&trash_boxes), sizeof(struct trash_mailbox),
+	      trash_mailbox_priority_cmp);
+	return 0;
+}
+
+void trash_plugin_init(void)
+{
+	quota_initialized = FALSE;
+	trash_next_hook_mail_storage_created = hook_mail_storage_created;
+
+	config_pool = pool_alloconly_create("trash config", 1024);
+	if (read_configuration(home_expand(LOCAL_CONFIG_FILE)) < 0) {
+		if (read_configuration(GLOBAL_CONFIG_FILE) < 0)
+			return;
+	}
+
+	hook_mail_storage_created = trash_mail_storage_created;
+}
+
+void trash_plugin_deinit(void)
+{
+	pool_unref(config_pool);
+	hook_mail_storage_created = trash_next_hook_mail_storage_created;
+}