Refactor

5 files changed, 212 insertions, 503 deletions

diff --git a/src/mail/incoming.rs b/src/mail/incoming.rs
index 781d8dc..e2ad97d 100644
--- a/src/mail/incoming.rs
+++ b/src/mail/incoming.rs
@@ -16,7 +16,7 @@ use crate::login::{Credentials, PublicCredentials};
 use crate::mail::mailbox::Mailbox;
 use crate::mail::uidindex::ImapUidvalidity;
 use crate::mail::unique_ident::*;
-use crate::mail::user::User;
+use crate::user::User;
 use crate::mail::IMF;
 use crate::storage;
 use crate::timestamp::now_msec;
diff --git a/src/mail/mailbox.rs b/src/mail/mailbox.rs
index 9190883..d1a5473 100644
--- a/src/mail/mailbox.rs
+++ b/src/mail/mailbox.rs
@@ -17,7 +17,7 @@ pub struct Mailbox {
 }
 
 impl Mailbox {
-    pub(super) async fn open(
+    pub(crate) async fn open(
         creds: &Credentials,
         id: UniqueIdent,
         min_uidvalidity: ImapUidvalidity,
diff --git a/src/mail/mod.rs b/src/mail/mod.rs
index 37578b8..03e85cd 100644
--- a/src/mail/mod.rs
+++ b/src/mail/mod.rs
@@ -6,7 +6,7 @@ pub mod query;
 pub mod snapshot;
 pub mod uidindex;
 pub mod unique_ident;
-pub mod user;
+pub mod namespace;
 
 // Internet Message Format
 // aka RFC 822 - RFC 2822 - RFC 5322
diff --git a/src/mail/namespace.rs b/src/mail/namespace.rs
new file mode 100644
index 0000000..5e67173
--- /dev/null
+++ b/src/mail/namespace.rs
@@ -0,0 +1,209 @@
+use std::collections::{BTreeMap, HashMap};
+use std::sync::{Arc, Weak};
+
+use anyhow::{anyhow, bail, Result};
+use lazy_static::lazy_static;
+use serde::{Deserialize, Serialize};
+use tokio::sync::watch;
+
+use crate::cryptoblob::{open_deserialize, seal_serialize};
+use crate::login::Credentials;
+use crate::mail::incoming::incoming_mail_watch_process;
+use crate::mail::mailbox::Mailbox;
+use crate::mail::uidindex::ImapUidvalidity;
+use crate::mail::unique_ident::{gen_ident, UniqueIdent};
+use crate::storage;
+use crate::timestamp::now_msec;
+
+pub const MAILBOX_HIERARCHY_DELIMITER: char = '.';
+
+/// INBOX is the only mailbox that must always exist.
+/// It is created automatically when the account is created.
+/// IMAP allows the user to rename INBOX to something else,
+/// in this case all messages from INBOX are moved to a mailbox
+/// with the new name and the INBOX mailbox still exists and is empty.
+/// In our implementation, we indeed move the underlying mailbox
+/// to the new name (i.e. the new name has the same id as the previous
+/// INBOX), and we create a new empty mailbox for INBOX.
+pub const INBOX: &str = "INBOX";
+
+/// For convenience purpose, we also create some special mailbox
+/// that are described in RFC6154 SPECIAL-USE
+/// @FIXME maybe it should be a configuration parameter
+/// @FIXME maybe we should have a per-mailbox flag mechanism, either an enum or a string, so we
+/// track which mailbox is used for what.
+/// @FIXME Junk could be useful but we don't have any antispam solution yet so...
+/// @FIXME IMAP supports virtual mailbox. \All or \Flagged are intended to be virtual mailboxes.
+/// \Trash might be one, or not one. I don't know what we should do there.
+pub const DRAFTS: &str = "Drafts";
+pub const ARCHIVE: &str = "Archive";
+pub const SENT: &str = "Sent";
+pub const TRASH: &str = "Trash";
+
+pub(crate) const MAILBOX_LIST_PK: &str = "mailboxes";
+pub(crate) const MAILBOX_LIST_SK: &str = "list";
+
+// ---- User's mailbox list (serialized in K2V) ----
+
+#[derive(Serialize, Deserialize)]
+pub(crate) struct MailboxList(BTreeMap<String, MailboxListEntry>);
+
+#[derive(Serialize, Deserialize, Clone, Copy, Debug)]
+pub(crate) struct MailboxListEntry {
+    id_lww: (u64, Option<UniqueIdent>),
+    uidvalidity: ImapUidvalidity,
+}
+
+impl MailboxListEntry {
+    fn merge(&mut self, other: &Self) {
+        // Simple CRDT merge rule
+        if other.id_lww.0 > self.id_lww.0
+            || (other.id_lww.0 == self.id_lww.0 && other.id_lww.1 > self.id_lww.1)
+        {
+            self.id_lww = other.id_lww;
+        }
+        self.uidvalidity = std::cmp::max(self.uidvalidity, other.uidvalidity);
+    }
+}
+
+impl MailboxList {
+    pub(crate) fn new() -> Self {
+        Self(BTreeMap::new())
+    }
+
+    pub(crate) fn merge(&mut self, list2: Self) {
+        for (k, v) in list2.0.into_iter() {
+            if let Some(e) = self.0.get_mut(&k) {
+                e.merge(&v);
+            } else {
+                self.0.insert(k, v);
+            }
+        }
+    }
+
+    pub(crate) fn existing_mailbox_names(&self) -> Vec<String> {
+        self.0
+            .iter()
+            .filter(|(_, v)| v.id_lww.1.is_some())
+            .map(|(k, _)| k.to_string())
+            .collect()
+    }
+
+    pub(crate) fn has_mailbox(&self, name: &str) -> bool {
+        matches!(
+            self.0.get(name),
+            Some(MailboxListEntry {
+                id_lww: (_, Some(_)),
+                ..
+            })
+        )
+    }
+
+    pub(crate) fn get_mailbox(&self, name: &str) -> Option<(ImapUidvalidity, Option<UniqueIdent>)> {
+        self.0.get(name).map(
+            |MailboxListEntry {
+                 id_lww: (_, mailbox_id),
+                 uidvalidity,
+             }| (*uidvalidity, *mailbox_id),
+        )
+    }
+
+    /// Ensures mailbox `name` maps to id `id`.
+    /// If it already mapped to that, returns None.
+    /// If a change had to be done, returns Some(new uidvalidity in mailbox).
+    pub(crate) fn set_mailbox(&mut self, name: &str, id: Option<UniqueIdent>) -> Option<ImapUidvalidity> {
+        let (ts, id, uidvalidity) = match self.0.get_mut(name) {
+            None => {
+                if id.is_none() {
+                    return None;
+                } else {
+                    (now_msec(), id, ImapUidvalidity::new(1).unwrap())
+                }
+            }
+            Some(MailboxListEntry {
+                id_lww,
+                uidvalidity,
+            }) => {
+                if id_lww.1 == id {
+                    return None;
+                } else {
+                    (
+                        std::cmp::max(id_lww.0 + 1, now_msec()),
+                        id,
+                        ImapUidvalidity::new(uidvalidity.get() + 1).unwrap(),
+                    )
+                }
+            }
+        };
+
+        self.0.insert(
+            name.into(),
+            MailboxListEntry {
+                id_lww: (ts, id),
+                uidvalidity,
+            },
+        );
+        Some(uidvalidity)
+    }
+
+    pub(crate) fn update_uidvalidity(&mut self, name: &str, new_uidvalidity: ImapUidvalidity) {
+        match self.0.get_mut(name) {
+            None => {
+                self.0.insert(
+                    name.into(),
+                    MailboxListEntry {
+                        id_lww: (now_msec(), None),
+                        uidvalidity: new_uidvalidity,
+                    },
+                );
+            }
+            Some(MailboxListEntry { uidvalidity, .. }) => {
+                *uidvalidity = std::cmp::max(*uidvalidity, new_uidvalidity);
+            }
+        }
+    }
+
+    pub(crate) fn create_mailbox(&mut self, name: &str) -> CreatedMailbox {
+        if let Some(MailboxListEntry {
+            id_lww: (_, Some(id)),
+            uidvalidity,
+        }) = self.0.get(name)
+        {
+            return CreatedMailbox::Existed(*id, *uidvalidity);
+        }
+
+        let id = gen_ident();
+        let uidvalidity = self.set_mailbox(name, Some(id)).unwrap();
+        CreatedMailbox::Created(id, uidvalidity)
+    }
+
+    pub(crate) fn rename_mailbox(&mut self, old_name: &str, new_name: &str) -> Result<()> {
+        if let Some((uidvalidity, Some(mbid))) = self.get_mailbox(old_name) {
+            if self.has_mailbox(new_name) {
+                bail!(
+                    "Cannot rename {} into {}: {} already exists",
+                    old_name,
+                    new_name,
+                    new_name
+                );
+            }
+
+            self.set_mailbox(old_name, None);
+            self.set_mailbox(new_name, Some(mbid));
+            self.update_uidvalidity(new_name, uidvalidity);
+            Ok(())
+        } else {
+            bail!(
+                "Cannot rename {} into {}: {} doesn't exist",
+                old_name,
+                new_name,
+                old_name
+            );
+        }
+    }
+}
+
+pub(crate) enum CreatedMailbox {
+    Created(UniqueIdent, ImapUidvalidity),
+    Existed(UniqueIdent, ImapUidvalidity),
+}
diff --git a/src/mail/user.rs b/src/mail/user.rs
deleted file mode 100644
index ad05615..0000000
--- a/src/mail/user.rs
+++ /dev/null
@@ -1,500 +0,0 @@
-use std::collections::{BTreeMap, HashMap};
-use std::sync::{Arc, Weak};
-
-use anyhow::{anyhow, bail, Result};
-use lazy_static::lazy_static;
-use serde::{Deserialize, Serialize};
-use tokio::sync::watch;
-
-use crate::cryptoblob::{open_deserialize, seal_serialize};
-use crate::login::Credentials;
-use crate::mail::incoming::incoming_mail_watch_process;
-use crate::mail::mailbox::Mailbox;
-use crate::mail::uidindex::ImapUidvalidity;
-use crate::mail::unique_ident::{gen_ident, UniqueIdent};
-use crate::storage;
-use crate::timestamp::now_msec;
-
-pub const MAILBOX_HIERARCHY_DELIMITER: char = '.';
-
-/// INBOX is the only mailbox that must always exist.
-/// It is created automatically when the account is created.
-/// IMAP allows the user to rename INBOX to something else,
-/// in this case all messages from INBOX are moved to a mailbox
-/// with the new name and the INBOX mailbox still exists and is empty.
-/// In our implementation, we indeed move the underlying mailbox
-/// to the new name (i.e. the new name has the same id as the previous
-/// INBOX), and we create a new empty mailbox for INBOX.
-pub const INBOX: &str = "INBOX";
-
-/// For convenience purpose, we also create some special mailbox
-/// that are described in RFC6154 SPECIAL-USE
-/// @FIXME maybe it should be a configuration parameter
-/// @FIXME maybe we should have a per-mailbox flag mechanism, either an enum or a string, so we
-/// track which mailbox is used for what.
-/// @FIXME Junk could be useful but we don't have any antispam solution yet so...
-/// @FIXME IMAP supports virtual mailbox. \All or \Flagged are intended to be virtual mailboxes.
-/// \Trash might be one, or not one. I don't know what we should do there.
-pub const DRAFTS: &str = "Drafts";
-pub const ARCHIVE: &str = "Archive";
-pub const SENT: &str = "Sent";
-pub const TRASH: &str = "Trash";
-
-const MAILBOX_LIST_PK: &str = "mailboxes";
-const MAILBOX_LIST_SK: &str = "list";
-
-pub struct User {
-    pub username: String,
-    pub creds: Credentials,
-    pub storage: storage::Store,
-    pub mailboxes: std::sync::Mutex<HashMap<UniqueIdent, Weak<Mailbox>>>,
-
-    tx_inbox_id: watch::Sender<Option<(UniqueIdent, ImapUidvalidity)>>,
-}
-
-impl User {
-    pub async fn new(username: String, creds: Credentials) -> Result<Arc<Self>> {
-        let cache_key = (username.clone(), creds.storage.unique());
-
-        {
-            let cache = USER_CACHE.lock().unwrap();
-            if let Some(u) = cache.get(&cache_key).and_then(Weak::upgrade) {
-                return Ok(u);
-            }
-        }
-
-        let user = Self::open(username, creds).await?;
-
-        let mut cache = USER_CACHE.lock().unwrap();
-        if let Some(concurrent_user) = cache.get(&cache_key).and_then(Weak::upgrade) {
-            drop(user);
-            Ok(concurrent_user)
-        } else {
-            cache.insert(cache_key, Arc::downgrade(&user));
-            Ok(user)
-        }
-    }
-
-    /// Lists user's available mailboxes
-    pub async fn list_mailboxes(&self) -> Result<Vec<String>> {
-        let (list, _ct) = self.load_mailbox_list().await?;
-        Ok(list.existing_mailbox_names())
-    }
-
-    /// Opens an existing mailbox given its IMAP name.
-    pub async fn open_mailbox(&self, name: &str) -> Result<Option<Arc<Mailbox>>> {
-        let (mut list, ct) = self.load_mailbox_list().await?;
-
-        //@FIXME it could be a trace or an opentelemtry trace thing.
-        // Be careful to not leak sensible data
-        /*
-        eprintln!("List of mailboxes:");
-        for ent in list.0.iter() {
-            eprintln!(" - {:?}", ent);
-        }
-        */
-
-        if let Some((uidvalidity, Some(mbid))) = list.get_mailbox(name) {
-            let mb = self.open_mailbox_by_id(mbid, uidvalidity).await?;
-            let mb_uidvalidity = mb.current_uid_index().await.uidvalidity;
-            if mb_uidvalidity > uidvalidity {
-                list.update_uidvalidity(name, mb_uidvalidity);
-                self.save_mailbox_list(&list, ct).await?;
-            }
-            Ok(Some(mb))
-        } else {
-            Ok(None)
-        }
-    }
-
-    /// Check whether mailbox exists
-    pub async fn has_mailbox(&self, name: &str) -> Result<bool> {
-        let (list, _ct) = self.load_mailbox_list().await?;
-        Ok(list.has_mailbox(name))
-    }
-
-    /// Creates a new mailbox in the user's IMAP namespace.
-    pub async fn create_mailbox(&self, name: &str) -> Result<()> {
-        if name.ends_with(MAILBOX_HIERARCHY_DELIMITER) {
-            bail!("Invalid mailbox name: {}", name);
-        }
-
-        let (mut list, ct) = self.load_mailbox_list().await?;
-        match list.create_mailbox(name) {
-            CreatedMailbox::Created(_, _) => {
-                self.save_mailbox_list(&list, ct).await?;
-                Ok(())
-            }
-            CreatedMailbox::Existed(_, _) => Err(anyhow!("Mailbox {} already exists", name)),
-        }
-    }
-
-    /// Deletes a mailbox in the user's IMAP namespace.
-    pub async fn delete_mailbox(&self, name: &str) -> Result<()> {
-        if name == INBOX {
-            bail!("Cannot delete INBOX");
-        }
-
-        let (mut list, ct) = self.load_mailbox_list().await?;
-        if list.has_mailbox(name) {
-            //@TODO: actually delete mailbox contents
-            list.set_mailbox(name, None);
-            self.save_mailbox_list(&list, ct).await?;
-            Ok(())
-        } else {
-            bail!("Mailbox {} does not exist", name);
-        }
-    }
-
-    /// Renames a mailbox in the user's IMAP namespace.
-    pub async fn rename_mailbox(&self, old_name: &str, new_name: &str) -> Result<()> {
-        let (mut list, ct) = self.load_mailbox_list().await?;
-
-        if old_name.ends_with(MAILBOX_HIERARCHY_DELIMITER) {
-            bail!("Invalid mailbox name: {}", old_name);
-        }
-        if new_name.ends_with(MAILBOX_HIERARCHY_DELIMITER) {
-            bail!("Invalid mailbox name: {}", new_name);
-        }
-
-        if old_name == INBOX {
-            list.rename_mailbox(old_name, new_name)?;
-            if !self.ensure_inbox_exists(&mut list, &ct).await? {
-                self.save_mailbox_list(&list, ct).await?;
-            }
-        } else {
-            let names = list.existing_mailbox_names();
-
-            let old_name_w_delim = format!("{}{}", old_name, MAILBOX_HIERARCHY_DELIMITER);
-            let new_name_w_delim = format!("{}{}", new_name, MAILBOX_HIERARCHY_DELIMITER);
-
-            if names
-                .iter()
-                .any(|x| x == new_name || x.starts_with(&new_name_w_delim))
-            {
-                bail!("Mailbox {} already exists", new_name);
-            }
-
-            for name in names.iter() {
-                if name == old_name {
-                    list.rename_mailbox(name, new_name)?;
-                } else if let Some(tail) = name.strip_prefix(&old_name_w_delim) {
-                    let nnew = format!("{}{}", new_name_w_delim, tail);
-                    list.rename_mailbox(name, &nnew)?;
-                }
-            }
-
-            self.save_mailbox_list(&list, ct).await?;
-        }
-        Ok(())
-    }
-
-    // ---- Internal user & mailbox management ----
-
-    async fn open(username: String, creds: Credentials) -> Result<Arc<Self>> {
-        let storage = creds.storage.build().await?;
-
-        let (tx_inbox_id, rx_inbox_id) = watch::channel(None);
-
-        let user = Arc::new(Self {
-            username,
-            creds: creds.clone(),
-            storage,
-            tx_inbox_id,
-            mailboxes: std::sync::Mutex::new(HashMap::new()),
-        });
-
-        // Ensure INBOX exists (done inside load_mailbox_list)
-        user.load_mailbox_list().await?;
-
-        tokio::spawn(incoming_mail_watch_process(
-            Arc::downgrade(&user),
-            user.creds.clone(),
-            rx_inbox_id,
-        ));
-
-        Ok(user)
-    }
-
-    pub(super) async fn open_mailbox_by_id(
-        &self,
-        id: UniqueIdent,
-        min_uidvalidity: ImapUidvalidity,
-    ) -> Result<Arc<Mailbox>> {
-        {
-            let cache = self.mailboxes.lock().unwrap();
-            if let Some(mb) = cache.get(&id).and_then(Weak::upgrade) {
-                return Ok(mb);
-            }
-        }
-
-        let mb = Arc::new(Mailbox::open(&self.creds, id, min_uidvalidity).await?);
-
-        let mut cache = self.mailboxes.lock().unwrap();
-        if let Some(concurrent_mb) = cache.get(&id).and_then(Weak::upgrade) {
-            drop(mb); // we worked for nothing but at least we didn't starve someone else
-            Ok(concurrent_mb)
-        } else {
-            cache.insert(id, Arc::downgrade(&mb));
-            Ok(mb)
-        }
-    }
-
-    // ---- Mailbox list management ----
-
-    async fn load_mailbox_list(&self) -> Result<(MailboxList, Option<storage::RowRef>)> {
-        let row_ref = storage::RowRef::new(MAILBOX_LIST_PK, MAILBOX_LIST_SK);
-        let (mut list, row) = match self
-            .storage
-            .row_fetch(&storage::Selector::Single(&row_ref))
-            .await
-        {
-            Err(storage::StorageError::NotFound) => (MailboxList::new(), None),
-            Err(e) => return Err(e.into()),
-            Ok(rv) => {
-                let mut list = MailboxList::new();
-                let (row_ref, row_vals) = match rv.into_iter().next() {
-                    Some(row_val) => (row_val.row_ref, row_val.value),
-                    None => (row_ref, vec![]),
-                };
-
-                for v in row_vals {
-                    if let storage::Alternative::Value(vbytes) = v {
-                        let list2 =
-                            open_deserialize::<MailboxList>(&vbytes, &self.creds.keys.master)?;
-                        list.merge(list2);
-                    }
-                }
-                (list, Some(row_ref))
-            }
-        };
-
-        let is_default_mbx_missing = [DRAFTS, ARCHIVE, SENT, TRASH]
-            .iter()
-            .map(|mbx| list.create_mailbox(mbx))
-            .fold(false, |acc, r| {
-                acc || matches!(r, CreatedMailbox::Created(..))
-            });
-        let is_inbox_missing = self.ensure_inbox_exists(&mut list, &row).await?;
-        if is_default_mbx_missing && !is_inbox_missing {
-            // It's the only case where we created some mailboxes and not saved them
-            // So we save them!
-            self.save_mailbox_list(&list, row.clone()).await?;
-        }
-
-        Ok((list, row))
-    }
-
-    async fn ensure_inbox_exists(
-        &self,
-        list: &mut MailboxList,
-        ct: &Option<storage::RowRef>,
-    ) -> Result<bool> {
-        // If INBOX doesn't exist, create a new mailbox with that name
-        // and save new mailbox list.
-        // Also, ensure that the mpsc::watch that keeps track of the
-        // inbox id is up-to-date.
-        let saved;
-        let (inbox_id, inbox_uidvalidity) = match list.create_mailbox(INBOX) {
-            CreatedMailbox::Created(i, v) => {
-                self.save_mailbox_list(list, ct.clone()).await?;
-                saved = true;
-                (i, v)
-            }
-            CreatedMailbox::Existed(i, v) => {
-                saved = false;
-                (i, v)
-            }
-        };
-        let inbox_id = Some((inbox_id, inbox_uidvalidity));
-        if *self.tx_inbox_id.borrow() != inbox_id {
-            self.tx_inbox_id.send(inbox_id).unwrap();
-        }
-
-        Ok(saved)
-    }
-
-    async fn save_mailbox_list(
-        &self,
-        list: &MailboxList,
-        ct: Option<storage::RowRef>,
-    ) -> Result<()> {
-        let list_blob = seal_serialize(list, &self.creds.keys.master)?;
-        let rref = ct.unwrap_or(storage::RowRef::new(MAILBOX_LIST_PK, MAILBOX_LIST_SK));
-        let row_val = storage::RowVal::new(rref, list_blob);
-        self.storage.row_insert(vec![row_val]).await?;
-        Ok(())
-    }
-}
-
-// ---- User's mailbox list (serialized in K2V) ----
-
-#[derive(Serialize, Deserialize)]
-struct MailboxList(BTreeMap<String, MailboxListEntry>);
-
-#[derive(Serialize, Deserialize, Clone, Copy, Debug)]
-struct MailboxListEntry {
-    id_lww: (u64, Option<UniqueIdent>),
-    uidvalidity: ImapUidvalidity,
-}
-
-impl MailboxListEntry {
-    fn merge(&mut self, other: &Self) {
-        // Simple CRDT merge rule
-        if other.id_lww.0 > self.id_lww.0
-            || (other.id_lww.0 == self.id_lww.0 && other.id_lww.1 > self.id_lww.1)
-        {
-            self.id_lww = other.id_lww;
-        }
-        self.uidvalidity = std::cmp::max(self.uidvalidity, other.uidvalidity);
-    }
-}
-
-impl MailboxList {
-    fn new() -> Self {
-        Self(BTreeMap::new())
-    }
-
-    fn merge(&mut self, list2: Self) {
-        for (k, v) in list2.0.into_iter() {
-            if let Some(e) = self.0.get_mut(&k) {
-                e.merge(&v);
-            } else {
-                self.0.insert(k, v);
-            }
-        }
-    }
-
-    fn existing_mailbox_names(&self) -> Vec<String> {
-        self.0
-            .iter()
-            .filter(|(_, v)| v.id_lww.1.is_some())
-            .map(|(k, _)| k.to_string())
-            .collect()
-    }
-
-    fn has_mailbox(&self, name: &str) -> bool {
-        matches!(
-            self.0.get(name),
-            Some(MailboxListEntry {
-                id_lww: (_, Some(_)),
-                ..
-            })
-        )
-    }
-
-    fn get_mailbox(&self, name: &str) -> Option<(ImapUidvalidity, Option<UniqueIdent>)> {
-        self.0.get(name).map(
-            |MailboxListEntry {
-                 id_lww: (_, mailbox_id),
-                 uidvalidity,
-             }| (*uidvalidity, *mailbox_id),
-        )
-    }
-
-    /// Ensures mailbox `name` maps to id `id`.
-    /// If it already mapped to that, returns None.
-    /// If a change had to be done, returns Some(new uidvalidity in mailbox).
-    fn set_mailbox(&mut self, name: &str, id: Option<UniqueIdent>) -> Option<ImapUidvalidity> {
-        let (ts, id, uidvalidity) = match self.0.get_mut(name) {
-            None => {
-                if id.is_none() {
-                    return None;
-                } else {
-                    (now_msec(), id, ImapUidvalidity::new(1).unwrap())
-                }
-            }
-            Some(MailboxListEntry {
-                id_lww,
-                uidvalidity,
-            }) => {
-                if id_lww.1 == id {
-                    return None;
-                } else {
-                    (
-                        std::cmp::max(id_lww.0 + 1, now_msec()),
-                        id,
-                        ImapUidvalidity::new(uidvalidity.get() + 1).unwrap(),
-                    )
-                }
-            }
-        };
-
-        self.0.insert(
-            name.into(),
-            MailboxListEntry {
-                id_lww: (ts, id),
-                uidvalidity,
-            },
-        );
-        Some(uidvalidity)
-    }
-
-    fn update_uidvalidity(&mut self, name: &str, new_uidvalidity: ImapUidvalidity) {
-        match self.0.get_mut(name) {
-            None => {
-                self.0.insert(
-                    name.into(),
-                    MailboxListEntry {
-                        id_lww: (now_msec(), None),
-                        uidvalidity: new_uidvalidity,
-                    },
-                );
-            }
-            Some(MailboxListEntry { uidvalidity, .. }) => {
-                *uidvalidity = std::cmp::max(*uidvalidity, new_uidvalidity);
-            }
-        }
-    }
-
-    fn create_mailbox(&mut self, name: &str) -> CreatedMailbox {
-        if let Some(MailboxListEntry {
-            id_lww: (_, Some(id)),
-            uidvalidity,
-        }) = self.0.get(name)
-        {
-            return CreatedMailbox::Existed(*id, *uidvalidity);
-        }
-
-        let id = gen_ident();
-        let uidvalidity = self.set_mailbox(name, Some(id)).unwrap();
-        CreatedMailbox::Created(id, uidvalidity)
-    }
-
-    fn rename_mailbox(&mut self, old_name: &str, new_name: &str) -> Result<()> {
-        if let Some((uidvalidity, Some(mbid))) = self.get_mailbox(old_name) {
-            if self.has_mailbox(new_name) {
-                bail!(
-                    "Cannot rename {} into {}: {} already exists",
-                    old_name,
-                    new_name,
-                    new_name
-                );
-            }
-
-            self.set_mailbox(old_name, None);
-            self.set_mailbox(new_name, Some(mbid));
-            self.update_uidvalidity(new_name, uidvalidity);
-            Ok(())
-        } else {
-            bail!(
-                "Cannot rename {} into {}: {} doesn't exist",
-                old_name,
-                new_name,
-                old_name
-            );
-        }
-    }
-}
-
-enum CreatedMailbox {
-    Created(UniqueIdent, ImapUidvalidity),
-    Existed(UniqueIdent, ImapUidvalidity),
-}
-
-// ---- User cache ----
-
-lazy_static! {
-    static ref USER_CACHE: std::sync::Mutex<HashMap<(String, storage::UnicityBuffer), Weak<User>>> =
-        std::sync::Mutex::new(HashMap::new());
-}