add uid cache for UID of a mailbox (folder) to improve performance

src/Client.php

@@ -357,6 +357,10 @@ public function connect() {
  $this->connection->enableDebug();
  }
 
+ if (!ClientManager::get('options.uid_cache')) {
+ $this->connection->disableUidCache();
+ }
+
  try {
  $this->connection->connect($this->host, $this->port);
  } catch (ErrorException $e) {

src/Connection/Protocols/ImapProtocol.php

@@ -432,7 +432,9 @@ public function logout() {
  } catch (Exception $e) {}
  fclose($this->stream);
  $this->stream = null;
+ $this->uid_cache = null;
  }
+
  return $result;
  }
 
@@ -513,6 +515,8 @@ public function examineOrSelect($command = 'EXAMINE', $folder = 'INBOX') {
  * @throws RuntimeException
  */
  public function selectFolder($folder = 'INBOX') {
+ $this->uid_cache = null;
+
  return $this->examineOrSelect('SELECT', $folder);
  }
 
@@ -678,18 +682,31 @@ public function flags($uids, $uid = IMAP::ST_UID){
  * @throws MessageNotFoundException
  */
  public function getUid($id = null) {
- try {
- $uids = $this->fetch('UID', 1, INF);
- if ($id == null) {
- return $uids;
- }
 
- foreach ($uids as $k => $v) {
- if ($k == $id) {
- return $v;
- }
+ if ($this->enable_uid_cache && $this->uid_cache) {
+ $uids = $this->uid_cache;
+ } else {
+ try {
+ $uids = $this->fetch('UID', 1, INF);
+ $this->setUidCache($uids); // set cache for this folder
+ } catch (RuntimeException $e) {}
+ }
+
+ if ($id == null) {
+ return $uids;
+ }
+
+ foreach ($uids as $k => $v) {
+ if ($k == $id) {
+ return $v;
  }
- } catch (RuntimeException $e) {}
+ }
+
+ // clear uid cache and run method again
+ if ($this->enable_uid_cache && $this->uid_cache) {
+ $this->setUidCache(null);
+ return $this->getUid($id);
+ }
 
  throw new MessageNotFoundException('unique id not found');
  }

src/Connection/Protocols/LegacyProtocol.php

@@ -149,6 +149,7 @@ public function logout() {
  if ($this->stream) {
  $result = \imap_close($this->stream, IMAP::CL_EXPUNGE);
  $this->stream = false;
+ $this->uid_cache = null;
  return $result;
  }
  return false;
@@ -181,6 +182,7 @@ public function getCapabilities() {
  */
  public function selectFolder($folder = 'INBOX') {
  \imap_reopen($this->stream, $folder, IMAP::OP_READONLY, 3);
+ $this->uid_cache = null;
  return $this->examineFolder($folder);
  }
 
@@ -275,13 +277,20 @@ public function flags($uids, $uid = IMAP::ST_UID){
  */
  public function getUid($id = null) {
  if ($id === null) {
+ if ($this->enable_uid_cache && $this->uid_cache) {
+ return $this->uid_cache;
+ }
+
  $overview = $this->overview("1:*");
  $uids = [];
  foreach($overview as $set){
  $uids[$set->msgno] = $set->uid;
  }
+
+ $this->setUidCache($uids);
  return $uids;
  }
+
  return \imap_uid($this->stream, $id);
  }
 
@@ -618,4 +627,4 @@ public function setProtocol($protocol) {
  $this->protocol = $protocol;
  return $this;
  }
-}
+}

src/Connection/Protocols/Protocol.php

@@ -32,6 +32,11 @@ abstract class Protocol implements ProtocolInterface {
  */
  protected $debug = false;
 
+ /**
+ * @var boolean
+ */
+ protected $enable_uid_cache = true;
+
  /**
  * @var false|resource
  */
@@ -60,6 +65,13 @@ abstract class Protocol implements ProtocolInterface {
  'password' => null,
  ];
 
+ /**
+ * Cache for uid of active folder.
+ *
+ * @var null|array
+ */
+ protected $uid_cache = null;
+
  /**
  * Get an available cryptographic method
  *
@@ -242,4 +254,32 @@ public function buildUIDCommand($command, $uid) {
  return trim($this->getUIDKey($uid)." ".$command);
  }
 
-}
+ /**
+ * Set the uid cache of current active folder
+ *
+ * @param array|null $uids
+ */
+ public function setUidCache($uids) {
+ if (is_null($uids)) {
+ $this->uid_cache = null;
+ return;
+ }
+
+ $messageNumber = 1;
+
+ $uid_cache = [];
+ foreach ($uids as $uid) {
+ $uid_cache[$messageNumber++] = $uid;
+ }
+
+ $this->uid_cache = $uid_cache;
+ }
+
+ public function enableUidCache() {
+ $this->enable_uid_cache = true;
+ }
+
+ public function disableUidCache() {
+ $this->enable_uid_cache = false;
+ }
+}

src/Connection/Protocols/ProtocolInterface.php

@@ -13,6 +13,7 @@
 namespace Webklex\PHPIMAP\Connection\Protocols;
 
 use ErrorException;
+use Webklex\PHPIMAP\Client;
 use Webklex\PHPIMAP\Exceptions\AuthFailedException;
 use Webklex\PHPIMAP\Exceptions\ConnectionFailedException;
 use Webklex\PHPIMAP\Exceptions\InvalidMessageDateException;
@@ -392,4 +393,21 @@ public function enableDebug();
  * Disable the debug mode
  */
  public function disableDebug();
-}
+
+ /**
+ * Enable uid caching
+ */
+ public function enableUidCache();
+
+ /**
+ * Disable uid caching
+ */
+ public function disableUidCache();
+
+ /**
+ * Set the uid cache of current active folder
+ *
+ * @param array|null $uids
+ */
+ public function setUidCache($uids);
+}

src/config/imap.php

@@ -148,6 +148,7 @@
  'soft_fail' => false,
  'rfc822' => true,
  'debug' => false,
+ 'uid_cache' => true,
  'boundary' => '/boundary=(.*?(?=;)|(.*))/i',
  'message_key' => 'list',
  'fetch_order' => 'asc',