diff --git a/src/file/cache/CacheData.php b/src/file/cache/CacheData.php
index ec96a14..a680f9e 100644
--- a/src/file/cache/CacheData.php
+++ b/src/file/cache/CacheData.php
@@ -12,10 +12,9 @@ class CacheData {
   /** @var callable une fonction permettant de calculer la donnée */
   const COMPUTE = null;
 
-  function __construct(?array $params=null) {
-    $this->name = $params["name"] ?? static::NAME;
-    $this->name ??= bin2hex(random_bytes(8));
-    $this->compute = func::withn($params["compute"] ?? static::COMPUTE);
+  function __construct(?string $name=null, $compute=null) {
+    $this->name = $name ?? static::NAME ?? bin2hex(random_bytes(8));
+    $this->compute = func::withn($compute ?? static::COMPUTE);
   }
 
   protected string $name;
@@ -27,9 +26,12 @@ class CacheData {
     return $compute !== null? $compute->invoke(): null;
   }
 
+  function getName() : string {
+    return $this->name;
+  }
+
   /** obtenir la donnée, en l'itérant au préalable si elle est traversable */
-  function get(?string &$name, $compute=null) {
-    $name = $this->name;
+  function get($compute=null) {
     $this->compute ??= func::withn($compute);
     $data = $this->compute();
     if ($data instanceof Traversable) {
@@ -39,8 +41,7 @@ class CacheData {
   }
 
   /** obtenir un itérateur sur la donnée ou null s'il n'y a pas de données */
-  function all(?string &$name, $compute=null): ?iterable {
-    $name = $this->name;
+  function all($compute=null): ?iterable {
     $this->compute ??= func::withn($compute);
     $data = $this->compute();
     if ($data !== null && !is_iterable($data)) $data = [$data];
diff --git a/src/file/cache/CacheFile.php b/src/file/cache/CacheFile.php
index 07b30cc..0c9e810 100644
--- a/src/file/cache/CacheFile.php
+++ b/src/file/cache/CacheFile.php
@@ -1,6 +1,8 @@
 <?php
 namespace nulib\file\cache;
 
+use Exception;
+use nulib\file;
 use nulib\file\SharedFile;
 use nulib\os\path;
 use nulib\php\time\DateTime;
@@ -23,7 +25,6 @@ class CacheFile extends SharedFile {
     $this->duration = Delay::with($params["duration"] ?? static::DURATION);
     $this->overrideDuration = $params["override_duration"] ?? false;
     $this->cacheNull = $params["cache_null"] ?? false;
-    $this->datafiles = [];
     parent::__construct($file);
   }
 
@@ -39,8 +40,6 @@ class CacheFile extends SharedFile {
 
   protected bool $cacheNull;
 
-  protected array $datafiles;
-
   /**
    * vérifier si le fichier est valide. s'il est invalide, il faut le recréer.
    *
@@ -52,7 +51,7 @@ class CacheFile extends SharedFile {
   }
 
   /** charger les données. le fichier a déjà été verrouillé en lecture */
-  protected function loadData(): ?array {
+  protected function loadMetadata(): ?array {
     $this->rewind();
     [
       "start" => $start,
@@ -74,7 +73,7 @@ class CacheFile extends SharedFile {
     if ($this->isValid()) {
       /** @var Delay $duration */
       ["duration" => $duration,
-      ] = $this->loadData();
+      ] = $this->loadMetadata();
       $expired = $duration->isElapsed();
     } else {
       $expired = false;
@@ -84,7 +83,7 @@ class CacheFile extends SharedFile {
   }
 
   /** sauvegarder les données. le fichier a déjà été verrouillé en écriture */
-  protected function saveData(?DateTime $start=null, ?Delay $duration=null): void {
+  protected function saveMetadata(?DateTime $start, ?Delay $duration, array $datafiles): void {
     $duration ??= $this->duration;
     if ($start === null) {
       $start = new DateTime();
@@ -94,15 +93,76 @@ class CacheFile extends SharedFile {
     $this->serialize([
       "start" => $start,
       "duration" => $duration,
-      "datafiles" => $this->datafiles,
+      "datafiles" => $datafiles,
     ], false, true);
   }
 
+  function loadData(string $datafile) {
+    $datafile = path::join($this->basedir, $datafile);
+    return file::reader($datafile)->unserialize();
+  }
+
+  function saveData(string $datafile, $data): void {
+    $datafile = path::join($this->basedir, $datafile);
+    file::writer($datafile)->serialize($data);
+  }
+
+  protected function unlinkDatafile(string $datafile): void {
+    @unlink(path::join($this->basedir, $datafile));
+  }
+
+  protected function unlinkFiles(?array $datafiles): void {
+    if ($datafiles === null && $this->isValid()) {
+      $this->lockRead();
+      try {
+        ["datafiles" => $datafiles
+        ] = $this->loadMetadata();
+      } finally {
+        $this->unlock();
+      }
+    }
+    @unlink($this->file);
+    if ($datafiles !== null) {
+      foreach ($datafiles as $datafile) {
+        $this->unlinkDatafile($datafile);
+      }
+    }
+  }
+
   /** tester si $value peut être mis en cache */
-  function shouldCache($value): bool {
+  protected function shouldCache($value): bool {
     return $this->cacheNull || $value !== null;
   }
 
+  function get(?CacheData $data=null, bool $noCache=false) {
+    $this->lockRead();
+    try {
+      $datafile = $data->getName();
+      $datafile = "{$this->basename}.data.{$datafile}.cache";
+      #XXX mettre à jour datafiles dans metadata
+      if ($this->shouldUpdate($noCache)) {
+        $this->lockWrite();
+        try {
+          $data = $data->get();
+          if ($this->shouldCache($data)) {
+            $this->saveData($datafile, $data);
+          } else {
+            # ne pas garder le fichier s'il ne faut pas mettre en cache
+            $this->unlinkDatafile($datafile);
+          }
+        } catch (Exception $e) {
+          $this->unlinkDatafile($datafile);
+          throw $e;
+        }
+      } else {
+        $data = $this->loadData($datafile);
+      }
+      return $data;
+    } finally {
+      $this->unlock();
+    }
+  }
+
   /** obtenir les informations sur le fichier */
   function getInfos(): array {
     $this->lockRead();
@@ -118,7 +178,7 @@ class CacheFile extends SharedFile {
         "start" => $start,
         "duration" => $duration,
         "datafiles" => $datafiles,
-      ] = $this->loadData();
+      ] = $this->loadMetadata();
       return [
         "valid" => true,
         "size" => $this->getSize(),
@@ -148,10 +208,10 @@ class CacheFile extends SharedFile {
       [
         "start" => $start,
         "duration" => $duration,
-      ] = $this->loadData();
+      ] = $this->loadMetadata();
       if ($action < 0) $duration->subDuration($nduration);
       elseif ($action > 0) $duration->addDuration($nduration);
-      $this->saveData($start, $duration);
+      $this->saveMetadata($start, $duration);
     } finally {
       $this->unlock();
     }
@@ -163,11 +223,7 @@ class CacheFile extends SharedFile {
     try {
       if ($force || $this->shouldUpdate()) {
         $this->lockWrite();
-        @unlink($this->file);
-        $basedir = $this->basedir;
-        foreach ($this->datafiles as $datafile) {
-          @unlink(path::join($basedir, $datafile));
-        }
+        $this->unlinkFiles();
         return true;
       }
     } finally {