extend namestore API to enable faster iterations by returning more than one result at a time

1 files changed, 73 insertions, 27 deletions

diff --git a/src/namestore/plugin_namestore_flat.c b/src/namestore/plugin_namestore_flat.c
index 305fe7ba1..e9ed1cc4f 100644
--- a/src/namestore/plugin_namestore_flat.c
+++ b/src/namestore/plugin_namestore_flat.c
@@ -86,6 +86,7 @@ struct Plugin
 
 };
 
+
 struct FlatFileEntry
 {
   /**
@@ -501,9 +502,7 @@ namestore_flat_lookup_records (void *cls,
   size_t key_len;
 
   if (NULL == zone)
-  {
     return GNUNET_SYSERR;
-  }
   key_len = strlen (label) + sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey);
   key = GNUNET_malloc (key_len);
   GNUNET_memcpy (key,
@@ -532,30 +531,77 @@ namestore_flat_lookup_records (void *cls,
 }
 
 
+/**
+ * Closure for #iterate_zones.
+ */
+struct IterateContext
+{
+  /**
+   * How many more records should we skip before returning results?
+   */
+  uint64_t offset;
+
+  /**
+   * How many more records should we return?
+   */
+  uint64_t limit;
+
+  /**
+   * Target zone.
+   */
+  const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone;
+
+  /**
+   * Function to call on each record.
+   */
+  GNUNET_NAMESTORE_RecordIterator iter;
+
+  /**
+   * Closure for @e iter.
+   */
+  void *iter_cls;
+
+};
+
+
+/**
+ * Helper function for #namestore_flat_iterate_records().
+ *
+ * @param cls a `struct IterateContext`
+ * @param key unused
+ * @param value a `struct FlatFileEntry`
+ * @return #GNUNET_YES to continue the iteration
+ */
 static int
 iterate_zones (void *cls,
                const struct GNUNET_HashCode *key,
                void *value)
 {
-  struct Plugin *plugin = cls;
+  struct IterateContext *ic = cls;
   struct FlatFileEntry *entry = value;
 
   (void) key;
-  if ((plugin->target_offset > plugin->offset) ||
-      ( (NULL != plugin->iter_zone) &&
-        (0 != memcmp (entry->private_key,
-                      plugin->iter_zone,
-                      sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey))))) {
-    plugin->offset++;
+  if (0 == ic->limit)
+    return GNUNET_NO;
+  if ( (NULL != it->zone) &&
+       (0 != memcmp (entry->private_key,
+                     ic->zone,
+                     sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey))) )
+    return GNUNET_YES;
+  if (ic->offset > 0)
+  {
+    ic->offset--;
     return GNUNET_YES;
   }
-  plugin->iter (plugin->iter_cls,
-                entry->private_key,
-                entry->label,
-                entry->record_count,
-                entry->record_data);
-  plugin->iter_result_found = GNUNET_YES;
-  return GNUNET_NO;
+  ic->iter (ic->iter_cls,
+            entry->private_key,
+            entry->label,
+            entry->record_count,
+            entry->record_data);
+  ic->limit--;
+  if (0 == ic->limit)
+    return GNUNET_NO;
+  return GNUNET_YES;
 }
 
 
@@ -566,31 +612,31 @@ iterate_zones (void *cls,
  * @param cls closure (internal context for the plugin)
  * @param zone hash of public key of the zone, NULL to iterate over all zones
  * @param offset offset in the list of all matching records
+ * @param limit maximum number of results to return to @a iter
  * @param iter function to call with the result
  * @param iter_cls closure for @a iter
- * @return #GNUNET_OK on success, #GNUNET_NO if there were no results, #GNUNET_SYSERR on error
+ * @return #GNUNET_OK on success, #GNUNET_NO if there were no more results, #GNUNET_SYSERR on error
  */
 static int
 namestore_flat_iterate_records (void *cls,
                                 const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone,
                                 uint64_t offset,
+                                uint64_t limit,
                                 GNUNET_NAMESTORE_RecordIterator iter,
                                 void *iter_cls)
 {
   struct Plugin *plugin = cls;
+  struct IterateContext ic;
 
-  /* FIXME: maybe use separate closure to better handle
-     recursive calls? */
-  plugin->target_offset = offset;
-  plugin->offset = 0;
-  plugin->iter = iter;
-  plugin->iter_cls = iter_cls;
-  plugin->iter_zone = zone;
-  plugin->iter_result_found = GNUNET_NO;
+  ic.offset = offset;
+  ic.limit = limit;
+  ic.iter = iter;
+  ic.iter_cls = iter_cls;
+  ic.zone = zone;
   GNUNET_CONTAINER_multihashmap_iterate (plugin->hm,
                                          &iterate_zones,
-                                         plugin);
-  return plugin->iter_result_found;
+                                         &ic);
+  return (0 == ic.limit) ? GNUNET_OK : GNUNET_NO;
 }