[datastore] Fix #3743

This change adds support for key == NULL to the datastore plugins
and replaces the offset argument with a next_uid and random arguments to
increase performance in the key == NULL case.

With the offset argument a datastore plugin would have to count all
matching keys before fetching the key at the right offset, which would
iterate over the entire database in the case of key == NULL.

The offset argument was used in two ways: to iterate over a set of
matching values and to start iteration at a random matching value. The new API
seperates these into two arguments: if random is true it will return a
random matching value, otherwise next_uid can be set to uid + 1 to return the
next matching value.

The random argument was not added to get_zero_anonymity. This function
is used to periodically insert zero anonymity values into the DHT. I
don't think it's necessary to randomize this.

1 files changed, 0 insertions, 10 deletions

diff --git a/src/fs/fs_api.h b/src/fs/fs_api.h
index e85de94a7..be22ea73e 100644
--- a/src/fs/fs_api.h
+++ b/src/fs/fs_api.h
@@ -1464,21 +1464,11 @@ struct GNUNET_FS_UnindexContext
   struct GNUNET_CRYPTO_FileHashContext *fhc;
 
   /**
-   * Which values have we seen already?
-   */
-  struct GNUNET_CONTAINER_MultiHashMap *seen_dh;
-
-  /**
    * Overall size of the file.
    */
   uint64_t file_size;
 
   /**
-   * Random offset given to #GNUNET_DATASTORE_get_key.
-   */
-  uint64_t roff;
-
-  /**
    * When did we start?
    */
   struct GNUNET_TIME_Absolute start_time;