randomApply

src/blobsets.nim

@@ -645,3 +645,25 @@ proc union*(store: BlobStore; sets: varargs[BlobSet]): BlobSet =
     assert(not bs.isnil)
     bs.apply(freshInsert)
   result = fresh
+
+import random
+
+proc randomApply*(store: BlobStore; trie: BlobSet; seed: int64;
+                  f: proc(id: BlobId; size: BiggestInt)) =
+  ## Apply to random leaf if the set is not empty.
+  var
+    rng = initRand(seed)
+    retry = 0
+    trie = trie
+    i = rng.rand(countSetBits(trie.bitmap)-1)
+  while trie.bitmap != 0:
+    let next = trie.table[i]
+    case next.kind
+    of leafNode:
+      f(next.blob, next.size)
+      break
+    of coldNode:
+      trie.table[i] = store.load(next.setId)
+    of hotNode:
+      trie = next
+      i = rng.rand(countSetBits(trie.bitmap)-1)

tests/test_http.nim

@@ -41,7 +41,7 @@ suite "store":
       let
         name = $i
         blob = blobHash name
-      bs = insert(bs, name, blob, 0)
+      bs = insert(bs, name, blob, i)
     setId = commit(client, bs).setId
 
   test "load":
@@ -60,3 +60,6 @@ suite "store":
         echo "inserted ", name, " - ", name.toKey
         echo "applied ", name, " - ", ($(i xor 0x8000)).toKey
         raiseAssert("apply succedded for a key not inserted")
+    for i in 1..count:
+      store.randomApply(bs, i) do (id: BlobId; size: BiggestInt):
+        echo "randomApply: ", id, " ", size