Merge pull request #2 from codeboost/improve-hashing

improve hashing

Author: codeboost

src/xitdb/array_list.clj

@@ -44,12 +44,9 @@
       (common/-read-from-cursor cursor)))
 
   (nth [_ i not-found]
-    (try
-      (let [cursor (.getCursor ral (long i))]
-        (if cursor
-          (common/-read-from-cursor cursor)
-          not-found))
-      (catch Exception _
+    (let [cursor (.getCursor ral (long i))]
+      (if cursor
+        (common/-read-from-cursor cursor)
         not-found)))
 
   clojure.lang.ILookup

src/xitdb/linked_list.clj

@@ -38,12 +38,9 @@
       (common/-read-from-cursor cursor)))
 
   (nth [_ i not-found]
-    (try
-      (let [cursor (.getCursor rlal (long i))]
-        (if cursor
-          (common/-read-from-cursor cursor)
-          not-found))
-      (catch Exception _
+    (let [cursor (.getCursor rlal (long i))]
+      (if cursor
+        (common/-read-from-cursor cursor)
         not-found)))
 
   clojure.lang.ILookup

src/xitdb/util/conversion.clj

@@ -56,12 +56,33 @@
   Uses the MessageDigest from the database."
   ^bytes [^Database jdb v]
   (if (nil? v)
-    (byte-array (-> jdb .-header .hashSize))
-    (let [hash-code (hash v)
-          buffer    (ByteBuffer/allocate Integer/BYTES)
-          _         (.putInt buffer hash-code)
-          bytes     (.array buffer)]
-      (.digest (.md jdb) bytes))))
+    (byte-array (-> jdb .md .getDigestLength))
+    (do
+      ;; add type name
+      (.update (.md jdb) (-> v .getClass .getCanonicalName (.getBytes "UTF-8")))
+      ;; add null byte as separator
+      (.update (.md jdb) (byte-array 1))
+      ;; add the value
+      (cond
+        (validation/lazy-seq? v)
+        (throw (IllegalArgumentException. "Lazy sequences can be infinite and not allowed!"))
+
+        (bytes? v)
+        (.update (.md jdb) v)
+
+        (instance? Database$Bytes v)
+        (.update (.md jdb) (.value v))
+
+        (coll? v)
+        (with-open [os (java.security.DigestOutputStream. (java.io.OutputStream/nullOutputStream) (.md jdb))]
+          (with-open [writer (java.io.OutputStreamWriter. os)]
+            (binding [*out* writer]
+              (pr v))))
+
+        :else
+        (.update (.md jdb) (.getBytes (str v) "UTF-8")))
+      ;; finish hash
+      (.digest (.md jdb)))))
 
 (defn ^Slot primitive-for
   "Converts a Clojure primitive value to its corresponding XitDB representation.