[new] Re-enable Snappy compressor

Upstream safety issue has been resolved,
Ref. <https://github.com/airlift/aircompressor/issues/183>.

src/taoensso/nippy.clj

@@ -337,7 +337,7 @@
   compression/lz4-compressor
   compression/lz4hc-compressor
   #_compression/lzo-compressor
-  #_compression/snappy-compressor ; Can be unsafe
+  compression/snappy-compressor
   compression/lzma2-compressor
 
   encryption/encrypt

src/taoensso/nippy/compression.clj

@@ -201,13 +201,16 @@
   See `taoensso.nippy-benchmarks` for detailed comparative benchmarks."
   (LZMA2Compressor. 0))
 
+(enc/def* snappy-compressor
+  "Default `Snappy` compressor:
+    -   Compression ratio: `C`  (0.58      on reference benchmark).
+    -   Compression speed: `A+` (206 msecs on reference benchmark).
+    - Decompression speed: `B`  (134 msecs on reference benchmark).
+  Good general-purpose compressor, favours speed.
+  See `taoensso.nippy-benchmarks` for detailed comparative benchmarks."
+  (SnappyCompressor. false))
+
 (enc/def* ^:no-doc lz4hc-compressor
   "Different LZ4 modes no longer supported, prefer `lz4-compressor`."
   {:deprecated "v3.4.0-RC1 (2024-02-06)"}
   (LZ4Compressor.))
-
-(enc/def* ^:no-doc snappy-compressor
-  "Snappy compressor no longer recommended, prefer `lz4-compressor`.
-  Decompression can be unsafe against untrusted data!"
-  {:deprecated "v3.4.0-RC1 (2024-02-06)"}
-  (SnappyCompressor. false))

test/taoensso/nippy_tests.clj

@@ -423,16 +423,21 @@
 ;;;; Compressors
 
 (deftest _compressors
+  (println "\nTesting decompression of random data...")
   (doseq [c [compr/zstd-compressor
              compr/lz4-compressor
              compr/lzo-compressor
-             #_compr/snappy-compressor ; Ref. <https://github.com/airlift/aircompressor/issues/183>
+             compr/snappy-compressor
              compr/lzma2-compressor]]
 
-    (dotimes [_ 2e4]
+    (print (str "  With " (name (compr/header-id c)))) (flush)
-      (is
+    (dotimes [_ 5] ; Slow, a few k laps should be sufficient for CI
-        (nil? (enc/catching (compr/decompress c (crypto/rand-bytes 1024))))
+      (print ".") (flush)
-        "Decompression never crashes JVM, even against invalid data"))))
+      (dotimes [_ 1000]
+        (is
+          (nil? (enc/catching (compr/decompress c (crypto/rand-bytes 1024))))
+          "Decompression never crashes JVM, even against invalid data")))
+    (println)))
 
 ;;;; Benchmarks