Add BM_ZFlatAll, BM_ZFlatIncreasingTableSize benchmarks to see how good zippy performs when it is processing different data one after the other.

PiperOrigin-RevId: 257518137

snappy.cc

@@ -444,12 +444,14 @@ bool GetUncompressedLength(const char* start, size_t n, size_t* result) {
 
 namespace {
 uint32 CalculateTableSize(uint32 input_size) {
-  assert(kMaxHashTableSize >= 256);
+  static_assert(
+      kMaxHashTableSize >= kMinHashTableSize,
+      "kMaxHashTableSize should be greater or equal to kMinHashTableSize.");
   if (input_size > kMaxHashTableSize) {
     return kMaxHashTableSize;
   }
-  if (input_size < 256) {
-    return 256;
+  if (input_size < kMinHashTableSize) {
+    return kMinHashTableSize;
   }
   // This is equivalent to Log2Ceiling(input_size), assuming input_size > 1.
   // 2 << Log2Floor(x - 1) is equivalent to 1 << (1 + Log2Floor(x - 1)).