Add a missing function to calculate a batch of hashes

Add a test for batch calculation

src/randomx.cpp

@@ -380,4 +380,14 @@ extern "C" {
 		blake2b(machine->tempHash, sizeof(machine->tempHash), nextInput, nextInputSize, nullptr, 0);
 		machine->hashAndFill(output, RANDOMX_HASH_SIZE, machine->tempHash);
 	}
+
+	void randomx_calculate_hash_last(randomx_vm* machine, void* output) {
+		machine->resetRoundingMode();
+		for (int chain = 0; chain < RANDOMX_PROGRAM_COUNT - 1; ++chain) {
+			machine->run(machine->tempHash);
+			blake2b(machine->tempHash, sizeof(machine->tempHash), machine->getRegisterFile(), sizeof(randomx::RegisterFile), nullptr, 0);
+		}
+		machine->run(machine->tempHash);
+		machine->getFinalResult(output, RANDOMX_HASH_SIZE);
+	}
 }

src/randomx.h

@@ -240,9 +240,11 @@ RANDOMX_EXPORT void randomx_destroy_vm(randomx_vm *machine);
 RANDOMX_EXPORT void randomx_calculate_hash(randomx_vm *machine, const void *input, size_t inputSize, void *output);
 
 /**
- * Paired functions used to calculate multiple RandomX hashes more efficiently.
- * randomx_calculate_hash_first is called for the first input value.
- * randomx_calculate_hash_next will output the hash value of the previous input.
+ * Set of functions used to calculate multiple RandomX hashes more efficiently.
+ * randomx_calculate_hash_first will begin a hash calculation.
+ * randomx_calculate_hash_next  will output the hash value of the previous input
+ *                              and begin the calculation of the next hash.
+ * randomx_calculate_hash_last  will output the hash value of the previous input.
  *
  * @param machine is a pointer to a randomx_vm structure. Must not be NULL.
  * @param input is a pointer to memory to be hashed. Must not be NULL.
@@ -254,6 +256,7 @@ RANDOMX_EXPORT void randomx_calculate_hash(randomx_vm *machine, const void *inpu
 */
 RANDOMX_EXPORT void randomx_calculate_hash_first(randomx_vm* machine, const void* input, size_t inputSize);
 RANDOMX_EXPORT void randomx_calculate_hash_next(randomx_vm* machine, const void* nextInput, size_t nextInputSize, void* output);
+RANDOMX_EXPORT void randomx_calculate_hash_last(randomx_vm* machine, void* output);
 
 #if defined(__cplusplus)
 }

src/tests/tests.cpp

@@ -1026,9 +1026,6 @@ int main() {
 
 	runTest("Hash test 2e (compiler)", RANDOMX_HAVE_COMPILER && stringsEqual(RANDOMX_ARGON_SALT, "RandomX\x03"), test_e);
 
-	randomx_destroy_vm(vm);
-	vm = nullptr;
-
 	auto flags = randomx_get_flags();
 
 	randomx_release_cache(cache);
@@ -1054,6 +1051,28 @@ int main() {
 		assert(cacheMemory[33554431] == 0x1f47f056d05cd99b);
 	});
 
+	runTest("Hash batch test", RANDOMX_HAVE_COMPILER && stringsEqual(RANDOMX_ARGON_SALT, "RandomX\x03"), []() {
+		char hash1[RANDOMX_HASH_SIZE];
+		char hash2[RANDOMX_HASH_SIZE];
+		char hash3[RANDOMX_HASH_SIZE];
+		initCache("test key 000");
+		char input1[] = "This is a test";
+		char input2[] = "Lorem ipsum dolor sit amet";
+		char input3[] = "sed do eiusmod tempor incididunt ut labore et dolore magna aliqua";
+
+		randomx_calculate_hash_first(vm, input1, sizeof(input1) - 1);
+		randomx_calculate_hash_next(vm, input2, sizeof(input2) - 1, &hash1);
+		randomx_calculate_hash_next(vm, input3, sizeof(input3) - 1, &hash2);
+		randomx_calculate_hash_last(vm, &hash3);
+
+		assert(equalsHex(hash1, "639183aae1bf4c9a35884cb46b09cad9175f04efd7684e7262a0ac1c2f0b4e3f"));
+		assert(equalsHex(hash2, "300a0adb47603dedb42228ccb2b211104f4da45af709cd7547cd049e9489c969"));
+		assert(equalsHex(hash3, "c36d4ed4191e617309867ed66a443be4075014e2b061bcdaf9ce7b721d2b77a8"));
+	});
+
+	randomx_destroy_vm(vm);
+	vm = nullptr;
+
 	if (cache != nullptr)
 		randomx_release_cache(cache);