Started replacing DataBlockFixture with DataFixture.

Step 1: Create DataFixture

data/DataFixture.cpp

@@ -0,0 +1,23 @@
+#include "DataFixture.h"
+
+namespace cpputils {
+  Data DataFixture::generate(size_t size, long long int seed) {
+    Data result(size);
+    long long int val = seed;
+    for(size_t i=0; i<size/sizeof(long long int); ++i) {
+      //MMIX linear congruential generator
+      val *= 6364136223846793005L;
+      val += 1442695040888963407;
+      reinterpret_cast<long long int*>(result.data())[i] = val;
+    }
+    uint64_t alreadyWritten = (size/sizeof(long long int))*sizeof(long long int);
+    val *= 6364136223846793005L;
+    val += 1442695040888963407;
+    char *remainingBytes = reinterpret_cast<char*>(&val);
+    //Fill remaining bytes
+    for(size_t i=0; i<size-alreadyWritten; ++i) {
+      reinterpret_cast<char*>(result.data())[alreadyWritten + i] = remainingBytes[i];
+    }
+    return result;
+  }
+}

data/DataFixture.h

@@ -0,0 +1,16 @@
+#pragma once
+#ifndef MESSMER_CPP_UTILS_DATA_DATAFIXTURE_H_
+#define MESSMER_CPP_UTILS_DATA_DATAFIXTURE_H_
+
+#include "Data.h"
+
+namespace cpputils {
+
+class DataFixture {
+public:
+  static Data generate(size_t size, long long int seed = 1);
+};
+
+}
+
+#endif