add a test

deps/test/CMakeLists.txt

@@ -6,3 +6,5 @@ endif(${BUILD_WITH_ROCKSDB})
 if(${BUILD_WITH_LUCENE})
     add_subdirectory(lucene)
 endif(${BUILD_WITH_LUCENE})
+
+add_subdirectory(tdev)

deps/test/tdev/CMakeLists.txt

+aux_source_directory(src TDEV_SRC)
+add_executable(tdev ${TDEV_SRC})
+
+target_include_directories(tdev PUBLIC inc)
\ No newline at end of file

deps/test/tdev/src/main.c

+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+
+#define POINTER_SHIFT(ptr, s) ((void *)(((char *)ptr) + (s)))
+#define POINTER_DISTANCE(pa, pb) ((char *)(pb) - (char *)(pa))
+
+#define tPutA(buf, val)              \
+  ({                                 \
+    memcpy(buf, &val, sizeof(val));  \
+    POINTER_SHIFT(buf, sizeof(val)); \
+  })
+
+#define tPutB(buf, val)                         \
+  ({                                            \
+    ((uint8_t *)buf)[3] = ((val) >> 24) & 0xff; \
+    ((uint8_t *)buf)[2] = ((val) >> 16) & 0xff; \
+    ((uint8_t *)buf)[1] = ((val) >> 8) & 0xff;  \
+    ((uint8_t *)buf)[0] = (val)&0xff;           \
+    POINTER_SHIFT(buf, sizeof(val));            \
+  })
+
+#define tPutC(buf, val)              \
+  ({                                 \
+    ((uint64_t *)buf)[0] = (val);    \
+    POINTER_SHIFT(buf, sizeof(val)); \
+  })
+
+typedef enum { A, B, C } T;
+
+static void func(T t) {
+  uint64_t val = 198;
+  char     buf[1024];
+  void *   pBuf = buf;
+
+  switch (t) {
+    case A:
+      for (size_t i = 0; i < 10 * 1024l * 1024l * 1024l; i++) {
+        pBuf = tPutA(pBuf, val);
+        if (POINTER_DISTANCE(buf, pBuf) == 1024) {
+          pBuf = buf;
+        }
+      }
+      break;
+    case B:
+      for (size_t i = 0; i < 10 * 1024l * 1024l * 1024l; i++) {
+        pBuf = tPutB(pBuf, val);
+        if (POINTER_DISTANCE(buf, pBuf) == 1024) {
+          pBuf = buf;
+        }
+      }
+      break;
+    case C:
+      for (size_t i = 0; i < 10 * 1024l * 1024l * 1024l; i++) {
+        pBuf = tPutC(pBuf, val);
+        if (POINTER_DISTANCE(buf, pBuf) == 1024) {
+          pBuf = buf;
+        }
+      }
+      break;
+
+    default:
+      break;
+  }
+}
+
+static uint64_t now() {
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+
+  return tv.tv_sec * 1000000 + tv.tv_usec;
+}
+
+int main(int argc, char const *argv[]) {
+  uint64_t t1 = now();
+  func(A);
+  uint64_t t2 = now();
+  printf("A: %ld\n", t2 - t1);
+  func(B);
+  uint64_t t3 = now();
+  printf("B: %ld\n", t3 - t2);
+  func(C);
+  uint64_t t4 = now();
+  printf("C: %ld\n", t4 - t3);
+  return 0;
+}