Rearrange files to prepare to merge into Ray.

src/common/common.c

@@ -0,0 +1,36 @@
+#include "common.h"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+const unique_id NIL_ID = {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+                           255, 255, 255, 255, 255, 255, 255, 255, 255, 255}};
+
+unique_id globally_unique_id(void) {
+  /* Use /dev/urandom for "real" randomness. */
+  int fd;
+  if ((fd = open("/dev/urandom", O_RDONLY)) == -1) {
+    LOG_ERR("Could not generate random number");
+  }
+  unique_id result;
+  read(fd, &result.id[0], UNIQUE_ID_SIZE);
+  close(fd);
+  return result;
+}
+
+char *sha1_to_hex(const unsigned char *sha1, char *buffer) {
+  static const char hex[] = "0123456789abcdef";
+  char *buf = buffer;
+
+  for (int i = 0; i < UNIQUE_ID_SIZE; i++) {
+    unsigned int val = *sha1++;
+    *buf++ = hex[val >> 4];
+    *buf++ = hex[val & 0xf];
+  }
+  *buf = '\0';
+
+  return buffer;
+}