feat: add UUID generation logic

Author: bduranleau-nr

axiom/Makefile

@@ -124,6 +124,7 @@ OBJS := \
 	nr_span_queue.o \
 	nr_synthetics.o \
 	nr_txn.o \
+	nr_uuid.o \
 	nr_version.o \
 	nr_php_packages.o \
 	util_apdex.o \

axiom/nr_uuid.c

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdlib.h>
+#include <time.h>
+
+#include "nr_uuid.h"
+#include "util_memory.h"
+
+static const char hex_values[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
+                                    '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+char* nr_uuid_create(int seed) {
+  char* uuid = nr_zalloc(NR_UUID_SIZE + 1);
+  if (0 < seed) {
+    srand(seed);
+  } else {
+    srand(time(NULL));
+  }
+
+  for (int i = 0; i < NR_UUID_SIZE; i++) {
+    int r = rand() % NR_UUID_RANGE;
+
+    uuid[i] = hex_values[r];
+  }
+
+  return uuid;
+}

axiom/nr_uuid.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * This file contains functions for simple uuid generation.
+ */
+#ifndef NR_UUID_HDR
+#define NR_UUID_HDR
+
+#define NR_UUID_SIZE 32
+#define NR_UUID_RANGE 16
+
+/**
+ * nr_uuid_create: pseudo-implementation of uuid generation logic
+ *
+ * This function will simply return a randomly generated 32 character hex
+ * string. It does not implement the spec for UUID generation, which requires
+ * specific adherence to implementation details and setting bits within the UUID
+ * to signify which UUID generation variant was used.
+ *
+ * Params: int seed (<1 for time based seed)
+ *
+ * Returns: 32 byte hex string (must be freed by caller)
+ */
+char* nr_uuid_create(int seed);
+#endif

axiom/tests/.gitignore

@@ -125,4 +125,5 @@ test_threads
 test_time
 test_txn
 test_url
+test_uuid
 test_vector

axiom/tests/Makefile

@@ -199,6 +199,7 @@ TESTS := \
   test_time \
   test_txn \
   test_url \
+  test_uuid \
   test_vector
 
 #

axiom/tests/test_uuid.c

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "nr_axiom.h"
+
+#include "nr_uuid.h"
+#include "util_memory.h"
+
+#include "tlib_main.h"
+#include "util_sleep.h"
+
+static void test_uuid_create(void) {
+  char* uuid = NULL;
+  char* tmp = NULL;
+
+  uuid = nr_uuid_create(1234);
+  tlib_pass_if_not_null("uuid create success", uuid);
+
+  tmp = nr_strdup(uuid);
+  nr_free(uuid);
+
+  uuid = nr_uuid_create(4321);
+  tlib_pass_if_true("new uuid != old uuid", 0 != nr_strcmp(tmp, uuid),
+                    "old=%s, new=%s", tmp, uuid);
+
+  nr_free(tmp);
+
+  tmp = nr_strdup(uuid);
+
+  nr_free(uuid);
+
+  uuid = nr_uuid_create(0);
+  tlib_pass_if_true("rand uuid != old uuid", 0 != nr_strcmp(tmp, uuid),
+                    "old=%s, new=%s", tmp, uuid);
+
+  nr_free(uuid);
+  nr_free(tmp);
+}
+
+tlib_parallel_info_t parallel_info = {.suggested_nthreads = 2, .state_size = 0};
+
+void test_main(void* p NRUNUSED) {
+  test_uuid_create();
+}