Proper ID generation and conversion

Author: pglombardo

instana/util.py

@@ -0,0 +1,41 @@
+import random
+import os
+import time
+import struct
+import binascii
+
+_rnd = random.Random()
+_current_pid = 0
+
+
+def generate_id():
+    """ Generate a 64bit signed integer for use as a Span or Trace ID """
+    global _current_pid
+
+    pid = os.getpid()
+    if (_current_pid != pid):
+        _current_pid = pid
+        _rnd.seed(int(1000000 * time.time()) ^ pid)
+    return _rnd.randint(-9223372036854775808, 9223372036854775807)
+
+
+def id_to_header(id):
+    """ Convert a 64bit signed integer to an unsigned base 16 hex string """
+
+    if not isinstance(id, int):
+        return ""
+
+    byteString = struct.pack('>q', id)
+    return binascii.hexlify(byteString).lstrip('0')
+
+
+def header_to_id(header):
+    """ Convert an unsigned base 16 hex string into a 64bit signed integer """
+
+    if not isinstance(header, basestring):
+        return 0
+
+    # Pad the header to 16 chars
+    header = header.zfill(16)
+    r = binascii.unhexlify(header)
+    return struct.unpack('>q', r)[0]