tests: functional: Add pretty random generators

Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

tests/functional/tests/utils/random.py

@@ -0,0 +1,90 @@
+#
+# Copyright(c) 2019 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause-Clear
+#
+
+import random
+import string
+import enum
+from functools import reduce
+from ctypes import (
+    c_uint64,
+    c_uint32,
+    c_uint16,
+    c_uint8,
+    c_int,
+    c_uint
+)
+
+
+class Range:
+    def __init__(self, min_val, max_val):
+        self.min = min_val
+        self.max = max_val
+
+    def is_within(self, val):
+        return val >= self.min and val <= self.max
+
+
+class DefaultRanges(Range, enum.Enum):
+    UINT8 = 0, c_uint8(-1).value
+    UINT16 = 0, c_uint16(-1).value
+    UINT32 = 0, c_uint32(-1).value
+    UINT64 = 0, c_uint64(-1).value
+    INT = int(-c_uint(-1).value / 2) - 1, int(c_uint(-1).value / 2)
+
+
+class RandomGenerator:
+    def __init__(self, base_range=DefaultRanges.INT, count=1000):
+        self.exclude = []
+        self.range = base_range
+        self.count = count
+        self.n = 0
+
+    def exclude_range(self, excl_range):
+        self.exclude.append(excl_range)
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.n >= self.count:
+            raise StopIteration()
+        self.n += 1
+        while True:
+            val = random.randint(self.range.min, self.range.max)
+            if self.exclude:
+                excl_map = map(lambda e: e.is_within(val), self.exclude)
+                is_excluded = reduce(lambda a, b: a or b, excl_map)
+                if is_excluded:
+                    continue
+            return val
+
+
+class RandomStringGenerator:
+    def __init__(self, len_range=Range(0, 20), count=700):
+        self.generator = self.__string_generator(len_range)
+        self.count = count
+        self.n = 0
+
+    def __string_generator(self, len_range):
+        while True:
+            for t in [string.digits,
+                      string.ascii_letters + string.digits,
+                      string.ascii_lowercase,
+                      string.ascii_uppercase,
+                      string.printable,
+                      string.punctuation,
+                      string.hexdigits]:
+                yield ''.join(random.choice(t) for _ in range(
+                    random.randint(len_range.min, len_range.max)
+                ))
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.n >= self.count:
+            raise StopIteration()
+        self.n += 1
+        return next(self.generator)