1 files changed, 86 insertions, 0 deletions
diff --git a/pathod/language/generators.py b/pathod/language/generators.py
new file mode 100644
index 00000000..a17e7052
--- /dev/null
+++ b/pathod/language/generators.py
@@ -0,0 +1,86 @@
+import string
+import random
+import mmap
+
+DATATYPES = dict(
+    ascii_letters=string.ascii_letters,
+    ascii_lowercase=string.ascii_lowercase,
+    ascii_uppercase=string.ascii_uppercase,
+    digits=string.digits,
+    hexdigits=string.hexdigits,
+    octdigits=string.octdigits,
+    punctuation=string.punctuation,
+    whitespace=string.whitespace,
+    ascii=string.printable,
+    bytes="".join(chr(i) for i in range(256))
+)
+
+
+class TransformGenerator(object):
+
+    """
+        Perform a byte-by-byte transform another generator - that is, for each
+        input byte, the transformation must produce one output byte.
+
+        gen: A generator to wrap
+        transform: A function (offset, data) -> transformed
+    """
+
+    def __init__(self, gen, transform):
+        self.gen = gen
+        self.transform = transform
+
+    def __len__(self):
+        return len(self.gen)
+
+    def __getitem__(self, x):
+        d = self.gen.__getitem__(x)
+        return self.transform(x, d)
+
+    def __getslice__(self, a, b):
+        d = self.gen.__getslice__(a, b)
+        return self.transform(a, d)
+
+    def __repr__(self):
+        return "'transform(%s)'" % self.gen
+
+
+class RandomGenerator(object):
+
+    def __init__(self, dtype, length):
+        self.dtype = dtype
+        self.length = length
+
+    def __len__(self):
+        return self.length
+
+    def __getitem__(self, x):
+        return random.choice(DATATYPES[self.dtype])
+
+    def __getslice__(self, a, b):
+        b = min(b, self.length)
+        chars = DATATYPES[self.dtype]
+        return "".join(random.choice(chars) for x in range(a, b))
+
+    def __repr__(self):
+        return "%s random from %s" % (self.length, self.dtype)
+
+
+class FileGenerator(object):
+
+    def __init__(self, path):
+        self.path = path
+        self.fp = file(path, "rb")
+        self.map = mmap.mmap(self.fp.fileno(), 0, access=mmap.ACCESS_READ)
+
+    def __len__(self):
+        return len(self.map)
+
+    def __getitem__(self, x):
+        return self.map.__getitem__(x)
+
+    def __getslice__(self, a, b):
+        return self.map.__getslice__(a, b)
+
+    def __repr__(self):
+        return "<%s" % self.path