new block OTA system tools

Replace the xdelta/xz-based block OTA generation with a new system
based on the existing bsdiff/imgdiff tools.

Bug: 16984795
Change-Id: Ia9732516ffdfc12be86260b2cc4b1dd2d210e886

tools/releasetools/rangelib.py

@@ -0,0 +1,161 @@
+from __future__ import print_function
+import heapq
+import itertools
+
+__all__ = ["RangeSet"]
+
+class RangeSet(object):
+  """A RangeSet represents a set of nonoverlapping ranges on the
+  integers (ie, a set of integers, but efficient when the set contains
+  lots of runs."""
+
+  def __init__(self, data=None):
+    if data:
+      self.data = tuple(self._remove_pairs(data))
+    else:
+      self.data = ()
+
+  def __iter__(self):
+    for i in range(0, len(self.data), 2):
+      yield self.data[i:i+2]
+
+  def __eq__(self, other):
+    return self.data == other.data
+  def __ne__(self, other):
+    return self.data != other.data
+  def __nonzero__(self):
+    return bool(self.data)
+
+  def __str__(self):
+    if not self.data:
+      return "empty"
+    else:
+      return self.to_string()
+
+  @classmethod
+  def parse(cls, text):
+    """Parse a text string consisting of a space-separated list of
+    blocks and ranges, eg "10-20 30 35-40".  Ranges are interpreted to
+    include both their ends (so the above example represents 18
+    individual blocks.  Returns a RangeSet object.
+
+    If the input has all its blocks in increasing order, then returned
+    RangeSet will have an extra attribute 'monotonic' that is set to
+    True.  For example the input "10-20 30" is monotonic, but the input
+    "15-20 30 10-14" is not, even though they represent the same set
+    of blocks (and the two RangeSets will compare equal with ==).
+    """
+
+    data = []
+    last = -1
+    monotonic = True
+    for p in text.split():
+      if "-" in p:
+        s, e = p.split("-")
+        data.append(int(s))
+        data.append(int(e)+1)
+        if last <= s <= e:
+          last = e
+        else:
+          monotonic = False
+      else:
+        s = int(p)
+        data.append(s)
+        data.append(s+1)
+        if last <= s:
+          last = s+1
+        else:
+          monotonic = True
+    data.sort()
+    r = RangeSet(cls._remove_pairs(data))
+    r.monotonic = monotonic
+    return r
+
+  @staticmethod
+  def _remove_pairs(source):
+    last = None
+    for i in source:
+      if i == last:
+        last = None
+      else:
+        if last is not None:
+          yield last
+        last = i
+    if last is not None:
+      yield last
+
+  def to_string(self):
+    out = []
+    for i in range(0, len(self.data), 2):
+      s, e = self.data[i:i+2]
+      if e == s+1:
+        out.append(str(s))
+      else:
+        out.append(str(s) + "-" + str(e-1))
+    return " ".join(out)
+
+  def to_string_raw(self):
+    return str(len(self.data)) + "," + ",".join(str(i) for i in self.data)
+
+  def union(self, other):
+    """Return a new RangeSet representing the union of this RangeSet
+    with the argument."""
+    out = []
+    z = 0
+    for p, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
+                            zip(other.data, itertools.cycle((+1, -1)))):
+      if (z == 0 and d == 1) or (z == 1 and d == -1):
+        out.append(p)
+      z += d
+    return RangeSet(data=out)
+
+  def intersect(self, other):
+    """Return a new RangeSet representing the intersection of this
+    RangeSet with the argument."""
+    out = []
+    z = 0
+    for p, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
+                            zip(other.data, itertools.cycle((+1, -1)))):
+      if (z == 1 and d == 1) or (z == 2 and d == -1):
+        out.append(p)
+      z += d
+    return RangeSet(data=out)
+
+  def subtract(self, other):
+    """Return a new RangeSet representing subtracting the argument
+    from this RangeSet."""
+
+    out = []
+    z = 0
+    for p, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
+                            zip(other.data, itertools.cycle((-1, +1)))):
+      if (z == 0 and d == 1) or (z == 1 and d == -1):
+        out.append(p)
+      z += d
+    return RangeSet(data=out)
+
+  def overlaps(self, other):
+    """Returns true if the argument has a nonempty overlap with this
+    RangeSet."""
+
+    # This is like intersect, but we can stop as soon as we discover the
+    # output is going to be nonempty.
+    z = 0
+    for p, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
+                            zip(other.data, itertools.cycle((+1, -1)))):
+      if (z == 1 and d == 1) or (z == 2 and d == -1):
+        return True
+      z += d
+    return False
+
+  def size(self):
+    """Returns the total size of the RangeSet (ie, how many integers
+    are in the set)."""
+
+    total = 0
+    for i, p in enumerate(self.data):
+      if i % 2:
+        total += p
+      else:
+        total -= p
+    return total