| # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved. |

| # |

| # Use of this source code is governed by a BSD-style license |

| # that can be found in the LICENSE file in the root of the source |

| # tree. An additional intellectual property rights grant can be found |

| # in the file PATENTS. All contributing project authors may |

| # be found in the AUTHORS file in the root of the source tree. |

| """Utility functions for calculating statistics. |

| """ |

| |

| from __future__ import division |

| import collections |

| import sys |

| |

| |

| def CountReordered(sequence_numbers): |

| """Returns number of reordered indices. |

| |

| A reordered index is an index `i` for which sequence_numbers[i] >= |

| sequence_numbers[i + 1] |

| """ |

| return sum(1 for (s1, s2) in zip(sequence_numbers, sequence_numbers[1:]) |

| if s1 >= s2) |

| |

| |

| def SsrcNormalizedSizeTable(data_points): |

| """Counts proportion of data for every SSRC. |

| |

| Args: |

| data_points: list of pb_parse.DataPoint |

| |

| Returns: |

| A dictionary mapping from every SSRC in the data points. The |

| value of an SSRC `s` is the proportion of sizes of packets with |

| SSRC `s` to the total size of all packets. |

| |

| """ |

| mapping = collections.defaultdict(int) |

| for point in data_points: |

| mapping[point.ssrc] += point.size |

| return NormalizeCounter(mapping) |

| |

| |

| def NormalizeCounter(counter): |

| """Returns a normalized version of the dictionary `counter`. |

| |

| Does not modify `counter`. |

| |

| Returns: |

| A new dictionary, in which every value in `counter` |

| has been divided by the total to sum up to 1. |

| """ |

| total = sum(counter.values()) |

| return {key: counter[key] / total for key in counter} |

| |

| |

| def Unwrap(data, mod): |

| """Returns `data` unwrapped modulo `mod`. Does not modify data. |

| |

| Adds integer multiples of mod to all elements of data except the |

| first, such that all pairs of consecutive elements (a, b) satisfy |

| -mod / 2 <= b - a < mod / 2. |

| |

| E.g. Unwrap([0, 1, 2, 0, 1, 2, 7, 8], 3) -> [0, 1, 2, 3, |

| 4, 5, 4, 5] |

| """ |

| lst = data[:] |

| for i in range(1, len(data)): |

| lst[i] = lst[i - 1] + (lst[i] - lst[i - 1] + mod // 2) % mod - (mod // |

| 2) |

| return lst |

| |

| |

| def SsrcDirections(data_points): |

| ssrc_is_incoming = {} |

| for point in data_points: |

| ssrc_is_incoming[point.ssrc] = point.incoming |

| return ssrc_is_incoming |

| |

| |

| # Python 2/3-compatible input function |

| if sys.version_info[0] <= 2: |

| get_input = raw_input # pylint: disable=invalid-name |

| else: |

| get_input = input # pylint: disable=invalid-name |