/b-gtk/fix-viz

# -*- coding: UTF-8 -*-

"""Directed graph production.

This module contains the code to produce an ordered directed graph of a

bzr branch, such as we display in the tree view at the top of the bzrk

window.

"""

__copyright__ = "Copyright © 2005 Canonical Ltd."

__author__    = "Scott James Remnant <scott@ubuntu.com>"

from bzrlib.tsort import merge_sort

def linegraph(branch, start, maxnum):

    """Produce a directed graph of a bzr branch.

    Returns a list of tuples of (revid,

                                 node,

                                 lines,

                                 parents,

                                 children,

                                 revno_sequence).

    Node is a tuple of (column, colour) with column being a zero-indexed

    column number of the graph that this revision represents and colour

    being a zero-indexed colour (which doesn't specify any actual colour

    in particular) to draw the node in.

    Lines is a list of tuples which represent lines you should draw away

    from the revision, if you also need to draw lines into the revision

    you should use the lines list from the previous iteration.  Each

    typle in the list is in the form (start, end, colour) with start and

    end being zero-indexed column numbers and colour as in node.

    It's up to you how to actually draw the nodes and lines (straight,

    curved, kinked, etc.) and to pick the actual colours for each index.

    """

    # We get the mainline so we can pass it to merge_sort to make merge_sort

    # run faster.

    mainline = branch.revision_history()

    graph_parents = branch.repository.get_revision_graph(start)

    graph_children = {}

    for revid in graph_parents.iterkeys():

        graph_children[revid] = []

    merge_sorted_revisions = merge_sort(

        graph_parents,

        start,

        mainline,

        generate_revno=True)

    revid_index = {}

    revno_index = {}

    # This will hold an item for each "branch". For a revisions, the revsion

    # number less the least significant digit is the branch_id, and used as the

    # key for the dict. Hence revision with the same revsion number less the

    # least significant digit are considered to be in the same branch line.

    # e.g.: for revisions 290.12.1 and 290.12.2, the branch_id would be 290.12,

    # and these two revisions will be in the same branch line. Each value is

    # a list of [rev_indexes, min_index, max_index, col_index].

    branch_lines = {}

    BL_REV_INDEXES = 0

    BL_MIN_INDEX = 1

    BL_MAX_INDEX = 2

    BL_COL_INDEX = 3

    linegraph = []    

    for (rev_index, (sequence_number,

                     revid,

                     merge_depth,

                     revno_sequence,

                     end_of_merge)) in enumerate(merge_sorted_revisions):

        revid_index[revid] = rev_index

        revno_index[revno_sequence] = rev_index

        branch_id = revno_sequence[0:-1]

        branch_line = None

        if branch_id not in branch_lines:

            branch_line = [[],        # BL_REV_INDEXES

                           rev_index, # BL_MIN_INDEX

                           0,         # BL_MAX_INDEX

                           None]      # BL_COL_INDEX

            branch_lines[branch_id] = branch_line

        else:

            branch_line = branch_lines[branch_id]

        branch_line[BL_REV_INDEXES].append(rev_index)

        if rev_index > branch_line[BL_MAX_INDEX]:

            branch_line[BL_MAX_INDEX] = rev_index

        parents = graph_parents[revid]

        for parent_revid in parents:

            graph_children[parent_revid].append(revid)

        linegraph.append([revid,

                          None,

                          [],

                          parents,

                          None,

                          revno_sequence])

    branch_ids = branch_lines.keys()

    def branch_id_cmp(x, y):

        """Compaire branch_id's first by the number of digits, then reversed

        by their value"""

        len_x = len(x)

        len_y = len(y)

        if len_x == len_y:

            return -cmp(x, y)

        return cmp(len_x, len_y)

    branch_ids.sort(branch_id_cmp)

    # This will hold a tuple of (child_index, parent_index, col_index) for each

    # line that needs to be drawn. If col_index is not none, then the line is

    # drawn along that column, else the the line can be drawn directly between

    # the child and parent because either the child and parent are in the same

    # branch line, or the child and parent are 1 row apart.

    lines = []

    empty_column = [False for i in range(len(graph_parents))]

    # This will hold a bit map for each cell. If the cell is true, then the

    # cell allready contains a node or line. This use when deciding what column

    # to place a branch line or line in, without it overlaping something else.

    columns = [list(empty_column)]

    for branch_id in branch_ids:

        branch_line = branch_lines[branch_id]

        # Find the col_index for the direct parent branch. This will be the

        # starting point when looking for a free column.

        parent_col_index = 0

        if len(branch_id) > 1:

            parent_branch_id = branch_id[0:-2]

            parent_col_index = branch_lines[parent_branch_id][BL_COL_INDEX]

            parent_revno = branch_id[0:-1]

            if parent_revno in revno_index:

                parent_index = revno_index[parent_revno]

                branch_line[BL_MAX_INDEX] = parent_index - 1

        col_search_order = _branch_line_col_search_order(columns,

                                                         parent_col_index)

        branch_line[BL_COL_INDEX] = _append_line(columns,

                                                (branch_line[BL_MIN_INDEX],

                                                 branch_line[BL_MAX_INDEX]),

                                                empty_column,

                                                col_search_order)

        color = reduce(lambda x, y: x+y, branch_id, 0)

        col_index = branch_line[BL_COL_INDEX]

        node = (col_index, color)        

        for rev_index in branch_line[BL_REV_INDEXES]:

            (sequence_number,

                 revid,

                 merge_depth,

                 revno_sequence,

                 end_of_merge) = merge_sorted_revisions[rev_index]

            linegraph[rev_index][1] = node

            linegraph[rev_index][4] = graph_children[revid]

            for parent_revid in graph_parents[revid]:

                if parent_revid in revid_index:

                    parent_index = revid_index[parent_revid]

                    parent_revno = merge_sorted_revisions[parent_index][3]

                    parent_branch_id = parent_revno[0:-1]

                    col_index = None

                    is_direct_parent_line = False

                    if len(branch_id) > 1:

                        if parent_revno == branch_id[0:-1]:

                            is_direct_parent_line = True

                    # A line only needs it's own column if it is going from

                    # one branch line to another, it's not the line to the

                    # direct parent, and if it is longer than one row.

                    if branch_id != parent_branch_id and \

                       parent_index - rev_index > 1 and \

                       not is_direct_parent_line:

                        parent_node = linegraph[parent_index][1]

                        if parent_node:

                            parent_col_index = parent_node[0]

                        else:

                            parent_col_index = None

                        col_search_order = \

                                _line_col_search_order(columns,

                                                       parent_col_index,

                                                       branch_line[BL_COL_INDEX])

                        col_index = _append_line(columns,

                                                 (rev_index+1, parent_index-1),

                                                 empty_column,

                                                 col_search_order)

                    lines.append((rev_index, parent_index, col_index))

    for (child_index, parent_index, line_col_index) in lines:

        child_col_index = linegraph[child_index][1][0]

        parent_node = linegraph[parent_index][1]

        parent_col_index = parent_node[0]

        color = parent_node[1]

        if line_col_index:

            # line from the child's column to the lines column

            linegraph[child_index][2].append(

                (child_col_index,

                 line_col_index,

                 color))

            # lines down the line's column

            for line_part_index in range(child_index+1, parent_index-1):

                linegraph[line_part_index][2].append(

                    (line_col_index,   

                     line_col_index,

                     color))

            # line from the line's column to the parent's column

            linegraph[parent_index-1][2].append(

                (line_col_index,

                 parent_col_index,

                 color))

        else:

            # lines down the child's column

            for line_part_index in range(child_index, parent_index-1):

                linegraph[line_part_index][2].append(

                    (child_col_index,   

                     child_col_index,

                     color))

            # line from the child's column to the parent's column

            linegraph[parent_index-1][2].append(

                (child_col_index,

                 parent_col_index,

                 color))

    return (linegraph, revid_index)

def _branch_line_col_search_order(columns, parent_col_index):

    return range(parent_col_index, len(columns)) + \

           range(parent_col_index-1, -1, -1)

def _line_col_search_order(columns, parent_col_index, child_col_index):

    dest_col_indexes = []

    if parent_col_index is not None:

        dest_col_indexes.append(parent_col_index)

    else:

        dest_col_indexes.append(child_col_index)

    dest_col_indexes.append(child_col_index)

    dest_col_indexes.sort()

    col_search_order = range(dest_col_indexes[1], dest_col_indexes[0] -1, -1) 

    i = 1

    while dest_col_indexes[1] + i < len(columns) or \

          dest_col_indexes[0] - i > -1:

        if dest_col_indexes[1] + i < len(columns):

            col_search_order.append(dest_col_indexes[1] + i)

        if dest_col_indexes[0] - i > -1:

            col_search_order.append(dest_col_indexes[0] - i)

        i += 1

    return col_search_order

def _append_line(columns, line, empty_column, col_search_order):

    line_range = range(line[0], line[1]+1)

    for col_index in col_search_order:

        column = columns[col_index]

        has_overlaping_line = False

        for row_index in line_range:

            if column[row_index]:

                has_overlaping_line = True

                break

        if not has_overlaping_line:

            break

    else:

        col_index = len(columns)

        column = list(empty_column)

        columns.append(column)

    for row_index in line_range:

        column[row_index] = True

    return col_index

def same_branch(a, b):

    """Return whether we think revisions a and b are on the same branch."""

    if len(a.parent_ids) == 1:

        # Defacto same branch if only parent

        return True

    elif a.committer == b.committer:

        # Same committer so may as well be

        return True

    else:

        return False