444 lines
11 KiB
Ruby
444 lines
11 KiB
Ruby
# heavily based off difflib.py - see that file for documentation
|
|
# ported from Python by Bill Atkins
|
|
|
|
# This does not support all features offered by difflib; it
|
|
# implements only the subset of features necessary
|
|
# to support a Ruby version of HTML Differ. You're welcome to finish this off.
|
|
|
|
# By default, String#each iterates by line. This isn't really appropriate
|
|
# for diff, so often a string will be split by // to get an array of one-
|
|
# character strings.
|
|
|
|
# Some methods in Diff are untested and are not guaranteed to work. The
|
|
# methods in HTMLDiff and any methods it calls should work quite well.
|
|
|
|
# changes by DenisMertz
|
|
# * main change:
|
|
# ** get the tag soup away
|
|
# the tag soup problem was first reported with <p> tags, but it appeared also with
|
|
# <li>, <ul> etc... tags
|
|
# this version should mostly fix these problems
|
|
# ** added a Builder class to manage the creation of the final htmldiff
|
|
# * minor changes:
|
|
# ** use symbols instead of string to represent opcodes
|
|
# ** small fix to html2list
|
|
#
|
|
|
|
module Enumerable
|
|
def reduce(init)
|
|
result = init
|
|
each { |item| result = yield(result, item) }
|
|
result
|
|
end
|
|
end
|
|
|
|
module Diff
|
|
|
|
class SequenceMatcher
|
|
def initialize(a=[''], b=[''], isjunk=nil, byline=false)
|
|
a = (!byline and a.kind_of? String) ? a.split(//) : a
|
|
b = (!byline and b.kind_of? String) ? b.split(//) : b
|
|
@isjunk = isjunk || proc {}
|
|
set_seqs a, b
|
|
end
|
|
|
|
def set_seqs(a, b)
|
|
set_seq_a a
|
|
set_seq_b b
|
|
end
|
|
|
|
def set_seq_a(a)
|
|
@a = a
|
|
@matching_blocks = @opcodes = nil
|
|
end
|
|
|
|
def set_seq_b(b)
|
|
@b = b
|
|
@matching_blocks = @opcodes = nil
|
|
chain_b
|
|
end
|
|
|
|
def chain_b
|
|
@fullbcount = nil
|
|
@b2j = {}
|
|
pophash = {}
|
|
junkdict = {}
|
|
|
|
@b.each_with_index do |elt, i|
|
|
if @b2j.has_key? elt
|
|
indices = @b2j[elt]
|
|
if @b.length >= 200 and indices.length * 100 > @b.length
|
|
pophash[elt] = 1
|
|
indices.clear
|
|
else
|
|
indices.push i
|
|
end
|
|
else
|
|
@b2j[elt] = [i]
|
|
end
|
|
end
|
|
|
|
pophash.each_key { |elt| @b2j.delete elt }
|
|
|
|
junkdict = {}
|
|
|
|
unless @isjunk.nil?
|
|
[pophash, @b2j].each do |d|
|
|
d.each_key do |elt|
|
|
if @isjunk.call(elt)
|
|
junkdict[elt] = 1
|
|
d.delete elt
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
@isbjunk = junkdict.method(:has_key?)
|
|
@isbpopular = junkdict.method(:has_key?)
|
|
end
|
|
|
|
def find_longest_match(alo, ahi, blo, bhi)
|
|
besti, bestj, bestsize = alo, blo, 0
|
|
|
|
j2len = {}
|
|
|
|
(alo..ahi).step do |i|
|
|
newj2len = {}
|
|
(@b2j[@a[i]] || []).each do |j|
|
|
if j < blo
|
|
next
|
|
end
|
|
if j >= bhi
|
|
break
|
|
end
|
|
|
|
k = newj2len[j] = (j2len[j - 1] || 0) + 1
|
|
if k > bestsize
|
|
besti, bestj, bestsize = i - k + 1, j - k + 1, k
|
|
end
|
|
end
|
|
j2len = newj2len
|
|
end
|
|
|
|
while besti > alo and bestj > blo and
|
|
not @isbjunk.call(@b[bestj-1]) and
|
|
@a[besti-1] == @b[bestj-1]
|
|
besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
|
|
end
|
|
|
|
while besti+bestsize < ahi and bestj+bestsize < bhi and
|
|
not @isbjunk.call(@b[bestj+bestsize]) and
|
|
@a[besti+bestsize] == @b[bestj+bestsize]
|
|
bestsize += 1
|
|
end
|
|
|
|
while besti > alo and bestj > blo and
|
|
@isbjunk.call(@b[bestj-1]) and
|
|
@a[besti-1] == @b[bestj-1]
|
|
besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
|
|
end
|
|
|
|
while besti+bestsize < ahi and bestj+bestsize < bhi and
|
|
@isbjunk.call(@b[bestj+bestsize]) and
|
|
@a[besti+bestsize] == @b[bestj+bestsize]
|
|
bestsize += 1
|
|
end
|
|
|
|
[besti, bestj, bestsize]
|
|
end
|
|
|
|
def get_matching_blocks
|
|
return @matching_blocks unless @matching_blocks.nil? or
|
|
@matching_blocks.empty?
|
|
|
|
@matching_blocks = []
|
|
la, lb = @a.length, @b.length
|
|
match_block_helper(0, la, 0, lb, @matching_blocks)
|
|
@matching_blocks.push [la, lb, 0]
|
|
end
|
|
|
|
def match_block_helper(alo, ahi, blo, bhi, answer)
|
|
i, j, k = x = find_longest_match(alo, ahi, blo, bhi)
|
|
if not k.zero?
|
|
if alo < i and blo < j
|
|
match_block_helper(alo, i, blo, j, answer)
|
|
end
|
|
answer.push x
|
|
if i + k < ahi and j + k < bhi
|
|
match_block_helper(i + k, ahi, j + k, bhi, answer)
|
|
end
|
|
end
|
|
end
|
|
|
|
def get_opcodes
|
|
unless @opcodes.nil? or @opcodes.empty?
|
|
return @opcodes
|
|
end
|
|
|
|
i = j = 0
|
|
@opcodes = answer = []
|
|
get_matching_blocks.each do |ai, bj, size|
|
|
tag = if i < ai and j < bj
|
|
:replace
|
|
elsif i < ai
|
|
:delete
|
|
elsif j < bj
|
|
:insert
|
|
end
|
|
|
|
answer.push [tag, i, ai, j, bj] if tag
|
|
|
|
i, j = ai + size, bj + size
|
|
|
|
answer.push [:equal, ai, i, bj, j] unless size.zero?
|
|
|
|
end
|
|
return answer
|
|
end
|
|
|
|
# XXX: untested
|
|
def get_grouped_opcodes(n=3)
|
|
codes = get_opcodes
|
|
if codes[0][0] == :equal
|
|
tag, i1, i2, j1, j2 = codes[0]
|
|
codes[0] = tag, [i1, i2 - n].max, i2, [j1, j2-n].max, j2
|
|
end
|
|
|
|
if codes[-1][0] == :equal
|
|
tag, i1, i2, j1, j2 = codes[-1]
|
|
codes[-1] = tag, i1, min(i2, i1+n), j1, min(j2, j1+n)
|
|
end
|
|
nn = n + n
|
|
group = []
|
|
codes.each do |tag, i1, i2, j1, j2|
|
|
if tag == :equal and i2-i1 > nn
|
|
group.push [tag, i1, [i2, i1 + n].min, j1, [j2, j1 + n].min]
|
|
yield group
|
|
group = []
|
|
i1, j1 = [i1, i2-n].max, [j1, j2-n].max
|
|
group.push [tag, i1, i2, j1 ,j2]
|
|
end
|
|
end
|
|
if group and group.length != 1 and group[0][0] == :equal
|
|
yield group
|
|
end
|
|
end
|
|
|
|
def ratio
|
|
matches = get_matching_blocks.reduce(0) do |sum, triple|
|
|
sum + triple[-1]
|
|
end
|
|
Diff.calculate_ratio(matches, @a.length + @b.length)
|
|
end
|
|
|
|
def quick_ratio
|
|
if @fullbcount.nil? or @fullbcount.empty?
|
|
@fullbcount = {}
|
|
@b.each do |elt|
|
|
@fullbcount[elt] = (@fullbcount[elt] || 0) + 1
|
|
end
|
|
end
|
|
|
|
avail = {}
|
|
matches = 0
|
|
@a.each do |elt|
|
|
if avail.has_key? elt
|
|
numb = avail[elt]
|
|
else
|
|
numb = @fullbcount[elt] || 0
|
|
end
|
|
avail[elt] = numb - 1
|
|
if numb > 0
|
|
matches += 1
|
|
end
|
|
end
|
|
Diff.calculate_ratio matches, @a.length + @b.length
|
|
end
|
|
|
|
def real_quick_ratio
|
|
la, lb = @a.length, @b.length
|
|
Diff.calculate_ratio([la, lb].min, la + lb)
|
|
end
|
|
|
|
protected :chain_b, :match_block_helper
|
|
end # end class SequenceMatcher
|
|
|
|
def self.calculate_ratio(matches, length)
|
|
return 1.0 if length.zero?
|
|
2.0 * matches / length
|
|
end
|
|
|
|
# XXX: untested
|
|
def self.get_close_matches(word, possibilities, n=3, cutoff=0.6)
|
|
unless n > 0
|
|
raise "n must be > 0: #{n}"
|
|
end
|
|
unless 0.0 <= cutoff and cutoff <= 1.0
|
|
raise "cutoff must be in (0.0..1.0): #{cutoff}"
|
|
end
|
|
|
|
result = []
|
|
s = SequenceMatcher.new
|
|
s.set_seq_b word
|
|
possibilities.each do |x|
|
|
s.set_seq_a x
|
|
if s.real_quick_ratio >= cutoff and
|
|
s.quick_ratio >= cutoff and
|
|
s.ratio >= cutoff
|
|
result.push [s.ratio, x]
|
|
end
|
|
end
|
|
|
|
unless result.nil? or result.empty?
|
|
result.sort
|
|
result.reverse!
|
|
result = result[-n..-1]
|
|
end
|
|
result.collect { |score, x| x }
|
|
end
|
|
|
|
def self.count_leading(line, ch)
|
|
i, n = 0, line.length
|
|
while i < n and line[i].chr == ch
|
|
i += 1
|
|
end
|
|
i
|
|
end
|
|
end
|
|
|
|
|
|
module HTMLDiff
|
|
include Diff
|
|
class Builder
|
|
VALID_METHODS = [:replace, :insert, :delete, :equal]
|
|
def initialize(a, b)
|
|
@a = a
|
|
@b = b
|
|
@content = []
|
|
end
|
|
|
|
def do_op(opcode)
|
|
@opcode = opcode
|
|
op = @opcode[0]
|
|
VALID_METHODS.include?(op) or raise(NameError, "Invalid opcode #{op}")
|
|
self.method(op).call
|
|
end
|
|
|
|
def result
|
|
@content.join('')
|
|
end
|
|
|
|
#this methods have to be called via do_op(opcode) so that @opcode is set properly
|
|
private
|
|
|
|
def replace
|
|
delete("diffmod")
|
|
insert("diffmod")
|
|
end
|
|
|
|
def insert(tagclass="diffins")
|
|
op_helper("ins", tagclass, @b[@opcode[3]...@opcode[4]])
|
|
end
|
|
|
|
def delete(tagclass="diffdel")
|
|
op_helper("del", tagclass, @a[@opcode[1]...@opcode[2]])
|
|
end
|
|
|
|
def equal
|
|
@content += @b[@opcode[3]...@opcode[4]]
|
|
end
|
|
|
|
# using this as op_helper would be equivalent to the first version of diff.rb by Bill Atkins
|
|
def op_helper_simple(tagname, tagclass, to_add)
|
|
@content << "<#{tagname} class=\"#{tagclass}\">"
|
|
@content += to_add
|
|
@content << "</#{tagname}>"
|
|
end
|
|
|
|
# this tries to put <p> tags or newline chars before the opening diff tags (<ins> or <del>)
|
|
# or after the ending diff tags
|
|
# as a result the diff tags should be the "more inside" possible.
|
|
# this seems to work nice with html containing only paragraphs
|
|
# but not sure it works if there are other tags (div, span ... ? ) around
|
|
def op_helper(tagname, tagclass, to_add)
|
|
@content << to_add.shift while ( HTMLDiff.is_newline(to_add.first) or
|
|
HTMLDiff.is_p_close_tag(to_add.first) or
|
|
HTMLDiff.is_p_open_tag(to_add.first) )
|
|
@content << "<#{tagname} class=\"#{tagclass}\">"
|
|
@content += to_add
|
|
last_tags = []
|
|
last_tags.unshift(@content.pop) while ( HTMLDiff.is_newline(@content.last) or
|
|
HTMLDiff.is_p_close_tag(@content.last) or
|
|
HTMLDiff.is_p_open_tag(@content.last) )
|
|
last_tags.unshift "</#{tagname}>"
|
|
@content += last_tags
|
|
remove_empty_diff(tagname, tagclass)
|
|
end
|
|
|
|
def remove_empty_diff(tagname, tagclass)
|
|
if @content[-2] == "<#{tagname} class=\"#{tagclass}\">" and @content[-1] == "</#{tagname}>" then
|
|
@content.pop
|
|
@content.pop
|
|
end
|
|
end
|
|
|
|
end
|
|
|
|
def self.is_newline(x)
|
|
(x == "\n") or (x == "\r") or (x == "\t")
|
|
end
|
|
|
|
def self.is_p_open_tag(x)
|
|
x =~ /\A<(p|li|ul|ol|dir|dt|dl)/
|
|
end
|
|
|
|
def self.is_p_close_tag(x)
|
|
x =~ %r!\A</(p|li|ul|ol|dir|dt|dl)!
|
|
end
|
|
|
|
def self.diff(a, b)
|
|
a = html2list(a)
|
|
b = html2list(b)
|
|
|
|
out = Builder.new(a, b)
|
|
s = SequenceMatcher.new(a, b)
|
|
|
|
s.get_opcodes.each do |opcode|
|
|
out.do_op(opcode)
|
|
end
|
|
|
|
out.result
|
|
end
|
|
|
|
def self.html2list(x)
|
|
mode = :char
|
|
cur = ''
|
|
out = []
|
|
|
|
x.split('').each do |c|
|
|
if mode == :tag
|
|
cur += c
|
|
if c == '>'
|
|
out.push(cur)
|
|
cur = ''
|
|
mode = :char
|
|
end
|
|
elsif mode == :char
|
|
if c == '<'
|
|
out.push cur
|
|
cur = c
|
|
mode = :tag
|
|
elsif c =~ /\s/
|
|
out.push cur + c
|
|
cur = ''
|
|
else
|
|
cur += c
|
|
end
|
|
end
|
|
end
|
|
|
|
out.push cur
|
|
out.find_all { |x| x != '' }
|
|
end
|
|
|
|
end
|