diff2html.py

#! /usr/bin/python
# coding=utf-8

import sys, re, htmlentitydefs, getopt, StringIO, codecs, datetime

# minimum line size, we add a zero-sized breakable space every
# LINESIZE characters
linesize = 20
tabsize = 8
show_CR = False
encoding = "utf-8"
lang = "en"
algorithm = 0

desc = "File comparison"
dtnow = datetime.datetime.now()
modified_date = "%s+01:00"%dtnow.isoformat()

DIFFON = "\x01"
DIFFOFF = "\x02"

buf = []
add_cpt, del_cpt = 0, 0
line1, line2 = 0, 0
hunk_off1, hunk_size1, hunk_off2, hunk_size2 = 0, 0, 0, 0


# Characters we're willing to word wrap on
WORDBREAK = " \t;.,/):-"


def sane(x):
    r = ""
    for i in x:
        j = ord(i)
        if i not in ['\t', '\n'] and (j < 32):
            r = r + " "
        else:
            r = r + i
    return r


def linediff(s, t):
    '''
    Original line diff algorithm of diff2html. It's character based.
    '''
    if len(s):
        s = unicode(reduce(lambda x, y:x+y, [ sane(c) for c in s ]))
    if len(t):
        t = unicode(reduce(lambda x, y:x+y, [ sane(c) for c in t ]))

    m, n = len(s), len(t)
    d = [[(0, 0) for i in range(n+1)] for i in range(m+1)]


    d[0][0] = (0, (0, 0))
    for i in range(m+1)[1:]:
        d[i][0] = (i,(i-1, 0))
    for j in range(n+1)[1:]:
        d[0][j] = (j,(0, j-1))

    for i in range(m+1)[1:]:
        for j in range(n+1)[1:]:
            if s[i-1] == t[j-1]:
                cost = 0
            else:
                cost = 1
            d[i][j] = min((d[i-1][j][0] + 1, (i-1, j)),
                          (d[i][j-1][0] + 1, (i, j-1)),
                          (d[i-1][j-1][0] + cost, (i-1, j-1)))

    l = []
    coord = (m, n)
    while coord != (0, 0):
        l.insert(0, coord)
        x, y = coord
        coord = d[x][y][1]

    l1 = []
    l2 = []

    for coord in l:
        cx, cy = coord
        child_val = d[cx][cy][0]

        father_coord = d[cx][cy][1]
        fx, fy = father_coord
        father_val = d[fx][fy][0]

        diff = (cx-fx, cy-fy)

        if diff == (0, 1):
            l1.append("")
            l2.append(DIFFON + t[fy] + DIFFOFF)
        elif diff == (1, 0):
            l1.append(DIFFON + s[fx] + DIFFOFF)
            l2.append("")
        elif child_val-father_val == 1:
            l1.append(DIFFON + s[fx] + DIFFOFF)
            l2.append(DIFFON + t[fy] + DIFFOFF)
        else:
            l1.append(s[fx])
            l2.append(t[fy])

    r1, r2 = (reduce(lambda x, y:x+y, l1), reduce(lambda x, y:x+y, l2))
    return r1, r2


def diff_changed(old, new):
    '''
    Returns the differences basend on characters between two strings
    wrapped with DIFFON and DIFFOFF using `diff`.
    '''
    con = {'=': (lambda x: x),
           '+': (lambda x: DIFFON + x + DIFFOFF),
           '-': (lambda x: '')}
    return "".join([(con[a])("".join(b)) for a, b in diff(old, new)])


def diff_changed_ts(old, new):
    '''
    Returns a tuple for a two sided comparison based on characters, see `diff_changed`.
    '''
    return (diff_changed(new, old), diff_changed(old, new))


def word_diff(old, new):
    '''
    Returns the difference between the old and new strings based on words. Punctuation is not part of the word.

    Params:
        old the old string
        new the new string

    Returns:
        the output of `diff` on the two strings after splitting them
        on whitespace (a list of change instructions; see the docstring
        of `diff`)
    '''
    separator_pattern = '(\W+)';
    return diff(re.split(separator_pattern, old, flags=re.UNICODE), re.split(separator_pattern, new, flags=re.UNICODE))


def diff_changed_words(old, new):
    '''
    Returns the difference between two strings based on words (see `word_diff`)
    wrapped with DIFFON and DIFFOFF.

    Returns:
        the output of the diff expressed delimited with DIFFON and DIFFOFF.
    '''
    con = {'=': (lambda x: x),
           '+': (lambda x: DIFFON + x + DIFFOFF),
           '-': (lambda x: '')}
    return "".join([(con[a])("".join(b)) for a, b in word_diff(old, new)])


def diff_changed_words_ts(old, new):
    '''
    Returns a tuple for a two sided comparison based on words, see `diff_changed_words`.
    '''
    return (diff_changed_words(new, old), diff_changed_words(old, new))


def convert(s, linesize=0, ponct=0):
    i = 0
    t = u""
    for c in s:
        # used by diffs
        if c == DIFFON:
            t += u'<span class="diffchanged2">'
        elif c == DIFFOFF:
            t += u"</span>"

        # special html chars
        elif htmlentitydefs.codepoint2name.has_key(ord(c)):
            t += u"&%s;" % (htmlentitydefs.codepoint2name[ord(c)])
            i += 1

        # special highlighted chars
        elif c == "\t" and ponct == 1:
            n = tabsize-(i%tabsize)
            if n == 0:
                n = tabsize
            t += (u'<span class="diffponct">&raquo;</span>'+'&nbsp;'*(n-1))
        #elif c == " " and ponct == 1:
        #    t += u'<span class="diffponct">&middot;</span>'
        elif c == "\n" and ponct == 1:
            if show_CR:
                t += u'<span class="diffponct">\</span>'
        else:
            t += c
            i += 1

        if linesize and (WORDBREAK.count(c) == 1):
            t += u'&#8203;'
            i = 0
        if linesize and i > linesize:
            i = 0
            t += u"&#8203;"

    return t


def add_collapsable(s, output_file):
    output_file.write(('<div class="diffmisc"><td colspan="4">%s</td>\n'%convert(s)).encode(encoding))


def add_newfile(output_file):
    output_file.write('<tr class="diffhunk"><td colspan="2">Null</td>')
    output_file.write('<td colspan="2"><font color="#880000" float="right">New</font></td></tr>\n')


def add_filename(output_file):
    output_file.write("<tr><th class='difftablehead' colspan='2'>修改前</th>")
    output_file.write("<th class='difftablehead' colspan='2'>修改后</th></tr>\n")


def add_hunk(output_file, show_hunk_infos):
    if show_hunk_infos:
        output_file.write('<tr class="diffhunk"><td colspan="2">Offset %d, %d lines modified</td>'%(hunk_off1, hunk_size1))
        output_file.write('<td colspan="2">Offset %d, %d lines modified</td></tr>\n'%(hunk_off2, hunk_size2))
    else:
        # &#8942; - vertical ellipsis
        output_file.write('<tr class="diffhunk"><td colspan="2">&#8942;</td><td colspan="2">&#8942;</td></tr>')


def add_line(s1, s2, output_file):
    global line1
    global line2

    orig1 = s1
    orig2 = s2

    if s1 == None and s2 == None:
        type_name = "unmodified"
    elif s1 == None or s1 == "":
        type_name = "added"
    elif s2 == None or s1 == "":
        type_name = "deleted"
    elif s1 == s2:
        type_name = "unmodified"
    else:
        type_name = "changed"
        if algorithm == 1:
            s1, s2 = diff_changed_words_ts(orig1, orig2)
        elif algorithm == 2:
            s1, s2 = diff_changed_ts(orig1, orig2)
        else: # default
            s1, s2 = linediff(orig1, orig2)

    output_file.write(('<tr class="diff%s">' % type_name).encode(encoding))
    if s1 != None and s1 != "":
        output_file.write(('<td class="diffline">%d </td>' % line1).encode(encoding))
        output_file.write('<td class="diffpresent">'.encode(encoding))
        output_file.write(convert(s1, linesize=linesize, ponct=1).encode(encoding))
        output_file.write('</td>')
    else:
        s1 = ""
        output_file.write('<td colspan="2"> </td>')

    if s2 != None and s2 != "":
        output_file.write(('<td class="diffline">%d </td>'%line2).encode(encoding))
        output_file.write('<td class="diffpresent">')
        output_file.write(convert(s2, linesize=linesize, ponct=1).encode(encoding))
        output_file.write('</td>')
    else:
        s2 = ""
        output_file.write('<td colspan="2"></td>')

    output_file.write('</tr>\n')

    if s1 != "":
        line1 += 1
    if s2 != "":
        line2 += 1


def empty_buffer(output_file):
    global buf
    global add_cpt
    global del_cpt

    if del_cpt == 0 or add_cpt == 0:
        for l in buf:
            add_line(l[0], l[1], output_file)

    elif del_cpt != 0 and add_cpt != 0:
        l0, l1 = [], []
        for l in buf:
            if l[0] != None:
                l0.append(l[0])
            if l[1] != None:
                l1.append(l[1])
        max_len = (len(l0) > len(l1)) and len(l0) or len(l1)
        for i in range(max_len):
            s0, s1 = "", ""
            if i < len(l0):
                s0 = l0[i]
            if i < len(l1):
                s1 = l1[i]
            add_line(s0, s1, output_file)

    add_cpt, del_cpt = 0, 0
    buf = []


def parse_input(input_file, output_file, input_file_name, output_file_name,
                show_hunk_infos):
    global add_cpt, del_cpt
    global line1, line2
    global hunk_off1, hunk_size1, hunk_off2, hunk_size2
    table_flag = False
    changefilenum = 0
    newfilenum = 0

    while True:
        l = input_file.readline()
        # input_file content must have no blank line
        if l == "":
            break

        m = re.match('^diff -ru\s+(\S+)\s+(\S+)', l)
        n = re.match('^Only in\s+(\S+):\s(\S+)', l)
        if m or n:
            empty_buffer(output_file)
            if m:
                changefilenum += 1
                filename = m.group(2)
            if n:
                newfilenum += 1
                filename = '/'.join(n.groups())
            if table_flag:
                output_file.write(('</table></div>').encode(encoding))
            else:
                table_flag = True
            add_collapsable(filename, output_file)
            output_file.write(('<table id="difftable%d" class="diff_exp_table">'%changefilenum).encode(encoding))
            if n:
                empty_buffer(output_file)
                add_filename(output_file)
                add_newfile(output_file)
            continue

            
        m = re.match('^--- ([^\s]*)', l)
        if m:
            empty_buffer(output_file)
            file1 = m.groups()[0]
            while True:
                l = input_file.readline()
                m = re.match('^\+\+\+ ([^\s]*)', l)
                if m:
                    file2 = m.groups()[0]
                    break
            add_filename(output_file)
            hunk_off1, hunk_size1, hunk_off2, hunk_size2 = 0, 0, 0, 0
            continue

        m = re.match("@@ -(\d+),?(\d*) \+(\d+),?(\d*)", l)
        if m:
            empty_buffer(output_file)
            hunk_data = map(lambda x:x=="" and 1 or int(x), m.groups())
            hunk_off1, hunk_size1, hunk_off2, hunk_size2 = hunk_data
            line1, line2 = hunk_off1, hunk_off2
            add_hunk(output_file, show_hunk_infos)
            continue

        if re.match("^\+", l):
            add_cpt += 1
            hunk_size2 -= 1
            buf.append((None, l[1:]))
            continue

        if re.match("^\-", l):
            del_cpt += 1
            hunk_size1 -= 1
            buf.append((l[1:], None))
            continue

        if re.match("^\ ", l) and hunk_size1 and hunk_size2:
            empty_buffer(output_file)
            hunk_size1 -= 1
            hunk_size2 -= 1
            buf.append((l[1:], l[1:]))
            continue

    empty_buffer(output_file)
    output_file.write(('</table></div>').encode(encoding))
    output_file.write(('<br /><div class="notemessage"><font color="#880000">NOTE:</font>').encode(encoding))
    output_file.write(('<br />----%d File(s) Are Changed.\n'%changefilenum).encode(encoding))
    output_file.write(('<br />----%d File(s) Are Added.</div>'%newfilenum).encode(encoding))

def parse_from_memory(txt, show_hunk_infos):
    " Parses diff from memory and returns a string with html "
    input_stream = StringIO.StringIO(txt)
    output_stream = StringIO.StringIO()
    parse_input(input_stream, output_stream, '', '', show_hunk_infos)
    return output_stream.getvalue()