contrib/hgdiff

templater: return data in increasing chunk sizes

Currently hgweb is not streaming its output -- it accumulates the
entire response before sending it. This patch restores streaming
behaviour. To avoid having to synchronously write many tiny fragments,
this patch also adds buffering to the template generator. Local
testing of a fetch of a 100,000 line file with wget produces a slight
slowdown overall (up from 6.5 seconds to 7.2 seconds), but instead of
waiting 6 seconds for headers to arrive, output begins immediately.

#!/usr/bin/env python

import os, sys, struct, stat
import difflib
import re
from optparse import OptionParser
from mercurial.bdiff import bdiff, blocks
from mercurial.mdiff import bunidiff, diffopts

VERSION="0.3"
usage = "usage: %prog [options] file1 file2"
parser = OptionParser(usage=usage)

parser.add_option("-d", "--difflib", action="store_true", default=False)
parser.add_option('-x', '--count', default=1)
parser.add_option('-c', '--context', type="int", default=3)
parser.add_option('-p', '--show-c-function', action="store_true", default=False)
parser.add_option('-w', '--ignore-all-space', action="store_true",
                  default=False)

(options, args) = parser.parse_args()

if not args:
    parser.print_help()
    sys.exit(1)

# simple utility function to put all the
# files from a directory tree into a dict
def buildlist(names, top):
    tlen = len(top)
    for root, dirs, files in os.walk(top):
        l = root[tlen + 1:]
        for x in files:
            p = os.path.join(root, x)
            st = os.lstat(p)
            if stat.S_ISREG(st.st_mode):
                names[os.path.join(l, x)] = (st.st_dev, st.st_ino)

def diff_files(file1, file2):
    if file1 == None:
        b = file(file2).read().splitlines(1)
        l1 = "--- %s\n" % (file2)
        l2 = "+++ %s\n" % (file2)
        l3 = "@@ -0,0 +1,%d @@\n" % len(b)
        l = [l1, l2, l3] + ["+" + e for e in b]
    elif file2 == None:
        a = file(file1).read().splitlines(1)
        l1 = "--- %s\n" % (file1)
        l2 = "+++ %s\n" % (file1)
        l3 = "@@ -1,%d +0,0 @@\n" % len(a)
        l = [l1, l2, l3] + ["-" + e for e in a]
    else:
        t1 = file(file1).read()
        t2 = file(file2).read()
        l1 = t1.splitlines(1)
        l2 = t2.splitlines(1)
        if options.difflib:
            l = difflib.unified_diff(l1, l2, file1, file2)
        else:
            l = bunidiff(t1, t2, l1, l2, file1, file2,
                         diffopts(context=options.context,
                                  showfunc=options.show_c_function,
                                  ignorews=options.ignore_all_space))
    for x in l:
        if x[-1] != '\n':
            x += "\n\ No newline at end of file\n"
        print x,

file1 = args[0]
file2 = args[1]

if os.path.isfile(file1) and os.path.isfile(file2):
    diff_files(file1, file2)
elif os.path.isdir(file1):
    if not os.path.isdir(file2):
        sys.stderr.write("file types don't match\n")
        sys.exit(1)

    d1 = {}
    d2 = {}

    buildlist(d1, file1)
    buildlist(d2, file2)
    keys = d1.keys()
    keys.sort()
    for x in keys:
        if x not in d2:
            f2 = None
        else:
            f2 = os.path.join(file2, x)
            st1 = d1[x]
            st2 = d2[x]
            del d2[x]
            if st1[0] == st2[0] and st1[1] == st2[1]:
                sys.stderr.write("%s is a hard link\n" % x)
                continue
        x = os.path.join(file1, x)
        diff_files(x, f2)
    keys = d2.keys()
    keys.sort()
    for x in keys:
        f1 = None
        x = os.path.join(file2, x)
        diff_files(f1, x)