Re: [gentoo-portage-dev] [PATCH] multiple hash functions

[Brian Harring]

On Wed, Nov 23, 2005 at 08:05:33PM +0100, Marius Mauch wrote:
> --- pym/portage_checksum.py	2005-11-13 14:55:16.000000000 +0100
> +++ pym/portage_checksum.py	2005-11-23 19:53:53.000000000 +0100
> @@ -4,7 +4,7 @@
>  # $Id: /var/cvsroot/gentoo-src/portage/pym/portage_checksum.py,v 1.10.2.2 2005/08/10 05:42:03 ferringb Exp $

+hashfuncs = {}

> -from portage_const import PRIVATE_PATH,PRELINK_BINARY
> +from portage_const import PRIVATE_PATH,PRELINK_BINARY,HASHING_BLOCKSIZE
>  import os
>  import shutil
>  import stat
> @@ -14,6 +14,42 @@
>  import commands
>  import sha
>
> +
> +# actual hash functions first
> +# We _try_ to load this module. If it fails we do the slightly slower fallback.
> +try:
> +	import fchksum
> +
> +	def md5hash(filename):
> +		return fchksum.fmd5t(filename)
> +
> +except ImportError:
> +	import md5
> +	def md5hash(filename):
> +		return pyhash(filename, md5)

+hashfuncs["md5"] = md5hash

> +def sha1hash(filename):
> +	return pyhash(filename, sha)

+hashfuncs["sha1"] = sha1hash

> +# Keep pycrypto optional for now, there are no internal fallbacks for these
> +try:
> +	import Crypto.Hash.SHA256
> +
> +	def sha256hash(filename):
> +		return pyhash(filename, Crypto.Hash.SHA256)

+	hashfuncs["sha256"] = sha256hash

> +except ImportError:
	pass
> +
> +try:
> +	import Crypto.Hash.RIPEMD
> +
> +	def rmd160hash(filename):
> +		return pyhash(filename, Crypto.Hash.RIPEMD)

+	hashfuncs["rmd160hash"] = rmd160hash

> +except ImportError:
	pass

> +# end actual hash functions
> +
>  prelink_capable = False
>  if os.path.exists(PRELINK_BINARY):
>  	results = commands.getstatusoutput(PRELINK_BINARY+" --version > /dev/null 2>&1")
> @@ -21,20 +57,29 @@
>  		prelink_capable=1
>  	del results
>

<snip>

Add the keys only if there is a func that can be used- list of 
required chksums is a config thing (and repoman thing during 
commiting), so I'm not seeing any reason to have None as a value in 
your hashfunc mapping...
~harring