[gentoo-commits] proj/R_overlay:master commit in: roverlay/

["André Erdmann" <dywi@mailerd.de>]

commit:     ce623a4736308104f0c11e27c2e94feeda7bbb26
Author:     André Erdmann <dywi <AT> mailerd <DOT> de>
AuthorDate: Wed Jun 19 18:43:33 2013 +0000
Commit:     André Erdmann <dywi <AT> mailerd <DOT> de>
CommitDate: Wed Jun 19 18:43:33 2013 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/R_overlay.git;a=commit;h=ce623a47

roverlay/digest: support sha* and multihash mode

This commit adds support for sha1/sha256/sha512 (via hashlib) and whirlpool (via
portage.util).

It also adds the mulihash[_file]() function(s) that create more than one digest
at once.

---
 roverlay/digest.py | 89 +++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 82 insertions(+), 7 deletions(-)

diff --git a/roverlay/digest.py b/roverlay/digest.py
index 218f98c..983ca1a 100644
--- a/roverlay/digest.py
+++ b/roverlay/digest.py
@@ -11,23 +11,98 @@ __all__ = [ 'digest_compare', 'digest_supported',
 ]
 
 import hashlib
+import portage.util.whirlpool
 
-def md5sum_file ( fh, binary_digest=False ):
-   """Returns the md5 sum for an already opened file."""
-   md5 = hashlib.md5()
-   blocksize = 16384
+_HASH_CREATE_MAP = {
+   'md5'       : hashlib.md5,
+   'sha1'      : hashlib.sha1,
+   'sha256'    : hashlib.sha256,
+   'sha512'    : hashlib.sha512,
+   'whirlpool' : portage.util.whirlpool.new,
+}
 
+def _generic_obj_hash ( hashobj, fh, binary_digest=False, blocksize=16384 ):
    block = fh.read ( blocksize )
    while block:
-      md5.update ( block )
+      hashobj.update ( block )
       block = fh.read ( blocksize )
 
-   return md5.digest() if binary_digest else md5.hexdigest()
+   return hashobj.digest() if binary_digest else hashobj.hexdigest()
+# --- end of _hashsum_generic (...) ---
+
+def multihash ( fh, hashlist, binary_digest=False, blocksize=16384 ):
+   """Calculates multiple digests for an already openened file and returns the
+   resulting hashes as dict.
+
+   arguments:
+   * fh            -- file handle
+   * hashlist      -- iterable with hash names (e.g. md5)
+   * binary_digest -- whether the hashes should be binary or not
+   * blocksize     -- block size for reading
+   """
+   hashobj_dict = {
+      h: _HASH_CREATE_MAP[h]() for h in hashlist
+   }
+   block = fh.read ( blocksize )
+   while block:
+      for hashobj in hashobj_dict.values():
+         hashobj.update ( block )
+      block = fh.read ( blocksize )
+
+   if binary_digest:
+      return { h: hashobj.digest() for h, hashobj in hashobj_dict.items() }
+   else:
+      return { h: hashobj.hexdigest() for h, hashobj in hashobj_dict.items() }
+# --- end of multihash (...) ---
+
+def multihash_file ( filepath, digest_types, **kwargs ):
+   """Calculates multiple digests for the given file path.
+
+   Returns an empty dict if digest_types is empty.
+
+   arguments:
+   * filepath     --
+   * digest_types --
+   * **kwargs     -- passed to multihash()
+   """
+   if digest_types:
+      with open ( filepath, mode='rb' ) as fh:
+         hashdict = multihash ( fh, digest_types, **kwargs )
+      return hashdict
+   else:
+      return dict()
+# --- end of multihash_file (...) ---
+
+def md5sum_file ( fh, binary_digest=False ):
+   """Returns the md5 sum for an already opened file."""
+   return _generic_obj_hash ( hashlib.md5(), fh, binary_digest )
 # --- end of md5sum_file (...) ---
 
+def sha1_file ( fh, binary_digest=False ):
+   return _generic_obj_hash ( hashlib.sha1(), fh, binary_digest )
+# --- end of sha1_file (...) ---
+
+def sha256_file ( fh, binary_digest=False ):
+   return _generic_obj_hash ( hashlib.sha256(), fh, binary_digest )
+# --- end of sha256_file (...) ---
+
+def sha512_file ( fh, binary_digest=False ):
+   return _generic_obj_hash ( hashlib.sha512(), fh, binary_digest )
+# --- end of sha512_file (...) ---
+
+def whirlpool_file ( fh, binary_digest=False ):
+   return _generic_obj_hash (
+      portage.util.whirlpool.new(), fh, binary_digest
+   )
+# --- end of whirlpool_file (...) ---
 
+# TODO: remove
 _DIGEST_MAP = dict (
-   md5 = md5sum_file,
+   md5       = md5sum_file,
+   sha1      = sha1_file,
+   sha256    = sha256_file,
+   sha512    = sha512_file,
+   whirlpool = whirlpool_file,
 )
 
 def digest_supported ( digest_type ):