From 7e265d284e352de7eb924b8883a452bb75bcb1bc Mon Sep 17 00:00:00 2001
From: Jonathan Dieter <jdieter@gmail.com>
Date: Mon, 7 Apr 2008 15:10:11 +0300
Subject: Show information on savings and put together a (not yet functioning)
 daemon to generate deltarpms

Signed-off-by: Jonathan Dieter <jdieter@gmail.com>
---
 presto-utils/deltasig.py | 103 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 presto-utils/deltasig.py

(limited to 'presto-utils/deltasig.py')

diff --git a/presto-utils/deltasig.py b/presto-utils/deltasig.py
new file mode 100644
index 0000000..d5a9b18
--- /dev/null
+++ b/presto-utils/deltasig.py
@@ -0,0 +1,103 @@
+#!/usr/bin/python -t
+
+import gzip
+import types
+import struct
+import sys
+from dumpMetadata import byteranges
+
+BUF_SIZE = 32768
+    
+
+def get_signature_from_file(sigfile):
+    f = open(sigfile, "r")
+    sig = f.read()
+    f.close()
+    return sig
+    
+def make_delta_from_sig(src_delta, sigfile, dst_delta):
+    # Open source deltarpm and read/write header
+    (range_start, range_end) = byteranges(src_delta)
+    
+    sfd = open(src_delta, "r")
+    dfd = open(dst_delta, "w")
+    
+    dfd.write(sfd.read(range_end))
+
+    # Switch to compressed mode
+    try:
+        scfd = gzip.GzipFile("", "rb", 9, sfd)
+    except:
+        raise zlibError("Data not stored in gzip format")
+
+    if scfd.read(4) != "DLT3":
+        raise Exception("Not a deltarpm")
+    
+    dcfd = gzip.GzipFile("", "wb", 9, dfd)
+    dcfd.write("DLT3")
+    
+    # Get nevr and write it
+    len_str     = scfd.read(4)
+    (length, )  = struct.unpack('>I', len_str)
+    nevr_length = len_str
+    nevr        = scfd.read(length)
+
+    dcfd.write("%s%s" % (nevr_length, nevr))
+    
+    # Read sequence and write it
+    len_str = scfd.read(4)
+    (length, ) = struct.unpack('>I', len_str)
+    dcfd.write(len_str + scfd.read(length))
+
+    # Read md5 and discard, replacing with \x00's.  New versions of deltarpm
+    # will see this and use the rpm's md5 checksum rather than this one.
+    scfd.read(16)
+    dcfd.write("\x00" * 16)
+    
+    # Read and write target size
+    dcfd.write(scfd.read(4))
+    
+    # Read and write other data
+    dcfd.write(scfd.read(12))
+    len_str = scfd.read(4)
+    (length, ) = struct.unpack('>I', len_str)
+    dcfd.write(len_str + scfd.read(length*2*4))
+    dcfd.write(scfd.read(4))
+    
+    # Read and write lead
+    dcfd.write(scfd.read(96))
+    
+    # Write signature from signature file and skip signature in src deltarpm
+    signature = get_signature_from_file(sigfile)
+    dcfd.write(signature)
+    
+    scfd.read(8)
+    binindex = scfd.read(4)
+    (sigindex, ) = struct.unpack('>I', binindex)
+    bindata = scfd.read(4)
+    (sigdata, ) = struct.unpack('>I', bindata)
+    # each index is 4 32bit segments - so each is 16 bytes
+    sigindexsize = sigindex * 16
+    sigsize = sigdata + sigindexsize
+    # we have to round off to the next 8 byte boundary
+    disttoboundary = (sigsize % 8)
+    if disttoboundary != 0:
+        disttoboundary = 8 - disttoboundary
+    scfd.read(sigsize + disttoboundary)
+    
+    data = scfd.read(BUF_SIZE)
+    while data != "":
+        dcfd.write(data)
+        data = scfd.read(BUF_SIZE)
+        
+def main():
+    if len(sys.argv) != 4:
+        print "Usage: %s <original deltarpm> <signature> <new deltarpm>" % sys.argv[0]
+        sys.exit(1)
+        
+    make_delta_from_sig(sys.argv[1], sys.argv[2], sys.argv[3])
+
+if __name__ == '__main__':
+    main()
+    
+
-- 
cgit