Sources_For_Win/ParaView/Lib/site-packages/win32/Demos/BackupRead_BackupWrite.py

## demonstrates using BackupRead and BackupWrite to copy all of a file's data streams

import win32file, win32api, win32con, win32security, ntsecuritycon
from win32com import storagecon
import pythoncom, pywintypes
import struct, traceback
from pywin32_testutil import str2bytes, ob2memory

all_sd_info=win32security.DACL_SECURITY_INFORMATION|win32security.DACL_SECURITY_INFORMATION|   \
            win32security.OWNER_SECURITY_INFORMATION|win32security.GROUP_SECURITY_INFORMATION

tempdir=win32api.GetTempPath()
tempfile=win32api.GetTempFileName(tempdir,'bkr')[0]
outfile=win32api.GetTempFileName(tempdir,'out')[0]
print('Filename:',tempfile,'Output file:',outfile)

f=open(tempfile,'w')
f.write('some random junk'+'x'*100)
f.close()

## add a couple of alternate data streams
f=open(tempfile+':streamdata','w')
f.write('data written to alternate stream'+'y'*100)
f.close()

f=open(tempfile+':anotherstream','w')
f.write('z'*100)
f.close()

## add Summary Information, which is stored as a separate stream
m=storagecon.STGM_READWRITE | storagecon.STGM_SHARE_EXCLUSIVE |storagecon.STGM_DIRECT
pss=pythoncom.StgOpenStorageEx(tempfile, m, storagecon.STGFMT_FILE, 0 , pythoncom.IID_IPropertySetStorage,None)
ps=pss.Create(pythoncom.FMTID_SummaryInformation,pythoncom.IID_IPropertyStorage,0,storagecon.STGM_READWRITE|storagecon.STGM_SHARE_EXCLUSIVE)
ps.WriteMultiple((storagecon.PIDSI_KEYWORDS,storagecon.PIDSI_COMMENTS),('keywords','comments'))
ps=None
pss=None

## add a custom security descriptor to make sure we don't
##   get a default that would always be the same for both files in temp dir
new_sd=pywintypes.SECURITY_DESCRIPTOR()
sid=win32security.LookupAccountName('','EveryOne')[0]
acl=pywintypes.ACL()
acl.AddAccessAllowedAce(1, win32con.GENERIC_READ, sid)
acl.AddAccessAllowedAce(1, ntsecuritycon.FILE_APPEND_DATA, sid)
acl.AddAccessAllowedAce(1, win32con.GENERIC_WRITE, sid)
acl.AddAccessAllowedAce(1, ntsecuritycon.FILE_ALL_ACCESS, sid)

new_sd.SetSecurityDescriptorDacl(True, acl, False)
win32security.SetFileSecurity(tempfile,win32security.DACL_SECURITY_INFORMATION,new_sd)

                              
sa=pywintypes.SECURITY_ATTRIBUTES()
sa.bInheritHandle=True
h=win32file.CreateFile(tempfile, win32con.GENERIC_ALL ,win32con.FILE_SHARE_READ,
    sa, win32con.OPEN_EXISTING, win32file.FILE_FLAG_BACKUP_SEMANTICS , None)

outh=win32file.CreateFile(outfile, win32con.GENERIC_ALL ,win32con.FILE_SHARE_READ|win32con.FILE_SHARE_WRITE,
    sa, win32con.OPEN_EXISTING, win32file.FILE_FLAG_BACKUP_SEMANTICS , None)

ctxt=0
outctxt=0
buf=None
readsize=100

while 1:
    bytes_read, buf, ctxt=win32file.BackupRead(h, readsize, buf, False, True, ctxt)
    if bytes_read==0:
        break
    bytes_written, outctxt=win32file.BackupWrite(outh, bytes_read, buf, False, True, outctxt)
    print('Written:',bytes_written,'Context:',outctxt)
win32file.BackupRead(h, 0, buf, True, True, ctxt)
win32file.BackupWrite(outh, 0, str2bytes(''), True, True, outctxt)
win32file.CloseHandle(h)
win32file.CloseHandle(outh)

assert open(tempfile).read()==open(outfile).read(),"File contents differ !"
assert open(tempfile+':streamdata').read()==open(outfile+':streamdata').read(),"streamdata contents differ !"
assert open(tempfile+':anotherstream').read()==open(outfile+':anotherstream').read(),"anotherstream contents differ !"
assert ob2memory(win32security.GetFileSecurity(tempfile,all_sd_info))[:]== \
       ob2memory(win32security.GetFileSecurity(outfile, all_sd_info))[:], "Security descriptors are different !"
## also should check Summary Info programatically