zodbdump - Tool to dump content of a ZODB database (draft)

WARNING output format is not stable yet.

README.rst

@@ -9,3 +9,4 @@ scripts anymore. So we are here:
 __ https://github.com/zopefoundation/ZODB/pull/128#issuecomment-260970932
 
 - `zodbcmp` - compare content of two ZODB databases bit-to-bit.
+- `zodbdump` - dump content of a ZODB database.

setup.py

@@ -27,6 +27,7 @@ setup(
     # zodb dump ...
     entry_points= {'console_scripts': [
                         'zodbcmp    = zodbtool.zodbcmp:main',
+                        'zodbdump   = zodbtool.zodbdump:main',
                       ]
                   },
 

zodbtool/util.py

@@ -2,9 +2,16 @@
 # Copyright (C) 2016  Nexedi SA and Contributors.
 #                     Kirill Smelkov <kirr@nexedi.com>
 
+import hashlib
+
 def ashex(s):
     return s.encode('hex')
 
+def sha1(data):
+    m = hashlib.sha1()
+    m.update(data)
+    return m.digest()
+
 # something that is greater than everything else
 class Inf:
     def __cmp__(self, other):

zodbtool/zodbdump.py

+#!/usr/bin/env python
+# Copyright (C) 2016  Nexedi SA and Contributors.
+#                     Kirill Smelkov <kirr@nexedi.com>
+"""Zodbdump - Tool to dump content of a ZODB database
+
+TODO format     (WARNING dump format is not yet stable)
+
+txn <tid> (<status>)
+user <user|encode?>
+description <description|encode?>
+extension <extension|encode?>
+obj <oid> (delete | from <tid> | <sha1> <size> (LF <content>)?) LF     XXX do we really need back <tid>
+---- // ----
+LF
+txn ...
+
+"""
+
+from __future__ import print_function
+from zodbtool.util import ashex, sha1, txnobjv, parse_tidrange, TidRangeInvalid
+
+
+def zodbdump(stor, tidmin, tidmax, hashonly=False):
+    first = True
+
+    for txn in stor.iterator(tidmin, tidmax):
+        if not first:
+            print()
+        first = False
+
+        print('txn %s (%s)' % (ashex(txn.tid), txn.status))
+        print('user: %r' % (txn.user,))                    # XXX encode
+        print('description:', txn.description)      # XXX encode
+        print('extension:', txn.extension)          # XXX dict, encode
+
+        objv = txnobjv(txn)
+
+        for obj in objv:
+            entry = 'obj %s ' % ashex(obj.oid)
+            if obj.data is None:
+                entry += 'delete'
+
+            # was undo and data taken from obj.data_txn
+            elif obj.data_txn is not None:
+                entry += 'from %s' % ashex(obj.data_txn)
+
+            else:
+                entry += '%s %i' % (ashex(sha1(obj.data)), len(obj.data))
+                if not hashonly:
+                    entry += '\n'
+                    entry += obj.data
+
+            print(entry)
+
+
+# ----------------------------------------
+import ZODB.config
+import sys, getopt
+
+def usage(out):
+    print("""\
+Usage: zodbdump [OPTIONS] <storage> [tidmin..tidmax]
+Dump content of a ZODB database.
+
+<storage> is a file with ZConfig-based storage definition, e.g.
+
+    %import neo.client
+    <NEOStorage>
+        master_nodes    ...
+        name            ...
+    </NEOStorage>
+
+Options:
+
+        --hashonly  dump only hashes of objects without content
+    -h  --help      show this help
+""", file=out)
+
+def main():
+    hashonly = False
+
+    try:
+        optv, argv = getopt.getopt(sys.argv[1:], "h", ["help", "hashonly"])
+    except getopt.GetoptError as e:
+        print(e, file=sys.stderr)
+        usage(sys.stderr)
+        sys.exit(2)
+
+    for opt, _ in optv:
+        if opt in ("-h", "--help"):
+            usage(sys.stdout)
+            sys.exit(0)
+        if opt in ("--hashonly"):
+            hashonly = True
+
+    try:
+        storconf = argv[0]
+    except IndexError:
+        usage(sys.stderr)
+        sys.exit(2)
+
+    # parse tidmin..tidmax
+    tidmin = tidmax = None
+    if len(argv) > 1:
+        try:
+            tidmin, tidmax = parse_tidrange(argv[1])
+        except TidRangeInvalid as e:
+            print("E: invalid tidrange: %s" % e, file=sys.stderr)
+            sys.exit(2)
+
+    stor = ZODB.config.storageFromFile(open(storconf, 'r'))
+
+    zodbdump(stor, tidmin, tidmax, hashonly)
+
+if __name__ == '__main__':
+    main()