1 files changed, 112 insertions, 0 deletions
diff --git a/tests/debug.py b/tests/debug.py
new file mode 100755
index 0000000..f8c0484
--- /dev/null
+++ b/tests/debug.py
@@ -0,0 +1,112 @@
+#!/usr/bin/env python2
+
+import struct
+import binascii
+
+TYPES = {
+    (0x700, 0x400): 'splice',
+    (0x7ff, 0x401): 'create',
+    (0x7ff, 0x4ff): 'delete',
+    (0x700, 0x000): 'name',
+    (0x7ff, 0x001): 'name reg',
+    (0x7ff, 0x002): 'name dir',
+    (0x7ff, 0x0ff): 'name superblock',
+    (0x700, 0x200): 'struct',
+    (0x7ff, 0x200): 'struct dir',
+    (0x7ff, 0x202): 'struct ctz',
+    (0x7ff, 0x201): 'struct inline',
+    (0x700, 0x300): 'userattr',
+    (0x700, 0x600): 'tail',
+    (0x7ff, 0x600): 'tail soft',
+    (0x7ff, 0x601): 'tail hard',
+    (0x700, 0x700): 'gstate',
+    (0x7ff, 0x7ff): 'gstate move',
+    (0x700, 0x500): 'crc',
+}
+
+def typeof(type):
+    for prefix in range(12):
+        mask = 0x7ff & ~((1 << prefix)-1)
+        if (mask, type & mask) in TYPES:
+            return TYPES[mask, type & mask] + (
+                ' %0*x' % (prefix/4, type & ((1 << prefix)-1))
+                if prefix else '')
+    else:
+        return '%02x' % type
+
+def main(*blocks):
+    # find most recent block
+    file = None
+    rev = None
+    crc = None
+    versions = []
+
+    for block in blocks:
+        try:
+            nfile = open(block, 'rb')
+            ndata = nfile.read(4)
+            ncrc = binascii.crc32(ndata)
+            nrev, = struct.unpack('<I', ndata)
+
+            assert rev != nrev
+            if not file or ((rev - nrev) & 0x80000000):
+                file = nfile
+                rev = nrev
+                crc = ncrc
+
+            versions.append((nrev, '%s (rev %d)' % (block, nrev)))
+        except (IOError, struct.error):
+            pass
+
+    if not file:
+        print 'Bad metadata pair {%s}' % ', '.join(blocks)
+        return 1
+
+    print "--- %s ---" % ', '.join(v for _,v in sorted(versions, reverse=True))
+
+    # go through each tag, print useful information
+    print "%-4s  %-8s  %-14s  %3s %4s  %s" % (
+        'off', 'tag', 'type', 'id', 'len', 'dump')
+
+    tag = 0xffffffff
+    off = 4
+    while True:
+        try:
+            data = file.read(4)
+            crc = binascii.crc32(data, crc)
+            ntag, = struct.unpack('>I', data)
+        except struct.error:
+            break
+
+        tag ^= ntag
+        off += 4
+
+        type = (tag & 0x7ff00000) >> 20
+        id   = (tag & 0x000ffc00) >> 10
+        size = (tag & 0x000003ff) >> 0
+        iscrc = (type & 0x700) == 0x500
+
+        data = file.read(size if size != 0x3ff else 0)
+        if iscrc:
+            crc = binascii.crc32(data[:4], crc)
+        else:
+            crc = binascii.crc32(data, crc)
+
+        print '%04x: %08x  %-15s %3s %4s  %-23s  %-8s' % (
+            off, tag,
+            typeof(type) + (' bad!' if iscrc and ~crc else ''),
+            id if id != 0x3ff else '.',
+            size if size != 0x3ff else 'x',
+            ' '.join('%02x' % ord(c) for c in data[:8]),
+            ''.join(c if c >= ' ' and c <= '~' else '.' for c in data[:8]))
+
+        off += size if size != 0x3ff else 0
+        if iscrc:
+            crc = 0
+            tag ^= (type & 1) << 31
+
+    return 0
+
+if __name__ == "__main__":
+    import sys
+    sys.exit(main(*sys.argv[1:]))