1 files changed, 118 insertions, 0 deletions
diff --git a/src/third_party/wiredtiger/lang/python/wiredtiger/fpacking.py b/src/third_party/wiredtiger/lang/python/wiredtiger/fpacking.py
new file mode 100644
index 00000000000..632c5c5a1c5
--- /dev/null
+++ b/src/third_party/wiredtiger/lang/python/wiredtiger/fpacking.py
@@ -0,0 +1,118 @@
+#!/usr/bin/env python
+#
+# Public Domain 2008-2014 WiredTiger, Inc.
+#
+# This is free and unencumbered software released into the public domain.
+#
+# Anyone is free to copy, modify, publish, use, compile, sell, or
+# distribute this software, either in source code form or as a compiled
+# binary, for any purpose, commercial or non-commercial, and by any
+# means.
+#
+# In jurisdictions that recognize copyright laws, the author or authors
+# of this software dedicate any and all copyright interest in the
+# software to the public domain. We make this dedication for the benefit
+# of the public at large and to the detriment of our heirs and
+# successors. We intend this dedication to be an overt act of
+# relinquishment in perpetuity of all present and future rights to this
+# software under copyright law.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+#
+# WiredTiger fixed-size packing and unpacking functions, using the Python
+# struct library.
+
+import struct
+
+def __wt2struct(fmt):
+    if not fmt:
+        return None, fmt
+    # Big endian with no alignment is the default
+    if fmt[0] in '@=<>!':
+        tfmt = fmt[0]
+        fmt = fmt[1:]
+    else:
+        tfmt = '>'
+    return tfmt, fmt.replace('r', 'Q')
+
+def unpack(fmt, s):
+    tfmt, fmt = __wt2struct(fmt)
+    if not fmt:
+        return ()
+    result = ()
+    pfmt = tfmt
+    sizebytes = 0
+    for offset, f in enumerate(fmt):
+        if f.isdigit():
+            sizebytes += 1
+        # With a fixed size, everything is encoded as a string
+        if f in 'Su' and sizebytes > 0:
+            f = 's'
+        if f not in 'Su':
+            pfmt += f
+            sizebytes = 0
+            continue
+
+        # We've hit something that needs special handling, split any fixed-size
+        # values we've already passed
+        if len(pfmt) > 1:
+            size = struct.calcsize(pfmt)
+            result += struct.unpack_from(pfmt, s)
+            s = s[size:]
+        if f == 'S':
+            l = s.find('\0')
+            result += (s[:l],)
+            s = s[l+1:]
+        if f == 'u':
+            if offset == len(fmt) - 1:
+                result += (s,)
+            else:
+                l = struct.unpack_from(tfmt + 'l', s)[0]
+                s = s[struct.calcsize(tfmt + 'l'):]
+                result += (s[:l],)
+                s = s[l:]
+        pfmt = tfmt
+        sizebytes = 0
+
+    if len(pfmt) > 1:
+        result += struct.unpack(pfmt, s)
+    return result
+
+def pack(fmt, *values):
+    pfmt, fmt = __wt2struct(fmt)
+    if not fmt:
+        return ''
+    i = sizebytes = 0
+    for offset, f in enumerate(fmt):
+        if f == 'S':
+            # Note: this code is being careful about embedded NUL characters
+            if sizebytes == 0:
+                l = values[i].find('\0') + 1
+                if not l:
+                    l = len(values[i]) + 1
+                pfmt += str(l)
+                sizebytes = len(str(l))
+            f = 's'
+        elif f == 'u':
+            if sizebytes == 0 and offset != len(fmt) - 1:
+                l = len(values[i])
+                pfmt += 'l' + str(l)
+                values = values[:i] + (l,) + values[i:]
+                sizebytes = len(str(l))
+            f = 's'
+        pfmt += f
+        if f.isdigit():
+            sizebytes += 1
+            continue
+        if f != 's' and sizebytes > 0:
+            i += int(pfmt[-sizebytes:])
+        else:
+            i += 1
+        sizebytes = 0
+    return struct.pack(pfmt, *values)