From ffec10dff3839ae182cff3d9fff67ab3fe6165be Mon Sep 17 00:00:00 2001
From: jnothman <jnothman@student.usyd.edu.au>
Date: Fri, 21 Sep 2012 16:03:41 +1000
Subject: [PATCH 1/2] Expose packed stream with Unpacker.read_bytes()

At present, Unpacker buffers reading from the stream, meaning the stream can no longer be read directly. Unpacker.read_bytes(n) provides access to the underlying data, allowing content of known size to be read without unpacking.
---
 msgpack/_msgpack.pyx | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/msgpack/_msgpack.pyx b/msgpack/_msgpack.pyx
index c9f5e31..d7ea4b4 100644
--- a/msgpack/_msgpack.pyx
+++ b/msgpack/_msgpack.pyx
@@ -455,6 +455,18 @@ cdef class Unpacker(object):
             else:
                 raise ValueError("Unpack failed: error = %d" % (ret,))
 
+    def read_bytes(self, Py_ssize_t nbytes):
+        """read a specified number of raw bytes from the stream"""
+        cdef size_t nread
+        ret = ''
+        while len(ret) < nbytes and self.file_like is not None:
+            if self.buf_head == self.buf_tail:
+                self.fill_buffer()
+            nread = min(self.buf_tail - self.buf_head, nbytes - len(ret))
+            ret += PyBytes_FromStringAndSize(self.buf + self.buf_head, nread)
+            self.buf_head += nread
+        return ret
+
     def __iter__(self):
         return self
 

From e7c51d9089e9270ce197c00a6af1c60e45f36e97 Mon Sep 17 00:00:00 2001
From: Joel Nothman <joel.nothman@gmail.com>
Date: Sun, 23 Sep 2012 11:13:44 +1000
Subject: [PATCH 2/2] Cleaner read_bytes and a test case

No longer reads via buffer for unbuffered bytes
---
 msgpack/_msgpack.pyx   | 12 +++++-------
 test/test_sequnpack.py | 16 ++++++++++++++++
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/msgpack/_msgpack.pyx b/msgpack/_msgpack.pyx
index d7ea4b4..30fb9fc 100644
--- a/msgpack/_msgpack.pyx
+++ b/msgpack/_msgpack.pyx
@@ -458,13 +458,11 @@ cdef class Unpacker(object):
     def read_bytes(self, Py_ssize_t nbytes):
         """read a specified number of raw bytes from the stream"""
         cdef size_t nread
-        ret = ''
-        while len(ret) < nbytes and self.file_like is not None:
-            if self.buf_head == self.buf_tail:
-                self.fill_buffer()
-            nread = min(self.buf_tail - self.buf_head, nbytes - len(ret))
-            ret += PyBytes_FromStringAndSize(self.buf + self.buf_head, nread)
-            self.buf_head += nread
+        nread = min(self.buf_tail - self.buf_head, nbytes)
+        ret = PyBytes_FromStringAndSize(self.buf + self.buf_head, nread)
+        self.buf_head += nread
+        if len(ret) < nbytes and self.file_like is not None:
+            ret += self.file_like.read(nbytes - len(ret))
         return ret
 
     def __iter__(self):
diff --git a/test/test_sequnpack.py b/test/test_sequnpack.py
index b1b80b2..c763f40 100644
--- a/test/test_sequnpack.py
+++ b/test/test_sequnpack.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 # coding: utf-8
 
+import six
 from msgpack import Unpacker, BufferFull
 import nose
 
@@ -42,5 +43,20 @@ def test_maxbuffersize():
     assert ord('b') == next(unpacker)
 
 
+def test_readbytes():
+    unpacker = Unpacker(read_size=3)
+    unpacker.feed(b'foobar')
+    assert unpacker.unpack() == ord(b'f')
+    assert unpacker.read_bytes(3) == b'oob'
+    assert unpacker.unpack() == ord(b'a')
+    assert unpacker.unpack() == ord(b'r')
+
+    # Test buffer refill
+    unpacker = Unpacker(six.BytesIO(b'foobar'), read_size=3)
+    assert unpacker.unpack() == ord(b'f')
+    assert unpacker.read_bytes(3) == b'oob'
+    assert unpacker.unpack() == ord(b'a')
+    assert unpacker.unpack() == ord(b'r')
+
 if __name__ == '__main__':
     nose.main()