bpo-25007: Add copy protocol support to zlib compressors and decompressors (GH-7940)

Doc/library/zlib.rst

@@ -231,6 +231,11 @@ Compression objects support the following methods:
    compress a set of data that share a common initial prefix.
 
 
+.. versionchanged:: 3.8
+   Added :func:`copy.copy` and :func:`copy.deepcopy` support to compression
+   objects.
+
+
 Decompression objects support the following methods and attributes:
 
 
@@ -298,6 +303,11 @@ Decompression objects support the following methods and attributes:
    seeks into the stream at a future point.
 
 
+.. versionchanged:: 3.8
+   Added :func:`copy.copy` and :func:`copy.deepcopy` support to decompression
+   objects.
+
+
 Information about the version of the zlib library in use is available through
 the following constants:
 

Lib/test/test_zlib.py

 import unittest
 from test import support
 import binascii
+import copy
 import pickle
 import random
 import sys
@@ -626,23 +627,24 @@ class CompressObjectTestCase(BaseCompressTestCase, unittest.TestCase):
         # Test copying a compression object
         data0 = HAMLET_SCENE
         data1 = bytes(str(HAMLET_SCENE, "ascii").swapcase(), "ascii")
-        c0 = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
-        bufs0 = []
-        bufs0.append(c0.compress(data0))
+        for func in lambda c: c.copy(), copy.copy, copy.deepcopy:
+            c0 = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
+            bufs0 = []
+            bufs0.append(c0.compress(data0))
 
-        c1 = c0.copy()
-        bufs1 = bufs0[:]
+            c1 = func(c0)
+            bufs1 = bufs0[:]
 
-        bufs0.append(c0.compress(data0))
-        bufs0.append(c0.flush())
-        s0 = b''.join(bufs0)
+            bufs0.append(c0.compress(data0))
+            bufs0.append(c0.flush())
+            s0 = b''.join(bufs0)
 
-        bufs1.append(c1.compress(data1))
-        bufs1.append(c1.flush())
-        s1 = b''.join(bufs1)
+            bufs1.append(c1.compress(data1))
+            bufs1.append(c1.flush())
+            s1 = b''.join(bufs1)
 
-        self.assertEqual(zlib.decompress(s0),data0+data0)
-        self.assertEqual(zlib.decompress(s1),data0+data1)
+            self.assertEqual(zlib.decompress(s0),data0+data0)
+            self.assertEqual(zlib.decompress(s1),data0+data1)
 
     @requires_Compress_copy
     def test_badcompresscopy(self):
@@ -651,6 +653,8 @@ class CompressObjectTestCase(BaseCompressTestCase, unittest.TestCase):
         c.compress(HAMLET_SCENE)
         c.flush()
         self.assertRaises(ValueError, c.copy)
+        self.assertRaises(ValueError, copy.copy, c)
+        self.assertRaises(ValueError, copy.deepcopy, c)
 
     @requires_Decompress_copy
     def test_decompresscopy(self):
@@ -660,21 +664,22 @@ class CompressObjectTestCase(BaseCompressTestCase, unittest.TestCase):
         # Test type of return value
         self.assertIsInstance(comp, bytes)
 
-        d0 = zlib.decompressobj()
-        bufs0 = []
-        bufs0.append(d0.decompress(comp[:32]))
+        for func in lambda c: c.copy(), copy.copy, copy.deepcopy:
+            d0 = zlib.decompressobj()
+            bufs0 = []
+            bufs0.append(d0.decompress(comp[:32]))
 
-        d1 = d0.copy()
-        bufs1 = bufs0[:]
+            d1 = func(d0)
+            bufs1 = bufs0[:]
 
-        bufs0.append(d0.decompress(comp[32:]))
-        s0 = b''.join(bufs0)
+            bufs0.append(d0.decompress(comp[32:]))
+            s0 = b''.join(bufs0)
 
-        bufs1.append(d1.decompress(comp[32:]))
-        s1 = b''.join(bufs1)
+            bufs1.append(d1.decompress(comp[32:]))
+            s1 = b''.join(bufs1)
 
-        self.assertEqual(s0,s1)
-        self.assertEqual(s0,data)
+            self.assertEqual(s0,s1)
+            self.assertEqual(s0,data)
 
     @requires_Decompress_copy
     def test_baddecompresscopy(self):
@@ -684,6 +689,8 @@ class CompressObjectTestCase(BaseCompressTestCase, unittest.TestCase):
         d.decompress(data)
         d.flush()
         self.assertRaises(ValueError, d.copy)
+        self.assertRaises(ValueError, copy.copy, d)
+        self.assertRaises(ValueError, copy.deepcopy, d)
 
     def test_compresspickle(self):
         for proto in range(pickle.HIGHEST_PROTOCOL + 1):

Misc/NEWS.d/next/Library/2018-06-26-16-55-59.bpo-25007.6LQWOF.rst

+Add :func:`copy.copy` and :func:`copy.deepcopy` support to zlib compressors
+and decompressors.  Patch by Zackery Spytz.

Modules/clinic/zlibmodule.c.h

@@ -335,6 +335,39 @@ zlib_Compress_copy(compobject *self, PyObject *Py_UNUSED(ignored))
 
 #if defined(HAVE_ZLIB_COPY)
 
+PyDoc_STRVAR(zlib_Compress___copy____doc__,
+"__copy__($self, /)\n"
+"--\n"
+"\n");
+
+#define ZLIB_COMPRESS___COPY___METHODDEF    \
+    {"__copy__", (PyCFunction)zlib_Compress___copy__, METH_NOARGS, zlib_Compress___copy____doc__},
+
+static PyObject *
+zlib_Compress___copy___impl(compobject *self);
+
+static PyObject *
+zlib_Compress___copy__(compobject *self, PyObject *Py_UNUSED(ignored))
+{
+    return zlib_Compress___copy___impl(self);
+}
+
+#endif /* defined(HAVE_ZLIB_COPY) */
+
+#if defined(HAVE_ZLIB_COPY)
+
+PyDoc_STRVAR(zlib_Compress___deepcopy____doc__,
+"__deepcopy__($self, memo, /)\n"
+"--\n"
+"\n");
+
+#define ZLIB_COMPRESS___DEEPCOPY___METHODDEF    \
+    {"__deepcopy__", (PyCFunction)zlib_Compress___deepcopy__, METH_O, zlib_Compress___deepcopy____doc__},
+
+#endif /* defined(HAVE_ZLIB_COPY) */
+
+#if defined(HAVE_ZLIB_COPY)
+
 PyDoc_STRVAR(zlib_Decompress_copy__doc__,
 "copy($self, /)\n"
 "--\n"
@@ -355,6 +388,39 @@ zlib_Decompress_copy(compobject *self, PyObject *Py_UNUSED(ignored))
 
 #endif /* defined(HAVE_ZLIB_COPY) */
 
+#if defined(HAVE_ZLIB_COPY)
+
+PyDoc_STRVAR(zlib_Decompress___copy____doc__,
+"__copy__($self, /)\n"
+"--\n"
+"\n");
+
+#define ZLIB_DECOMPRESS___COPY___METHODDEF    \
+    {"__copy__", (PyCFunction)zlib_Decompress___copy__, METH_NOARGS, zlib_Decompress___copy____doc__},
+
+static PyObject *
+zlib_Decompress___copy___impl(compobject *self);
+
+static PyObject *
+zlib_Decompress___copy__(compobject *self, PyObject *Py_UNUSED(ignored))
+{
+    return zlib_Decompress___copy___impl(self);
+}
+
+#endif /* defined(HAVE_ZLIB_COPY) */
+
+#if defined(HAVE_ZLIB_COPY)
+
+PyDoc_STRVAR(zlib_Decompress___deepcopy____doc__,
+"__deepcopy__($self, memo, /)\n"
+"--\n"
+"\n");
+
+#define ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF    \
+    {"__deepcopy__", (PyCFunction)zlib_Decompress___deepcopy__, METH_O, zlib_Decompress___deepcopy____doc__},
+
+#endif /* defined(HAVE_ZLIB_COPY) */
+
 PyDoc_STRVAR(zlib_Decompress_flush__doc__,
 "flush($self, length=zlib.DEF_BUF_SIZE, /)\n"
 "--\n"
@@ -468,7 +534,23 @@ exit:
     #define ZLIB_COMPRESS_COPY_METHODDEF
 #endif /* !defined(ZLIB_COMPRESS_COPY_METHODDEF) */
 
+#ifndef ZLIB_COMPRESS___COPY___METHODDEF
+    #define ZLIB_COMPRESS___COPY___METHODDEF
+#endif /* !defined(ZLIB_COMPRESS___COPY___METHODDEF) */
+
+#ifndef ZLIB_COMPRESS___DEEPCOPY___METHODDEF
+    #define ZLIB_COMPRESS___DEEPCOPY___METHODDEF
+#endif /* !defined(ZLIB_COMPRESS___DEEPCOPY___METHODDEF) */
+
 #ifndef ZLIB_DECOMPRESS_COPY_METHODDEF
     #define ZLIB_DECOMPRESS_COPY_METHODDEF
 #endif /* !defined(ZLIB_DECOMPRESS_COPY_METHODDEF) */
-/*[clinic end generated code: output=43dd29b8977765f9 input=a9049054013a1b77]*/
+
+#ifndef ZLIB_DECOMPRESS___COPY___METHODDEF
+    #define ZLIB_DECOMPRESS___COPY___METHODDEF
+#endif /* !defined(ZLIB_DECOMPRESS___COPY___METHODDEF) */
+
+#ifndef ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF
+    #define ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF
+#endif /* !defined(ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF) */
+/*[clinic end generated code: output=d46c646770146ade input=a9049054013a1b77]*/

Modules/zlibmodule.c

@@ -984,6 +984,32 @@ error:
     return NULL;
 }
 
+/*[clinic input]
+zlib.Compress.__copy__
+[clinic start generated code]*/
+
+static PyObject *
+zlib_Compress___copy___impl(compobject *self)
+/*[clinic end generated code: output=1875e6791975442e input=be97a05a788dfd83]*/
+{
+    return zlib_Compress_copy_impl(self);
+}
+
+/*[clinic input]
+zlib.Compress.__deepcopy__
+
+    memo: object
+    /
+
+[clinic start generated code]*/
+
+static PyObject *
+zlib_Compress___deepcopy__(compobject *self, PyObject *memo)
+/*[clinic end generated code: output=f47a2213282c9eb0 input=a9a8b0b40d83388e]*/
+{
+    return zlib_Compress_copy_impl(self);
+}
+
 /*[clinic input]
 zlib.Decompress.copy
 
@@ -1039,6 +1065,33 @@ error:
     Py_XDECREF(retval);
     return NULL;
 }
+
+/*[clinic input]
+zlib.Decompress.__copy__
+[clinic start generated code]*/
+
+static PyObject *
+zlib_Decompress___copy___impl(compobject *self)
+/*[clinic end generated code: output=80bae8bc43498ad4 input=efcb98b5472c13d2]*/
+{
+    return zlib_Decompress_copy_impl(self);
+}
+
+/*[clinic input]
+zlib.Decompress.__deepcopy__
+
+    memo: object
+    /
+
+[clinic start generated code]*/
+
+static PyObject *
+zlib_Decompress___deepcopy__(compobject *self, PyObject *memo)
+/*[clinic end generated code: output=1f77286ab490124b input=6e99bd0ac4b9cd8b]*/
+{
+    return zlib_Decompress_copy_impl(self);
+}
+
 #endif
 
 /*[clinic input]
@@ -1139,6 +1192,8 @@ static PyMethodDef comp_methods[] =
     ZLIB_COMPRESS_COMPRESS_METHODDEF
     ZLIB_COMPRESS_FLUSH_METHODDEF
     ZLIB_COMPRESS_COPY_METHODDEF
+    ZLIB_COMPRESS___COPY___METHODDEF
+    ZLIB_COMPRESS___DEEPCOPY___METHODDEF
     {NULL, NULL}
 };
 
@@ -1147,6 +1202,8 @@ static PyMethodDef Decomp_methods[] =
     ZLIB_DECOMPRESS_DECOMPRESS_METHODDEF
     ZLIB_DECOMPRESS_FLUSH_METHODDEF
     ZLIB_DECOMPRESS_COPY_METHODDEF
+    ZLIB_DECOMPRESS___COPY___METHODDEF
+    ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF
     {NULL, NULL}
 };