IGNIETFERRO-1816 Update Python 3 from 3.9.12 to 3.10.4

ref:9f96be6d02ee8044fdd6f124b799b270c20ce641

1 files changed, 492 insertions, 321 deletions

diff --git a/contrib/tools/python3/src/Modules/zlibmodule.c b/contrib/tools/python3/src/Modules/zlibmodule.c
index 4dfd4ae6722..a6940f2fd43 100644
--- a/contrib/tools/python3/src/Modules/zlibmodule.c
+++ b/contrib/tools/python3/src/Modules/zlibmodule.c
@@ -9,11 +9,166 @@
 #include "structmember.h"         // PyMemberDef
 #include "zlib.h"
 
+// Blocks output buffer wrappers
+#include "pycore_blocks_output_buffer.h"
 
-#define ENTER_ZLIB(obj) \
-    Py_BEGIN_ALLOW_THREADS; \
-    PyThread_acquire_lock((obj)->lock, 1); \
-    Py_END_ALLOW_THREADS;
+#if OUTPUT_BUFFER_MAX_BLOCK_SIZE > UINT32_MAX
+    #error "The maximum block size accepted by zlib is UINT32_MAX."
+#endif
+
+/* On success, return value >= 0
+   On failure, return -1 */
+static inline Py_ssize_t
+OutputBuffer_InitAndGrow(_BlocksOutputBuffer *buffer, Py_ssize_t max_length,
+                         Bytef **next_out, uint32_t *avail_out)
+{
+    Py_ssize_t allocated;
+
+    allocated = _BlocksOutputBuffer_InitAndGrow(
+                    buffer, max_length, (void**) next_out);
+    *avail_out = (uint32_t) allocated;
+    return allocated;
+}
+
+/* On success, return value >= 0
+   On failure, return -1 */
+static inline Py_ssize_t
+OutputBuffer_Grow(_BlocksOutputBuffer *buffer,
+                  Bytef **next_out, uint32_t *avail_out)
+{
+    Py_ssize_t allocated;
+
+    allocated = _BlocksOutputBuffer_Grow(
+                    buffer, (void**) next_out, (Py_ssize_t) *avail_out);
+    *avail_out = (uint32_t) allocated;
+    return allocated;
+}
+
+static inline Py_ssize_t
+OutputBuffer_GetDataSize(_BlocksOutputBuffer *buffer, uint32_t avail_out)
+{
+    return _BlocksOutputBuffer_GetDataSize(buffer, (Py_ssize_t) avail_out);
+}
+
+static inline PyObject *
+OutputBuffer_Finish(_BlocksOutputBuffer *buffer, uint32_t avail_out)
+{
+    return _BlocksOutputBuffer_Finish(buffer, (Py_ssize_t) avail_out);
+}
+
+static inline void
+OutputBuffer_OnError(_BlocksOutputBuffer *buffer)
+{
+    _BlocksOutputBuffer_OnError(buffer);
+}
+
+/* The max buffer size accepted by zlib is UINT32_MAX, the initial buffer size
+   `init_size` may > it in 64-bit build. These wrapper functions maintain an
+   UINT32_MAX sliding window for the first block:
+    1. OutputBuffer_WindowInitWithSize()
+    2. OutputBuffer_WindowGrow()
+    3. OutputBuffer_WindowFinish()
+    4. OutputBuffer_WindowOnError()
+
+   ==== is the sliding window:
+    1. ====------
+           ^ next_posi, left_bytes is 6
+    2. ----====--
+               ^ next_posi, left_bytes is 2
+    3. --------==
+                 ^ next_posi, left_bytes is 0  */
+typedef struct {
+    Py_ssize_t left_bytes;
+    Bytef *next_posi;
+} _Uint32Window;
+
+/* Initialize the buffer with an initial buffer size.
+
+   On success, return value >= 0
+   On failure, return value < 0 */
+static inline Py_ssize_t
+OutputBuffer_WindowInitWithSize(_BlocksOutputBuffer *buffer, _Uint32Window *window,
+                                Py_ssize_t init_size,
+                                Bytef **next_out, uint32_t *avail_out)
+{
+    Py_ssize_t allocated = _BlocksOutputBuffer_InitWithSize(
+                               buffer, init_size, (void**) next_out);
+
+    if (allocated >= 0) {
+        // the UINT32_MAX sliding window
+        Py_ssize_t window_size = Py_MIN((size_t)allocated, UINT32_MAX);
+        *avail_out = (uint32_t) window_size;
+
+        window->left_bytes = allocated - window_size;
+        window->next_posi = *next_out + window_size;
+    }
+    return allocated;
+}
+
+/* Grow the buffer.
+
+   On success, return value >= 0
+   On failure, return value < 0 */
+static inline Py_ssize_t
+OutputBuffer_WindowGrow(_BlocksOutputBuffer *buffer, _Uint32Window *window,
+                        Bytef **next_out, uint32_t *avail_out)
+{
+    Py_ssize_t allocated;
+
+    /* ensure no gaps in the data.
+       if inlined, this check could be optimized away.*/
+    if (*avail_out != 0) {
+        PyErr_SetString(PyExc_SystemError,
+                        "*avail_out != 0 in OutputBuffer_WindowGrow().");
+        return -1;
+    }
+
+    // slide the UINT32_MAX sliding window
+    if (window->left_bytes > 0) {
+        Py_ssize_t window_size = Py_MIN((size_t)window->left_bytes, UINT32_MAX);
+
+        *next_out = window->next_posi;
+        *avail_out = (uint32_t) window_size;
+
+        window->left_bytes -= window_size;
+        window->next_posi += window_size;
+
+        return window_size;
+    }
+    assert(window->left_bytes == 0);
+
+    // only the first block may > UINT32_MAX
+    allocated = _BlocksOutputBuffer_Grow(
+                    buffer, (void**) next_out, (Py_ssize_t) *avail_out);
+    *avail_out = (uint32_t) allocated;
+    return allocated;
+}
+
+/* Finish the buffer.
+
+   On success, return a bytes object
+   On failure, return NULL */
+static inline PyObject *
+OutputBuffer_WindowFinish(_BlocksOutputBuffer *buffer, _Uint32Window *window,
+                          uint32_t avail_out)
+{
+    Py_ssize_t real_avail_out = (Py_ssize_t) avail_out + window->left_bytes;
+    return _BlocksOutputBuffer_Finish(buffer, real_avail_out);
+}
+
+static inline void
+OutputBuffer_WindowOnError(_BlocksOutputBuffer *buffer, _Uint32Window *window)
+{
+    _BlocksOutputBuffer_OnError(buffer);
+}
+
+
+#define ENTER_ZLIB(obj) do {                      \
+    if (!PyThread_acquire_lock((obj)->lock, 0)) { \
+        Py_BEGIN_ALLOW_THREADS                    \
+        PyThread_acquire_lock((obj)->lock, 1);    \
+        Py_END_ALLOW_THREADS                      \
+    } } while (0)
 #define LEAVE_ZLIB(obj) PyThread_release_lock((obj)->lock);
 
 #if defined(ZLIB_VERNUM) && ZLIB_VERNUM >= 0x1221
@@ -37,18 +192,16 @@ typedef struct {
     PyTypeObject *Comptype;
     PyTypeObject *Decomptype;
     PyObject *ZlibError;
-} _zlibstate;
+} zlibstate;
 
-static inline _zlibstate*
+static inline zlibstate*
 get_zlib_state(PyObject *module)
 {
     void *state = PyModule_GetState(module);
     assert(state != NULL);
-    return (_zlibstate *)state;
+    return (zlibstate *)state;
 }
 
-#define _zlibstate_global ((_zlibstate *)PyModule_GetState(PyState_FindModule(&zlibmodule)))
-
 typedef struct
 {
     PyObject_HEAD
@@ -62,7 +215,7 @@ typedef struct
 } compobject;
 
 static void
-zlib_error(z_stream zst, int err, const char *msg)
+zlib_error(zlibstate *state, z_stream zst, int err, const char *msg)
 {
     const char *zmsg = Z_NULL;
     /* In case of a version mismatch, zst.msg won't be initialized.
@@ -85,9 +238,9 @@ zlib_error(z_stream zst, int err, const char *msg)
         }
     }
     if (zmsg == Z_NULL)
-        PyErr_Format(_zlibstate_global->ZlibError, "Error %d %s", err, msg);
+        PyErr_Format(state->ZlibError, "Error %d %s", err, msg);
     else
-        PyErr_Format(_zlibstate_global->ZlibError, "Error %d %s: %.200s", err, msg, zmsg);
+        PyErr_Format(state->ZlibError, "Error %d %s: %.200s", err, msg, zmsg);
 }
 
 /*[clinic input]
@@ -149,56 +302,6 @@ arrange_input_buffer(z_stream *zst, Py_ssize_t *remains)
     *remains -= zst->avail_in;
 }
 
-static Py_ssize_t
-arrange_output_buffer_with_maximum(z_stream *zst, PyObject **buffer,
-                                   Py_ssize_t length,
-                                   Py_ssize_t max_length)
-{
-    Py_ssize_t occupied;
-
-    if (*buffer == NULL) {
-        if (!(*buffer = PyBytes_FromStringAndSize(NULL, length)))
-            return -1;
-        occupied = 0;
-    }
-    else {
-        occupied = zst->next_out - (Byte *)PyBytes_AS_STRING(*buffer);
-
-        if (length == occupied) {
-            Py_ssize_t new_length;
-            assert(length <= max_length);
-            /* can not scale the buffer over max_length */
-            if (length == max_length)
-                return -2;
-            if (length <= (max_length >> 1))
-                new_length = length << 1;
-            else
-                new_length = max_length;
-            if (_PyBytes_Resize(buffer, new_length) < 0)
-                return -1;
-            length = new_length;
-        }
-    }
-
-    zst->avail_out = (uInt)Py_MIN((size_t)(length - occupied), UINT_MAX);
-    zst->next_out = (Byte *)PyBytes_AS_STRING(*buffer) + occupied;
-
-    return length;
-}
-
-static Py_ssize_t
-arrange_output_buffer(z_stream *zst, PyObject **buffer, Py_ssize_t length)
-{
-    Py_ssize_t ret;
-
-    ret = arrange_output_buffer_with_maximum(zst, buffer, length,
-                                             PY_SSIZE_T_MAX);
-    if (ret == -2)
-        PyErr_NoMemory();
-
-    return ret;
-}
-
 /*[clinic input]
 zlib.compress
 
@@ -215,20 +318,25 @@ static PyObject *
 zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
 /*[clinic end generated code: output=d80906d73f6294c8 input=638d54b6315dbed3]*/
 {
-    PyObject *RetVal = NULL;
-    Byte *ibuf;
-    Py_ssize_t ibuflen, obuflen = DEF_BUF_SIZE;
-    int err, flush;
+    PyObject *RetVal;
+    int flush;
     z_stream zst;
+    _BlocksOutputBuffer buffer = {.list = NULL};
 
-    ibuf = data->buf;
-    ibuflen = data->len;
+    zlibstate *state = get_zlib_state(module);
+
+    Byte *ibuf = data->buf;
+    Py_ssize_t ibuflen = data->len;
+
+    if (OutputBuffer_InitAndGrow(&buffer, -1, &zst.next_out, &zst.avail_out) < 0) {
+        goto error;
+    }
 
     zst.opaque = NULL;
     zst.zalloc = PyZlib_Malloc;
     zst.zfree = PyZlib_Free;
     zst.next_in = ibuf;
-    err = deflateInit(&zst, level);
+    int err = deflateInit(&zst, level);
 
     switch (err) {
     case Z_OK:
@@ -238,11 +346,11 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
                         "Out of memory while compressing data");
         goto error;
     case Z_STREAM_ERROR:
-        PyErr_SetString(_zlibstate_global->ZlibError, "Bad compression level");
+        PyErr_SetString(state->ZlibError, "Bad compression level");
         goto error;
     default:
         deflateEnd(&zst);
-        zlib_error(zst, err, "while compressing data");
+        zlib_error(state, zst, err, "while compressing data");
         goto error;
     }
 
@@ -251,10 +359,11 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
         flush = ibuflen == 0 ? Z_FINISH : Z_NO_FLUSH;
 
         do {
-            obuflen = arrange_output_buffer(&zst, &RetVal, obuflen);
-            if (obuflen < 0) {
-                deflateEnd(&zst);
-                goto error;
+            if (zst.avail_out == 0) {
+                if (OutputBuffer_Grow(&buffer, &zst.next_out, &zst.avail_out) < 0) {
+                    deflateEnd(&zst);
+                    goto error;
+                }
             }
 
             Py_BEGIN_ALLOW_THREADS
@@ -263,7 +372,7 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
 
             if (err == Z_STREAM_ERROR) {
                 deflateEnd(&zst);
-                zlib_error(zst, err, "while compressing data");
+                zlib_error(state, zst, err, "while compressing data");
                 goto error;
             }
 
@@ -275,49 +384,19 @@ zlib_compress_impl(PyObject *module, Py_buffer *data, int level)
 
     err = deflateEnd(&zst);
     if (err == Z_OK) {
-        if (_PyBytes_Resize(&RetVal, zst.next_out -
-                            (Byte *)PyBytes_AS_STRING(RetVal)) < 0)
+        RetVal = OutputBuffer_Finish(&buffer, zst.avail_out);
+        if (RetVal == NULL) {
             goto error;
+        }
         return RetVal;
     }
     else
-        zlib_error(zst, err, "while finishing compression");
+        zlib_error(state, zst, err, "while finishing compression");
  error:
-    Py_XDECREF(RetVal);
+    OutputBuffer_OnError(&buffer);
     return NULL;
 }
 
-/*[python input]
-
-class ssize_t_converter(CConverter):
-    type = 'Py_ssize_t'
-    converter = 'ssize_t_converter'
-    c_ignored_default = "0"
-
-[python start generated code]*/
-/*[python end generated code: output=da39a3ee5e6b4b0d input=5f34ba1b394cb8e7]*/
-
-static int
-ssize_t_converter(PyObject *obj, void *ptr)
-{
-    PyObject *long_obj;
-    Py_ssize_t val;
-
-    /* XXX Should be replaced with PyNumber_AsSsize_t after the end of the
-       deprecation period. */
-    long_obj = _PyLong_FromNbIndexOrNbInt(obj);
-    if (long_obj == NULL) {
-        return 0;
-    }
-    val = PyLong_AsSsize_t(long_obj);
-    Py_DECREF(long_obj);
-    if (val == -1 && PyErr_Occurred()) {
-        return 0;
-    }
-    *(Py_ssize_t *)ptr = val;
-    return 1;
-}
-
 /*[clinic input]
 zlib.decompress
 
@@ -326,7 +405,7 @@ zlib.decompress
     /
     wbits: int(c_default="MAX_WBITS") = MAX_WBITS
         The window buffer size and container format.
-    bufsize: ssize_t(c_default="DEF_BUF_SIZE") = DEF_BUF_SIZE
+    bufsize: Py_ssize_t(c_default="DEF_BUF_SIZE") = DEF_BUF_SIZE
         The initial output buffer size.
 
 Returns a bytes object containing the uncompressed data.
@@ -335,13 +414,17 @@ Returns a bytes object containing the uncompressed data.
 static PyObject *
 zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
                      Py_ssize_t bufsize)
-/*[clinic end generated code: output=77c7e35111dc8c42 input=21960936208e9a5b]*/
+/*[clinic end generated code: output=77c7e35111dc8c42 input=a9ac17beff1f893f]*/
 {
-    PyObject *RetVal = NULL;
+    PyObject *RetVal;
     Byte *ibuf;
     Py_ssize_t ibuflen;
     int err, flush;
     z_stream zst;
+    _BlocksOutputBuffer buffer = {.list = NULL};
+    _Uint32Window window;  // output buffer's UINT32_MAX sliding window
+
+    zlibstate *state = get_zlib_state(module);
 
     if (bufsize < 0) {
         PyErr_SetString(PyExc_ValueError, "bufsize must be non-negative");
@@ -350,6 +433,11 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
         bufsize = 1;
     }
 
+    if (OutputBuffer_WindowInitWithSize(&buffer, &window, bufsize,
+                                        &zst.next_out, &zst.avail_out) < 0) {
+        goto error;
+    }
+
     ibuf = data->buf;
     ibuflen = data->len;
 
@@ -369,7 +457,7 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
         goto error;
     default:
         inflateEnd(&zst);
-        zlib_error(zst, err, "while preparing to decompress data");
+        zlib_error(state, zst, err, "while preparing to decompress data");
         goto error;
     }
 
@@ -378,10 +466,12 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
         flush = ibuflen == 0 ? Z_FINISH : Z_NO_FLUSH;
 
         do {
-            bufsize = arrange_output_buffer(&zst, &RetVal, bufsize);
-            if (bufsize < 0) {
-                inflateEnd(&zst);
-                goto error;
+            if (zst.avail_out == 0) {
+                if (OutputBuffer_WindowGrow(&buffer, &window,
+                                            &zst.next_out, &zst.avail_out) < 0) {
+                    inflateEnd(&zst);
+                    goto error;
+                }
             }
 
             Py_BEGIN_ALLOW_THREADS
@@ -400,7 +490,7 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
                 goto error;
             default:
                 inflateEnd(&zst);
-                zlib_error(zst, err, "while decompressing data");
+                zlib_error(state, zst, err, "while decompressing data");
                 goto error;
             }
 
@@ -411,24 +501,23 @@ zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,
 
     if (err != Z_STREAM_END) {
         inflateEnd(&zst);
-        zlib_error(zst, err, "while decompressing data");
+        zlib_error(state, zst, err, "while decompressing data");
         goto error;
     }
 
     err = inflateEnd(&zst);
     if (err != Z_OK) {
-        zlib_error(zst, err, "while finishing decompression");
+        zlib_error(state, zst, err, "while finishing decompression");
         goto error;
     }
 
-    if (_PyBytes_Resize(&RetVal, zst.next_out -
-                        (Byte *)PyBytes_AS_STRING(RetVal)) < 0)
-        goto error;
-
-    return RetVal;
+    RetVal = OutputBuffer_WindowFinish(&buffer, &window, zst.avail_out);
+    if (RetVal != NULL) {
+        return RetVal;
+    }
 
  error:
-    Py_XDECREF(RetVal);
+    OutputBuffer_WindowOnError(&buffer, &window);
     return NULL;
 }
 
@@ -465,16 +554,14 @@ zlib_compressobj_impl(PyObject *module, int level, int method, int wbits,
                       int memLevel, int strategy, Py_buffer *zdict)
 /*[clinic end generated code: output=8b5bed9c8fc3814d input=2fa3d026f90ab8d5]*/
 {
-    compobject *self = NULL;
-    int err;
-
+    zlibstate *state = get_zlib_state(module);
     if (zdict->buf != NULL && (size_t)zdict->len > UINT_MAX) {
         PyErr_SetString(PyExc_OverflowError,
                         "zdict length does not fit in an unsigned int");
-        goto error;
+        return NULL;
     }
 
-    self = newcompobject(_zlibstate_global->Comptype);
+    compobject *self = newcompobject(state->Comptype);
     if (self == NULL)
         goto error;
     self->zst.opaque = NULL;
@@ -482,7 +569,7 @@ zlib_compressobj_impl(PyObject *module, int level, int method, int wbits,
     self->zst.zfree = PyZlib_Free;
     self->zst.next_in = NULL;
     self->zst.avail_in = 0;
-    err = deflateInit2(&self->zst, level, method, wbits, memLevel, strategy);
+    int err = deflateInit2(&self->zst, level, method, wbits, memLevel, strategy);
     switch (err) {
     case Z_OK:
         self->is_initialised = 1;
@@ -510,7 +597,7 @@ zlib_compressobj_impl(PyObject *module, int level, int method, int wbits,
         PyErr_SetString(PyExc_ValueError, "Invalid initialization option");
         goto error;
     default:
-        zlib_error(self->zst, err, "while creating compression object");
+        zlib_error(state, self->zst, err, "while creating compression object");
         goto error;
     }
 
@@ -521,11 +608,9 @@ zlib_compressobj_impl(PyObject *module, int level, int method, int wbits,
 }
 
 static int
-set_inflate_zdict(compobject *self)
+set_inflate_zdict(zlibstate *state, compobject *self)
 {
     Py_buffer zdict_buf;
-    int err;
-
     if (PyObject_GetBuffer(self->zdict, &zdict_buf, PyBUF_SIMPLE) == -1) {
         return -1;
     }
@@ -535,11 +620,12 @@ set_inflate_zdict(compobject *self)
         PyBuffer_Release(&zdict_buf);
         return -1;
     }
+    int err;
     err = inflateSetDictionary(&self->zst,
                                zdict_buf.buf, (unsigned int)zdict_buf.len);
     PyBuffer_Release(&zdict_buf);
     if (err != Z_OK) {
-        zlib_error(self->zst, err, "while setting zdict");
+        zlib_error(state, self->zst, err, "while setting zdict");
         return -1;
     }
     return 0;
@@ -561,8 +647,7 @@ static PyObject *
 zlib_decompressobj_impl(PyObject *module, int wbits, PyObject *zdict)
 /*[clinic end generated code: output=3069b99994f36906 input=d3832b8511fc977b]*/
 {
-    int err;
-    compobject *self;
+    zlibstate *state = get_zlib_state(module);
 
     if (zdict != NULL && !PyObject_CheckBuffer(zdict)) {
         PyErr_SetString(PyExc_TypeError,
@@ -570,7 +655,7 @@ zlib_decompressobj_impl(PyObject *module, int wbits, PyObject *zdict)
         return NULL;
     }
 
-    self = newcompobject(_zlibstate_global->Decomptype);
+    compobject *self = newcompobject(state->Decomptype);
     if (self == NULL)
         return NULL;
     self->zst.opaque = NULL;
@@ -582,18 +667,18 @@ zlib_decompressobj_impl(PyObject *module, int wbits, PyObject *zdict)
         Py_INCREF(zdict);
         self->zdict = zdict;
     }
-    err = inflateInit2(&self->zst, wbits);
+    int err = inflateInit2(&self->zst, wbits);
     switch (err) {
     case Z_OK:
         self->is_initialised = 1;
         if (self->zdict != NULL && wbits < 0) {
 #ifdef AT_LEAST_ZLIB_1_2_2_1
-            if (set_inflate_zdict(self) < 0) {
+            if (set_inflate_zdict(state, self) < 0) {
                 Py_DECREF(self);
                 return NULL;
             }
 #else
-            PyErr_Format(_zlibstate_global->ZlibError,
+            PyErr_Format(state->ZlibError,
                          "zlib version %s does not allow raw inflate with dictionary",
                          ZLIB_VERSION);
             Py_DECREF(self);
@@ -611,7 +696,7 @@ zlib_decompressobj_impl(PyObject *module, int wbits, PyObject *zdict)
                         "Can't allocate memory for decompression object");
         return NULL;
     default:
-        zlib_error(self->zst, err, "while creating decompression object");
+        zlib_error(state, self->zst, err, "while creating decompression object");
         Py_DECREF(self);
         return NULL;
     }
@@ -625,7 +710,7 @@ Dealloc(compobject *self)
     Py_XDECREF(self->unused_data);
     Py_XDECREF(self->unconsumed_tail);
     Py_XDECREF(self->zdict);
-    PyObject_Del(self);
+    PyObject_Free(self);
     Py_DECREF(type);
 }
 
@@ -648,6 +733,7 @@ Decomp_dealloc(compobject *self)
 /*[clinic input]
 zlib.Compress.compress
 
+    cls: defining_class
     data: Py_buffer
         Binary data to be compressed.
     /
@@ -660,32 +746,40 @@ Call the flush() method to clear these buffers.
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Compress_compress_impl(compobject *self, Py_buffer *data)
-/*[clinic end generated code: output=5d5cd791cbc6a7f4 input=0d95908d6e64fab8]*/
+zlib_Compress_compress_impl(compobject *self, PyTypeObject *cls,
+                            Py_buffer *data)
+/*[clinic end generated code: output=6731b3f0ff357ca6 input=04d00f65ab01d260]*/
 {
-    PyObject *RetVal = NULL;
-    Py_ssize_t ibuflen, obuflen = DEF_BUF_SIZE;
+    PyObject *RetVal;
     int err;
+    _BlocksOutputBuffer buffer = {.list = NULL};
+    zlibstate *state = PyType_GetModuleState(cls);
 
     ENTER_ZLIB(self);
 
     self->zst.next_in = data->buf;
-    ibuflen = data->len;
+    Py_ssize_t ibuflen = data->len;
+
+    if (OutputBuffer_InitAndGrow(&buffer, -1, &self->zst.next_out, &self->zst.avail_out) < 0) {
+        goto error;
+    }
 
     do {
         arrange_input_buffer(&self->zst, &ibuflen);
 
         do {
-            obuflen = arrange_output_buffer(&self->zst, &RetVal, obuflen);
-            if (obuflen < 0)
-                goto error;
+            if (self->zst.avail_out == 0) {
+                if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
+                    goto error;
+                }
+            }
 
             Py_BEGIN_ALLOW_THREADS
             err = deflate(&self->zst, Z_NO_FLUSH);
             Py_END_ALLOW_THREADS
 
             if (err == Z_STREAM_ERROR) {
-                zlib_error(self->zst, err, "while compressing data");
+                zlib_error(state, self->zst, err, "while compressing data");
                 goto error;
             }
 
@@ -694,12 +788,14 @@ zlib_Compress_compress_impl(compobject *self, Py_buffer *data)
 
     } while (ibuflen != 0);
 
-    if (_PyBytes_Resize(&RetVal, self->zst.next_out -
-                        (Byte *)PyBytes_AS_STRING(RetVal)) == 0)
+    RetVal = OutputBuffer_Finish(&buffer, self->zst.avail_out);
+    if (RetVal != NULL) {
         goto success;
+    }
 
  error:
-    Py_CLEAR(RetVal);
+    OutputBuffer_OnError(&buffer);
+    RetVal = NULL;
  success:
     LEAVE_ZLIB(self);
     return RetVal;
@@ -753,10 +849,11 @@ save_unconsumed_input(compobject *self, Py_buffer *data, int err)
 /*[clinic input]
 zlib.Decompress.decompress
 
+    cls: defining_class
     data: Py_buffer
         The binary data to decompress.
     /
-    max_length: ssize_t = 0
+    max_length: Py_ssize_t = 0
         The maximum allowable length of the decompressed data.
         Unconsumed input data will be stored in
         the unconsumed_tail attribute.
@@ -769,45 +866,47 @@ Call the flush() method to clear these buffers.
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Decompress_decompress_impl(compobject *self, Py_buffer *data,
-                                Py_ssize_t max_length)
-/*[clinic end generated code: output=6e5173c74e710352 input=b85a212a012b770a]*/
+zlib_Decompress_decompress_impl(compobject *self, PyTypeObject *cls,
+                                Py_buffer *data, Py_ssize_t max_length)
+/*[clinic end generated code: output=b024a93c2c922d57 input=bfb37b3864cfb606]*/
 {
     int err = Z_OK;
-    Py_ssize_t ibuflen, obuflen = DEF_BUF_SIZE, hard_limit;
-    PyObject *RetVal = NULL;
+    Py_ssize_t ibuflen;
+    PyObject *RetVal;
+    _BlocksOutputBuffer buffer = {.list = NULL};
+
+    PyObject *module = PyType_GetModule(cls);
+    if (module == NULL)
+        return NULL;
 
+    zlibstate *state = get_zlib_state(module);
     if (max_length < 0) {
         PyErr_SetString(PyExc_ValueError, "max_length must be non-negative");
         return NULL;
-    } else if (max_length == 0)
-        hard_limit = PY_SSIZE_T_MAX;
-    else
-        hard_limit = max_length;
+    } else if (max_length == 0) {
+        max_length = -1;
+    }
 
     ENTER_ZLIB(self);
 
     self->zst.next_in = data->buf;
     ibuflen = data->len;
 
-    /* limit amount of data allocated to max_length */
-    if (max_length && obuflen > max_length)
-        obuflen = max_length;
+    if (OutputBuffer_InitAndGrow(&buffer, max_length, &self->zst.next_out, &self->zst.avail_out) < 0) {
+        goto abort;
+    }
 
     do {
         arrange_input_buffer(&self->zst, &ibuflen);
 
         do {
-            obuflen = arrange_output_buffer_with_maximum(&self->zst, &RetVal,
-                                                         obuflen, hard_limit);
-            if (obuflen == -2) {
-                if (max_length > 0) {
+            if (self->zst.avail_out == 0) {
+                if (OutputBuffer_GetDataSize(&buffer, self->zst.avail_out) == max_length) {
                     goto save;
                 }
-                PyErr_NoMemory();
-            }
-            if (obuflen < 0) {
-                goto abort;
+                if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
+                    goto abort;
+                }
             }
 
             Py_BEGIN_ALLOW_THREADS
@@ -821,8 +920,9 @@ zlib_Decompress_decompress_impl(compobject *self, Py_buffer *data,
                 break;
             default:
                 if (err == Z_NEED_DICT && self->zdict != NULL) {
-                    if (set_inflate_zdict(self) < 0)
+                    if (set_inflate_zdict(state, self) < 0) {
                         goto abort;
+                    }
                     else
                         break;
                 }
@@ -846,16 +946,18 @@ zlib_Decompress_decompress_impl(compobject *self, Py_buffer *data,
            but there wasn't more output when we tried again, so it is
            not an error condition.
         */
-        zlib_error(self->zst, err, "while decompressing data");
+        zlib_error(state, self->zst, err, "while decompressing data");
         goto abort;
     }
 
-    if (_PyBytes_Resize(&RetVal, self->zst.next_out -
-                        (Byte *)PyBytes_AS_STRING(RetVal)) == 0)
+    RetVal = OutputBuffer_Finish(&buffer, self->zst.avail_out);
+    if (RetVal != NULL) {
         goto success;
+    }
 
  abort:
-    Py_CLEAR(RetVal);
+    OutputBuffer_OnError(&buffer);
+    RetVal = NULL;
  success:
     LEAVE_ZLIB(self);
     return RetVal;
@@ -864,6 +966,7 @@ zlib_Decompress_decompress_impl(compobject *self, Py_buffer *data,
 /*[clinic input]
 zlib.Compress.flush
 
+    cls: defining_class
     mode: int(c_default="Z_FINISH") = zlib.Z_FINISH
         One of the constants Z_SYNC_FLUSH, Z_FULL_FLUSH, Z_FINISH.
         If mode == Z_FINISH, the compressor object can no longer be
@@ -875,13 +978,14 @@ Return a bytes object containing any remaining compressed data.
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Compress_flush_impl(compobject *self, int mode)
-/*[clinic end generated code: output=a203f4cefc9de727 input=73ed066794bd15bc]*/
+zlib_Compress_flush_impl(compobject *self, PyTypeObject *cls, int mode)
+/*[clinic end generated code: output=c7efd13efd62add2 input=286146e29442eb6c]*/
 {
     int err;
-    Py_ssize_t length = DEF_BUF_SIZE;
-    PyObject *RetVal = NULL;
+    PyObject *RetVal;
+    _BlocksOutputBuffer buffer = {.list = NULL};
 
+    zlibstate *state = PyType_GetModuleState(cls);
     /* Flushing with Z_NO_FLUSH is a no-op, so there's no point in
        doing any work at all; just return an empty string. */
     if (mode == Z_NO_FLUSH) {
@@ -892,11 +996,15 @@ zlib_Compress_flush_impl(compobject *self, int mode)
 
     self->zst.avail_in = 0;
 
+    if (OutputBuffer_InitAndGrow(&buffer, -1, &self->zst.next_out, &self->zst.avail_out) < 0) {
+        goto error;
+    }
+
     do {
-        length = arrange_output_buffer(&self->zst, &RetVal, length);
-        if (length < 0) {
-            Py_CLEAR(RetVal);
-            goto error;
+        if (self->zst.avail_out == 0) {
+            if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {
+                goto error;
+            }
         }
 
         Py_BEGIN_ALLOW_THREADS
@@ -904,8 +1012,7 @@ zlib_Compress_flush_impl(compobject *self, int mode)
         Py_END_ALLOW_THREADS
 
         if (err == Z_STREAM_ERROR) {
-            zlib_error(self->zst, err, "while flushing");
-            Py_CLEAR(RetVal);
+            zlib_error(state, self->zst, err, "while flushing");
             goto error;
         }
     } while (self->zst.avail_out == 0);
@@ -917,8 +1024,7 @@ zlib_Compress_flush_impl(compobject *self, int mode)
     if (err == Z_STREAM_END && mode == Z_FINISH) {
         err = deflateEnd(&self->zst);
         if (err != Z_OK) {
-            zlib_error(self->zst, err, "while finishing compression");
-            Py_CLEAR(RetVal);
+            zlib_error(state, self->zst, err, "while finishing compression");
             goto error;
         }
         else
@@ -929,16 +1035,19 @@ zlib_Compress_flush_impl(compobject *self, int mode)
            not an error condition.
         */
     } else if (err != Z_OK && err != Z_BUF_ERROR) {
-        zlib_error(self->zst, err, "while flushing");
-        Py_CLEAR(RetVal);
+        zlib_error(state, self->zst, err, "while flushing");
         goto error;
     }
 
-    if (_PyBytes_Resize(&RetVal, self->zst.next_out -
-                        (Byte *)PyBytes_AS_STRING(RetVal)) < 0)
-        Py_CLEAR(RetVal);
+    RetVal = OutputBuffer_Finish(&buffer, self->zst.avail_out);
+    if (RetVal != NULL) {
+        goto success;
+    }
 
- error:
+error:
+    OutputBuffer_OnError(&buffer);
+    RetVal = NULL;
+success:
     LEAVE_ZLIB(self);
     return RetVal;
 }
@@ -948,24 +1057,25 @@ zlib_Compress_flush_impl(compobject *self, int mode)
 /*[clinic input]
 zlib.Compress.copy
 
+    cls: defining_class
+
 Return a copy of the compression object.
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Compress_copy_impl(compobject *self)
-/*[clinic end generated code: output=5144aa153c21e805 input=c656351f94b82718]*/
+zlib_Compress_copy_impl(compobject *self, PyTypeObject *cls)
+/*[clinic end generated code: output=c4d2cfb4b0d7350b input=235497e482d40986]*/
 {
-    compobject *retval = NULL;
-    int err;
+    zlibstate *state = PyType_GetModuleState(cls);
 
-    retval = newcompobject(_zlibstate_global->Comptype);
+    compobject *retval = newcompobject(state->Comptype);
     if (!retval) return NULL;
 
     /* Copy the zstream state
      * We use ENTER_ZLIB / LEAVE_ZLIB to make this thread-safe
      */
     ENTER_ZLIB(self);
-    err = deflateCopy(&retval->zst, &self->zst);
+    int err = deflateCopy(&retval->zst, &self->zst);
     switch (err) {
     case Z_OK:
         break;
@@ -977,7 +1087,7 @@ zlib_Compress_copy_impl(compobject *self)
                         "Can't allocate memory for compression object");
         goto error;
     default:
-        zlib_error(self->zst, err, "while copying compression object");
+        zlib_error(state, self->zst, err, "while copying compression object");
         goto error;
     }
     Py_INCREF(self->unused_data);
@@ -1002,51 +1112,57 @@ error:
 
 /*[clinic input]
 zlib.Compress.__copy__
+
+    cls: defining_class
+
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Compress___copy___impl(compobject *self)
-/*[clinic end generated code: output=1875e6791975442e input=be97a05a788dfd83]*/
+zlib_Compress___copy___impl(compobject *self, PyTypeObject *cls)
+/*[clinic end generated code: output=074613db332cb668 input=5c0188367ab0fe64]*/
 {
-    return zlib_Compress_copy_impl(self);
+    return zlib_Compress_copy_impl(self, cls);
 }
 
 /*[clinic input]
 zlib.Compress.__deepcopy__
 
+    cls: defining_class
     memo: object
     /
 
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Compress___deepcopy__(compobject *self, PyObject *memo)
-/*[clinic end generated code: output=f47a2213282c9eb0 input=a9a8b0b40d83388e]*/
+zlib_Compress___deepcopy___impl(compobject *self, PyTypeObject *cls,
+                                PyObject *memo)
+/*[clinic end generated code: output=24b3aed785f54033 input=c90347319a514430]*/
 {
-    return zlib_Compress_copy_impl(self);
+    return zlib_Compress_copy_impl(self, cls);
 }
 
 /*[clinic input]
 zlib.Decompress.copy
 
+    cls: defining_class
+
 Return a copy of the decompression object.
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Decompress_copy_impl(compobject *self)
-/*[clinic end generated code: output=02a883a2a510c8cc input=ba6c3e96712a596b]*/
+zlib_Decompress_copy_impl(compobject *self, PyTypeObject *cls)
+/*[clinic end generated code: output=a7ddc016e1d0a781 input=20ef3aa208282ff2]*/
 {
-    compobject *retval = NULL;
-    int err;
+    zlibstate *state = PyType_GetModuleState(cls);
 
-    retval = newcompobject(_zlibstate_global->Decomptype);
+    compobject *retval = newcompobject(state->Decomptype);
     if (!retval) return NULL;
 
     /* Copy the zstream state
      * We use ENTER_ZLIB / LEAVE_ZLIB to make this thread-safe
      */
     ENTER_ZLIB(self);
-    err = inflateCopy(&retval->zst, &self->zst);
+    int err = inflateCopy(&retval->zst, &self->zst);
     switch (err) {
     case Z_OK:
         break;
@@ -1058,7 +1174,7 @@ zlib_Decompress_copy_impl(compobject *self)
                         "Can't allocate memory for decompression object");
         goto error;
     default:
-        zlib_error(self->zst, err, "while copying decompression object");
+        zlib_error(state, self->zst, err, "while copying decompression object");
         goto error;
     }
 
@@ -1084,28 +1200,33 @@ error:
 
 /*[clinic input]
 zlib.Decompress.__copy__
+
+    cls: defining_class
+
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Decompress___copy___impl(compobject *self)
-/*[clinic end generated code: output=80bae8bc43498ad4 input=efcb98b5472c13d2]*/
+zlib_Decompress___copy___impl(compobject *self, PyTypeObject *cls)
+/*[clinic end generated code: output=cf1e6473744f53fa input=cc3143067b622bdf]*/
 {
-    return zlib_Decompress_copy_impl(self);
+    return zlib_Decompress_copy_impl(self, cls);
 }
 
 /*[clinic input]
 zlib.Decompress.__deepcopy__
 
+    cls: defining_class
     memo: object
     /
 
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Decompress___deepcopy__(compobject *self, PyObject *memo)
-/*[clinic end generated code: output=1f77286ab490124b input=6e99bd0ac4b9cd8b]*/
+zlib_Decompress___deepcopy___impl(compobject *self, PyTypeObject *cls,
+                                  PyObject *memo)
+/*[clinic end generated code: output=34f7b719a0c0d51b input=fc13b9c58622544e]*/
 {
-    return zlib_Decompress_copy_impl(self);
+    return zlib_Decompress_copy_impl(self, cls);
 }
 
 #endif
@@ -1113,7 +1234,8 @@ zlib_Decompress___deepcopy__(compobject *self, PyObject *memo)
 /*[clinic input]
 zlib.Decompress.flush
 
-    length: ssize_t(c_default="DEF_BUF_SIZE") = zlib.DEF_BUF_SIZE
+    cls: defining_class
+    length: Py_ssize_t(c_default="DEF_BUF_SIZE") = zlib.DEF_BUF_SIZE
         the initial size of the output buffer.
     /
 
@@ -1121,13 +1243,23 @@ Return a bytes object containing any remaining decompressed data.
 [clinic start generated code]*/
 
 static PyObject *
-zlib_Decompress_flush_impl(compobject *self, Py_ssize_t length)
-/*[clinic end generated code: output=68c75ea127cbe654 input=aa4ec37f3aef4da0]*/
+zlib_Decompress_flush_impl(compobject *self, PyTypeObject *cls,
+                           Py_ssize_t length)
+/*[clinic end generated code: output=4532fc280bd0f8f2 input=42f1f4b75230e2cd]*/
 {
     int err, flush;
     Py_buffer data;
-    PyObject *RetVal = NULL;
+    PyObject *RetVal;
     Py_ssize_t ibuflen;
+    _BlocksOutputBuffer buffer = {.list = NULL};
+    _Uint32Window window;  // output buffer's UINT32_MAX sliding window
+
+    PyObject *module = PyType_GetModule(cls);
+    if (module == NULL) {
+        return NULL;
+    }
+
+    zlibstate *state = get_zlib_state(module);
 
     if (length <= 0) {
         PyErr_SetString(PyExc_ValueError, "length must be greater than zero");
@@ -1144,14 +1276,22 @@ zlib_Decompress_flush_impl(compobject *self, Py_ssize_t length)
     self->zst.next_in = data.buf;
     ibuflen = data.len;
 
+    if (OutputBuffer_WindowInitWithSize(&buffer, &window, length,
+                                        &self->zst.next_out, &self->zst.avail_out) < 0) {
+        goto abort;
+    }
+
     do {
         arrange_input_buffer(&self->zst, &ibuflen);
         flush = ibuflen == 0 ? Z_FINISH : Z_NO_FLUSH;
 
         do {
-            length = arrange_output_buffer(&self->zst, &RetVal, length);
-            if (length < 0)
-                goto abort;
+            if (self->zst.avail_out == 0) {
+                if (OutputBuffer_WindowGrow(&buffer, &window,
+                                            &self->zst.next_out, &self->zst.avail_out) < 0) {
+                    goto abort;
+                }
+            }
 
             Py_BEGIN_ALLOW_THREADS
             err = inflate(&self->zst, flush);
@@ -1164,8 +1304,9 @@ zlib_Decompress_flush_impl(compobject *self, Py_ssize_t length)
                 break;
             default:
                 if (err == Z_NEED_DICT && self->zdict != NULL) {
-                    if (set_inflate_zdict(self) < 0)
+                    if (set_inflate_zdict(state, self) < 0) {
                         goto abort;
+                    }
                     else
                         break;
                 }
@@ -1177,8 +1318,9 @@ zlib_Decompress_flush_impl(compobject *self, Py_ssize_t length)
     } while (err != Z_STREAM_END && ibuflen != 0);
 
  save:
-    if (save_unconsumed_input(self, &data, err) < 0)
+    if (save_unconsumed_input(self, &data, err) < 0) {
         goto abort;
+    }
 
     /* If at end of stream, clean up any memory allocated by zlib. */
     if (err == Z_STREAM_END) {
@@ -1186,17 +1328,19 @@ zlib_Decompress_flush_impl(compobject *self, Py_ssize_t length)
         self->is_initialised = 0;
         err = inflateEnd(&self->zst);
         if (err != Z_OK) {
-            zlib_error(self->zst, err, "while finishing decompression");
+            zlib_error(state, self->zst, err, "while finishing decompression");
             goto abort;
         }
     }
 
-    if (_PyBytes_Resize(&RetVal, self->zst.next_out -
-                        (Byte *)PyBytes_AS_STRING(RetVal)) == 0)
+    RetVal = OutputBuffer_WindowFinish(&buffer, &window, self->zst.avail_out);
+    if (RetVal != NULL) {
         goto success;
+    }
 
  abort:
-    Py_CLEAR(RetVal);
+    OutputBuffer_WindowOnError(&buffer, &window);
+    RetVal = NULL;
  success:
     PyBuffer_Release(&data);
     LEAVE_ZLIB(self);
@@ -1332,11 +1476,10 @@ static PyType_Slot Comptype_slots[] = {
 };
 
 static PyType_Spec Comptype_spec = {
-    "zlib.Compress",
-    sizeof(compobject),
-    0,
-    Py_TPFLAGS_DEFAULT,
-    Comptype_slots
+    .name = "zlib.Compress",
+    .basicsize = sizeof(compobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
+    .slots= Comptype_slots,
 };
 
 static PyType_Slot Decomptype_slots[] = {
@@ -1347,11 +1490,10 @@ static PyType_Slot Decomptype_slots[] = {
 };
 
 static PyType_Spec Decomptype_spec = {
-    "zlib.Decompress",
-    sizeof(compobject),
-    0,
-    Py_TPFLAGS_DEFAULT,
-    Decomptype_slots
+    .name = "zlib.Decompress",
+    .basicsize = sizeof(compobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
+    .slots = Decomptype_slots,
 };
 
 PyDoc_STRVAR(zlib_module_documentation,
@@ -1370,9 +1512,9 @@ PyDoc_STRVAR(zlib_module_documentation,
 "objects support decompress() and flush().");
 
 static int
-zlib_clear(PyObject *m)
+zlib_clear(PyObject *mod)
 {
-    _zlibstate *state = get_zlib_state(m);
+    zlibstate *state = get_zlib_state(mod);
     Py_CLEAR(state->Comptype);
     Py_CLEAR(state->Decomptype);
     Py_CLEAR(state->ZlibError);
@@ -1380,9 +1522,9 @@ zlib_clear(PyObject *m)
 }
 
 static int
-zlib_traverse(PyObject *m, visitproc visit, void *arg)
+zlib_traverse(PyObject *mod, visitproc visit, void *arg)
 {
-    _zlibstate *state = get_zlib_state(m);
+    zlibstate *state = get_zlib_state(mod);
     Py_VISIT(state->Comptype);
     Py_VISIT(state->Decomptype);
     Py_VISIT(state->ZlibError);
@@ -1390,93 +1532,122 @@ zlib_traverse(PyObject *m, visitproc visit, void *arg)
 }
 
 static void
-zlib_free(void *m)
+zlib_free(void *mod)
 {
-    zlib_clear((PyObject *)m);
+    zlib_clear((PyObject *)mod);
 }
 
-static struct PyModuleDef zlibmodule = {
-        PyModuleDef_HEAD_INIT,
-        "zlib",
-        zlib_module_documentation,
-        sizeof(_zlibstate),
-        zlib_methods,
-        NULL,
-        zlib_traverse,
-        zlib_clear,
-        zlib_free,
-};
-
-PyMODINIT_FUNC
-PyInit_zlib(void)
+static int
+zlib_exec(PyObject *mod)
 {
-    PyObject *m, *ver;
-    m = PyState_FindModule(&zlibmodule);
-    if (m != NULL) {
-        Py_INCREF(m);
-        return m;
+    zlibstate *state = get_zlib_state(mod);
+
+    state->Comptype = (PyTypeObject *)PyType_FromModuleAndSpec(
+        mod, &Comptype_spec, NULL);
+    if (state->Comptype == NULL) {
+        return -1;
     }
-    m = PyModule_Create(&zlibmodule);
-    if (m == NULL)
-        return NULL;
 
-    PyTypeObject *Comptype = (PyTypeObject *)PyType_FromSpec(&Comptype_spec);
-    if (Comptype == NULL)
-        return NULL;
-    get_zlib_state(m)->Comptype = Comptype;
+    state->Decomptype = (PyTypeObject *)PyType_FromModuleAndSpec(
+        mod, &Decomptype_spec, NULL);
+    if (state->Decomptype == NULL) {
+        return -1;
+    }
 
-    PyTypeObject *Decomptype = (PyTypeObject *)PyType_FromSpec(&Decomptype_spec);
-    if (Decomptype == NULL)
-        return NULL;
-    get_zlib_state(m)->Decomptype = Decomptype;
+    state->ZlibError = PyErr_NewException("zlib.error", NULL, NULL);
+    if (state->ZlibError == NULL) {
+        return -1;
+    }
 
-    PyObject *ZlibError = PyErr_NewException("zlib.error", NULL, NULL);
-    if (ZlibError != NULL) {
-        Py_INCREF(ZlibError);
-        PyModule_AddObject(m, "error", ZlibError);
-        get_zlib_state(m)->ZlibError = ZlibError;
+    Py_INCREF(state->ZlibError);
+    if (PyModule_AddObject(mod, "error", state->ZlibError) < 0) {
+        Py_DECREF(state->ZlibError);
+        return -1;
     }
-    PyModule_AddIntMacro(m, MAX_WBITS);
-    PyModule_AddIntMacro(m, DEFLATED);
-    PyModule_AddIntMacro(m, DEF_MEM_LEVEL);
-    PyModule_AddIntMacro(m, DEF_BUF_SIZE);
+
+#define ZLIB_ADD_INT_MACRO(c)                           \
+    do {                                                \
+        if ((PyModule_AddIntConstant(mod, #c, c)) < 0) {  \
+            return -1;                                  \
+        }                                               \
+    } while(0)
+
+    ZLIB_ADD_INT_MACRO(MAX_WBITS);
+    ZLIB_ADD_INT_MACRO(DEFLATED);
+    ZLIB_ADD_INT_MACRO(DEF_MEM_LEVEL);
+    ZLIB_ADD_INT_MACRO(DEF_BUF_SIZE);
     // compression levels
-    PyModule_AddIntMacro(m, Z_NO_COMPRESSION);
-    PyModule_AddIntMacro(m, Z_BEST_SPEED);
-    PyModule_AddIntMacro(m, Z_BEST_COMPRESSION);
-    PyModule_AddIntMacro(m, Z_DEFAULT_COMPRESSION);
+    ZLIB_ADD_INT_MACRO(Z_NO_COMPRESSION);
+    ZLIB_ADD_INT_MACRO(Z_BEST_SPEED);
+    ZLIB_ADD_INT_MACRO(Z_BEST_COMPRESSION);
+    ZLIB_ADD_INT_MACRO(Z_DEFAULT_COMPRESSION);
     // compression strategies
-    PyModule_AddIntMacro(m, Z_FILTERED);
-    PyModule_AddIntMacro(m, Z_HUFFMAN_ONLY);
+    ZLIB_ADD_INT_MACRO(Z_FILTERED);
+    ZLIB_ADD_INT_MACRO(Z_HUFFMAN_ONLY);
 #ifdef Z_RLE // 1.2.0.1
-    PyModule_AddIntMacro(m, Z_RLE);
+    ZLIB_ADD_INT_MACRO(Z_RLE);
 #endif
 #ifdef Z_FIXED // 1.2.2.2
-    PyModule_AddIntMacro(m, Z_FIXED);
+    ZLIB_ADD_INT_MACRO(Z_FIXED);
 #endif
-    PyModule_AddIntMacro(m, Z_DEFAULT_STRATEGY);
+    ZLIB_ADD_INT_MACRO(Z_DEFAULT_STRATEGY);
     // allowed flush values
-    PyModule_AddIntMacro(m, Z_NO_FLUSH);
-    PyModule_AddIntMacro(m, Z_PARTIAL_FLUSH);
-    PyModule_AddIntMacro(m, Z_SYNC_FLUSH);
-    PyModule_AddIntMacro(m, Z_FULL_FLUSH);
-    PyModule_AddIntMacro(m, Z_FINISH);
+    ZLIB_ADD_INT_MACRO(Z_NO_FLUSH);
+    ZLIB_ADD_INT_MACRO(Z_PARTIAL_FLUSH);
+    ZLIB_ADD_INT_MACRO(Z_SYNC_FLUSH);
+    ZLIB_ADD_INT_MACRO(Z_FULL_FLUSH);
+    ZLIB_ADD_INT_MACRO(Z_FINISH);
 #ifdef Z_BLOCK // 1.2.0.5 for inflate, 1.2.3.4 for deflate
-    PyModule_AddIntMacro(m, Z_BLOCK);
+    ZLIB_ADD_INT_MACRO(Z_BLOCK);
 #endif
 #ifdef Z_TREES // 1.2.3.4, only for inflate
-    PyModule_AddIntMacro(m, Z_TREES);
+    ZLIB_ADD_INT_MACRO(Z_TREES);
 #endif
-    ver = PyUnicode_FromString(ZLIB_VERSION);
-    if (ver != NULL)
-        PyModule_AddObject(m, "ZLIB_VERSION", ver);
+    PyObject *ver = PyUnicode_FromString(ZLIB_VERSION);
+    if (ver == NULL) {
+        return -1;
+    }
+
+    if (PyModule_AddObject(mod, "ZLIB_VERSION", ver) < 0) {
+        Py_DECREF(ver);
+        return -1;
+    }
 
     ver = PyUnicode_FromString(zlibVersion());
-    if (ver != NULL)
-        PyModule_AddObject(m, "ZLIB_RUNTIME_VERSION", ver);
+    if (ver == NULL) {
+        return -1;
+    }
+
+    if (PyModule_AddObject(mod, "ZLIB_RUNTIME_VERSION", ver) < 0) {
+        Py_DECREF(ver);
+        return -1;
+    }
 
-    PyModule_AddStringConstant(m, "__version__", "1.0");
+    if (PyModule_AddStringConstant(mod, "__version__", "1.0") < 0) {
+        return -1;
+    }
+    return 0;
+}
+
+static PyModuleDef_Slot zlib_slots[] = {
+    {Py_mod_exec, zlib_exec},
+    {0, NULL}
+};
 
-    PyState_AddModule(m, &zlibmodule);
-    return m;
+static struct PyModuleDef zlibmodule = {
+    PyModuleDef_HEAD_INIT,
+    .m_name = "zlib",
+    .m_doc = zlib_module_documentation,
+    .m_size = sizeof(zlibstate),
+    .m_methods = zlib_methods,
+    .m_slots = zlib_slots,
+    .m_traverse = zlib_traverse,
+    .m_clear = zlib_clear,
+    .m_free = zlib_free,
+};
+
+PyMODINIT_FUNC
+PyInit_zlib(void)
+{
+    return PyModuleDef_Init(&zlibmodule);
 }