Wrap curl_slist in a Python object

The goal is for each curl_slist to have its own reference count that is
managed by Python. This allows for sharing of curl_slist data between
cloned handles (curl_easy_duphandle).

4 files changed, 118 insertions, 77 deletions

diff --git a/src/easy.c b/src/easy.c
index a22ad9c..9fd8be9 100644
--- a/src/easy.c
+++ b/src/easy.c
@@ -2,6 +2,41 @@
 #include "docstrings.h"
 
 /*************************************************************************
+// CurlSlistObject
+**************************************************************************/
+
+PYCURL_INTERNAL void
+util_curlslist_update(CurlSlistObject **old, struct curl_slist *slist)
+{
+    /* Decref previous object */
+    Py_XDECREF(*old);
+    /* Create a new object */
+    *old = PyObject_New(CurlSlistObject, p_CurlSlist_Type);
+    assert(*old != NULL);
+    /* Store curl_slist into the new object */
+    (*old)->slist = slist;
+}
+
+PYCURL_INTERNAL void
+do_curl_slist_dealloc(CurlSlistObject *self) {
+    if (self->slist != NULL) {
+        curl_slist_free_all(self->slist);
+        self->slist = NULL;
+    }
+    Py_TYPE(self)->tp_free((PyObject *) self);
+}
+
+/* TODO: Python 2 compatible */
+PYCURL_INTERNAL PyTypeObject CurlSlist_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    .tp_name = "pycurl.CurlSlist",
+    .tp_basicsize = sizeof(CurlSlistObject),
+    .tp_itemsize = 0,
+    .tp_dealloc = (destructor) do_curl_slist_dealloc,
+};
+
+
+/*************************************************************************
 // static utility functions
 **************************************************************************/
 
@@ -202,6 +237,28 @@ util_curl_xdecref(CurlObject *self, int flags, CURL *handle)
         /* Decrement refcounts for ca certs related references. */
         Py_CLEAR(self->ca_certs_obj);
     }
+
+    if (flags & PYCURL_MEMGROUP_SLIST) {
+        /* Decrement refcounts for slist objects. */
+        Py_CLEAR(self->httpheader);
+#if LIBCURL_VERSION_NUM >= MAKE_LIBCURL_VERSION(7, 37, 0)
+        Py_CLEAR(self->proxyheader);
+#endif
+        Py_CLEAR(self->http200aliases);
+        Py_CLEAR(self->quote);
+        Py_CLEAR(self->postquote);
+        Py_CLEAR(self->prequote);
+        Py_CLEAR(self->telnetoptions);
+#ifdef HAVE_CURLOPT_RESOLVE
+        Py_CLEAR(self->resolve);
+#endif
+#ifdef HAVE_CURL_7_20_0_OPTS
+        Py_CLEAR(self->mail_rcpt);
+#endif
+#ifdef HAVE_CURLOPT_CONNECT_TO
+        Py_CLEAR(self->connect_to);
+#endif
+    }
 }
 
 
@@ -247,32 +304,6 @@ util_curl_close(CurlObject *self)
     if (self->weakreflist != NULL) {
         PyObject_ClearWeakRefs((PyObject *) self);
     }
-
-    /* Free all variables allocated by setopt */
-#undef SFREE
-#define SFREE(v)   if ((v) != NULL) (curl_formfree(v), (v) = NULL)
-    SFREE(self->httppost);
-#undef SFREE
-#define SFREE(v)   if ((v) != NULL) (curl_slist_free_all(v), (v) = NULL)
-    SFREE(self->httpheader);
-#if LIBCURL_VERSION_NUM >= MAKE_LIBCURL_VERSION(7, 37, 0)
-    SFREE(self->proxyheader);
-#endif
-    SFREE(self->http200aliases);
-    SFREE(self->quote);
-    SFREE(self->postquote);
-    SFREE(self->prequote);
-    SFREE(self->telnetoptions);
-#ifdef HAVE_CURLOPT_RESOLVE
-    SFREE(self->resolve);
-#endif
-#ifdef HAVE_CURL_7_20_0_OPTS
-    SFREE(self->mail_rcpt);
-#endif
-#ifdef HAVE_CURLOPT_CONNECT_TO
-    SFREE(self->connect_to);
-#endif
-#undef SFREE
 }
 
 
@@ -351,6 +382,25 @@ do_curl_traverse(CurlObject *self, visitproc visit, void *arg)
 
     VISIT(self->ca_certs_obj);
 
+    VISIT((PyObject *) self->httpheader);
+#if LIBCURL_VERSION_NUM >= MAKE_LIBCURL_VERSION(7, 37, 0)
+    VISIT((PyObject *) self->proxyheader);
+#endif
+    VISIT((PyObject *) self->http200aliases);
+    VISIT((PyObject *) self->quote);
+    VISIT((PyObject *) self->postquote);
+    VISIT((PyObject *) self->prequote);
+    VISIT((PyObject *) self->telnetoptions);
+#ifdef HAVE_CURLOPT_RESOLVE
+    VISIT((PyObject *) self->resolve);
+#endif
+#ifdef HAVE_CURL_7_20_0_OPTS
+    VISIT((PyObject *) self->mail_rcpt);
+#endif
+#ifdef HAVE_CURLOPT_CONNECT_TO
+    VISIT((PyObject *) self->connect_to);
+#endif
+
     return 0;
 #undef VISIT
 }
@@ -368,31 +418,6 @@ do_curl_reset(CurlObject *self)
     /* Decref easy interface related objects */
     util_curl_xdecref(self, PYCURL_MEMGROUP_EASY, self->handle);
 
-    /* Free all variables allocated by setopt */
-#undef SFREE
-#define SFREE(v)   if ((v) != NULL) (curl_formfree(v), (v) = NULL)
-    SFREE(self->httppost);
-#undef SFREE
-#define SFREE(v)   if ((v) != NULL) (curl_slist_free_all(v), (v) = NULL)
-    SFREE(self->httpheader);
-#if LIBCURL_VERSION_NUM >= MAKE_LIBCURL_VERSION(7, 37, 0)
-    SFREE(self->proxyheader);
-#endif
-    SFREE(self->http200aliases);
-    SFREE(self->quote);
-    SFREE(self->postquote);
-    SFREE(self->prequote);
-    SFREE(self->telnetoptions);
-#ifdef HAVE_CURLOPT_RESOLVE
-    SFREE(self->resolve);
-#endif
-#ifdef HAVE_CURL_7_20_0_OPTS
-    SFREE(self->mail_rcpt);
-#endif
-#ifdef HAVE_CURLOPT_CONNECT_TO
-    SFREE(self->connect_to);
-#endif
-#undef SFREE
     res = util_curl_init(self);
     if (res < 0) {
         Py_DECREF(self);    /* this also closes self->handle */
diff --git a/src/easyopt.c b/src/easyopt.c
index ba4108c..5c6f29e 100644
--- a/src/easyopt.c
+++ b/src/easyopt.c
@@ -713,48 +713,48 @@ error:
 static PyObject *
 do_curl_setopt_list(CurlObject *self, int option, int which, PyObject *obj)
 {
-    struct curl_slist **old_slist = NULL;
+    CurlSlistObject **old_slist_obj = NULL;
     struct curl_slist *slist = NULL;
     Py_ssize_t len;
     int res;
 
     switch (option) {
     case CURLOPT_HTTP200ALIASES:
-        old_slist = &self->http200aliases;
+        old_slist_obj = &self->http200aliases;
         break;
     case CURLOPT_HTTPHEADER:
-        old_slist = &self->httpheader;
+        old_slist_obj = &self->httpheader;
         break;
 #if LIBCURL_VERSION_NUM >= MAKE_LIBCURL_VERSION(7, 37, 0)
     case CURLOPT_PROXYHEADER:
-        old_slist = &self->proxyheader;
+        old_slist_obj = &self->proxyheader;
         break;
 #endif
     case CURLOPT_POSTQUOTE:
-        old_slist = &self->postquote;
+        old_slist_obj = &self->postquote;
         break;
     case CURLOPT_PREQUOTE:
-        old_slist = &self->prequote;
+        old_slist_obj = &self->prequote;
         break;
     case CURLOPT_QUOTE:
-        old_slist = &self->quote;
+        old_slist_obj = &self->quote;
         break;
     case CURLOPT_TELNETOPTIONS:
-        old_slist = &self->telnetoptions;
+        old_slist_obj = &self->telnetoptions;
         break;
 #ifdef HAVE_CURLOPT_RESOLVE
     case CURLOPT_RESOLVE:
-        old_slist = &self->resolve;
+        old_slist_obj = &self->resolve;
         break;
 #endif
 #ifdef HAVE_CURL_7_20_0_OPTS
     case CURLOPT_MAIL_RCPT:
-        old_slist = &self->mail_rcpt;
+        old_slist_obj = &self->mail_rcpt;
         break;
 #endif
 #ifdef HAVE_CURLOPT_CONNECT_TO
     case CURLOPT_CONNECT_TO:
-        old_slist = &self->connect_to;
+        old_slist_obj = &self->connect_to;
         break;
 #endif
     default:
@@ -768,7 +768,7 @@ do_curl_setopt_list(CurlObject *self, int option, int which, PyObject *obj)
         Py_RETURN_NONE;
 
     /* Just to be sure we do not bug off here */
-    assert(old_slist != NULL && slist == NULL);
+    assert(old_slist_obj != NULL && slist == NULL);
 
     /* Handle regular list operations on the other options */
     slist = pycurl_list_or_tuple_to_slist(which, obj, len);
@@ -781,9 +781,9 @@ do_curl_setopt_list(CurlObject *self, int option, int which, PyObject *obj)
         curl_slist_free_all(slist);
         CURLERROR_RETVAL();
     }
-    /* Finally, free previously allocated list and update */
-    curl_slist_free_all(*old_slist);
-    *old_slist = slist;
+    /* Finally, decref previous slist object and replace it with a
+     * new one. */
+    util_curlslist_update(old_slist_obj, slist);
 
     Py_RETURN_NONE;
 }
diff --git a/src/module.c b/src/module.c
index 2331168..2f40e98 100644
--- a/src/module.c
+++ b/src/module.c
@@ -28,6 +28,7 @@ PYCURL_INTERNAL char *g_pycurl_useragent = NULL;
 /* Type objects */
 PYCURL_INTERNAL PyObject *ErrorObject = NULL;
 PYCURL_INTERNAL PyTypeObject *p_Curl_Type = NULL;
+PYCURL_INTERNAL PyTypeObject *p_CurlSlist_Type = NULL;
 PYCURL_INTERNAL PyTypeObject *p_CurlMulti_Type = NULL;
 PYCURL_INTERNAL PyTypeObject *p_CurlShare_Type = NULL;
 #ifdef HAVE_CURL_7_19_6_OPTS
@@ -416,9 +417,11 @@ initpycurl(void)
     /* Initialize the type of the new type objects here; doing it here
      * is required for portability to Windows without requiring C++. */
     p_Curl_Type = &Curl_Type;
+    p_CurlSlist_Type = &CurlSlist_Type;
     p_CurlMulti_Type = &CurlMulti_Type;
     p_CurlShare_Type = &CurlShare_Type;
     Py_SET_TYPE(&Curl_Type, &PyType_Type);
+    Py_SET_TYPE(&CurlSlist_Type, &PyType_Type);
     Py_SET_TYPE(&CurlMulti_Type, &PyType_Type);
     Py_SET_TYPE(&CurlShare_Type, &PyType_Type);
 
@@ -426,12 +429,16 @@ initpycurl(void)
     if (PyType_Ready(&Curl_Type) < 0)
         goto error;
 
+    if (PyType_Ready(&CurlSlist_Type) < 0)
+        goto error;
+
     if (PyType_Ready(&CurlMulti_Type) < 0)
         goto error;
 
     if (PyType_Ready(&CurlShare_Type) < 0)
         goto error;
 
+
 #if PY_MAJOR_VERSION >= 3
     m = PyModule_Create(&curlmodule);
     if (m == NULL)
diff --git a/src/pycurl.h b/src/pycurl.h
index 31d1eac..f4f71f6 100644
--- a/src/pycurl.h
+++ b/src/pycurl.h
@@ -371,16 +371,23 @@ create_and_set_error_object(struct CurlObject *self, int code);
 #define PYCURL_MEMGROUP_POSTFIELDS      64
 /* CA certs object */
 #define PYCURL_MEMGROUP_CACERTS         128
+/* Curl slist objects */
+#define PYCURL_MEMGROUP_SLIST           256
 
 #define PYCURL_MEMGROUP_EASY \
     (PYCURL_MEMGROUP_CALLBACK | PYCURL_MEMGROUP_FILE | \
     PYCURL_MEMGROUP_HTTPPOST | PYCURL_MEMGROUP_POSTFIELDS | \
-    PYCURL_MEMGROUP_CACERTS)
+    PYCURL_MEMGROUP_CACERTS | PYCURL_MEMGROUP_SLIST)
 
 #define PYCURL_MEMGROUP_ALL \
     (PYCURL_MEMGROUP_ATTRDICT | PYCURL_MEMGROUP_EASY | \
     PYCURL_MEMGROUP_MULTI | PYCURL_MEMGROUP_SHARE)
 
+typedef struct CurlSlistObject {
+    PyObject_HEAD
+    struct curl_slist *slist;
+} CurlSlistObject;
+
 typedef struct CurlObject {
     PyObject_HEAD
     PyObject *dict;                 /* Python attributes dictionary */
@@ -395,23 +402,23 @@ typedef struct CurlObject {
     struct curl_httppost *httppost;
     /* List of INC'ed references associated with httppost. */
     PyObject *httppost_ref_list;
-    struct curl_slist *httpheader;
+    struct CurlSlistObject *httpheader;
 #if LIBCURL_VERSION_NUM >= MAKE_LIBCURL_VERSION(7, 37, 0)
-    struct curl_slist *proxyheader;
+    struct CurlSlistObject *proxyheader;
 #endif
-    struct curl_slist *http200aliases;
-    struct curl_slist *quote;
-    struct curl_slist *postquote;
-    struct curl_slist *prequote;
-    struct curl_slist *telnetoptions;
+    struct CurlSlistObject *http200aliases;
+    struct CurlSlistObject *quote;
+    struct CurlSlistObject *postquote;
+    struct CurlSlistObject *prequote;
+    struct CurlSlistObject *telnetoptions;
 #ifdef HAVE_CURLOPT_RESOLVE
-    struct curl_slist *resolve;
+    struct CurlSlistObject *resolve;
 #endif
 #ifdef HAVE_CURL_7_20_0_OPTS
-    struct curl_slist *mail_rcpt;
+    struct CurlSlistObject *mail_rcpt;
 #endif
 #ifdef HAVE_CURLOPT_CONNECT_TO
-    struct curl_slist *connect_to;
+    struct CurlSlistObject *connect_to;
 #endif
     /* callbacks */
     PyObject *w_cb;
@@ -619,11 +626,13 @@ ssl_ctx_callback(CURL *curl, void *ssl_ctx, void *ptr);
 #if !defined(PYCURL_SINGLE_FILE)
 /* Type objects */
 extern PyTypeObject Curl_Type;
+extern PyTypeObject CurlSlist_Type;
 extern PyTypeObject CurlMulti_Type;
 extern PyTypeObject CurlShare_Type;
 
 extern PyObject *ErrorObject;
 extern PyTypeObject *p_Curl_Type;
+extern PyTypeObject *p_CurlSlist_Type;
 extern PyTypeObject *p_CurlMulti_Type;
 extern PyTypeObject *p_CurlShare_Type;
 extern PyObject *khkey_type;