Improved method of freeing memory used by the fetchone call. Now we j…

…ust call the C function free() directly, rather than relying on a custom wrapper.
ibrewster · Dec 23, 2014 · 706feaa · 706feaa
1 parent 4512ff7
commit 706feaa
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Showing 6 changed files with 8 additions and 12 deletions.
diff --git a/README b/README
@@ -1,5 +1,8 @@
 p4d is a Python Database API 2.0 compliant driver for the 4D (4th Dimension) database server. As such, usage should be familiar to anyone who has used any python database modules before. This module is based off of a C library provided by 4D, and integrated with Python using CFFI. As such, installation of this module does require CFFI.
 
+v0.5.1 2014-12-23:
+ - Imporoved method of freeing memory used by the fetchone call
+
 v0.5 2014-12-22:
  - Fix remaining memory leak with execute many call. Turns out there were leaks both in the C library as well as in how I was calling the library. Testing now shows memory usage stable at 11MB when processing a 1,000,000 record result set.
 

diff --git a/lib4d_sql/fourd.c b/lib4d_sql/fourd.c
@@ -241,12 +241,6 @@ void * fourd_field(FOURD_RESULT *res,unsigned int numCol)
 	return elmt->pValue;
 }
 
-//This function is for use by the python 4d driver, as it appears to be the only
-//way to get this block of memory freed. Hopefully that will change.
-void _free_field_string(char **value){
-	free(*value);
-}
-
 int fourd_field_to_string(FOURD_RESULT *res,unsigned int numCol,char **value,size_t *len)
 {
 	unsigned int nbCol=res->row_type.nbColumn;

diff --git a/lib4d_sql/fourd.h b/lib4d_sql/fourd.h
@@ -263,9 +263,6 @@ const char * fourd_sqlstate(FOURD *cnx);
 void fourd_free(FOURD* cnx);
 void fourd_free_statement(FOURD_STATEMENT *state);
 void fourd_timeout(FOURD* cnx,int timeout);
-//For use by external non-c code that can't access/clear this block of memory
-//directly.
-void _free_field_string(char **value);
 
 /*function on FOURD_RESULT*/
 FOURD_LONG8 fourd_num_rows(FOURD_RESULT *result);

diff --git a/p4d/p4d.py b/p4d/p4d.py
@@ -413,7 +413,7 @@ def fetchone(self):
             self.lib4d_sql.fourd_field_to_string(self.result, col, inbuff, strlen)
             strdata = inbuff[0]
             output = str(ffi.buffer(strdata, strlen[0])[:])
-            self.lib4d_sql._free_field_string(inbuff)
+            self.lib4d_sql.free(strdata)  #must call free explicitly, otherwise we leak.
 
             if fieldtype==self.lib4d_sql.VK_STRING or fieldtype==self.lib4d_sql.VK_TEXT:
                 row.append(output.decode('UTF-16LE'))

diff --git a/p4d/py_fourd.h b/p4d/py_fourd.h
@@ -170,5 +170,7 @@ int fourd_field_to_string(FOURD_RESULT *res,unsigned int numCol,char **value,siz
 
 int fourd_errno(FOURD *cnx);
 const char * fourd_error(FOURD *cnx);
-void _free_field_string(char **value);
+
+/* Misc other C functions needed by the p4d driver */
+void free(void *);
 
diff --git a/setup.py b/setup.py
@@ -26,7 +26,7 @@ def finalize_options(self):
 setup(
     zip_safe=False,
     name="p4d",
-    version="0.5",
+    version="0.5.1",
     install_requires=["cffi", ],
     setup_requires=['cffi', ],
     packages=find_packages(),