pytdbpack_unpack: Handle unpacking Buffers into (LEN, DATA): form list

by appending, rather than preallocating.

diff --git a/source/python/py_tdbpack.c b/source/python/py_tdbpack.c
index 446a2e548018163744a867764d3f399ef6c207d8..ba1e86384ed4c9c34c42579d989f39fdf54dad0d 100644 (file)
--- a/source/python/py_tdbpack.c
+++ b/source/python/py_tdbpack.c
@@ -30,9 +30,7 @@
 static int pytdbpack_calc_reqd_len(char *format_str,
                                   PyObject *val_seq);
 
-static PyObject *pytdbpack_unpack_item(char,
-                                      char **pbuf,
-                                      int *plen);
+static PyObject *pytdbpack_unpack_item(char, char **pbuf, int *plen, PyObject *);
 
 static PyObject *pytdbpack_pack_data(const char *format_str,
                                     PyObject *val_seq,
@@ -220,8 +218,9 @@ pytdbpack_unpack(PyObject *self,
 
        format_len = strlen(format_str);
        
-       /* allocate list to hold results */
-       val_list = PyList_New(format_len);
+       /* Allocate list to hold results.  Initially empty, and we append
+          results as we go along. */
+       val_list = PyList_New(0);
        if (!val_list)
                goto failed;
        ret_tuple = PyTuple_New(2);
@@ -230,7 +229,6 @@ pytdbpack_unpack(PyObject *self,
        
        /* For every object, unpack.  */
        for (ppacked = packed_str, i = 0; i < format_len; i++) {
-               PyObject *val_obj;
                char format;
 
                format = format_str[i];
@@ -246,13 +244,9 @@ pytdbpack_unpack(PyObject *self,
                        }
                }
 
-               val_obj = pytdbpack_unpack_item(format,
-                                               &ppacked,
-                                               &packed_len);
-               if (!val_obj)
+               if (!pytdbpack_unpack_item(format, &ppacked, &packed_len, val_list))
                        goto failed;
-
-               PyList_SET_ITEM(val_list, i, val_obj);
+               
                last_format = format;
        }
 
@@ -269,7 +263,8 @@ pytdbpack_unpack(PyObject *self,
        return ret_tuple;
 
   failed:
-       /* handle failure: deallocate anything */
+       /* handle failure: deallocate anything.  XDECREF forms handle NULL
+          pointers for objects that haven't been allocated yet. */
        Py_XDECREF(val_list);
        Py_XDECREF(ret_tuple);
        Py_XDECREF(rest_string);
@@ -482,12 +477,13 @@ unpack_string(char **pbuf, int *plen)
 
 
 static PyObject *
-unpack_buffer(char **pbuf, int *plen)
+unpack_buffer(char **pbuf, int *plen, PyObject *val_list)
 {
        /* first get 32-bit len */
        long slen;
        unsigned char *b;
        unsigned char *start;
+       PyObject *str_obj = NULL, *len_obj = NULL;
        
        if (*plen < 4) {
                unpack_err_too_short();
@@ -518,7 +514,24 @@ unpack_buffer(char **pbuf, int *plen)
        (*pbuf) += slen;
        (*plen) -= slen;
 
-       return PyString_FromStringAndSize(start, slen);
+       if (!(len_obj = PyInt_FromLong(slen)))
+               goto failed;
+
+       if (PyList_Append(val_list, len_obj) == -1)
+               goto failed;
+       
+       if (!(str_obj = PyString_FromStringAndSize(start, slen)))
+               goto failed;
+       
+       if (PyList_Append(val_list, str_obj) == -1)
+               goto failed;
+       
+       return val_list;
+
+  failed:
+       Py_XDECREF(len_obj);    /* handles NULL */
+       Py_XDECREF(str_obj);
+       return NULL;
 }
 
 
@@ -528,24 +541,27 @@ unpack_buffer(char **pbuf, int *plen)
    *PBUF is advanced, and *PLEN reduced to reflect the amount of data that has
    been consumed.
 
-   Returns a reference to the unpacked Python object, or NULL for failure.
+   Returns a reference to None, or NULL for failure.
 */
 static PyObject *pytdbpack_unpack_item(char ch,
                                       char **pbuf,
-                                      int *plen)
+                                      int *plen,
+                                      PyObject *val_list)
 {
+       PyObject *result;
+       
        if (ch == 'w') {        /* 16-bit int */
-               return unpack_int16(pbuf, plen);
+               result = unpack_int16(pbuf, plen);
        }
        else if (ch == 'd' || ch == 'p') { /* 32-bit int */
                /* pointers can just come through as integers */
-               return unpack_uint32(pbuf, plen);
+               result = unpack_uint32(pbuf, plen);
        }
        else if (ch == 'f' || ch == 'P') { /* nul-term string  */
-               return unpack_string(pbuf, plen);
+               result = unpack_string(pbuf, plen);
        }
        else if (ch == 'B') { /* length, buffer */
-               return unpack_buffer(pbuf, plen);
+               return unpack_buffer(pbuf, plen, val_list);
        }
        else {
                PyErr_Format(PyExc_ValueError,
@@ -554,6 +570,14 @@ static PyObject *pytdbpack_unpack_item(char ch,
                
                return NULL;
        }
+
+       /* otherwise OK */
+       if (!result)
+               return NULL;
+       if (PyList_Append(val_list, result) == -1)
+               return NULL;
+       
+       return val_list;
 }