PostgreSQL Source Code  git master
plpy_util.c
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1 /*
2  * utility functions
3  *
4  * src/pl/plpython/plpy_util.c
5  */
6 
7 #include "postgres.h"
8 
9 #include "mb/pg_wchar.h"
10 #include "plpy_elog.h"
11 #include "plpy_util.h"
12 #include "plpython.h"
13 #include "utils/memutils.h"
14 
15 /*
16  * Convert a Python unicode object to a Python string/bytes object in
17  * PostgreSQL server encoding. Reference ownership is passed to the
18  * caller.
19  */
20 PyObject *
21 PLyUnicode_Bytes(PyObject *unicode)
22 {
23  PyObject *bytes,
24  *rv;
25  char *utf8string,
26  *encoded;
27 
28  /* First encode the Python unicode object with UTF-8. */
29  bytes = PyUnicode_AsUTF8String(unicode);
30  if (bytes == NULL)
31  PLy_elog(ERROR, "could not convert Python Unicode object to bytes");
32 
33  utf8string = PyBytes_AsString(bytes);
34  if (utf8string == NULL)
35  {
36  Py_DECREF(bytes);
37  PLy_elog(ERROR, "could not extract bytes from encoded string");
38  }
39 
40  /*
41  * Then convert to server encoding if necessary.
42  *
43  * PyUnicode_AsEncodedString could be used to encode the object directly
44  * in the server encoding, but Python doesn't support all the encodings
45  * that PostgreSQL does (EUC_TW and MULE_INTERNAL). UTF-8 is used as an
46  * intermediary in PLyUnicode_FromString as well.
47  */
49  {
50  PG_TRY();
51  {
52  encoded = pg_any_to_server(utf8string,
53  strlen(utf8string),
54  PG_UTF8);
55  }
56  PG_CATCH();
57  {
58  Py_DECREF(bytes);
59  PG_RE_THROW();
60  }
61  PG_END_TRY();
62  }
63  else
64  encoded = utf8string;
65 
66  /* finally, build a bytes object in the server encoding */
67  rv = PyBytes_FromStringAndSize(encoded, strlen(encoded));
68 
69  /* if pg_any_to_server allocated memory, free it now */
70  if (utf8string != encoded)
71  pfree(encoded);
72 
73  Py_DECREF(bytes);
74  return rv;
75 }
76 
77 /*
78  * Convert a Python unicode object to a C string in PostgreSQL server
79  * encoding. No Python object reference is passed out of this
80  * function. The result is palloc'ed.
81  *
82  * Note that this function is disguised as PyString_AsString() when
83  * using Python 3. That function returns a pointer into the internal
84  * memory of the argument, which isn't exactly the interface of this
85  * function. But in either case you get a rather short-lived
86  * reference that you ought to better leave alone.
87  */
88 char *
89 PLyUnicode_AsString(PyObject *unicode)
90 {
91  PyObject *o = PLyUnicode_Bytes(unicode);
92  char *rv = pstrdup(PyBytes_AsString(o));
93 
94  Py_XDECREF(o);
95  return rv;
96 }
97 
98 #if PY_MAJOR_VERSION >= 3
99 /*
100  * Convert a C string in the PostgreSQL server encoding to a Python
101  * unicode object. Reference ownership is passed to the caller.
102  */
103 PyObject *
104 PLyUnicode_FromStringAndSize(const char *s, Py_ssize_t size)
105 {
106  char *utf8string;
107  PyObject *o;
108 
109  utf8string = pg_server_to_any(s, size, PG_UTF8);
110 
111  if (utf8string == s)
112  {
113  o = PyUnicode_FromStringAndSize(s, size);
114  }
115  else
116  {
117  o = PyUnicode_FromString(utf8string);
118  pfree(utf8string);
119  }
120 
121  return o;
122 }
123 
124 PyObject *
125 PLyUnicode_FromString(const char *s)
126 {
127  return PLyUnicode_FromStringAndSize(s, strlen(s));
128 }
129 
130 #endif /* PY_MAJOR_VERSION >= 3 */
char * pstrdup(const char *in)
Definition: mcxt.c:1187
def bytes(source, encoding='ascii', errors='strict')
char * pg_server_to_any(const char *s, int len, int encoding)
Definition: mbutils.c:692
char * PLyUnicode_AsString(PyObject *unicode)
Definition: plpy_util.c:89
void pfree(void *pointer)
Definition: mcxt.c:1057
#define ERROR
Definition: elog.h:43
#define PLy_elog
int GetDatabaseEncoding(void)
Definition: mbutils.c:1151
#define PG_CATCH()
Definition: elog.h:305
#define PG_RE_THROW()
Definition: elog.h:336
PyObject * PLyUnicode_Bytes(PyObject *unicode)
Definition: plpy_util.c:21
#define PLyUnicode_FromStringAndSize
char * pg_any_to_server(const char *s, int len, int encoding)
Definition: mbutils.c:619
#define PG_TRY()
Definition: elog.h:295
#define PG_END_TRY()
Definition: elog.h:320