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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 "utils/memutils.h"
11 #include "utils/palloc.h"
12 
13 #include "plpython.h"
14 
15 #include "plpy_util.h"
16 
17 #include "plpy_elog.h"
18 
19 
20 /*
21  * Convert a Python unicode object to a Python string/bytes object in
22  * PostgreSQL server encoding. Reference ownership is passed to the
23  * caller.
24  */
25 PyObject *
26 PLyUnicode_Bytes(PyObject *unicode)
27 {
28  PyObject *bytes,
29  *rv;
30  char *utf8string,
31  *encoded;
32 
33  /* First encode the Python unicode object with UTF-8. */
34  bytes = PyUnicode_AsUTF8String(unicode);
35  if (bytes == NULL)
36  PLy_elog(ERROR, "could not convert Python Unicode object to bytes");
37 
38  utf8string = PyBytes_AsString(bytes);
39  if (utf8string == NULL)
40  {
41  Py_DECREF(bytes);
42  PLy_elog(ERROR, "could not extract bytes from encoded string");
43  }
44 
45  /*
46  * Then convert to server encoding if necessary.
47  *
48  * PyUnicode_AsEncodedString could be used to encode the object directly
49  * in the server encoding, but Python doesn't support all the encodings
50  * that PostgreSQL does (EUC_TW and MULE_INTERNAL). UTF-8 is used as an
51  * intermediary in PLyUnicode_FromString as well.
52  */
54  {
55  PG_TRY();
56  {
57  encoded = pg_any_to_server(utf8string,
58  strlen(utf8string),
59  PG_UTF8);
60  }
61  PG_CATCH();
62  {
63  Py_DECREF(bytes);
64  PG_RE_THROW();
65  }
66  PG_END_TRY();
67  }
68  else
69  encoded = utf8string;
70 
71  /* finally, build a bytes object in the server encoding */
72  rv = PyBytes_FromStringAndSize(encoded, strlen(encoded));
73 
74  /* if pg_any_to_server allocated memory, free it now */
75  if (utf8string != encoded)
76  pfree(encoded);
77 
78  Py_DECREF(bytes);
79  return rv;
80 }
81 
82 /*
83  * Convert a Python unicode object to a C string in PostgreSQL server
84  * encoding. No Python object reference is passed out of this
85  * function. The result is palloc'ed.
86  *
87  * Note that this function is disguised as PyString_AsString() when
88  * using Python 3. That function retuns a pointer into the internal
89  * memory of the argument, which isn't exactly the interface of this
90  * function. But in either case you get a rather short-lived
91  * reference that you ought to better leave alone.
92  */
93 char *
94 PLyUnicode_AsString(PyObject *unicode)
95 {
96  PyObject *o = PLyUnicode_Bytes(unicode);
97  char *rv = pstrdup(PyBytes_AsString(o));
98 
99  Py_XDECREF(o);
100  return rv;
101 }
102 
103 #if PY_MAJOR_VERSION >= 3
104 /*
105  * Convert a C string in the PostgreSQL server encoding to a Python
106  * unicode object. Reference ownership is passed to the caller.
107  */
108 PyObject *
109 PLyUnicode_FromStringAndSize(const char *s, Py_ssize_t size)
110 {
111  char *utf8string;
112  PyObject *o;
113 
114  utf8string = pg_server_to_any(s, size, PG_UTF8);
115 
116  if (utf8string == s)
117  {
118  o = PyUnicode_FromStringAndSize(s, size);
119  }
120  else
121  {
122  o = PyUnicode_FromString(utf8string);
123  pfree(utf8string);
124  }
125 
126  return o;
127 }
128 
129 PyObject *
130 PLyUnicode_FromString(const char *s)
131 {
132  return PLyUnicode_FromStringAndSize(s, strlen(s));
133 }
134 
135 #endif /* PY_MAJOR_VERSION >= 3 */
char * pstrdup(const char *in)
Definition: mcxt.c:1076
void PLy_elog(int elevel, const char *fmt,...)
Definition: plpy_elog.c:47
#define PyBytes_FromStringAndSize
Definition: plpython.h:85
#define PyBytes_AsString
Definition: plpython.h:84
int Py_ssize_t
Definition: plpython.h:64
char * pg_server_to_any(const char *s, int len, int encoding)
Definition: mbutils.c:645
char * PLyUnicode_AsString(PyObject *unicode)
Definition: plpy_util.c:94
void pfree(void *pointer)
Definition: mcxt.c:949
#define ERROR
Definition: elog.h:43
int GetDatabaseEncoding(void)
Definition: mbutils.c:1015
#define PG_CATCH()
Definition: elog.h:293
#define PG_RE_THROW()
Definition: elog.h:314
PyObject * PLyUnicode_Bytes(PyObject *unicode)
Definition: plpy_util.c:26
#define PLyUnicode_FromStringAndSize
char * pg_any_to_server(const char *s, int len, int encoding)
Definition: mbutils.c:572
#define PG_TRY()
Definition: elog.h:284
#define PG_END_TRY()
Definition: elog.h:300