Include/stringobject.h

   1
   2 /* String object interface */
   3
   4 #ifndef Py_STRINGOBJECT_H
   5 #define Py_STRINGOBJECT_H
   6 #ifdef __cplusplus
   7 extern "C" {
   8 #endif
   9
  10 #include <stdarg.h>
  11
  12 /*
  13 Type PyStringObject represents a character string.  An extra zero byte is
  14 reserved at the end to ensure it is zero-terminated, but a size is
  15 present so strings with null bytes in them can be represented.  This
  16 is an immutable object type.
  17
  18 There are functions to create new string objects, to test
  19 an object for string-ness, and to get the
  20 string value.  The latter function returns a null pointer
  21 if the object is not of the proper type.
  22 There is a variant that takes an explicit size as well as a
  23 variant that assumes a zero-terminated string.  Note that none of the
  24 functions should be applied to nil objects.
  25 */
  26
  27 /* Caching the hash (ob_shash) saves recalculation of a string's hash value.
  28    Interning strings (ob_sstate) tries to ensure that only one string
  29    object with a given value exists, so equality tests can be one pointer
  30    comparison.  This is generally restricted to strings that "look like"
  31    Python identifiers, although the intern() builtin can be used to force
  32    interning of any string.
  33    Together, these sped the interpreter by up to 20%. */
  34
  35 typedef struct {
  36     PyObject_VAR_HEAD
  37     long ob_shash;
  38     int ob_sstate;
  39     char ob_sval[1];
  40
  41     /* Invariants:
  42      *     ob_sval contains space for 'ob_size+1' elements.
  43      *     ob_sval[ob_size] == 0.
  44      *     ob_shash is the hash of the string or -1 if not computed yet.
  45      *     ob_sstate != 0 iff the string object is in stringobject.c's
  46      *       'interned' dictionary; in this case the two references
  47      *       from 'interned' to this object are *not counted* in ob_refcnt.
  48      */
  49 } PyStringObject;
  50
  51 #define SSTATE_NOT_INTERNED 0
  52 #define SSTATE_INTERNED_MORTAL 1
  53 #define SSTATE_INTERNED_IMMORTAL 2
  54
  55 PyAPI_DATA(PyTypeObject) PyBaseString_Type;
  56 PyAPI_DATA(PyTypeObject) PyString_Type;
  57
  58 #define PyString_Check(op) PyObject_TypeCheck(op, &PyString_Type)
  59 #define PyString_CheckExact(op) ((op)->ob_type == &PyString_Type)
  60
  61 PyAPI_FUNC(PyObject *) PyString_FromStringAndSize(const char *, Py_ssize_t);
  62 PyAPI_FUNC(PyObject *) PyString_FromString(const char *);
  63 PyAPI_FUNC(PyObject *) PyString_FromFormatV(const char*, va_list)
  64                                 Py_GCC_ATTRIBUTE((format(printf, 1, 0)));
  65 PyAPI_FUNC(PyObject *) PyString_FromFormat(const char*, ...)
  66                                 Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
  67 PyAPI_FUNC(Py_ssize_t) PyString_Size(PyObject *);
  68 PyAPI_FUNC(char *) PyString_AsString(PyObject *);
  69 PyAPI_FUNC(PyObject *) PyString_Repr(PyObject *, int);
  70 PyAPI_FUNC(void) PyString_Concat(PyObject **, PyObject *);
  71 PyAPI_FUNC(void) PyString_ConcatAndDel(PyObject **, PyObject *);
  72 PyAPI_FUNC(int) _PyString_Resize(PyObject **, Py_ssize_t);
  73 PyAPI_FUNC(int) _PyString_Eq(PyObject *, PyObject*);
  74 PyAPI_FUNC(PyObject *) PyString_Format(PyObject *, PyObject *);
  75 PyAPI_FUNC(PyObject *) _PyString_FormatLong(PyObject*, int, int,
  76                                                   int, char**, int*);
  77 PyAPI_FUNC(PyObject *) PyString_DecodeEscape(const char *, Py_ssize_t,
  78                                                    const char *, Py_ssize_t,
  79                                                    const char *);
  80
  81 PyAPI_FUNC(void) PyString_InternInPlace(PyObject **);
  82 PyAPI_FUNC(void) PyString_InternImmortal(PyObject **);
  83 PyAPI_FUNC(PyObject *) PyString_InternFromString(const char *);
  84 PyAPI_FUNC(void) _Py_ReleaseInternedStrings(void);
  85
  86 /* Use only if you know it's a string */
  87 #define PyString_CHECK_INTERNED(op) (((PyStringObject *)(op))->ob_sstate)
  88
  89 /* Macro, trading safety for speed */
  90 #define PyString_AS_STRING(op) (((PyStringObject *)(op))->ob_sval)
  91 #define PyString_GET_SIZE(op)  (((PyStringObject *)(op))->ob_size)
  92
  93 /* _PyString_Join(sep, x) is like sep.join(x).  sep must be PyStringObject*,
  94    x must be an iterable object. */
  95 PyAPI_FUNC(PyObject *) _PyString_Join(PyObject *sep, PyObject *x);
  96
  97 /* --- Generic Codecs ----------------------------------------------------- */
  98
  99 /* Create an object by decoding the encoded string s of the
 100    given size. */
 101
 102 PyAPI_FUNC(PyObject*) PyString_Decode(
 103     const char *s,              /* encoded string */
 104     Py_ssize_t size,            /* size of buffer */
 105     const char *encoding,       /* encoding */
 106     const char *errors          /* error handling */
 107     );
 108
 109 /* Encodes a char buffer of the given size and returns a
 110    Python object. */
 111
 112 PyAPI_FUNC(PyObject*) PyString_Encode(
 113     const char *s,              /* string char buffer */
 114     Py_ssize_t size,            /* number of chars to encode */
 115     const char *encoding,       /* encoding */
 116     const char *errors          /* error handling */
 117     );
 118
 119 /* Encodes a string object and returns the result as Python
 120    object. */
 121
 122 PyAPI_FUNC(PyObject*) PyString_AsEncodedObject(
 123     PyObject *str,              /* string object */
 124     const char *encoding,       /* encoding */
 125     const char *errors          /* error handling */
 126     );
 127
 128 /* Encodes a string object and returns the result as Python string
 129    object.
 130
 131    If the codec returns an Unicode object, the object is converted
 132    back to a string using the default encoding.
 133
 134    DEPRECATED - use PyString_AsEncodedObject() instead. */
 135
 136 PyAPI_FUNC(PyObject*) PyString_AsEncodedString(
 137     PyObject *str,              /* string object */
 138     const char *encoding,       /* encoding */
 139     const char *errors          /* error handling */
 140     );
 141
 142 /* Decodes a string object and returns the result as Python
 143    object. */
 144
 145 PyAPI_FUNC(PyObject*) PyString_AsDecodedObject(
 146     PyObject *str,              /* string object */
 147     const char *encoding,       /* encoding */
 148     const char *errors          /* error handling */
 149     );
 150
 151 /* Decodes a string object and returns the result as Python string
 152    object.
 153
 154    If the codec returns an Unicode object, the object is converted
 155    back to a string using the default encoding.
 156
 157    DEPRECATED - use PyString_AsDecodedObject() instead. */
 158
 159 PyAPI_FUNC(PyObject*) PyString_AsDecodedString(
 160     PyObject *str,              /* string object */
 161     const char *encoding,       /* encoding */
 162     const char *errors          /* error handling */
 163     );
 164
 165 /* Provides access to the internal data buffer and size of a string
 166    object or the default encoded version of an Unicode object. Passing
 167    NULL as *len parameter will force the string buffer to be
 168    0-terminated (passing a string with embedded NULL characters will
 169    cause an exception).  */
 170
 171 PyAPI_FUNC(int) PyString_AsStringAndSize(
 172     register PyObject *obj,     /* string or Unicode object */
 173     register char **s,          /* pointer to buffer variable */
 174     register Py_ssize_t *len    /* pointer to length variable or NULL
 175                                    (only possible for 0-terminated
 176                                    strings) */
 177     );
 178
 179
 180 #ifdef __cplusplus
 181 }
 182 #endif
 183 #endif /* !Py_STRINGOBJECT_H */