1  #ifndef Py_CPYTHON_BYTESOBJECT_H
       2  #  error "this header file must not be included directly"
       3  #endif
       4  
       5  typedef struct {
       6      PyObject_VAR_HEAD
       7      Py_DEPRECATED(3.11) Py_hash_t ob_shash;
       8      char ob_sval[1];
       9  
      10      /* Invariants:
      11       *     ob_sval contains space for 'ob_size+1' elements.
      12       *     ob_sval[ob_size] == 0.
      13       *     ob_shash is the hash of the byte string or -1 if not computed yet.
      14       */
      15  } PyBytesObject;
      16  
      17  PyAPI_FUNC(int) _PyBytes_Resize(PyObject **, Py_ssize_t);
      18  PyAPI_FUNC(PyObject*) _PyBytes_FormatEx(
      19      const char *format,
      20      Py_ssize_t format_len,
      21      PyObject *args,
      22      int use_bytearray);
      23  PyAPI_FUNC(PyObject*) _PyBytes_FromHex(
      24      PyObject *string,
      25      int use_bytearray);
      26  
      27  /* Helper for PyBytes_DecodeEscape that detects invalid escape chars. */
      28  PyAPI_FUNC(PyObject *) _PyBytes_DecodeEscape(const char *, Py_ssize_t,
      29                                               const char *, const char **);
      30  
      31  /* Macros and static inline functions, trading safety for speed */
      32  #define _PyBytes_CAST(op) \
      33      (assert(PyBytes_Check(op)), _Py_CAST(PyBytesObject*, op))
      34  
      35  static inline char* PyBytes_AS_STRING(PyObject *op)
      36  {
      37      return _PyBytes_CAST(op)->ob_sval;
      38  }
      39  #define PyBytes_AS_STRING(op) PyBytes_AS_STRING(_PyObject_CAST(op))
      40  
      41  static inline Py_ssize_t PyBytes_GET_SIZE(PyObject *op) {
      42      PyBytesObject *self = _PyBytes_CAST(op);
      43      return Py_SIZE(self);
      44  }
      45  #define PyBytes_GET_SIZE(self) PyBytes_GET_SIZE(_PyObject_CAST(self))
      46  
      47  /* _PyBytes_Join(sep, x) is like sep.join(x).  sep must be PyBytesObject*,
      48     x must be an iterable object. */
      49  PyAPI_FUNC(PyObject *) _PyBytes_Join(PyObject *sep, PyObject *x);
      50  
      51  
      52  /* The _PyBytesWriter structure is big: it contains an embedded "stack buffer".
      53     A _PyBytesWriter variable must be declared at the end of variables in a
      54     function to optimize the memory allocation on the stack. */
      55  typedef struct {
      56      /* bytes, bytearray or NULL (when the small buffer is used) */
      57      PyObject *buffer;
      58  
      59      /* Number of allocated size. */
      60      Py_ssize_t allocated;
      61  
      62      /* Minimum number of allocated bytes,
      63         incremented by _PyBytesWriter_Prepare() */
      64      Py_ssize_t min_size;
      65  
      66      /* If non-zero, use a bytearray instead of a bytes object for buffer. */
      67      int use_bytearray;
      68  
      69      /* If non-zero, overallocate the buffer (default: 0).
      70         This flag must be zero if use_bytearray is non-zero. */
      71      int overallocate;
      72  
      73      /* Stack buffer */
      74      int use_small_buffer;
      75      char small_buffer[512];
      76  } _PyBytesWriter;
      77  
      78  /* Initialize a bytes writer
      79  
      80     By default, the overallocation is disabled. Set the overallocate attribute
      81     to control the allocation of the buffer. */
      82  PyAPI_FUNC(void) _PyBytesWriter_Init(_PyBytesWriter *writer);
      83  
      84  /* Get the buffer content and reset the writer.
      85     Return a bytes object, or a bytearray object if use_bytearray is non-zero.
      86     Raise an exception and return NULL on error. */
      87  PyAPI_FUNC(PyObject *) _PyBytesWriter_Finish(_PyBytesWriter *writer,
      88      void *str);
      89  
      90  /* Deallocate memory of a writer (clear its internal buffer). */
      91  PyAPI_FUNC(void) _PyBytesWriter_Dealloc(_PyBytesWriter *writer);
      92  
      93  /* Allocate the buffer to write size bytes.
      94     Return the pointer to the beginning of buffer data.
      95     Raise an exception and return NULL on error. */
      96  PyAPI_FUNC(void*) _PyBytesWriter_Alloc(_PyBytesWriter *writer,
      97      Py_ssize_t size);
      98  
      99  /* Ensure that the buffer is large enough to write *size* bytes.
     100     Add size to the writer minimum size (min_size attribute).
     101  
     102     str is the current pointer inside the buffer.
     103     Return the updated current pointer inside the buffer.
     104     Raise an exception and return NULL on error. */
     105  PyAPI_FUNC(void*) _PyBytesWriter_Prepare(_PyBytesWriter *writer,
     106      void *str,
     107      Py_ssize_t size);
     108  
     109  /* Resize the buffer to make it larger.
     110     The new buffer may be larger than size bytes because of overallocation.
     111     Return the updated current pointer inside the buffer.
     112     Raise an exception and return NULL on error.
     113  
     114     Note: size must be greater than the number of allocated bytes in the writer.
     115  
     116     This function doesn't use the writer minimum size (min_size attribute).
     117  
     118     See also _PyBytesWriter_Prepare().
     119     */
     120  PyAPI_FUNC(void*) _PyBytesWriter_Resize(_PyBytesWriter *writer,
     121      void *str,
     122      Py_ssize_t size);
     123  
     124  /* Write bytes.
     125     Raise an exception and return NULL on error. */
     126  PyAPI_FUNC(void*) _PyBytesWriter_WriteBytes(_PyBytesWriter *writer,
     127      void *str,
     128      const void *bytes,
     129      Py_ssize_t size);