Buffer.c

//-----------------------------------------------------------------------------
// Buffer.c
//   Defines buffer structure and routines for populating it. These are used
// to translate Python objects into the buffers needed for Dameng, including
// Unicode or buffer objects.
//-----------------------------------------------------------------------------
#include "Buffer.h"

//-----------------------------------------------------------------------------
// pyBuffer_Init()
//   Initialize the buffer with an empty string. Returns 0 as a convenience to
// the caller.
//-----------------------------------------------------------------------------
static 
sdint2
dmBuffer_Init(
    dm_Buffer*     buf     // buffer to initialize
)                    
{
    buf->ptr = NULL;
    buf->size = 0;
    buf->numCharacters = 0;
    buf->obj = NULL;
    return 0;
}


//-----------------------------------------------------------------------------
// cxBuffer_Copy()
//   Copy the contents of the buffer.
//-----------------------------------------------------------------------------
static 
int
dmBuffer_Copy(
    dm_Buffer*     buf,                    // buffer to copy into
    dm_Buffer*     copyFromBuf             // buffer to copy from
)            
{
    buf->ptr = copyFromBuf->ptr;
    buf->size = copyFromBuf->size;
    buf->numCharacters = copyFromBuf->numCharacters;
    Py_XINCREF(copyFromBuf->obj);
    buf->obj = copyFromBuf->obj;
    return 0;
}


//-----------------------------------------------------------------------------
// cxBuffer_FromObject()
//   Populate the string buffer from a unicode object.
//-----------------------------------------------------------------------------
sdint2 
dmBuffer_FromObject(
    dm_Buffer*      buf,                    // buffer to fill
    PyObject*       obj,                      // object (string or Unicode object)
    const char*     encoding               // encoding to use, if applicable
)
{
    if (!obj)
        return dmBuffer_Init(buf);	
    if (encoding && PyUnicode_Check(obj)) {		
        buf->obj = PyUnicode_AsEncodedString(obj, encoding, NULL);
        if (!buf->obj)
            return -1;
        buf->ptr = PyBytes_AS_STRING(buf->obj);
        buf->size = PyBytes_GET_SIZE(buf->obj);
#if PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION > 11
        buf->numCharacters = PyUnicode_GET_LENGTH(obj);
#else
        buf->numCharacters = PyUnicode_GET_SIZE(obj);
#endif
    } else if (PyBytes_Check(obj)) {		
        Py_INCREF(obj);
        buf->obj = obj;
        buf->ptr = PyBytes_AS_STRING(buf->obj);
        buf->size = buf->numCharacters = PyBytes_GET_SIZE(buf->obj);
#if PY_MAJOR_VERSION < 3
    } else if (PyBuffer_Check(obj)) {
        if (PyObject_AsReadBuffer(obj, &buf->ptr, &buf->size) < 0)
            return -1;
        Py_INCREF(obj);
        buf->obj = obj;
        buf->numCharacters = buf->size;
#endif
    } else {
        PyErr_SetString(PyExc_TypeError, "buffer type error!");
        return -1;
    }
    return 0;
}