Function ion_c_sys::ion_reader_open_stream

pub unsafe extern "C" fn ion_reader_open_stream(
    p_hreader: *mut hREADER, 
    handler_state: *mut c_void, 
    fn_input_handler: ION_STREAM_HANDLER, 
    p_options: *mut ION_READER_OPTIONS
) -> iERR

Create hREADER object, and associate it with the stream for reading.

The hREADER object itself does not have a read data buffer, it’s using the buffer from handler_state, which usually contains a BYTE[].

hREADER object will invoke fn_input_handler to read from input data source (File, for example) and fill the BYTE[] in handler_state.

typedef struct _test_file {
FILE *in;
int   block_size;
BYTE *buffer;
} TEST_FILE;
BYTE      g_buffer[1024];
TEST_FILE g_test_file =
{
NULL,
TEST_FILE_BUF_MAX,
g_buffer
};
iERR test_stream_handler(struct _ion_stream *pstream)
{
iENTER;
TEST_FILE *tfile;
SIZE len;
tfile = (TEST_FILE *)pstream->handler_state;
pstream->curr = tfile->buffer;
len = fread( tfile->buffer, sizeof(*tfile->buffer), tfile->block_size, g_test_file.in );
if (len < 1) {
pstream->limit = NULL;
DONTFAILWITH(IERR_EOF);
}
pstream->limit = pstream->curr + len;
iRETURN;
}
fstream = fopen(pathname, "r");
g_test_file.in = fstream;
ion_reader_open_stream(&reader, &g_test_file, test_stream_handler, NULL);

@param p_hreader Newly created reader object will be stored here. @param p_stream stream opened with ion_stream functions @param p_options const, Reader configuration data object, used while creating reader object. @return IERR_OK if succeeded