static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count)
{
- uint8_t *source = (uint8_t*)stream->state;
- stream->state = source + count;
+ const uint8_t *source = (const uint8_t*)stream->state;
+ stream->state = (uint8_t*)stream->state + count;
if (buf != NULL)
{
if (!stream->callback(stream, buf, 1))
PB_RETURN_ERROR(stream, "io error");
#else
- *buf = *(uint8_t*)stream->state;
+ *buf = *(const uint8_t*)stream->state;
stream->state = (uint8_t*)stream->state + 1;
#endif
return true;
}
-pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize)
+pb_istream_t pb_istream_from_buffer(const uint8_t *buf, size_t bufsize)
{
pb_istream_t stream;
+ /* Cast away the const from buf without a compiler error. We are
+ * careful to use it only in a const manner in the callbacks.
+ */
+ union {
+ void *state;
+ const void *c_state;
+ } state;
#ifdef PB_BUFFER_ONLY
stream.callback = NULL;
#else
stream.callback = &buf_read;
#endif
- stream.state = buf;
+ state.c_state = buf;
+ stream.state = state.state;
stream.bytes_left = bufsize;
#ifndef PB_NO_ERRMSG
stream.errmsg = NULL;
* Alternatively, you can use a custom stream that reads directly from e.g.
* a file or a network socket.
*/
-pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize);
+pb_istream_t pb_istream_from_buffer(const uint8_t *buf, size_t bufsize);
/* Function to read from a pb_istream_t. You can use this if you need to
* read some custom header data, or to read data in field callbacks.