a buffer to read data into (which should be at least count bytes long).
the number of bytes that will be read from the stream
location to store the number of bytes that was read from the stream. out
optional GCancellable object, NULL to ignore. [allow-none]
TRUE on success, FALSE if there was an error
GException on failure.
Tries to read count bytes from the stream into the buffer starting at buffer. Will block during this read. This function is similar to g_input_stream_read(), except it tries to read as many bytes as requested, only stopping on an error or end of stream. On a successful read of count bytes, or if we reached the end of the stream, TRUE is returned, and bytes_read is set to the number of bytes read into buffer. If there is an error during the operation FALSE is returned and error is set to indicate the error status, bytes_read is updated to contain the number of bytes read into buffer before the error occurred.