Tries to read count bytes from the stream into the buffer starting at buffer. Will block during this read.
This function is similar to InputStream.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.
As a special exception to the normal conventions for functions that use GError, if this function returns FALSE (and sets error) then bytes_read will be set to the number of bytes that were successfully read before the error was encountered. This functionality is only available from C. If you need it from another language then you must write your own loop around InputStream.read.
a buffer to read data into (which should be at least count bytes long).
location to store the number of bytes that was read from the stream
optional gio.Cancellable object, NULL to ignore.
TRUE on success, FALSE if there was an error
GException on failure.