Synchronous C Data Types
Description
Function pointers of read_from_data_source type are used to upload object data. The function pointer and opaque cookie reference are supplied as arguments to “hc_store_both_ez” on page 87 and other functions that store object data. The data source reader function will be called repeatedly, with the supplied cookie as an argument, to gather the object data to upload into storage.
A read_from_data_source function should read up to buf_size bytes from the data source indicated by cookie into the buffer at location buff and return the actual number of bytes read as the return value from the function.
There are two special return codes:
■A return value of 0 indicates the
■A return value of
Parameters
cookie
An opaque data structure to identify this data cookie. The cookie is likely to be an open file descriptor.
buf
Where to store the data.
buf_size
The number of available bytes of space in buf.
See Also
“hc_store_both_ez” on page 87
write_to_data_destination
Data destination template used to download object data to the cluster.
Synopsis
typedef long (*write_to_data_destination)
(void *cookie, char *buff, long buff_len);
50 | Sun StorageTek 5800 System Client API Reference Manual • June 2008 |
