Notes

The RHT library is unaware of any internal structure in the keys and values it stores and exactly replicates (byte-for-byte) inserted keys and values at each of a rht's replicas. The user specifies how keys should be locally compared to one another at replica creation through rht_create. By default, the total size of each key-value pair inserted into the dictionary must be smaller than approximately 100KB. To alter this compile-time limitation, please contact Spread Concepts.

Of all the rht_* functions, only rht_strerror is completely non-blocking. All of the other function calls can block based on thread contention over a lock and/or network I/O. In particular, the query functions (rht_size, rht_get, etc.) will, by default, block until any previous updates (inserts or deletes) generated at this replica have been incorporated into the rht. This enforces causality.

For example, if a thread puts a key-value pair into a replica and then takes a snapshot, then any remaining effect of that put update will be reflected in the returned snapshot. This functionality can be overridden if such causality is not necessary by specifying the RHT_DIRTY_READ flag in the function call.