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ABI Functions Reference

Host functions

Below is the list of functions exported by the W3bstream VM that you can import into your WASM module to access functionalities provided by the W3bstream host.
/**
* Get event data.
*
* Provides access to the buffer of data attached to W3bstream event
*
* @param resource_id the event id, provided by W3bstream in the _start function.
* @param return_ptr pointer to the data buffer
* @param return_size the size in bytes of the data buffer
* @return 0 if no errors.
*/
fn ws_get_data(resource_id i32, return_ptr i32, return_size i32) -> i32
​
/**
* Set event data.
*
* Inject modified event data back in the source event for further processing
* @Notice: This is not used yet
*
* @param resource_id the event id, provided by W3bstream in the _start function.
* @param ptr pointer to the data buffer
* @size the size in bytes of the data buffer
* @return 0 if no errors.
*/
fn ws_set_data(resource_id i32, ptr i32, size i32) -> i32
​
/**
* Read data from DB
*
* Get a serialized object from the W3bstream database at a specific key.
*
* @param namespace_data the namespace name (depends on the DB config)
* @param namespace_size the length of the namespace string
* @param key_data the key you want to fetch from the DB
* @param key_size the length of the key string
* @param return_value_ptr is the pointer to the fetched DB data
* @param return_value_size the size of fetched DB data
* @return 0 if there are no errors.
*/
fn ws_get_db(namespace_data i32, namespace_size i32, key_data i32, key_size i32,
return_value_ptr i32, return_value_size i32) -> i32
​
/**
* Store data in DB
*
* Store a serialized object in the W3bstream database at a specific key.
*
* @param namespace_data the namespace name (depends on the DB config)
* @param namespace_size the length of the namespace string
* @param key_data the key you want to store the data under in the DB
* @param key_size the length of the key string
* @param value_ptr is the pointer to the data to store
* @param value_size the size of the data
* @return 0 if there are no errors.
*/
fn ws_set_db(namespace_data i32, namespace_size i32, key_data i32, key_size i32,
value_ptr i32, value_size i32) -> i32
​
/**
* Log a message
*
* Log a string to the W3bstream console
*
* @param log_level The log level (Trace = 1, Debug, Info, Warn, Error)
* @param ptr The pointer to the string to be logged
* @param size the length of the string
* @param key_data the key you want to fetch from the DB
* @return 0 if no errors.
*/
fn ws_log(log_level i32, ptr i32, size i32) -> i32
​
/**
* Send a blockchain transaction
*
* Sends a transaction to the blockchain network that has been
* configured on the host side.
*
* @param ptr The pointer to the stringified transaction data
* @param size the length of the data
* @return 0 if no errors.
*/
fn ws_send_tx(ptr i32, size: i32) -> i32;
​
/**
* Call a contract function
*
* Calls a (view or pure) contract function on the blockchain network
* configured on the host side.
*
* @param ptr The pointer to the stringified transaction data
* @param size the length of the data
* @return 0 if no errors.
*/
fn ws_call_contract(ptr i32, size: i32, return_ptr i32, return_size i32 ) -> i32;
​

Applet functions

Below is the list of functions that your WASM module is required to export to the W3bstream host:
// Provide an implementation unless already provided by the WASM compiler you're using
fn malloc(size: usize) -> *mut c_void
​
// Default handler called by W3bstream upon a new event
fn _start(resource_id i32) -> i32