spec.md

Webassembly System Interface

The system interface defines which imports are avaible to Webassembly programs running inside Primea.

We define the following types:

• i32: same as i32 in WebAssembly
• i32ptr: same as i32 in WebAssembly, but treated as a pointer to a WebAssembly memory offset
• i32ref: same as i32 in WebAssembly, but treated as a reference to a Primea object

Storage

storeMessage

Store a message along with it's data and associated capablilities persistently at a given index

Parameters

• index i32 - an index to store the capability at
• msgRef i32ref - the reference to the message being stored

loadMessage

Loads a message along with it's data and associated capablilities from persistant storage at a given index

Parameters

• index i32
• callback i32ptr - the callback function which is given an i32ref of a message containing the loaded data

Returns

• i32ref - the reference to the capability being loaded

deleteMessage

Deletes a message from persistant storage at a given index

Parameters

• index i32

Messages

createMessage

Messages can contain data which is read from memory starting at the offset and going for len bytes.

Parameters

• offset i32ptr - a pointer to the location in memory to start reading from
• len i32 - the number of bytes to read starting from offset
• responseCap i32ref - A capability that is used to send a response. If no response is desired then a negitive integer can be used instead of a referance.

Returns

• i32ref the refence to a the message

loadMessageData

Loads the message's data into memory

Parameters

• message i32ref - the reference to the message
• writeOffset i32ptr
• readOffset i32ptr
• len i32

addCapToMessage

Add a capability reference to a message

Parameters

• message i32ref - the reference to the message
• port i32ref - the reference to the capability

messageCapLen

get the number of caps contained in the message

Parameters

• message i32ref - the reference to the message

Returns

• i32

loadMessageCap

loads a capabilities reference from the message

Parameters

• message i32ref - the reference to the message
• index i32 which capability to in the message to load

Returns

• i32

sendMessage

sends a message

Parameters

• cap i32ref - the reference to the capability to send the message
• message i32ref - the reference to the message
• ticks i32 - the number of ticks to allocate to this message

messageDataLen

Gets the number of bytes contain in the message's data payload

Parameters

• message i32ref - the reference to the message

Returns

• i32

getMessageTag

Gets the tag of the capabilbilty that was used to send the message

Parameters

• message i32ref - The reference to the message

Returns

• i32

getNextMessage

Gets the next message from the inbox, if any, while maintaing the current state of the VM.

Parameters

• timeout i32 - The amount of ticks to wait before timeing out.
• timeout_callback i32ptr - the callback function which is called if getNextMessage timeseout

respond

Sends a response to the current message using its response capability.

Parameters

• message i32Ref - The message to send in response.

createActor

Creates a new actor given a message. A message's data field must contain the wasm binary of the new actor.

Parameters

• message i32Ref - The message to send in response.

references

mintCap

Mints a new capability to message the minter

Returns

• i32ref the refence to a the capability

isValidRef

test if a given i32 is a valid reference or not

Parameters

• message i32ref

Returns

• i32

deleteRef

deletes a reference

Parameters

• message i32ref