Constant MAX_TX_BUFFERS

pub const MAX_TX_BUFFERS: u32 = 481; // 481u32

The maximum number of TxBuffer structs that could be sent in a single FIDL message while staying within the maximum message size enforced by the bindings.

At the time of writing, FIDL messages are limited to 65 KiB. In the current FIDL wire format, the size of a TxBuffer is 136 bytes, and the fixed overhead of the QueueTx request is 32 bytes (16 for the FIDL message header + 16 for the vector), so we selected the maximum N where 32 + N * 136 <= 65 KiB.