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use crate::CommandClient;
use mechutil::ipc::CommandMessage;
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum State {
Idle,
WaitingForResponse,
}
/// Function block for reading a file from the DataStore.
pub struct DataStoreRead {
/// True while waiting for a response from the datastore.
pub busy: bool,
/// True when the read operation finishes successfully. Stays true until reset or restarted.
pub done: bool,
/// True if the operation failed.
pub error: bool,
/// Error description (empty when no error).
pub error_message: String,
/// The parsed JSON data from the file. `Some` after a successful read, `None` otherwise.
pub data: Option<serde_json::Value>,
state: State,
start_time: Option<std::time::Instant>,
pending_tid: Option<u32>,
}
impl DataStoreRead {
/// Create a new DataStoreRead function block.
pub fn new() -> Self {
Self {
busy: false,
done: false,
error: false,
error_message: String::new(),
data: None,
state: State::Idle,
start_time: None,
pending_tid: None,
}
}
/// The FB is currently awaiting a response.
pub fn is_busy(&self) -> bool {
self.busy
}
/// The last read resulted in an error.
pub fn is_error(&self) -> bool {
self.error
}
/// Start a new file read from the DataStore.
///
/// # Arguments
/// * `path` - The path to the file relative to the datastore root (e.g., `"config.json"`).
/// * `client` - The IPC command client.
pub fn start(&mut self, path: &str, client: &mut CommandClient) {
self.error = false;
self.error_message.clear();
self.data = None;
self.done = false;
let msg = CommandMessage::read(&format!("datastore.{}", path));
self.pending_tid = Some(client.send_message(msg));
self.start_time = Some(std::time::Instant::now());
self.busy = true;
self.state = State::WaitingForResponse;
}
/// Cancel the read and return to idle.
pub fn reset(&mut self) {
self.state = State::Idle;
self.busy = false;
self.done = false;
self.pending_tid = None;
}
/// Execute one scan cycle of the read state machine.
pub fn tick(&mut self, timeout_ms: u32, client: &mut CommandClient) {
match self.state {
State::Idle => {}
State::WaitingForResponse => {
if self.check_timeout(timeout_ms) {
return;
}
if let Some(tid) = self.pending_tid {
if let Some(resp) = client.take_response(tid) {
self.pending_tid = None;
self.busy = false;
if resp.success {
self.data = Some(resp.data);
self.done = true;
self.state = State::Idle;
} else {
self.set_error(&resp.error_message);
}
}
}
}
}
}
fn check_timeout(&mut self, timeout_ms: u32) -> bool {
if let Some(t) = self.start_time {
if t.elapsed().as_millis() as u32 > timeout_ms {
self.set_error("Datastore read timeout");
return true;
}
}
false
}
fn set_error(&mut self, message: &str) {
self.state = State::Idle;
self.busy = false;
self.error = true;
self.error_message = message.to_string();
self.pending_tid = None;
}
}
impl Default for DataStoreRead {
fn default() -> Self {
Self::new()
}
}
/// Function block for writing a file to the DataStore.
pub struct DataStoreWrite {
/// True while waiting for a response from the datastore.
pub busy: bool,
/// True when the write operation finishes successfully. Stays true until reset or restarted.
pub done: bool,
/// True if the operation failed.
pub error: bool,
/// Error description (empty when no error).
pub error_message: String,
state: State,
start_time: Option<std::time::Instant>,
pending_tid: Option<u32>,
}
impl DataStoreWrite {
/// Create a new DataStoreWrite function block.
pub fn new() -> Self {
Self {
busy: false,
done: false,
error: false,
error_message: String::new(),
state: State::Idle,
start_time: None,
pending_tid: None,
}
}
/// The FB is currently awaiting a response.
pub fn is_busy(&self) -> bool {
self.busy
}
/// The last write resulted in an error.
pub fn is_error(&self) -> bool {
self.error
}
/// Start a new file write to the DataStore.
///
/// # Arguments
/// * `path` - The path to the file relative to the datastore root (e.g., `"config.json"`).
/// * `data` - The JSON payload to save to the file.
/// * `options` - Write options, such as `{"create_dirs": true}`.
/// * `client` - The IPC command client.
pub fn start(&mut self, path: &str, data: serde_json::Value, options: serde_json::Value, client: &mut CommandClient) {
self.error = false;
self.error_message.clear();
self.done = false;
let payload = serde_json::json!({
"value": data,
"options": options
});
let msg = CommandMessage::write(&format!("datastore.{}", path), payload);
self.pending_tid = Some(client.send_message(msg));
self.start_time = Some(std::time::Instant::now());
self.busy = true;
self.state = State::WaitingForResponse;
}
/// Cancel the write and return to idle.
pub fn reset(&mut self) {
self.state = State::Idle;
self.busy = false;
self.done = false;
self.pending_tid = None;
}
/// Execute one scan cycle of the write state machine.
pub fn tick(&mut self, timeout_ms: u32, client: &mut CommandClient) {
match self.state {
State::Idle => {}
State::WaitingForResponse => {
if self.check_timeout(timeout_ms) {
return;
}
if let Some(tid) = self.pending_tid {
if let Some(resp) = client.take_response(tid) {
self.pending_tid = None;
self.busy = false;
if resp.success {
self.done = true;
self.state = State::Idle;
} else {
self.set_error(&resp.error_message);
}
}
}
}
}
}
fn check_timeout(&mut self, timeout_ms: u32) -> bool {
if let Some(t) = self.start_time {
if t.elapsed().as_millis() as u32 > timeout_ms {
self.set_error("Datastore write timeout");
return true;
}
}
false
}
fn set_error(&mut self, message: &str) {
self.state = State::Idle;
self.busy = false;
self.error = true;
self.error_message = message.to_string();
self.pending_tid = None;
}
}
impl Default for DataStoreWrite {
fn default() -> Self {
Self::new()
}
}