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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use super::{
action::Action,
error::{BitsTaskError, ErrorStage::CommandThread, ErrorType::MissingBitsClient},
string::nsCString_to_OsString,
};
use bits_client::BitsClient;
use nsstring::nsCString;
use std::cell::Cell;
thread_local! {
// This is used to store the `BitsClient` on the Command thread.
// Keeping it here solves the problem of how to allow multiple runnables to
// be simultaneously queued on the Command thread while giving them all
// access to the same `BitsClient`.
static BITS_CLIENT: Cell<Option<BitsClient>> = Cell::new(None);
}
/// This structure holds the data needed to initialize `BitsClient` and
/// `BitsMonitorClient`.
#[derive(Debug, Clone)]
pub struct ClientInitData {
pub job_name: nsCString,
pub save_path_prefix: nsCString,
pub monitor_timeout_ms: u32,
}
impl ClientInitData {
pub fn new(
job_name: nsCString,
save_path_prefix: nsCString,
monitor_timeout_ms: u32,
) -> ClientInitData {
ClientInitData {
job_name,
save_path_prefix,
monitor_timeout_ms,
}
}
}
/// This function constructs a `BitsClient`, if one does not already exist. If
/// the `BitsClient` cannot be constructed, a `BitsTaskError` will be returned.
/// If the `BitsClient` could be obtained, then the function then calls the
/// closure passed to it, passing a mutable reference to the `BitsClient`.
/// This function will then return whatever the closure returned, which must be
/// a `Result<_, BitsTaskError>`.
pub fn with_maybe_new_bits_client<F, R>(
init_data: &ClientInitData,
action: Action,
closure: F,
) -> Result<R, BitsTaskError>
where
F: FnOnce(&mut BitsClient) -> Result<R, BitsTaskError>,
{
_with_bits_client(Some(init_data), action, closure)
}
/// This function assumes that a `BitsClient` has already been constructed. If
/// there is not one available, a `BitsTaskError` will be returned. Otherwise,
/// the function calls the closure passed to it, passing a mutable reference to
/// the `BitsClient`. This function will then return whatever the closure
/// returned, which must be a `Result<_, BitsTaskError>`.
pub fn with_bits_client<F, R>(action: Action, closure: F) -> Result<R, BitsTaskError>
where
F: FnOnce(&mut BitsClient) -> Result<R, BitsTaskError>,
{
_with_bits_client(None, action, closure)
}
fn _with_bits_client<F, R>(
maybe_init_data: Option<&ClientInitData>,
action: Action,
closure: F,
) -> Result<R, BitsTaskError>
where
F: FnOnce(&mut BitsClient) -> Result<R, BitsTaskError>,
{
BITS_CLIENT.with(|cell| {
let maybe_client = cell.take();
let mut client = match (maybe_client, maybe_init_data) {
(Some(r), _) => r,
(None, Some(init_data)) => {
// Immediately invoked function to allow for the ? operator
BitsClient::new(
nsCString_to_OsString(&init_data.job_name, action, CommandThread)?,
nsCString_to_OsString(&init_data.save_path_prefix, action, CommandThread)?,
)
.map_err(|pipe_error| BitsTaskError::from_pipe(action, pipe_error))?
}
(None, None) => {
return Err(BitsTaskError::new(MissingBitsClient, action, CommandThread));
}
};
let result = closure(&mut client);
cell.set(Some(client));
result
})
}