1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
use quote::quote_spanned;
use super::{
OperatorCategory, OperatorConstraints, OperatorWriteOutput, RANGE_0, RANGE_1, WriteContextArgs,
};
// TODO(mingwei): more doc
/// Multiset delta from the previous tick.
///
/// ```rustbook
/// let (input_send, input_recv) = dfir_rs::util::unbounded_channel::<u32>();
/// let mut flow = dfir_rs::dfir_syntax! {
/// source_stream(input_recv)
/// -> multiset_delta()
/// -> for_each(|n| println!("{}", n));
/// };
///
/// input_send.send(3).unwrap();
/// input_send.send(4).unwrap();
/// input_send.send(3).unwrap();
/// flow.run_tick();
/// // 3, 4,
///
/// input_send.send(3).unwrap();
/// input_send.send(5).unwrap();
/// input_send.send(3).unwrap();
/// input_send.send(3).unwrap();
/// flow.run_tick();
/// // 5, 3
/// // First two "3"s are removed due to previous tick.
/// ```
pub const MULTISET_DELTA: OperatorConstraints = OperatorConstraints {
name: "multiset_delta",
categories: &[OperatorCategory::Persistence],
hard_range_inn: RANGE_1,
soft_range_inn: RANGE_1,
hard_range_out: RANGE_1,
soft_range_out: RANGE_1,
num_args: 0,
persistence_args: RANGE_0,
type_args: RANGE_0,
is_external_input: false,
// If this is set to true, the state will need to be cleared using `#context.set_state_lifespan_hook`
// to prevent reading uncleared data if this subgraph doesn't run.
// https://github.com/hydro-project/hydro/issues/1298
// If `'tick` lifetimes are added.
has_singleton_output: false,
flo_type: None,
ports_inn: None,
ports_out: None,
input_delaytype_fn: |_| None,
write_fn: |wc @ &WriteContextArgs {
root,
op_span,
context,
df_ident,
ident,
inputs,
outputs,
is_pull,
work_fn,
..
},
_| {
let input = &inputs[0];
let output = &outputs[0];
let prev_data = wc.make_ident("prev_data");
let curr_data = wc.make_ident("curr_data");
let write_prologue = quote_spanned! {op_span=>
let #prev_data = #df_ident.add_state(::std::cell::RefCell::new(#root::rustc_hash::FxHashMap::default()));
let #curr_data = #df_ident.add_state(::std::cell::RefCell::new(#root::rustc_hash::FxHashMap::default()));
};
let tick_swap = quote_spanned! {op_span=>
{
if context.is_first_run_this_tick() {
let (mut prev_map, mut curr_map) = unsafe {
// SAFETY: handle from `#df_ident.add_state(..)`.
(
#context.state_ref_unchecked(#prev_data).borrow_mut(),
#context.state_ref_unchecked(#curr_data).borrow_mut(),
)
};
::std::mem::swap(::std::ops::DerefMut::deref_mut(&mut prev_map), ::std::ops::DerefMut::deref_mut(&mut curr_map));
curr_map.clear();
}
}
};
let filter_fn = quote_spanned! {op_span=>
|item| {
let (mut prev_map, mut curr_map) = unsafe {
// SAFETY: handle from `#df_ident.add_state(..)`.
(
#context.state_ref_unchecked(#prev_data).borrow_mut(),
#context.state_ref_unchecked(#curr_data).borrow_mut(),
)
};
*curr_map.entry(#[allow(clippy::clone_on_copy)] item.clone()).or_insert(0_usize) += 1;
if let Some(old_count) = prev_map.get_mut(item) {
#[allow(clippy::absurd_extreme_comparisons)] // Usize cannot be less than zero.
if *old_count <= 0 {
true
} else {
*old_count -= 1;
false
}
} else {
true
}
}
};
let write_iterator = if is_pull {
quote_spanned! {op_span=>
#work_fn(|| #tick_swap);
let #ident = #root::dfir_pipes::pull::Pull::filter(#input, #filter_fn);
}
} else {
quote_spanned! {op_span=>
#work_fn(|| #tick_swap);
let #ident = #root::dfir_pipes::push::filter(#filter_fn, #output);
}
};
Ok(OperatorWriteOutput {
write_prologue,
write_iterator,
..Default::default()
})
},
};