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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
use super::mailbox::MailMeta;
use super::snapshot::FrozenMailbox;
use super::uidindex::IndexEntry;
use super::unique_ident::UniqueIdent;
use anyhow::{anyhow, Result};
use futures::stream::{FuturesUnordered, StreamExt};
/// Query is in charge of fetching efficiently
/// requested data for a list of emails
pub struct Query<'a, 'b> {
pub frozen: &'a FrozenMailbox,
pub emails: &'b [UniqueIdent],
pub scope: QueryScope,
}
#[allow(dead_code)]
pub enum QueryScope {
Index,
Partial,
Full,
}
impl<'a, 'b> Query<'a, 'b> {
pub async fn fetch(&self) -> Result<Vec<QueryResult<'a>>> {
match self.scope {
QueryScope::Index => self.index(),
QueryScope::Partial => self.partial().await,
QueryScope::Full => self.full().await,
}
}
// --- functions below are private *for reasons*
fn index(&self) -> Result<Vec<QueryResult<'a>>> {
self.emails
.iter()
.map(|uuid| {
self.frozen
.snapshot
.table
.get(uuid)
.map(|index| QueryResult::IndexResult { uuid: *uuid, index })
.ok_or(anyhow!("missing email in index"))
})
.collect::<Result<Vec<_>, _>>()
}
async fn partial(&self) -> Result<Vec<QueryResult<'a>>> {
let meta = self.frozen.mailbox.fetch_meta(self.emails).await?;
let result = meta
.into_iter()
.zip(self.index()?)
.map(|(metadata, index)| {
index
.into_partial(metadata)
.expect("index to be IndexResult")
})
.collect::<Vec<_>>();
Ok(result)
}
/// @FIXME WARNING: THIS CAN ALLOCATE A LOT OF MEMORY
/// AND GENERATE SO MUCH NETWORK TRAFFIC.
/// THIS FUNCTION SHOULD BE REWRITTEN, FOR EXAMPLE WITH
/// SOMETHING LIKE AN ITERATOR
async fn full(&self) -> Result<Vec<QueryResult<'a>>> {
let meta_list = self.partial().await?;
meta_list
.into_iter()
.map(|meta| async move {
let content = self
.frozen
.mailbox
.fetch_full(
*meta.uuid(),
&meta
.metadata()
.expect("meta to be PartialResult")
.message_key,
)
.await?;
Ok(meta.into_full(content).expect("meta to be PartialResult"))
})
.collect::<FuturesUnordered<_>>()
.collect::<Vec<_>>()
.await
.into_iter()
.collect::<Result<Vec<_>, _>>()
}
}
pub enum QueryResult<'a> {
IndexResult {
uuid: UniqueIdent,
index: &'a IndexEntry,
},
PartialResult {
uuid: UniqueIdent,
index: &'a IndexEntry,
metadata: MailMeta,
},
FullResult {
uuid: UniqueIdent,
index: &'a IndexEntry,
metadata: MailMeta,
content: Vec<u8>,
},
}
impl<'a> QueryResult<'a> {
pub fn uuid(&self) -> &UniqueIdent {
match self {
Self::IndexResult { uuid, .. } => uuid,
Self::PartialResult { uuid, .. } => uuid,
Self::FullResult { uuid, .. } => uuid,
}
}
#[allow(dead_code)]
pub fn index(&self) -> &IndexEntry {
match self {
Self::IndexResult { index, .. } => index,
Self::PartialResult { index, .. } => index,
Self::FullResult { index, .. } => index,
}
}
pub fn metadata(&'a self) -> Option<&'a MailMeta> {
match self {
Self::IndexResult { .. } => None,
Self::PartialResult { metadata, .. } => Some(metadata),
Self::FullResult { metadata, .. } => Some(metadata),
}
}
#[allow(dead_code)]
pub fn content(&'a self) -> Option<&'a [u8]> {
match self {
Self::FullResult { content, .. } => Some(content),
_ => None,
}
}
fn into_partial(self, metadata: MailMeta) -> Option<Self> {
match self {
Self::IndexResult { uuid, index } => Some(Self::PartialResult {
uuid,
index,
metadata,
}),
_ => None,
}
}
fn into_full(self, content: Vec<u8>) -> Option<Self> {
match self {
Self::PartialResult {
uuid,
index,
metadata,
} => Some(Self::FullResult {
uuid,
index,
metadata,
content,
}),
_ => None,
}
}
}
|
