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
|
use lastfm;
use failure::Fail;
const SCHEMA: &'static str = "
CREATE TABLE `tracks` (
artist varchar(1024) NOT NULL,
album varchar(1024) DEFAULT NULL,
name varchar(1024) NOT NULL,
timestamp integer(11) NOT NULL
);
";
pub struct DB {
conn: rusqlite::Connection,
}
impl DB {
pub fn new<P: AsRef<std::path::Path>>(path: &P) -> failure::Fallible<DB> {
let conn = if path.as_ref().exists() {
rusqlite::Connection::open(path)
.map_err(|e| {
let msg = format!(
"couldn't open db at {}",
path.as_ref().display()
);
e.context(msg)
})?
}
else {
Self::create(path)?
};
return Ok(DB { conn })
}
fn create<P: AsRef<std::path::Path>>(
path: &P
) -> failure::Fallible<rusqlite::Connection> {
println!(
"Initializing database at {}",
path.as_ref().to_string_lossy(),
);
if let Some(parent) = path.as_ref().parent() {
std::fs::create_dir_all(parent)?;
let conn = rusqlite::Connection::open(path)
.map_err(|e| {
let msg = format!(
"couldn't create db at {}",
path.as_ref().display()
);
e.context(msg)
})?;
conn.execute(SCHEMA, rusqlite::NO_PARAMS)
.map_err(|e| e.context("failed to execute schema"))?;
Ok(conn)
}
else {
unimplemented!();
}
}
pub fn most_recent_timestamp(&self) -> failure::Fallible<Option<i64>> {
Ok(self.conn.query_row(
"SELECT timestamp FROM tracks ORDER BY timestamp DESC LIMIT 1",
rusqlite::NO_PARAMS,
|row| Some(row.get(0))
).or_else(|e| {
match e {
rusqlite::Error::QueryReturnedNoRows => Ok(None),
_ => Err(e),
}
})?)
}
pub fn insert_tracks<F: FnMut(lastfm::Track)>(
&self,
tracks: impl Iterator<Item=lastfm::Track>,
mut f: F
) -> failure::Fallible<()> {
let mut sth = self.conn.prepare("INSERT INTO tracks VALUES (?, ?, ?, ?)")?;
for track in tracks {
sth.execute(
&[
&track.artist as &rusqlite::types::ToSql,
&track.album,
&track.name,
&track.timestamp,
]).map(|_| ())?;
f(track);
}
Ok(())
}
}
|