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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
// Any copyright is dedicated to the Public Domain.
// http://creativecommons.org/publicdomain/zero/1.0/
//! A simple rkv demo that showcases the basic usage (put/get/delete) of rkv.
//!
//! You can test this out by running:
//!
//! cargo run --example simple-store
use std::fs;
use tempfile::Builder;
use rkv::{
backend::{SafeMode, SafeModeDatabase, SafeModeEnvironment, SafeModeRwTransaction},
Manager, Rkv, StoreOptions, Value,
};
type MultiStore = rkv::MultiStore<SafeModeDatabase>;
type Writer<'w> = rkv::Writer<SafeModeRwTransaction<'w>>;
fn getput<'w, 's>(store: MultiStore, writer: &'w mut Writer, ids: &'s mut Vec<String>) {
let keys = vec!["str1", "str2", "str3"];
// we convert the writer into a cursor so that we can safely read
for k in keys.iter() {
// this is a multi-valued database, so get returns an iterator
let mut iter = store.get(writer, k).unwrap();
while let Some(Ok((_key, val))) = iter.next() {
if let Value::Str(s) = val {
ids.push(s.to_owned());
} else {
panic!("didn't get a string back!");
}
}
}
for id in ids {
store.put(writer, &id, &Value::Blob(b"weeeeeee")).unwrap();
}
}
fn delete(store: MultiStore, writer: &mut Writer) {
let keys = vec!["str1", "str2", "str3"];
let vals = vec!["string uno", "string quatro", "string siete"];
// we convert the writer into a cursor so that we can safely read
for i in 0..keys.len() {
store
.delete(writer, &keys[i], &Value::Str(vals[i]))
.unwrap();
}
}
fn main() {
let root = Builder::new().prefix("simple-db").tempdir().unwrap();
fs::create_dir_all(root.path()).unwrap();
let p = root.path();
// The manager enforces that each process opens the same lmdb environment at most once
let mut manager = Manager::<SafeModeEnvironment>::singleton().write().unwrap();
let created_arc = manager.get_or_create(p, Rkv::new::<SafeMode>).unwrap();
let k = created_arc.read().unwrap();
// Creates a store called "store"
let store = k.open_single("store", StoreOptions::create()).unwrap();
let multistore = k.open_multi("multistore", StoreOptions::create()).unwrap();
println!("Inserting data...");
{
// Use a writer to mutate the store
let mut writer = k.write().unwrap();
store.put(&mut writer, "int", &Value::I64(1234)).unwrap();
store
.put(&mut writer, "uint", &Value::U64(1234_u64))
.unwrap();
store
.put(&mut writer, "float", &Value::F64(1234.0.into()))
.unwrap();
store
.put(&mut writer, "instant", &Value::Instant(1_528_318_073_700))
.unwrap();
store
.put(&mut writer, "boolean", &Value::Bool(true))
.unwrap();
store
.put(&mut writer, "string", &Value::Str("héllo, yöu"))
.unwrap();
store
.put(
&mut writer,
"json",
&Value::Json(r#"{"foo":"bar", "number": 1}"#),
)
.unwrap();
store
.put(&mut writer, "blob", &Value::Blob(b"blob"))
.unwrap();
writer.commit().unwrap();
}
println!("Testing getput");
{
let mut ids = Vec::new();
let mut writer = k.write().unwrap();
multistore
.put(&mut writer, "str1", &Value::Str("string uno"))
.unwrap();
multistore
.put(&mut writer, "str1", &Value::Str("string dos"))
.unwrap();
multistore
.put(&mut writer, "str1", &Value::Str("string tres"))
.unwrap();
multistore
.put(&mut writer, "str2", &Value::Str("string quatro"))
.unwrap();
multistore
.put(&mut writer, "str2", &Value::Str("string cinco"))
.unwrap();
multistore
.put(&mut writer, "str2", &Value::Str("string seis"))
.unwrap();
multistore
.put(&mut writer, "str3", &Value::Str("string siete"))
.unwrap();
multistore
.put(&mut writer, "str3", &Value::Str("string ocho"))
.unwrap();
multistore
.put(&mut writer, "str3", &Value::Str("string nueve"))
.unwrap();
getput(multistore, &mut writer, &mut ids);
writer.commit().unwrap();
let mut writer = k.write().unwrap();
delete(multistore, &mut writer);
writer.commit().unwrap();
}
println!("Looking up keys...");
{
// Use a reader to query the store
let reader = k.read().unwrap();
println!("Get int {:?}", store.get(&reader, "int").unwrap());
println!("Get uint {:?}", store.get(&reader, "uint").unwrap());
println!("Get float {:?}", store.get(&reader, "float").unwrap());
println!("Get instant {:?}", store.get(&reader, "instant").unwrap());
println!("Get boolean {:?}", store.get(&reader, "boolean").unwrap());
println!("Get string {:?}", store.get(&reader, "string").unwrap());
println!("Get json {:?}", store.get(&reader, "json").unwrap());
println!("Get blob {:?}", store.get(&reader, "blob").unwrap());
println!(
"Get non-existent {:?}",
store.get(&reader, "non-existent").unwrap()
);
}
println!("Looking up keys via Writer.get()...");
{
let mut writer = k.write().unwrap();
store.put(&mut writer, "foo", &Value::Str("bar")).unwrap();
store.put(&mut writer, "bar", &Value::Str("baz")).unwrap();
store.delete(&mut writer, "foo").unwrap();
println!(
"It should be None! ({:?})",
store.get(&writer, "foo").unwrap()
);
println!("Get bar ({:?})", store.get(&writer, "bar").unwrap());
writer.commit().unwrap();
let reader = k.read().expect("reader");
println!(
"It should be None! ({:?})",
store.get(&reader, "foo").unwrap()
);
println!("Get bar {:?}", store.get(&reader, "bar").unwrap());
}
println!("Aborting transaction...");
{
// Aborting a write transaction rollbacks the change(s)
let mut writer = k.write().unwrap();
store.put(&mut writer, "foo", &Value::Str("bar")).unwrap();
writer.abort();
let reader = k.read().expect("reader");
println!(
"It should be None! ({:?})",
store.get(&reader, "foo").unwrap()
);
// Explicitly aborting a transaction is not required unless an early
// abort is desired, since both read and write transactions will
// implicitly be aborted once they go out of scope.
}
println!("Deleting keys...");
{
// Deleting a key/value also requires a write transaction
let mut writer = k.write().unwrap();
store.put(&mut writer, "foo", &Value::Str("bar")).unwrap();
store.delete(&mut writer, "foo").unwrap();
println!(
"It should be None! ({:?})",
store.get(&writer, "foo").unwrap()
);
writer.commit().unwrap();
// Committing a transaction consumes the writer, preventing you
// from reusing it by failing and reporting a compile-time error.
// This line would report error[E0382]: use of moved value: `writer`.
// store.put(&mut writer, "baz", &Value::Str("buz")).unwrap();
}
println!("Clearing store...");
{
// Clearing a store deletes all the entries in that store
let mut writer = k.write().unwrap();
store.put(&mut writer, "foo", &Value::Str("bar")).unwrap();
store.put(&mut writer, "bar", &Value::Str("baz")).unwrap();
store.clear(&mut writer).unwrap();
writer.commit().unwrap();
let reader = k.read().expect("reader");
println!(
"It should be None! ({:?})",
store.get(&reader, "foo").unwrap()
);
println!(
"It should be None! ({:?})",
store.get(&reader, "bar").unwrap()
);
}
println!("Write and read on multiple stores...");
{
let another_store = k
.open_single("another_store", StoreOptions::create())
.unwrap();
let mut writer = k.write().unwrap();
store.put(&mut writer, "foo", &Value::Str("bar")).unwrap();
another_store
.put(&mut writer, "foo", &Value::Str("baz"))
.unwrap();
writer.commit().unwrap();
let reader = k.read().unwrap();
println!(
"Get from store value: {:?}",
store.get(&reader, "foo").unwrap()
);
println!(
"Get from another store value: {:?}",
another_store.get(&reader, "foo").unwrap()
);
}
}
|
