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
|
// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
//! Traits for data providers that produce opaque buffers.
use crate::prelude::*;
/// [`DataMarker`] for raw buffers. Returned by [`BufferProvider`].
///
/// The data is expected to be deserialized before it can be used; see
/// [`DataPayload::into_deserialized`].
#[allow(clippy::exhaustive_structs)] // marker type
pub struct BufferMarker;
impl DataMarker for BufferMarker {
type Yokeable = &'static [u8];
}
/// A data provider that returns opaque bytes.
///
/// Generally, these bytes are expected to be deserializable with Serde. To get an object
/// implementing [`DataProvider`] via Serde, use [`as_deserializing()`], which requires
/// enabling at least one of the deserialization Cargo features:
///
/// - `deserialize_json`
/// - `deserialize_postcard_1`
/// - `deserialize_bincode_1`
///
/// Along with [`DataProvider`], this is one of the two foundational traits in this crate.
///
/// [`BufferProvider`] can be made into a trait object. It is used over FFI.
///
/// # Examples
///
/// ```
/// # #[cfg(feature = "deserialize_json")] {
/// use icu_locid::locale;
/// use icu_provider::hello_world::*;
/// use icu_provider::prelude::*;
///
/// let buffer_provider = HelloWorldProvider.into_json_provider();
///
/// let data_provider = buffer_provider.as_deserializing();
///
/// let german_hello_world: DataPayload<HelloWorldV1Marker> = data_provider
/// .load(DataRequest {
/// locale: &locale!("de").into(),
/// metadata: Default::default(),
/// })
/// .expect("Loading should succeed")
/// .take_payload()
/// .expect("Data should be present");
///
/// assert_eq!("Hallo Welt", german_hello_world.get().message);
/// # }
/// ```
///
/// [`as_deserializing()`]: AsDeserializingBufferProvider::as_deserializing
pub trait BufferProvider {
/// Loads a [`DataPayload`]`<`[`BufferMarker`]`>` according to the key and request.
fn load_buffer(
&self,
key: DataKey,
req: DataRequest,
) -> Result<DataResponse<BufferMarker>, DataError>;
}
impl<T: BufferProvider + ?Sized> BufferProvider for alloc::boxed::Box<T> {
fn load_buffer(
&self,
key: DataKey,
req: DataRequest,
) -> Result<DataResponse<BufferMarker>, DataError> {
(**self).load_buffer(key, req)
}
}
/// An enum expressing all Serde formats known to ICU4X.
#[derive(Debug, PartialEq, Eq, Hash, Copy, Clone)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[non_exhaustive]
pub enum BufferFormat {
/// Serialize using JavaScript Object Notation (JSON).
Json,
/// Serialize using Bincode version 1.
Bincode1,
/// Serialize using Postcard version 0.7.
Postcard1,
}
impl BufferFormat {
/// Returns an error if the buffer format is not enabled.
pub fn check_available(&self) -> Result<(), DataError> {
match self {
#[cfg(feature = "deserialize_json")]
BufferFormat::Json => Ok(()),
#[cfg(feature = "deserialize_bincode_1")]
BufferFormat::Bincode1 => Ok(()),
#[cfg(feature = "deserialize_postcard_1")]
BufferFormat::Postcard1 => Ok(()),
// Allowed for cases in which all features are enabled
#[allow(unreachable_patterns)]
_ => Err(DataErrorKind::UnavailableBufferFormat(*self).into_error()),
}
}
}
|
