neco-cid 0.2.0

necosystems series CIDv1 and multibase core
Documentation 
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

# neco-cid

[日本語](README-ja.md)

A minimal CIDv1 library with only a `sha2` dependency, providing CID computation and multibase encode/decode for IPLD and AT Protocol use cases.

## Features

- Single dependency: `sha2` (core functionality)
- CIDv1 compute, byte serialization, and deserialization
- Multibase encode/decode (base32lower, `b` prefix)
- Supported codecs: `dag-cbor` (0x71), `raw` (0x55)
- Hash function: SHA-256 only

## Usage

### Compute a CID

```rust
use neco_cid::{Cid, Codec, Base};

let data = b"hello world";
let cid = Cid::compute(Codec::DagCbor, data);

let s = cid.to_multibase(Base::Base32Lower);
// base32lower string like "bafyrei..."
```

### Decode from a CID string

```rust
use neco_cid::Cid;

let cid = Cid::from_multibase("bafyreib...").unwrap();
```

### Round-trip through bytes

```rust
use neco_cid::Cid;

let bytes = cid.to_bytes();
let (cid2, consumed) = Cid::from_bytes(&bytes).unwrap();
assert_eq!(cid, cid2);
assert_eq!(consumed, bytes.len());
```

## API

### `Cid`

Represents a CIDv1. Implements `Debug`, `Clone`, `PartialEq`, `Eq`, `Hash`.

| Item | Description |
|------|-------------|
| `Cid::compute(codec: Codec, data: &[u8]) -> Cid` | Compute a CID from the SHA-256 hash of data |
| `Cid::from_bytes(input: &[u8]) -> Result<(Cid, usize), CidError>` | Deserialize a CID from bytes, returning the number of bytes consumed |
| `Cid::to_bytes(&self) -> Vec<u8>` | Serialize the CID to bytes |
| `Cid::to_multibase(&self, base: Base) -> String` | Encode the CID as a multibase string in the given base |
| `Cid::from_multibase(input: &str) -> Result<Cid, CidError>` | Decode a CID from a multibase string |
| `Cid::codec(&self) -> Codec` | Return the codec |
| `Cid::digest(&self) -> &[u8; 32]` | Return the SHA-256 digest |

### `Codec`

| Variant | Value | Description |
|---------|-------|-------------|
| `Codec::DagCbor` | `0x71` | DAG-CBOR |
| `Codec::Raw` | `0x55` | Raw bytes |

### `Base`

| Variant | Prefix | Description |
|---------|--------|-------------|
| `Base::Base32Lower` | `b` | RFC 4648 base32 lowercase, no padding |

### `CidError`

| Variant | Description |
|---------|-------------|
| `InvalidVersion(u64)` | Version other than CIDv1 |
| `UnsupportedCodec(u64)` | Unsupported codec code |
| `UnsupportedHashCode(u64)` | Unsupported hash function code |
| `InvalidDigestLength` | Digest length is not 32 bytes |
| `InvalidMultibase` | Malformed multibase string |
| `UnexpectedEnd` | Input ended prematurely |

## License

MIT