owasm-kit 0.3.1

Standard library for oracle scripts on BandChain
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

mod raw;

/// Returns the number of validators to asked to report data from raw requests.
pub fn get_ask_count() -> i64 {
    unsafe { raw::get_ask_count() }
}

/// Returns the minimum number of data reports as specified by the oracle request.
pub fn get_min_count() -> i64 {
    unsafe { raw::get_min_count() }
}

/// Return the prepare block time as specified by the oracle request.
pub fn get_prepare_time() -> i64 {
    unsafe { raw::get_prepare_time() }
}

/// Return the execute block time during the call of execution phase. Must only
/// be called during execution phase.
pub fn get_execute_time() -> i64 {
    unsafe { raw::get_execute_time() }
}

/// Returns the number of validators that report data to this oracle request. Must
/// only be called during execution phase.
pub fn get_ans_count() -> i64 {
    unsafe { raw::get_ans_count() }
}

/// Returns the raw calldata as specified when the oracle request is submitted.
pub fn get_calldata() -> Vec<u8> {
    unsafe {
        let mut data = Vec::with_capacity(raw::get_span_size() as usize);
        let len = raw::read_calldata(data.as_mut_ptr() as i64);
        data.set_len(len as usize);
        data
    }
}

/// Saves the given data as the result of the oracle execution. Must only be called
/// during execution phase and must be called exactly once.
pub fn save_return_data(data: &[u8]) {
    unsafe { raw::set_return_data(data.as_ptr() as i64, data.len() as i64) }
}

/// Issues a new raw request to the host environement using the specified data
/// source ID and calldata, and assigns it to the given external ID. Must only be
/// called during preparation phase.
pub fn ask_external_data(eid: i64, did: i64, calldata: &[u8]) {
    unsafe { raw::ask_external_data(eid, did, calldata.as_ptr() as i64, calldata.len() as i64) }
}

/// Returns the data reported from the given validator index for the given external
/// data ID. Result is OK if the validator reports data with zero return status, and
/// Err otherwise. Must only be called during execution phase.
pub fn get_external_data(eid: i64, vid: i64) -> Result<String, i64> {
    unsafe {
        let status = raw::get_external_data_status(eid, vid);
        if status != 0 {
            Err(status)
        } else {
            let mut data = Vec::with_capacity(raw::get_span_size() as usize);
            let len = raw::read_external_data(eid, vid, data.as_mut_ptr() as i64);
            data.set_len(len as usize);
            Ok(String::from_utf8_unchecked(data))
        }
    }
}

/// Return the verification result of ecvrf given a pubkey, a vrf proof, and the
/// corresponding result.
pub fn ecvrf_verify(y: &[u8], pi: &[u8], alpha: &[u8]) -> Result<bool, u32> {
    unsafe {
        match raw::ecvrf_verify(
            y.as_ptr() as i64,
            y.len() as i64,
            pi.as_ptr() as i64,
            pi.len() as i64,
            alpha.as_ptr() as i64,
            alpha.len() as i64,
        ) {
            0 => Ok(true),
            1 => Ok(false),
            x => Err(x),
        }
    }
}