ckb-script 0.119.0

CKB component to run the type/lock scripts.
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
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

use crate::types::Indices;
use crate::{
    cost_model::transferred_byte_cycles,
    syscalls::{
        utils::store_data, Source, SourceEntry, INDEX_OUT_OF_BOUND, ITEM_MISSING,
        LOAD_BLOCK_EXTENSION, SUCCESS,
    },
};
use ckb_traits::ExtensionProvider;
use ckb_types::core::cell::ResolvedTransaction;
use ckb_types::{
    core::cell::CellMeta,
    packed::{self, Byte32Vec},
};
use ckb_vm::{
    registers::{A0, A3, A4, A7},
    Error as VMError, Register, SupportMachine, Syscalls,
};
use std::sync::Arc;

#[derive(Debug)]
pub struct LoadBlockExtension<DL> {
    data_loader: DL,
    rtx: Arc<ResolvedTransaction>,
    group_inputs: Indices,
}

impl<DL: ExtensionProvider> LoadBlockExtension<DL> {
    pub fn new(
        data_loader: DL,
        rtx: Arc<ResolvedTransaction>,
        group_inputs: Indices,
    ) -> LoadBlockExtension<DL> {
        LoadBlockExtension {
            data_loader,
            rtx,
            group_inputs,
        }
    }

    #[inline]
    fn header_deps(&self) -> Byte32Vec {
        self.rtx.transaction.header_deps()
    }

    #[inline]
    fn resolved_inputs(&self) -> &Vec<CellMeta> {
        &self.rtx.resolved_inputs
    }

    #[inline]
    fn resolved_cell_deps(&self) -> &Vec<CellMeta> {
        &self.rtx.resolved_cell_deps
    }

    fn load_block_extension(&self, cell_meta: &CellMeta) -> Option<packed::Bytes> {
        let block_hash = &cell_meta
            .transaction_info
            .as_ref()
            .expect("block_info of CellMeta should exists when load_block_extension in syscall")
            .block_hash;
        if self
            .header_deps()
            .into_iter()
            .any(|hash| &hash == block_hash)
        {
            self.data_loader.get_block_extension(block_hash)
        } else {
            None
        }
    }

    fn fetch_extension(&self, source: Source, index: usize) -> Result<packed::Bytes, u8> {
        match source {
            Source::Transaction(SourceEntry::Input) => self
                .resolved_inputs()
                .get(index)
                .ok_or(INDEX_OUT_OF_BOUND)
                .and_then(|cell_meta| self.load_block_extension(cell_meta).ok_or(ITEM_MISSING)),
            Source::Transaction(SourceEntry::Output) => Err(INDEX_OUT_OF_BOUND),
            Source::Transaction(SourceEntry::CellDep) => self
                .resolved_cell_deps()
                .get(index)
                .ok_or(INDEX_OUT_OF_BOUND)
                .and_then(|cell_meta| self.load_block_extension(cell_meta).ok_or(ITEM_MISSING)),
            Source::Transaction(SourceEntry::HeaderDep) => self
                .header_deps()
                .get(index)
                .ok_or(INDEX_OUT_OF_BOUND)
                .and_then(|block_hash| {
                    self.data_loader
                        .get_block_extension(&block_hash)
                        .ok_or(ITEM_MISSING)
                }),
            Source::Group(SourceEntry::Input) => self
                .group_inputs
                .get(index)
                .ok_or(INDEX_OUT_OF_BOUND)
                .and_then(|actual_index| {
                    self.resolved_inputs()
                        .get(*actual_index)
                        .ok_or(INDEX_OUT_OF_BOUND)
                })
                .and_then(|cell_meta| self.load_block_extension(cell_meta).ok_or(ITEM_MISSING)),
            Source::Group(SourceEntry::Output) => Err(INDEX_OUT_OF_BOUND),
            Source::Group(SourceEntry::CellDep) => Err(INDEX_OUT_OF_BOUND),
            Source::Group(SourceEntry::HeaderDep) => Err(INDEX_OUT_OF_BOUND),
        }
    }
}

impl<DL: ExtensionProvider + Send + Sync, Mac: SupportMachine> Syscalls<Mac>
    for LoadBlockExtension<DL>
{
    fn initialize(&mut self, _machine: &mut Mac) -> Result<(), VMError> {
        Ok(())
    }

    fn ecall(&mut self, machine: &mut Mac) -> Result<bool, VMError> {
        if machine.registers()[A7].to_u64() != LOAD_BLOCK_EXTENSION {
            return Ok(false);
        }

        let index = machine.registers()[A3].to_u64();
        let source = Source::parse_from_u64(machine.registers()[A4].to_u64())?;

        let extension = self.fetch_extension(source, index as usize);
        if let Err(err) = extension {
            machine.set_register(A0, Mac::REG::from_u8(err));
            return Ok(true);
        }
        let extension = extension.unwrap();
        let data = extension.raw_data();
        let wrote_size = store_data(machine, &data)?;

        machine.add_cycles_no_checking(transferred_byte_cycles(wrote_size))?;
        machine.set_register(A0, Mac::REG::from_u8(SUCCESS));
        Ok(true)
    }
}