aboutsummaryrefslogtreecommitdiffstats
path: root/src/node.rs
blob: 582bf3d736e9b816be693a640106fdc91b3486d0 (plain)
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

use errors::*;
use network_msgs::*;
use protocol::{DatNetMessage, DatConnection};
use integer_encoding::VarInt;
use bit_field::BitArray;
use sleep_register::HyperRegister;

fn decode_bitfiled(raw_bf: &[u8]) -> Result<Vec<u8>> {
    let mut offset = 0; // byte offset that we have read up to
    if raw_bf.len() < 1 {
        bail!("Expected (varint-encoded) bitfield to have len>=1");
    }
    let mut bit_array: Vec<u8> = vec![];
    while offset < raw_bf.len() {
        let (header, inc): (u64, usize) = VarInt::decode_var(&raw_bf[offset..]);
        offset += inc;

        if (header & 0x01) == 0x01 {
            // compressed
            let bit = (header & 0x02) == 0x02;
            let run_len = header >> 2;
            if bit {
                bit_array.append(&mut vec![0xFF; run_len as usize]);
            } else {
                bit_array.append(&mut vec![0x00; run_len as usize]);
            }
        } else {
            // uncompressed
            let byte_count = header >> 1;
            let mut data = raw_bf[offset..(offset + byte_count as usize)].to_vec();
            bit_array.append(&mut data);
            offset += byte_count as usize;
        }
    }
    // XXX: HACK
    bit_array.reverse();
    return Ok(bit_array);
}

/// Finds the index of the lowest bit
fn max_high_bit(bf: &[u8]) -> u64 {
    // XXX: HACK, going backwards
    for i in 0..bf.bit_length() {
        if bf.get_bit(i) {
            return (bf.bit_length() - i - 1) as u64;
        }
    }
    return 0;
}

fn max_index(have_msg: &Have) -> Result<u64> {
    if have_msg.has_length() {
        return Ok(have_msg.get_start() + have_msg.get_length());
    } else if have_msg.has_bitfield() {
        let raw_bf = have_msg.get_bitfield();
        let bf = decode_bitfiled(raw_bf)?;
        trace!("decoded bitfield: {:?}", bf);
        return Ok(max_high_bit(&bf));
    } else {
        return Ok(have_msg.get_start() + 1);
    }
}

#[test]
fn test_max_index() {
    let mut hm = Have::new();
    hm.set_start(0);
    hm.set_bitfield(vec![7,2,128]);
    assert_eq!(max_index(&hm).unwrap(), 8);

    hm.set_bitfield(vec![2, 207]);
    assert_eq!(max_index(&hm).unwrap(), 7);

    // Alphabet test dat
    hm.set_bitfield(vec![2, 254]);
    assert_eq!(max_index(&hm).unwrap(), 6);
    hm.set_bitfield(vec![2, 252]);
    assert_eq!(max_index(&hm).unwrap(), 5);
}

/// Tries to connect to a single peer, pull register, and close.
pub fn node_simple_clone(host_port: &str, key: &[u8], register: &mut HyperRegister, is_content: bool) -> Result<()> {

    if register.len()? > 0 {
        bail!("Register already had data in it (expected empty for naive clone)");
    }

    let mut dc = DatConnection::connect(host_port, key, false)?;

    // Info: downloading, not uploading
    let mut im = Info::new();
    im.set_uploading(false);
    im.set_downloading(true);
    let im = DatNetMessage::Info(im);
    dc.send_msg(&im, is_content)?;

    // Have: nothing (so far)
    let mut hm = Have::new();
    hm.set_start(0);
    hm.set_length(0);
    let hm = DatNetMessage::Have(hm);
    dc.send_msg(&hm, is_content)?;

    // UnHave: still nothing
    let mut uhm = Unhave::new();
    uhm.set_start(0);
    let uhm = DatNetMessage::Unhave(uhm);
    dc.send_msg(&uhm, is_content)?;

    // Want: everything
    let mut wm = Want::new();
    wm.set_start(0);
    let wm = DatNetMessage::Want(wm);
    dc.send_msg(&wm, is_content)?;

    let last_entry: u64;

    // Receive Have messages to determine lengths
    loop {
        let (was_content, msg) = dc.recv_msg()?;
        match msg {
            DatNetMessage::Have(dh) =>  {
                info!("is_content={}; {:?}; bitfield={:?}", was_content, dh, dh.get_bitfield());
                last_entry = max_index(&dh)?;
                break;
            },
            _ => {
                info!("Other message: {:?}", &msg);
            }
        }
    }

    info!("last_entry={}", last_entry);

    // Request / Data loops
    for i in 0..(last_entry+1) {
        let mut rm = Request::new();
        rm.set_index(i);
        info!("Sending request: {:?}", rm);
        dc.send_msg(&DatNetMessage::Request(rm), false)?;
        let (was_content, msg) = dc.recv_msg()?;
        assert!(!was_content);
        match msg {
            DatNetMessage::Data(dm) =>  {
                info!("Got data: index={}", dm.get_index());
                assert!(dm.has_value());
                assert!(dm.get_index() == i);
                register.append(dm.get_value())?;
            },
            _ => {
                info!("Other message: {:?}", &msg);
            }
        }
    }
    Ok(())
}