1 files changed, 157 insertions, 0 deletions
diff --git a/src/node.rs b/src/node.rs
new file mode 100644
index 0000000..582bf3d
--- /dev/null
+++ b/src/node.rs
@@ -0,0 +1,157 @@
+
+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(())
+}