Able to replay an entire DEEP file!

src/iex.rs

@@ -2,8 +2,42 @@ use std::convert::TryInto;
 
 use nom::{bytes::complete::take, IResult, number::complete::*, sequence::tuple};
 
+use crate::parsers::{Block, extract_iex_data, read_block};
+
+pub struct IexParser<'a> {
+    pcap_buffer: &'a [u8]
+}
+
+impl<'a> IexParser<'a> {
+    pub fn new(pcap_buffer: &[u8]) -> IexParser {
+        IexParser { pcap_buffer }
+    }
+}
+
+impl<'a> Iterator for IexParser<'a> {
+    type Item = IexPayload;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let mut buffer = self.pcap_buffer;
+        while let Ok((rem, block)) = read_block(buffer) {
+            self.pcap_buffer = rem;
+            buffer = rem;
+            match block {
+                Block::EnhancedPacket(e) => {
+                    let (_, iex_data) = extract_iex_data(e.packet_data).unwrap();
+                    let (_, payload) = IexPayload::parse(iex_data).unwrap();
+                    return Some(payload);
+                }
+                _ => ()
+            }
+        }
+
+        None
+    }
+}
+
 #[derive(Debug)]
-struct IexPayload {
+pub struct IexPayload {
     version: u8,
     _reserved: u8,
     proto_id: u16,
@@ -17,8 +51,40 @@ struct IexPayload {
     messages: smallvec::SmallVec<[IexMessage; 8]>,
 }
 
+impl IexPayload {
+    pub fn parse(payload: &[u8]) -> IResult<&[u8], IexPayload> {
+        let (mut rem, (version, _reserved, proto_id, channel_id, session_id, payload_len, msg_count, stream_offset, first_seq_no, send_time)) =
+            tuple((le_u8, le_u8, le_u16, le_u32, le_u32, le_u16, le_u16, le_u64, le_u64, le_i64))(payload)?;
+
+        let mut messages = smallvec::SmallVec::new();
+        for _i in 0..msg_count {
+            let (_rem, msg) = IexMessage::parse(rem)?;
+            rem = _rem;
+            messages.push(msg);
+        }
+
+        debug_assert!(rem.len() == 0);
+        Ok((
+            rem,
+            IexPayload {
+                version,
+                _reserved,
+                proto_id,
+                channel_id,
+                session_id,
+                payload_len,
+                msg_count,
+                stream_offset,
+                first_seq_no,
+                send_time,
+                messages,
+            }
+        ))
+    }
+}
+
 #[derive(Debug)]
-enum IexMessage {
+pub enum IexMessage {
     SystemEvent(SystemEvent),
     SecurityDirectory(SecurityDirectory),
     TradingStatus(TradingStatus),
@@ -33,35 +99,43 @@ enum IexMessage {
 }
 
 macro_rules! parse_msg {
-    ($input:ident, $msg_type:ident) => {{
-        let (rem, msg) = $msg_type::parse($input)?;
-        Ok((rem, IexMessage::$msg_type(msg)))
+    ($input:ident, $len:ident, $msg_type:ident) => {{
+        let (_, msg) = $msg_type::parse($input)?;
+        IexMessage::$msg_type(msg)
     }};
 }
 
 impl IexMessage {
     // TODO: Benchmark a version where we cast a packed struct instead of parsing
-    fn parse(input: &[u8]) -> IResult<&[u8], IexMessage> {
-        let msg_type = input[0];
-        match msg_type {
-            0x53 => parse_msg!(input, SystemEvent),
-            0x44 => parse_msg!(input, SecurityDirectory),
-            0x48 => parse_msg!(input, TradingStatus),
-            0x4f => parse_msg!(input, OperationalHaltStatus),
-            0x50 => parse_msg!(input, ShortSalePriceTest),
-            0x45 => parse_msg!(input, SecurityEvent),
+    pub fn parse(input: &[u8]) -> IResult<&[u8], IexMessage> {
+        let (payload, msg_len) = le_u16(input)?;
+
+        // Minor technical note: IEX's docs state that the message format
+        // can grow at any time, and we should always trust the msg_len field,
+        // so we first slice off the total msg_len for future compatibility
+        let (rem, payload) = take(msg_len)(payload)?;
+        let msg = match payload[0] {
+            0x53 => parse_msg!(payload, msg_len, SystemEvent),
+            0x44 => parse_msg!(payload, msg_len, SecurityDirectory),
+            0x48 => parse_msg!(payload, msg_len, TradingStatus),
+            0x4f => parse_msg!(payload, msg_len, OperationalHaltStatus),
+            0x50 => parse_msg!(payload, msg_len, ShortSalePriceTest),
+            0x45 => parse_msg!(payload, msg_len, SecurityEvent),
             // Why the "match multiple" looks like bitwise-OR is beyond me.
-            0x38 | 0x35 => parse_msg!(input, PriceLevelUpdate),
-            0x54 => parse_msg!(input, TradeReport),
-            0x58 => parse_msg!(input, OfficialPrice),
-            0x42 => parse_msg!(input, TradeBreak),
-            _ => panic!("Unrecognized message type"),
-        }
+            0x38 | 0x35 => parse_msg!(payload, msg_len, PriceLevelUpdate),
+            0x54 => parse_msg!(payload, msg_len, TradeReport),
+            0x58 => parse_msg!(payload, msg_len, OfficialPrice),
+            0x42 => parse_msg!(payload, msg_len, TradeBreak),
+            0x41 => parse_msg!(payload, msg_len, AuctionInformation),
+            t => panic!("Unrecognized message type={}, payload={:?}", t, payload),
+        };
+
+        Ok((rem, msg))
     }
 }
 
 #[derive(Debug)]
-struct SystemEvent {
+pub struct SystemEvent {
     msg_type: u8,
     system_event: u8,
     timestamp: i64,
@@ -83,7 +157,7 @@ impl SystemEvent {
 }
 
 #[derive(Debug)]
-struct SecurityDirectory {
+pub struct SecurityDirectory {
     msg_type: u8,
     flags: u8,
     timestamp: i64,
@@ -114,7 +188,7 @@ impl SecurityDirectory {
 }
 
 #[derive(Debug)]
-struct TradingStatus {
+pub struct TradingStatus {
     msg_type: u8,
     trading_status: u8,
     timestamp: i64,
@@ -141,7 +215,7 @@ impl TradingStatus {
 }
 
 #[derive(Debug)]
-struct OperationalHaltStatus {
+pub struct OperationalHaltStatus {
     msg_type: u8,
     halt_status: u8,
     timestamp: i64,
@@ -166,7 +240,7 @@ impl OperationalHaltStatus {
 }
 
 #[derive(Debug)]
-struct ShortSalePriceTest {
+pub struct ShortSalePriceTest {
     msg_type: u8,
     sspt_status: u8,
     timestamp: i64,
@@ -193,7 +267,7 @@ impl ShortSalePriceTest {
 }
 
 #[derive(Debug)]
-struct SecurityEvent {
+pub struct SecurityEvent {
     msg_type: u8,
     security_event: u8,
     timestamp: i64,
@@ -218,7 +292,7 @@ impl SecurityEvent {
 }
 
 #[derive(Debug)]
-struct PriceLevelUpdate {
+pub struct PriceLevelUpdate {
     msg_type: u8,
     event_flags: u8,
     timestamp: i64,
@@ -247,7 +321,7 @@ impl PriceLevelUpdate {
 }
 
 #[derive(Debug)]
-struct TradeReport {
+pub struct TradeReport {
     msg_type: u8,
     sale_condition: u8,
     timestamp: i64,
@@ -278,7 +352,7 @@ impl TradeReport {
 }
 
 #[derive(Debug)]
-struct OfficialPrice {
+pub struct OfficialPrice {
     msg_type: u8,
     price_type: u8,
     timestamp: i64,
@@ -305,7 +379,7 @@ impl OfficialPrice {
 }
 
 #[derive(Debug)]
-struct TradeBreak {
+pub struct TradeBreak {
     msg_type: u8,
     sale_condition: u8,
     timestamp: i64,
@@ -336,7 +410,7 @@ impl TradeBreak {
 }
 
 #[derive(Debug)]
-struct AuctionInformation {
+pub struct AuctionInformation {
     msg_type: u8,
     auction_type: u8,
     timestamp: i64,

src/main.rs

@@ -3,9 +3,8 @@ use std::io::Read;
 use std::path::Path;
 
 use clap::{App, Arg};
-use nom::sequence::tuple;
 
-use parsers::Block;
+use crate::iex::IexParser;
 
 // Cap'n'Proto and Flatbuffers typically ask that you generate code on the fly to match
 // the schemas. For purposes of auto-complete and easy browsing in the repository,
@@ -35,16 +34,7 @@ fn main() {
     let mut buf = Vec::new();
     file.read_to_end(&mut buf).expect(&format!("Unable to read file={}", path.display()));
 
-    let mut rem = &buf[..];
-    while let Ok((unparsed, block)) = parsers::read_block(rem) {
-        let offset = (unparsed.as_ptr() as usize) - (buf.as_ptr() as usize);
-        rem = unparsed;
-        match block {
-            Block::SectionHeader(sh) => println!("{:?}, next offset={}", sh, offset),
-            Block::InterfaceDescription(id) => println!("{:?}, next offset={}", id, offset),
-            Block::EnhancedPacket(epb) => println!("EnhancedPacketBlock {{ block_len: {}, packet_len: {} }}, next offset={}", epb.block_len, epb.packet_data.len(), offset)
+    for _payload in IexParser::new(&buf[..]) {
+        //dbg!(payload);
     }
 }
-
-    println!("Remaining unparsed len={}", rem.len());
-}

src/parsers.rs

@@ -1,6 +1,3 @@
-use std::convert::TryInto;
-use std::mem::size_of;
-
 use nom::{
     branch::alt, bytes::complete::tag, bytes::complete::take, IResult, number::complete::*,
     sequence::tuple,
@@ -13,10 +10,14 @@ pub enum Block<'a> {
 }
 
 pub fn read_block(input: &[u8]) -> IResult<&[u8], Block> {
+    // TODO: Curious if this is faster than `match`
+    // Theoretically it should be because we're almost always using
+    // enhanced packet blocks, but don't know if the branch predictor
+    // would catch on as well.
     alt((
+        enhanced_packet_block,
         section_header_block,
         interface_description_block,
-        enhanced_packet_block,
     ))(input)
 }