itch::transport::PcapReader Class Reference

Replays ITCH market data straight from a captured network trace. More...

#include <pcap.hpp>

Public Member Functions
	PcapReader (MessageCallback callback)
	Constructs a reader that forwards each decoded ITCH message to callback.
auto	read (std::span< const std::byte > capture) -> bool
	Decodes an in-memory capture buffer.
auto	read_file (const std::string &path) -> bool
	Reads and decodes a capture file from disk.
auto	set_udp_port_filter (std::uint16_t port) -> void
	Restricts decoding to UDP datagrams sent to this destination port.
auto	clear_udp_port_filter () noexcept -> void
	Clears any destination-port filter previously installed.
auto	mold_decoder () noexcept -> MoldUdp64Decoder &
	The embedded MoldUDP64 decoder (sequence tracking lives here).
auto	mold_decoder () const noexcept -> const MoldUdp64Decoder &
	The embedded MoldUDP64 decoder (sequence tracking lives here).
auto	udp_datagrams () const noexcept -> std::uint64_t
	Number of UDP datagrams extracted and handed to the MoldUDP64 decoder.
auto	messages_decoded () const noexcept -> std::uint64_t
	Total ITCH messages decoded across the whole capture.

Detailed Description

Replays ITCH market data straight from a captured network trace.

Firms most often archive and share feeds as packet captures, so being able to consume a .pcap/.pcapng file directly removes the need to pre-strip the transport framing. The reader is implemented entirely in-house (no libpcap dependency): it understands the classic pcap and the pcapng container formats, walks the Ethernet / IPv4 / IPv6 / UDP layers of each captured frame, extracts the UDP payload, and feeds it through an embedded MoldUdp64Decoder, which in turn yields the decoded ITCH messages to the caller's callback.

Note

Only offline capture files are supported. Live capture would require a platform packet-capture library and is tracked as future work behind a separate build option.

Definition at line 39 of file pcap.hpp.

Constructor & Destructor Documentation

PcapReader()

itch::transport::PcapReader::PcapReader ( MessageCallback  callback )

explicit

Constructs a reader that forwards each decoded ITCH message to callback.

Parameters

callback

Invoked with each ITCH message decoded from the capture.

Definition at line 85 of file pcap.cpp.

Member Function Documentation

read()

auto itch::transport::PcapReader::read

(

std::span< const std::byte >

capture

)

-> bool

Decodes an in-memory capture buffer.

Parameters

capture

The full contents of a .pcap or .pcapng file.

Returns

true if the buffer was a recognized capture format, false otherwise (in which case nothing was decoded).

Definition at line 87 of file pcap.cpp.

read_file()

auto itch::transport::PcapReader::read_file

(

const std::string &

path

)

-> bool

Reads and decodes a capture file from disk.

Parameters

path	Filesystem path to the .pcap or .pcapng file to read.

Returns

true on a recognized, readable file; false if the file cannot be opened or is not a capture.

Definition at line 106 of file pcap.cpp.

set_udp_port_filter()

auto itch::transport::PcapReader::set_udp_port_filter ( std::uint16_t  port ) -> void

inline

Restricts decoding to UDP datagrams sent to this destination port.

When unset, datagrams on any port are decoded.

Parameters

port	The destination UDP port to accept.

Definition at line 66 of file pcap.hpp.

clear_udp_port_filter()

auto itch::transport::PcapReader::clear_udp_port_filter ( ) -> void

inlinenoexcept

Clears any destination-port filter previously installed.

Definition at line 69 of file pcap.hpp.

mold_decoder() [1/2]

auto itch::transport::PcapReader::mold_decoder ( ) -> MoldUdp64Decoder&

inlinenoexcept

The embedded MoldUDP64 decoder (sequence tracking lives here).

Returns

Reference to the embedded MoldUdp64Decoder.

Definition at line 73 of file pcap.hpp.

mold_decoder() [2/2]

auto itch::transport::PcapReader::mold_decoder ( ) const -> const MoldUdp64Decoder&

inlinenoexcept

The embedded MoldUDP64 decoder (sequence tracking lives here).

Returns

Const reference to the embedded MoldUdp64Decoder.

Definition at line 76 of file pcap.hpp.

udp_datagrams()

auto itch::transport::PcapReader::udp_datagrams ( ) const -> std::uint64_t

inlinenoexcept

Number of UDP datagrams extracted and handed to the MoldUDP64 decoder.

Returns

The count of UDP datagrams processed so far.

Definition at line 81 of file pcap.hpp.

messages_decoded()

auto itch::transport::PcapReader::messages_decoded ( ) const -> std::uint64_t

inlinenoexcept

Total ITCH messages decoded across the whole capture.

Returns

The total count of decoded ITCH messages.

Definition at line 85 of file pcap.hpp.

References itch::transport::MoldUdp64Decoder::messages_decoded().

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The documentation for this class was generated from the following files:

• pcap.hpp
• pcap.cpp