WIP: aquatic_ws: add half-crappy load test, fix infinite loop bug

aquatic_ws_protocol/src/lib.rs

@@ -0,0 +1,300 @@
+use hashbrown::HashMap;
+use serde::{Serialize, Deserialize};
+
+mod serde_helpers;
+
+use serde_helpers::*;
+
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct PeerId(
+    #[serde(
+        deserialize_with = "deserialize_20_bytes",
+        serialize_with = "serialize_20_bytes"
+    )]
+    pub [u8; 20]
+);
+
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct InfoHash(
+    #[serde(
+        deserialize_with = "deserialize_20_bytes",
+        serialize_with = "serialize_20_bytes"
+    )]
+    pub [u8; 20]
+);
+
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct OfferId(
+    #[serde(
+        deserialize_with = "deserialize_20_bytes",
+        serialize_with = "serialize_20_bytes"
+    )]
+    pub [u8; 20]
+);
+
+
+/// Some kind of nested structure from https://www.npmjs.com/package/simple-peer
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct JsonValue(pub ::serde_json::Value);
+
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum AnnounceEvent {
+    Started,
+    Stopped,
+    Completed,
+    Update
+}
+
+
+impl Default for AnnounceEvent {
+    fn default() -> Self {
+        Self::Update
+    }
+}
+
+
+/// Apparently, these are sent to a number of peers when they are set
+/// in an AnnounceRequest
+/// action = "announce"
+#[derive(Debug, Clone, Serialize)]
+pub struct MiddlemanOfferToPeer {
+    /// Peer id of peer sending offer
+    /// Note: if equal to client peer_id, client ignores offer
+    pub peer_id: PeerId,
+    pub info_hash: InfoHash,
+    /// Gets copied from AnnounceRequestOffer
+    pub offer: JsonValue, 
+    /// Gets copied from AnnounceRequestOffer
+    pub offer_id: OfferId,
+}
+
+
+/// If announce request has answer = true, send this to peer with
+/// peer id == "to_peer_id" field
+/// Action field should be 'announce'
+#[derive(Debug, Clone, Serialize)]
+pub struct MiddlemanAnswerToPeer {
+    /// Note: if equal to client peer_id, client ignores answer
+    pub peer_id: PeerId,
+    pub info_hash: InfoHash,
+    pub answer: JsonValue,
+    pub offer_id: OfferId,
+}
+
+
+/// Element of AnnounceRequest.offers
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AnnounceRequestOffer {
+    pub offer: JsonValue,
+    pub offer_id: OfferId,
+}
+
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AnnounceRequest {
+    pub info_hash: InfoHash,
+    pub peer_id: PeerId,
+    /// Just called "left" in protocol. Is set to None in some cases, such as
+    /// when opening a magnet link
+    #[serde(rename = "left")]
+    pub bytes_left: Option<usize>,
+    /// Can be empty. Then, default is "update"
+    #[serde(default)]
+    pub event: AnnounceEvent,
+
+    /// Only when this is an array offers are sent to random peers
+    /// Length of this is number of peers wanted?
+    /// Max length of this is 10 in reference client code
+    /// Not sent when announce event is stopped or completed
+    pub offers: Option<Vec<AnnounceRequestOffer>>, 
+    /// Seems to only get sent by client when sending offers, and is also same
+    /// as length of offers vector (or at least never less)
+    /// Max length of this is 10 in reference client code
+    /// Could probably be ignored, `offers.len()` should provide needed info
+    pub numwant: Option<usize>,
+
+    /// If empty, send response before sending offers (or possibly "skip sending update back"?)
+    /// Else, send MiddlemanAnswerToPeer to peer with "to_peer_id" as peer_id.
+    /// I think using Option is good, it seems like this isn't always set
+    /// (same as `offers`)
+    pub answer: Option<JsonValue>, 
+    /// Likely undefined if !(answer == true)
+    pub to_peer_id: Option<PeerId>, 
+    /// Sent if answer is set
+    pub offer_id: Option<OfferId>,
+}
+
+
+#[derive(Debug, Clone, Serialize)]
+pub struct AnnounceResponse {
+    pub info_hash: InfoHash,
+    /// Client checks if this is null, not clear why
+    pub complete: usize,
+    pub incomplete: usize,
+    #[serde(rename = "interval")]
+    pub announce_interval: usize, // Default 2 min probably
+}
+
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ScrapeRequest {
+    // If omitted, scrape for all torrents, apparently
+    // There is some kind of parsing here too which accepts a single info hash
+    // and puts it into a vector
+    #[serde(
+        rename = "info_hash",
+        deserialize_with = "deserialize_info_hashes",
+        default
+    )]
+    pub info_hashes: Vec<InfoHash>,
+}
+
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ScrapeStatistics {
+    pub complete: usize,
+    pub incomplete: usize,
+    pub downloaded: usize,
+}
+
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ScrapeResponse {
+    pub files: HashMap<InfoHash, ScrapeStatistics>,
+    // Looks like `flags` field is ignored in reference client
+    // pub flags: HashMap<String, usize>,
+}
+
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum Action {
+    Announce,
+    Scrape
+}
+
+
+/// Helper for serializing and deserializing messages
+#[derive(Debug, Clone, Serialize, Deserialize)]
+struct ActionWrapper<T> {
+    pub action: Action,
+    #[serde(flatten)]
+    pub inner: T,
+}
+
+
+impl <T>ActionWrapper<T> {
+    #[inline]
+    pub fn announce(t: T) -> Self {
+        Self {
+            action: Action::Announce,
+            inner: t
+        }
+    }
+    #[inline]
+    pub fn scrape(t: T) -> Self {
+        Self {
+            action: Action::Scrape,
+            inner: t
+        }
+    }
+}
+
+
+#[derive(Debug, Clone)]
+pub enum InMessage {
+    AnnounceRequest(AnnounceRequest),
+    ScrapeRequest(ScrapeRequest),
+}
+
+
+impl InMessage {
+    /// Try parsing as announce request first. If that fails, try parsing as
+    /// scrape request, or return None
+    #[inline]
+    pub fn from_ws_message(ws_message: tungstenite::Message) -> Option<Self> {
+        use tungstenite::Message::{Text, Binary};
+
+        let text = match ws_message {
+            Text(text) => Some(text),
+            Binary(bytes) => String::from_utf8(bytes).ok(),
+            _ => None
+        }?;
+
+        let res: Result<ActionWrapper<AnnounceRequest>, _> = serde_json::from_str(&text);
+
+        if let Ok(ActionWrapper { action: Action::Announce, inner }) = res {
+            return Some(InMessage::AnnounceRequest(inner));
+        }
+        
+        let res: Result<ActionWrapper<ScrapeRequest>, _> = serde_json::from_str(&text);
+
+        if let Ok(ActionWrapper { action: Action::Scrape, inner }) = res {
+            return Some(InMessage::ScrapeRequest(inner));
+        }
+
+        None
+    }
+
+    pub fn to_ws_message(&self) -> ::tungstenite::Message {
+        let text = match self {
+            InMessage::AnnounceRequest(r) => {
+                serde_json::to_string(&ActionWrapper::announce(r)).unwrap()
+            },
+            InMessage::ScrapeRequest(r) => {
+                serde_json::to_string(&ActionWrapper::scrape(r)).unwrap()
+            },
+        };
+
+        ::tungstenite::Message::from(text)
+    }
+}
+
+
+#[derive(Debug, Clone)]
+pub enum OutMessage {
+    AnnounceResponse(AnnounceResponse),
+    ScrapeResponse(ScrapeResponse),
+    Offer(MiddlemanOfferToPeer),
+    Answer(MiddlemanAnswerToPeer),
+}
+
+
+impl OutMessage {
+    #[inline]
+    pub fn to_ws_message(self) -> tungstenite::Message {
+        let json = match self {
+            Self::AnnounceResponse(message) => {
+                serde_json::to_string(
+                    &ActionWrapper::announce(message)
+                ).unwrap()
+            },
+            Self::Offer(message) => {
+                serde_json::to_string(
+                    &ActionWrapper::announce(message)
+                ).unwrap()
+            },
+            Self::Answer(message) => {
+                serde_json::to_string(
+                    &ActionWrapper::announce(message)
+                ).unwrap()
+            },
+            Self::ScrapeResponse(message) => {
+                serde_json::to_string(
+                    &ActionWrapper::scrape(message)
+                ).unwrap()
+            },
+        };
+                
+        tungstenite::Message::from(json)
+    }
+}