Graph

README.md

@@ -11,7 +11,6 @@ Program Flow:
     * [X] Download token contract state to determine contract types and basic info.
     * [X] Download swap contract state to determine contract types.
     * [X] Continually download state of swap contracts, to ensure liquidity and pricing information is up to date.
-    * [ ] Construct swap graph.
 
 - Logging in:
     * [X] User presses relevant login button.
@@ -19,7 +18,7 @@ Program Flow:
 
 - Trading (Write!):
     * [X] User selects tokens and amount to move between.
-    * [ ] Compute shortest route; dijkstra's. (Can use one, or several weight algorithms: Liquidity, price, etc.)
+    * [X] Compute shortest route; dijkstra's. (Can use one, or several weight algorithms: Liquidity, price, etc.)
     * [ ] Present route, fees, gas usage, etc.
     * [ ] User presses TRADE!
     * [ ] Sends transactions: _Approve to router_ and _route_ with the given route.

package.json

@@ -18,7 +18,9 @@
     "hash.js": "^1.1.7",
     "partisia-blockchain-applications-sdk": "^0.1.2",
     "stream-browserify": "^3.0.0",
-    "bip32-path": "^0.4.2"
+    "bip32-path": "^0.4.2",
+    "graphology": "^0.25.4",
+    "graphology-shortest-path": "2"
   },
   "devDependencies": {
     "@babel/plugin-transform-runtime": "^7.19.6",

src/main/swap/Main.ts

@@ -19,6 +19,8 @@ import { NETWORK } from "../constant";
 import { AvlClient } from "../client/AvlClient";
 import {TokenV1Contract  } from "../token/contract/TokenV1Contract";
 import {TokenV2Contract  } from "../token/contract/TokenV2Contract";
+import UndirectedGraph from 'graphology';
+import dijkstra from 'graphology-shortest-path/dijkstra';
 
 // UI constants
 const TOKEN_LIST = <Element>document.querySelector("#token-list");
@@ -31,15 +33,22 @@ type ContractType = "token_v1" | "token_v2" | "swap_lock_v1"
 
 interface ContractState {
     address: BlockchainAddress,
-    latest_state: TokenStateV1 | TokenStateV2 | null;
-    swaps: BlockchainAddress[] | null,
     type: ContractType | null,
+    latest_state: TokenStateV1 | TokenStateV2 | null;
+}
+
+interface TokenContractState extends ContractState {
+}
+
+interface SwapContractState extends ContractState {
+    swapTokens: BlockchainAddress[],
 }
 
 interface Route {
     from: BlockchainAddress | null,
     to: BlockchainAddress | null,
-    swaps: BlockchainAddress[],
+    tokenContracts: string[],
+    swapContracts: string[],
     user: BlockchainAddress | null,
 }
 
@@ -47,11 +56,11 @@ const ROUTERS: BlockchainAddress[] = [BlockchainAddress.fromString("02f8eb18e09d
 
 type BlockchainAddressKey = string;
 
-const TOKENS: Record<BlockchainAddressKey, ContractState> = {};
+const TOKENS: Record<BlockchainAddressKey, TokenContractState> = {};
 
-const SWAPS: Record<BlockchainAddressKey, ContractState> = {};
+const SWAPS: Record<BlockchainAddressKey, SwapContractState> = {};
 
-const CURRENT_ROUTE: Route = { from: null, to: null, swaps: [], user: null };
+const CURRENT_ROUTE: Route = { from: null, to: null, tokenContracts: [], swapContracts: [], user: null };
 
 const SHARDED_CLIENT: ShardedClient = new ShardedClient(NETWORK.node_base_url, NETWORK.network_shards);
 const AVL_CLIENT:AvlClient  = new AvlClient(NETWORK .node_base_url, NETWORK.network_shards);;
@@ -78,7 +87,6 @@ function address_to_url(address: BlockchainAddress): string {
 }
 
 function setInnerText(query: string, text: string) {
-    console.log(query, text);
     for (const a of document.querySelectorAll(query)) {
         (<HTMLElement>a).innerText = text;
     }
@@ -97,18 +105,43 @@ function ui_show_route() {
 
     setInnerText("[data-input-token]", symbolFrom);
     setInnerText("[data-output-token]", symbolTo);
+
+    setInnerText("[data-route-list]", "");
+    (<Element>document.querySelector("[data-route-list]")).innerHTML = CURRENT_ROUTE.swapContracts.map(s => `<div>${s}</div>`).join("");
+}
+
+function get_swap_graph(): UndirectedGraph {
+    const graph = new UndirectedGraph();
+    for (const addrStr in TOKENS) {
+        graph.addNode(addrStr);
+    }
+    for (const addrStr in SWAPS) {
+        const swap = SWAPS[addrStr];
+        graph.addEdgeWithKey(addrStr, swap.swapTokens[0].asString(), swap.swapTokens[1].asString(), { liquidity: 1000 });
+    }
+    return graph;
+}
+
+function node_path_to_edge_path(graph: UndirectedGraph, nodePath: string[]): string[] {
+    const edgeRoute = [];
+    for (let idx = 0; idx < nodePath.length - 1; idx++) {
+        edgeRoute.push(graph.edges(nodePath[idx], nodePath[idx+1])[0]);
+    }
+
+    return edgeRoute;
 }
 
 function reroute() {
-    console.log("Rerouting", CURRENT_ROUTE);
-
     // Do not route if from or to are not assigned yet.
     if (CURRENT_ROUTE.from == null || CURRENT_ROUTE.to == null) {
         return;
     }
 
     // Perform routing.
-    // TODO
+    const graph = get_swap_graph();
+
+    CURRENT_ROUTE.tokenContracts = dijkstra.bidirectional(graph, CURRENT_ROUTE.from.asString(), CURRENT_ROUTE.to.asString(), (_, attr) => attr.liquidity);
+    CURRENT_ROUTE.swapContracts  = node_path_to_edge_path(graph, CURRENT_ROUTE.tokenContracts);
 
     ui_show_route();
 }
@@ -232,7 +265,6 @@ async function get_token_state(tokenAddress: BlockchainAddress): Promise<[TokenS
 }
 
 async function get_token_balance(info: ContractState, account: BlockchainAddress): Promise<BN> {
-    console.log(info);
     if (info.type == "token_v2") {
         return await new TokenV2Contract(SHARDED_CLIENT, undefined).tokenBalance(info.address, account);
     } else {
@@ -263,14 +295,11 @@ function setup() {
 
     // Setup routes
     for (let router of ROUTERS) {
-        console.log(router);
         get_contract_state(router, deserializeRouterState).then((state) => {
-            console.log(state);
-
             for (const swapInfo of state.swapContracts) {
-                TOKENS[swapInfo.tokenAAddress.asString()] = { latest_state: null, swaps: null, type: null, address: swapInfo.tokenAAddress };
-                TOKENS[swapInfo.tokenBAddress.asString()] = { latest_state: null, swaps: null, type: null, address: swapInfo.tokenBAddress };
-                SWAPS[swapInfo.swapAddress.asString()] = { latest_state: null, swaps: [swapInfo.tokenAAddress, swapInfo.tokenBAddress], type: null, address: swapInfo.swapAddress };
+                TOKENS[swapInfo.tokenAAddress.asString()] = { latest_state: null, type: null, address: swapInfo.tokenAAddress };
+                TOKENS[swapInfo.tokenBAddress.asString()] = { latest_state: null, type: null, address: swapInfo.tokenBAddress };
+                SWAPS[swapInfo.swapAddress.asString()] = { latest_state: null, swapTokens: [swapInfo.tokenAAddress, swapInfo.tokenBAddress], type: null, address: swapInfo.swapAddress };
                 ui_add_swap(swapInfo.swapAddress);
             }
 

src/main/swap/index.html

@@ -106,7 +106,7 @@
                 type="submit"
                 value="Exchange!" />
 
-            <div class="route-list">
+            <div class="route-list" data-route-list="">
                 <div>1000 A   to  3000 B   (0.3% fee)</div>
                 <div>3000 B   to  9000 C   (0.3% fee)</div>
             </div>