|
| 1 | +interface Socket { |
| 2 | + on(event: "data", fn: (data: Buffer) => void): void; |
| 3 | + write(data: Buffer): void; |
| 4 | + destroy(): void; |
| 5 | +} |
| 6 | + |
| 7 | +enum ReaderStateKind { |
| 8 | + Header = 0, |
| 9 | + Body = 1, |
| 10 | +} |
| 11 | + |
| 12 | +interface ReaderStateHeader { |
| 13 | + readonly kind: ReaderStateKind.Header; |
| 14 | + contentLength?: number; |
| 15 | + contentType?: string; |
| 16 | +} |
| 17 | + |
| 18 | +interface ReaderStateBody { |
| 19 | + readonly kind: ReaderStateKind.Body; |
| 20 | + readonly contentLength: number; |
| 21 | + readonly contentType?: string; |
| 22 | +} |
| 23 | + |
| 24 | +type ReaderState = ReaderStateHeader | ReaderStateBody; |
| 25 | + |
| 26 | +interface JsonRpcRequest { |
| 27 | + jsonrpc: "2.0"; |
| 28 | + id: number; |
| 29 | + method: string; |
| 30 | + params: unknown; |
| 31 | +} |
| 32 | + |
| 33 | +function isJsonRpcRequest(message: JsonRpcMessage): message is JsonRpcRequest { |
| 34 | + return ( |
| 35 | + "id" in message && |
| 36 | + typeof message.id === "number" && |
| 37 | + "method" in message && |
| 38 | + typeof message.method === "string" && |
| 39 | + "params" in message |
| 40 | + ); |
| 41 | +} |
| 42 | + |
| 43 | +interface JsonRpcNotification { |
| 44 | + jsonrpc: "2.0"; |
| 45 | + method: string; |
| 46 | + params: unknown; |
| 47 | +} |
| 48 | + |
| 49 | +function isJsonRpcNotification( |
| 50 | + message: JsonRpcMessage, |
| 51 | +): message is JsonRpcNotification { |
| 52 | + return ( |
| 53 | + !("id" in message) && |
| 54 | + "method" in message && |
| 55 | + typeof message.method === "string" && |
| 56 | + "params" in message |
| 57 | + ); |
| 58 | +} |
| 59 | + |
| 60 | +type JsonRpcResponse = |
| 61 | + | { |
| 62 | + jsonrpc: "2.0"; |
| 63 | + id: number; |
| 64 | + result: unknown; |
| 65 | + } |
| 66 | + | { |
| 67 | + jsonrpc: "2.0"; |
| 68 | + id: number; |
| 69 | + error: unknown; |
| 70 | + }; |
| 71 | + |
| 72 | +function isJsonRpcResponse( |
| 73 | + message: JsonRpcMessage, |
| 74 | +): message is JsonRpcResponse { |
| 75 | + return ( |
| 76 | + "id" in message && |
| 77 | + typeof message.id === "number" && |
| 78 | + !("method" in message) && |
| 79 | + ("result" in message || "error" in message) |
| 80 | + ); |
| 81 | +} |
| 82 | + |
| 83 | +type JsonRpcMessage = JsonRpcRequest | JsonRpcNotification | JsonRpcResponse; |
| 84 | + |
| 85 | +function isJsonRpcMessage(message: unknown): message is JsonRpcMessage { |
| 86 | + return ( |
| 87 | + typeof message === "object" && |
| 88 | + message !== null && |
| 89 | + "jsonrpc" in message && |
| 90 | + message.jsonrpc === "2.0" |
| 91 | + ); |
| 92 | +} |
| 93 | + |
| 94 | +interface PendingRequest { |
| 95 | + resolve(result: unknown): void; |
| 96 | + reject(error: unknown): void; |
| 97 | +} |
| 98 | + |
| 99 | +const MIME_JSONRPC = "application/vscode-jsonrpc"; |
| 100 | + |
| 101 | +/** |
| 102 | + * Implements the daemon server JSON-RPC protocol over a Socket instance |
| 103 | + */ |
| 104 | +export class Transport { |
| 105 | + /** |
| 106 | + * Counter incremented for each outgoing request to generate a unique ID |
| 107 | + */ |
| 108 | + private nextRequestId = 0; |
| 109 | + |
| 110 | + /** |
| 111 | + * Storage for the promise resolver functions of pending requests, |
| 112 | + * keyed by ID of the request |
| 113 | + */ |
| 114 | + private pendingRequests: Map<number, PendingRequest> = new Map(); |
| 115 | + |
| 116 | + constructor(private socket: Socket) { |
| 117 | + socket.on("data", (data) => { |
| 118 | + this.processIncoming(data); |
| 119 | + }); |
| 120 | + } |
| 121 | + |
| 122 | + /** |
| 123 | + * Send a request to the remote server |
| 124 | + * |
| 125 | + * @param method Name of the remote method to call |
| 126 | + * @param params Parameters object the remote method should be called with |
| 127 | + * @return Promise resolving with the value returned by the remote method, or rejecting with an RPC error if the remote call failed |
| 128 | + */ |
| 129 | + // biome-ignore lint/suspicious/noExplicitAny: if i change it to Promise<unknown> typescript breaks |
| 130 | + request(method: string, params: unknown): Promise<any> { |
| 131 | + return new Promise((resolve, reject) => { |
| 132 | + const id = this.nextRequestId++; |
| 133 | + this.pendingRequests.set(id, { resolve, reject }); |
| 134 | + this.sendMessage({ |
| 135 | + jsonrpc: "2.0", |
| 136 | + id, |
| 137 | + method, |
| 138 | + params, |
| 139 | + }); |
| 140 | + }); |
| 141 | + } |
| 142 | + |
| 143 | + /** |
| 144 | + * Send a notification message to the remote server |
| 145 | + * |
| 146 | + * @param method Name of the remote method to call |
| 147 | + * @param params Parameters object the remote method should be called with |
| 148 | + */ |
| 149 | + notify(method: string, params: unknown) { |
| 150 | + this.sendMessage({ |
| 151 | + jsonrpc: "2.0", |
| 152 | + method, |
| 153 | + params, |
| 154 | + }); |
| 155 | + } |
| 156 | + |
| 157 | + /** |
| 158 | + * Destroy the internal socket instance for this Transport |
| 159 | + */ |
| 160 | + destroy() { |
| 161 | + this.socket.destroy(); |
| 162 | + } |
| 163 | + |
| 164 | + private sendMessage(message: JsonRpcMessage) { |
| 165 | + const body = Buffer.from(JSON.stringify(message)); |
| 166 | + const headers = Buffer.from( |
| 167 | + `Content-Length: ${body.length}\r\nContent-Type: ${MIME_JSONRPC};charset=utf-8\r\n\r\n`, |
| 168 | + ); |
| 169 | + this.socket.write(Buffer.concat([headers, body])); |
| 170 | + } |
| 171 | + |
| 172 | + private pendingData = Buffer.from(""); |
| 173 | + private readerState: ReaderState = { |
| 174 | + kind: ReaderStateKind.Header, |
| 175 | + }; |
| 176 | + |
| 177 | + private processIncoming(data: Buffer) { |
| 178 | + this.pendingData = Buffer.concat([this.pendingData, data]); |
| 179 | + |
| 180 | + while (this.pendingData.length > 0) { |
| 181 | + if (this.readerState.kind === ReaderStateKind.Header) { |
| 182 | + const lineBreakIndex = this.pendingData.indexOf("\n"); |
| 183 | + if (lineBreakIndex < 0) { |
| 184 | + break; |
| 185 | + } |
| 186 | + |
| 187 | + const header = this.pendingData.subarray(0, lineBreakIndex + 1); |
| 188 | + this.pendingData = this.pendingData.subarray(lineBreakIndex + 1); |
| 189 | + this.processIncomingHeader(this.readerState, header.toString("utf-8")); |
| 190 | + } else if (this.pendingData.length >= this.readerState.contentLength) { |
| 191 | + const body = this.pendingData.subarray( |
| 192 | + 0, |
| 193 | + this.readerState.contentLength, |
| 194 | + ); |
| 195 | + this.pendingData = this.pendingData.subarray( |
| 196 | + this.readerState.contentLength, |
| 197 | + ); |
| 198 | + this.processIncomingBody(body); |
| 199 | + |
| 200 | + this.readerState = { |
| 201 | + kind: ReaderStateKind.Header, |
| 202 | + }; |
| 203 | + } else { |
| 204 | + break; |
| 205 | + } |
| 206 | + } |
| 207 | + } |
| 208 | + |
| 209 | + private processIncomingHeader(readerState: ReaderStateHeader, line: string) { |
| 210 | + if (line === "\r\n") { |
| 211 | + const { contentLength, contentType } = readerState; |
| 212 | + if (typeof contentLength !== "number") { |
| 213 | + throw new Error( |
| 214 | + "incoming message from the remote workspace is missing the Content-Length header", |
| 215 | + ); |
| 216 | + } |
| 217 | + |
| 218 | + this.readerState = { |
| 219 | + kind: ReaderStateKind.Body, |
| 220 | + contentLength, |
| 221 | + contentType, |
| 222 | + }; |
| 223 | + return; |
| 224 | + } |
| 225 | + |
| 226 | + const colonIndex = line.indexOf(":"); |
| 227 | + if (colonIndex < 0) { |
| 228 | + throw new Error(`could not find colon token in "${line}"`); |
| 229 | + } |
| 230 | + |
| 231 | + const headerName = line.substring(0, colonIndex); |
| 232 | + const headerValue = line.substring(colonIndex + 1).trim(); |
| 233 | + |
| 234 | + switch (headerName) { |
| 235 | + case "Content-Length": { |
| 236 | + const value = Number.parseInt(headerValue); |
| 237 | + readerState.contentLength = value; |
| 238 | + break; |
| 239 | + } |
| 240 | + case "Content-Type": { |
| 241 | + if (!headerValue.startsWith(MIME_JSONRPC)) { |
| 242 | + throw new Error( |
| 243 | + `invalid value for Content-Type expected "${MIME_JSONRPC}", got "${headerValue}"`, |
| 244 | + ); |
| 245 | + } |
| 246 | + |
| 247 | + readerState.contentType = headerValue; |
| 248 | + break; |
| 249 | + } |
| 250 | + default: |
| 251 | + console.warn(`ignoring unknown header "${headerName}"`); |
| 252 | + } |
| 253 | + } |
| 254 | + |
| 255 | + private processIncomingBody(buffer: Buffer) { |
| 256 | + const data = buffer.toString("utf-8"); |
| 257 | + const body = JSON.parse(data); |
| 258 | + |
| 259 | + if (isJsonRpcMessage(body)) { |
| 260 | + if (isJsonRpcRequest(body)) { |
| 261 | + // TODO: Not implemented at the moment |
| 262 | + return; |
| 263 | + } |
| 264 | + |
| 265 | + if (isJsonRpcNotification(body)) { |
| 266 | + // TODO: Not implemented at the moment |
| 267 | + return; |
| 268 | + } |
| 269 | + |
| 270 | + if (isJsonRpcResponse(body)) { |
| 271 | + const pendingRequest = this.pendingRequests.get(body.id); |
| 272 | + if (pendingRequest) { |
| 273 | + this.pendingRequests.delete(body.id); |
| 274 | + const { resolve, reject } = pendingRequest; |
| 275 | + if ("result" in body) { |
| 276 | + resolve(body.result); |
| 277 | + } else { |
| 278 | + reject(body.error); |
| 279 | + } |
| 280 | + } else { |
| 281 | + throw new Error( |
| 282 | + `could not find any pending request matching RPC response ID ${body.id}`, |
| 283 | + ); |
| 284 | + } |
| 285 | + return; |
| 286 | + } |
| 287 | + } |
| 288 | + |
| 289 | + throw new Error( |
| 290 | + `failed to deserialize incoming message from remote workspace, "${data}" is not a valid JSON-RPC message body`, |
| 291 | + ); |
| 292 | + } |
| 293 | +} |
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