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| 1 | +import WebSocket from "ws"; |
| 2 | +import { randomUUID } from "node:crypto"; |
| 3 | + |
| 4 | +// ========================= // |
| 5 | +// = Copyright (c) NullDev = // |
| 6 | +// ========================= // |
| 7 | + |
| 8 | +/* eslint-disable camelcase */ |
| 9 | + |
| 10 | +export default class SageCell { |
| 11 | + /** |
| 12 | + * @param {Object} options |
| 13 | + * @param {string} [options.baseUrl] Base URL of SageCell |
| 14 | + * @param {number} [options.timeoutMs] How long to wait for a single execution |
| 15 | + */ |
| 16 | + constructor(options = {}){ |
| 17 | + this.baseUrl = options.baseUrl ?? "https://sagecell.sagemath.org"; |
| 18 | + this.timeoutMs = options.timeoutMs ?? 30000; |
| 19 | + } |
| 20 | + |
| 21 | + /** |
| 22 | + * High-level API: create kernel, run code, collect output, delete kernel. |
| 23 | + * @param {string} code |
| 24 | + * @returns {Promise<{ stdout: string, stderr: string, result: any }>} |
| 25 | + */ |
| 26 | + async askSage(code){ |
| 27 | + let kernelId = null; |
| 28 | + try { |
| 29 | + const { wsUrl, kernelId: id } = await this.#startKernel(); |
| 30 | + kernelId = id; |
| 31 | + |
| 32 | + const result = await this.#runOnKernel(wsUrl, kernelId, code); |
| 33 | + return result; |
| 34 | + } |
| 35 | + finally { |
| 36 | + if (kernelId){ |
| 37 | + try { |
| 38 | + await this.#deleteKernel(kernelId); |
| 39 | + } |
| 40 | + catch { /* noop */ } |
| 41 | + } |
| 42 | + } |
| 43 | + } |
| 44 | + |
| 45 | + /** |
| 46 | + * Starts a new SageCell kernel. |
| 47 | + * |
| 48 | + * @returns {Promise<{ wsUrl: string, kernelId: string }>} |
| 49 | + */ |
| 50 | + async #startKernel(){ |
| 51 | + const res = await fetch( |
| 52 | + `${this.baseUrl}/kernel?accepted_tos=true&timeout=0`, |
| 53 | + { method: "POST" }, |
| 54 | + ); |
| 55 | + |
| 56 | + if (!res.ok){ |
| 57 | + throw new Error(`Failed to start kernel: HTTP ${res.status}`); |
| 58 | + } |
| 59 | + |
| 60 | + const { ws_url, id } = await res.json(); |
| 61 | + if (!ws_url || !id){ |
| 62 | + throw new Error("Kernel start response missing ws_url or id"); |
| 63 | + } |
| 64 | + |
| 65 | + return { wsUrl: ws_url, kernelId: id }; |
| 66 | + } |
| 67 | + |
| 68 | + /** |
| 69 | + * Deletes a SageCell kernel. |
| 70 | + * |
| 71 | + * @param {string} kernelId |
| 72 | + * @returns {Promise<void>} |
| 73 | + */ |
| 74 | + async #deleteKernel(kernelId){ |
| 75 | + const res = await fetch(`${this.baseUrl}/kernel/${kernelId}`, { |
| 76 | + method: "DELETE", |
| 77 | + }); |
| 78 | + |
| 79 | + if (!res.ok && res.status !== 404){ |
| 80 | + throw new Error(`Failed to delete kernel: HTTP ${res.status}`); |
| 81 | + } |
| 82 | + } |
| 83 | + |
| 84 | + /** |
| 85 | + * Creates an execute_request message. |
| 86 | + * |
| 87 | + * @param {string} code |
| 88 | + * @returns {Object} |
| 89 | + */ |
| 90 | + #makeExecuteRequest(code){ |
| 91 | + const session = randomUUID(); |
| 92 | + const msgId = randomUUID(); |
| 93 | + return { |
| 94 | + header: { |
| 95 | + msg_id: msgId, |
| 96 | + username: "user", |
| 97 | + session, |
| 98 | + msg_type: "execute_request", |
| 99 | + version: "5.3", |
| 100 | + }, |
| 101 | + parent_header: {}, |
| 102 | + metadata: {}, |
| 103 | + content: { |
| 104 | + code, |
| 105 | + silent: false, |
| 106 | + store_history: false, |
| 107 | + user_expressions: {}, |
| 108 | + allow_stdin: false, |
| 109 | + stop_on_error: true, |
| 110 | + }, |
| 111 | + channel: "shell", |
| 112 | + buffers: [], |
| 113 | + }; |
| 114 | + } |
| 115 | + |
| 116 | + /** |
| 117 | + * Connects WS, sends execute_request, waits until status: idle. |
| 118 | + * |
| 119 | + * @param {string} wsUrl |
| 120 | + * @param {string} kernelId |
| 121 | + * @param {string} code |
| 122 | + * @returns {Promise<{ stdout: string, stderr: string, result: any }>} |
| 123 | + */ |
| 124 | + async #runOnKernel(wsUrl, kernelId, code){ |
| 125 | + const ws = new WebSocket(`${wsUrl}kernel/${kernelId}/channels`); |
| 126 | + |
| 127 | + const execMsg = this.#makeExecuteRequest(code); |
| 128 | + |
| 129 | + return new Promise((resolve, reject) => { |
| 130 | + let stdout = ""; |
| 131 | + let stderr = ""; |
| 132 | + let result = ""; |
| 133 | + let done = false; |
| 134 | + // @ts-ignore |
| 135 | + // eslint-disable-next-line prefer-const |
| 136 | + let timer; |
| 137 | + |
| 138 | + /** |
| 139 | + * Finishes the execution. |
| 140 | + * |
| 141 | + * @param {any} value |
| 142 | + * @param {boolean} isError |
| 143 | + */ |
| 144 | + const finish = (value, isError = false) => { |
| 145 | + if (done) return; |
| 146 | + done = true; // @ts-ignore |
| 147 | + clearTimeout(timer); |
| 148 | + try { |
| 149 | + ws.close(); |
| 150 | + } |
| 151 | + catch { |
| 152 | + // ignore |
| 153 | + } |
| 154 | + isError ? reject(value) : resolve(value); |
| 155 | + }; |
| 156 | + |
| 157 | + timer = setTimeout(() => { |
| 158 | + finish(new Error(`SageCell execution timed out after ${this.timeoutMs}ms`), true); |
| 159 | + }, this.timeoutMs); |
| 160 | + |
| 161 | + ws.on("open", () => { |
| 162 | + ws.send(JSON.stringify(execMsg)); |
| 163 | + }); |
| 164 | + |
| 165 | + ws.on("message", data => { |
| 166 | + let msg; |
| 167 | + try { |
| 168 | + msg = JSON.parse(data.toString()); |
| 169 | + } |
| 170 | + catch (e){ |
| 171 | + const errMsg = e instanceof Error ? e.message : String(e); |
| 172 | + return finish(new Error("Failed to parse message from SageCell " + errMsg), true); |
| 173 | + } |
| 174 | + |
| 175 | + const msgType = msg.msg_type || msg.header?.msg_type; |
| 176 | + |
| 177 | + if (msgType === "stream" && msg.content?.text){ |
| 178 | + if (msg.content.name === "stderr"){ |
| 179 | + stderr += msg.content.text; |
| 180 | + } |
| 181 | + else { |
| 182 | + stdout += msg.content.text; |
| 183 | + } |
| 184 | + } |
| 185 | + |
| 186 | + if (msgType === "execute_result"){ |
| 187 | + result = msg.content?.data ?? null; |
| 188 | + } |
| 189 | + |
| 190 | + if (msgType === "status" && |
| 191 | + msg.content?.execution_state === "idle"){ |
| 192 | + finish({ stdout, stderr, result }); |
| 193 | + } |
| 194 | + |
| 195 | + if (msgType === "error"){ |
| 196 | + const errText = msg.content?.evalue || "SageCell error"; |
| 197 | + finish(new Error(errText), true); |
| 198 | + } |
| 199 | + |
| 200 | + return null; |
| 201 | + }); |
| 202 | + |
| 203 | + ws.on("error", err => { |
| 204 | + finish(err, true); |
| 205 | + }); |
| 206 | + |
| 207 | + ws.on("close", () => { |
| 208 | + if (!done){ |
| 209 | + finish(new Error("WebSocket closed before completion"), true); |
| 210 | + } |
| 211 | + }); |
| 212 | + }); |
| 213 | + } |
| 214 | +} |
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