|
| 1 | +const paramDefaults = { |
| 2 | + stream: true, |
| 3 | + n_predict: 500, |
| 4 | + temperature: 0.2, |
| 5 | + stop: ["</s>"] |
| 6 | +}; |
| 7 | + |
| 8 | +let generation_settings = null; |
| 9 | + |
| 10 | + |
| 11 | +// Completes the prompt as a generator. Recommended for most use cases. |
| 12 | +// |
| 13 | +// Example: |
| 14 | +// |
| 15 | +// import { llama } from '/completion.js' |
| 16 | +// |
| 17 | +// const request = llama("Tell me a joke", {n_predict: 800}) |
| 18 | +// for await (const chunk of request) { |
| 19 | +// document.write(chunk.data.content) |
| 20 | +// } |
| 21 | +// |
| 22 | +export async function* llama(prompt, params = {}, config = {}) { |
| 23 | + let controller = config.controller; |
| 24 | + const api_url = config.api_url?.replace(/\/+$/, '') || ""; |
| 25 | + |
| 26 | + if (!controller) { |
| 27 | + controller = new AbortController(); |
| 28 | + } |
| 29 | + |
| 30 | + const completionParams = { ...paramDefaults, ...params, prompt }; |
| 31 | + |
| 32 | + const response = await fetch(`${api_url}${config.endpoint || '/completion'}`, { |
| 33 | + method: 'POST', |
| 34 | + body: JSON.stringify(completionParams), |
| 35 | + headers: { |
| 36 | + 'Connection': 'keep-alive', |
| 37 | + 'Content-Type': 'application/json', |
| 38 | + 'Accept': 'text/event-stream', |
| 39 | + ...(params.api_key ? {'Authorization': `Bearer ${params.api_key}`} : {}) |
| 40 | + }, |
| 41 | + signal: controller.signal, |
| 42 | + }); |
| 43 | + |
| 44 | + const reader = response.body.getReader(); |
| 45 | + const decoder = new TextDecoder(); |
| 46 | + |
| 47 | + let content = ""; |
| 48 | + let leftover = ""; // Buffer for partially read lines |
| 49 | + |
| 50 | + try { |
| 51 | + let cont = true; |
| 52 | + |
| 53 | + while (cont) { |
| 54 | + const result = await reader.read(); |
| 55 | + if (result.done) { |
| 56 | + break; |
| 57 | + } |
| 58 | + |
| 59 | + // Add any leftover data to the current chunk of data |
| 60 | + const text = leftover + decoder.decode(result.value); |
| 61 | + |
| 62 | + // Check if the last character is a line break |
| 63 | + const endsWithLineBreak = text.endsWith('\n'); |
| 64 | + |
| 65 | + // Split the text into lines |
| 66 | + let lines = text.split('\n'); |
| 67 | + |
| 68 | + // If the text doesn't end with a line break, then the last line is incomplete |
| 69 | + // Store it in leftover to be added to the next chunk of data |
| 70 | + if (!endsWithLineBreak) { |
| 71 | + leftover = lines.pop(); |
| 72 | + } else { |
| 73 | + leftover = ""; // Reset leftover if we have a line break at the end |
| 74 | + } |
| 75 | + |
| 76 | + // Parse all sse events and add them to result |
| 77 | + const regex = /^(\S+):\s(.*)$/gm; |
| 78 | + for (const line of lines) { |
| 79 | + const match = regex.exec(line); |
| 80 | + if (match) { |
| 81 | + result[match[1]] = match[2]; |
| 82 | + if (result.data === '[DONE]') { |
| 83 | + cont = false; |
| 84 | + break; |
| 85 | + } |
| 86 | + |
| 87 | + // since we know this is llama.cpp, let's just decode the json in data |
| 88 | + if (result.data) { |
| 89 | + result.data = JSON.parse(result.data); |
| 90 | + content += result.data.content; |
| 91 | + |
| 92 | + // yield |
| 93 | + yield result; |
| 94 | + |
| 95 | + // if we got a stop token from server, we will break here |
| 96 | + if (result.data.stop) { |
| 97 | + if (result.data.generation_settings) { |
| 98 | + generation_settings = result.data.generation_settings; |
| 99 | + } |
| 100 | + cont = false; |
| 101 | + break; |
| 102 | + } |
| 103 | + } |
| 104 | + if (result.error) { |
| 105 | + try { |
| 106 | + result.error = JSON.parse(result.error); |
| 107 | + if (result.error.message.includes('slot unavailable')) { |
| 108 | + // Throw an error to be caught by upstream callers |
| 109 | + throw new Error('slot unavailable'); |
| 110 | + } else { |
| 111 | + console.error(`llama.cpp error [${result.error.code} - ${result.error.type}]: ${result.error.message}`); |
| 112 | + } |
| 113 | + } catch(e) { |
| 114 | + console.error(`llama.cpp error ${result.error}`) |
| 115 | + } |
| 116 | + } |
| 117 | + } |
| 118 | + } |
| 119 | + } |
| 120 | + } catch (e) { |
| 121 | + if (e.name !== 'AbortError') { |
| 122 | + console.error("llama error: ", e); |
| 123 | + } |
| 124 | + throw e; |
| 125 | + } |
| 126 | + finally { |
| 127 | + controller.abort(); |
| 128 | + } |
| 129 | + |
| 130 | + return content; |
| 131 | +} |
| 132 | + |
| 133 | +// Call llama, return an event target that you can subscribe to |
| 134 | +// |
| 135 | +// Example: |
| 136 | +// |
| 137 | +// import { llamaEventTarget } from '/completion.js' |
| 138 | +// |
| 139 | +// const conn = llamaEventTarget(prompt) |
| 140 | +// conn.addEventListener("message", (chunk) => { |
| 141 | +// document.write(chunk.detail.content) |
| 142 | +// }) |
| 143 | +// |
| 144 | +export const llamaEventTarget = (prompt, params = {}, config = {}) => { |
| 145 | + const eventTarget = new EventTarget(); |
| 146 | + (async () => { |
| 147 | + let content = ""; |
| 148 | + for await (const chunk of llama(prompt, params, config)) { |
| 149 | + if (chunk.data) { |
| 150 | + content += chunk.data.content; |
| 151 | + eventTarget.dispatchEvent(new CustomEvent("message", { detail: chunk.data })); |
| 152 | + } |
| 153 | + if (chunk.data.generation_settings) { |
| 154 | + eventTarget.dispatchEvent(new CustomEvent("generation_settings", { detail: chunk.data.generation_settings })); |
| 155 | + } |
| 156 | + if (chunk.data.timings) { |
| 157 | + eventTarget.dispatchEvent(new CustomEvent("timings", { detail: chunk.data.timings })); |
| 158 | + } |
| 159 | + } |
| 160 | + eventTarget.dispatchEvent(new CustomEvent("done", { detail: { content } })); |
| 161 | + })(); |
| 162 | + return eventTarget; |
| 163 | +} |
| 164 | + |
| 165 | +// Call llama, return a promise that resolves to the completed text. This does not support streaming |
| 166 | +// |
| 167 | +// Example: |
| 168 | +// |
| 169 | +// llamaPromise(prompt).then((content) => { |
| 170 | +// document.write(content) |
| 171 | +// }) |
| 172 | +// |
| 173 | +// or |
| 174 | +// |
| 175 | +// const content = await llamaPromise(prompt) |
| 176 | +// document.write(content) |
| 177 | +// |
| 178 | +export const llamaPromise = (prompt, params = {}, config = {}) => { |
| 179 | + return new Promise(async (resolve, reject) => { |
| 180 | + let content = ""; |
| 181 | + try { |
| 182 | + for await (const chunk of llama(prompt, params, config)) { |
| 183 | + content += chunk.data.content; |
| 184 | + } |
| 185 | + resolve(content); |
| 186 | + } catch (error) { |
| 187 | + reject(error); |
| 188 | + } |
| 189 | + }); |
| 190 | +}; |
| 191 | + |
| 192 | +/** |
| 193 | + * (deprecated) |
| 194 | + */ |
| 195 | +export const llamaComplete = async (params, controller, callback) => { |
| 196 | + for await (const chunk of llama(params.prompt, params, { controller })) { |
| 197 | + callback(chunk); |
| 198 | + } |
| 199 | +} |
| 200 | + |
| 201 | +// Get the model info from the server. This is useful for getting the context window and so on. |
| 202 | +export const llamaModelInfo = async (config = {}) => { |
| 203 | + if (!generation_settings) { |
| 204 | + const api_url = config.api_url?.replace(/\/+$/, '') || ""; |
| 205 | + const props = await fetch(`${api_url}/props`).then(r => r.json()); |
| 206 | + generation_settings = props.default_generation_settings; |
| 207 | + } |
| 208 | + return generation_settings; |
| 209 | +} |
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