From 627d3ba8b5385377f8502399078767bb86ac4c26 Mon Sep 17 00:00:00 2001
From: tobi lutke <tobi@shopify.com>
Date: Sun, 25 Jun 2023 20:56:00 -0400
Subject: [PATCH] expose simple web interface on root domain

demonstrates how to use the stream option of generate.
---
 examples/server/server.cpp  |   9 +-
 examples/server/server.html | 287 ++++++++++++++++++++++++++++++++++++
 2 files changed, 295 insertions(+), 1 deletion(-)
 create mode 100644 examples/server/server.html
diff --git a/examples/server/server.cpp b/examples/server/server.cpp
index 3bf985957..2a492bdc9 100644
--- a/examples/server/server.cpp
+++ b/examples/server/server.cpp
@@ -889,7 +889,14 @@ int main(int argc, char ** argv) {
     });
 
     svr.Get("/", [](const Request &, Response & res) {
-        res.set_content("<h1>llama.cpp server works</h1>", "text/html");
+        // return content of server.html file
+
+        std::ifstream t("examples/server/server.html");
+        std::stringstream buffer;
+        buffer << t.rdbuf();
+
+        res.set_content(buffer.str(), "text/html");
+        return false;
     });
 
     svr.Post("/completion", [&llama](const Request & req, Response & res) {
diff --git a/examples/server/server.html b/examples/server/server.html
new file mode 100644
index 000000000..44b8db263
--- /dev/null
+++ b/examples/server/server.html
@@ -0,0 +1,287 @@
+<html>
+
+<head>
+  <title>Llama.cpp</title>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>llama.cpp - chat</title>
+
+  <style>
+    #container {
+      max-width: 80rem;
+      margin: 10em auto;
+    }
+
+    main {
+      border: 1px solid #ddd;
+      padding: 1em;
+
+    }
+
+    #chat {
+      height: 50vh;
+      overflow-y: auto;
+    }
+
+    body {
+      max-width: 650px;
+      line-height: 1.2;
+      font-size: 16px;
+      margin: 0 auto;
+    }
+
+    p {
+      overflow-wrap: break-word;
+      word-wrap: break-word;
+      hyphens: auto;
+      text-align: justify;
+      margin-top: 0.5em;
+      margin-bottom: 0.5em;
+    }
+
+    form {
+      margin: 1em 0;
+
+      display: flex;
+      gap: 0.5em;
+      flex-direction: row;
+      align-items: center;
+    }
+
+    form>* {
+      padding: 4px;
+    }
+
+    form input {
+      flex-grow: 1;
+    }
+
+    fieldset {
+      width: 100%;
+      padding: 1em;
+    }
+
+    fieldset label {
+      margin: 0.5em 0;
+      display: block;
+    }
+  </style>
+
+
+  <script type="module">
+    import { fetchEventSource } from "https://esm.sh/@microsoft/fetch-event-source"
+
+    import {
+      html, h, signal, effect, computed, render, useSignal, useEffect, useRef
+    } from 'https://npm.reversehttp.com/@preact/signals-core,@preact/signals,htm/preact,preact,preact/hooks';
+
+    const transcript = signal([])
+    const chatStarted = computed(() => transcript.value.length > 0)
+
+    const chatTemplate = signal("{{prompt}}\n\n{{history}}\n{{bot}}:")
+    const settings = signal({
+      prompt: "This is a conversation between user and llama, a friendly chatbot.",
+      bot: "llama",
+      user: "User"
+    })
+
+    const temperature = signal(0.2)
+    const nPredict = signal(80)
+
+
+    let controller;
+
+    // simple template replace
+    const template = (str, map) => {
+      let params = settings.value;
+      if (map) {
+        params = { ...params, ...map };
+      }
+      const result = String(str).replaceAll(/\{\{(.*?)\}\}/g, (_, key) => template(params[key]));
+      console.log("template", str, params, "=>", result);
+      return result;
+
+    }
+
+
+    // send message to server
+    const chat = async (msg) => {
+      if (controller) {
+        console.log('already running...');
+        return;
+      }
+      controller = new AbortController();
+
+      const history = [...transcript.value, ['{{user}}', msg]];
+      transcript.value = history;
+
+      let additionalParams = {
+        history: history.flatMap(([name, msg]) => `${name}: ${msg}`).join("\n"),
+      }
+
+      const payload = template(chatTemplate.value, additionalParams)
+      console.log("payload", payload)
+
+
+      let currentMessage = "";
+      await fetchEventSource('/completion', {
+        method: 'POST',
+        signal: controller.signal,
+        body: JSON.stringify({
+          stream: true,
+          prompt: payload,
+          n_predict: parseInt(nPredict.value),
+          temperature: parseFloat(temperature.value),
+          stop: ["</s>", template("{{bot}}"), template("{{user}}")]
+        }),
+        onmessage(e) {
+          const data = JSON.parse(e.data);
+          currentMessage += data.content;
+
+          if (data.stop) {
+            console.log("done:", data);
+          }
+
+          transcript.value = [...history, ['{{bot}}', currentMessage]]
+          return true;
+        },
+      });
+      console.log("transcript", transcript.value);
+      controller = null;
+    }
+
+    function MessageInput() {
+      const message = useSignal("")
+
+      const stop = (e) => {
+        e.preventDefault();
+        if (controller) {
+          controller.abort();
+          controller = null;
+        }
+      }
+
+      const reset = (e) => {
+        stop(e);
+        transcript.value = [];
+      }
+
+      const submit = (e) => {
+        stop(e);
+        chat(message.value);
+        message.value = "";
+      }
+
+      return html`
+        <form onsubmit=${submit}>
+          <input type="text" value="${message.value}" oninput=${(e) => message.value = e.target.value} autofocus placeholder="start chat here..."/>
+          <button type="submit">Send</button>
+          <button onclick=${(e) => stop(e)}>Stop</button>
+          <button onclick=${(e) => reset(e)}>Reset</button>
+        </form>
+      `
+    }
+
+    const ChatLog = (props) => {
+      const messages = transcript.value;
+      const container = useRef(null)
+
+      useEffect(() => {
+        // scroll to bottom (if needed)
+        if (container.current && container.current.scrollHeight <= container.current.scrollTop + container.current.offsetHeight + 100) {
+          container.current.scrollTo(0, container.current.scrollHeight)
+        }
+      }, [messages])
+
+      const chatLine = ([user, msg]) => {
+        return html`<p><strong>${template(user, {})}:</strong> ${template(msg, {})}</p>`
+      };
+
+      return html`
+        <section id="chat" ref=${container}>
+          ${messages.flatMap((m) => chatLine(m))}
+        </section>`;
+    };
+
+    const ConfigForm = (props) => {
+
+
+
+      return html`
+        <form>
+          <fieldset>
+            <legend>Settings</legend>
+
+            <div>
+              <label for="prompt">Prompt</label> 
+              <textarea type="text" id="prompt" value="${settings.value.prompt}" oninput=${(e) => settings.value.prompt = e.target.value} rows="3" cols="60" />
+            </div>
+
+            <div>
+              <label for="user">User name</label>
+              <input type="text" id="user" value="${settings.value.user}" oninput=${(e) => settings.value.user = e.target.value} />
+            </div>
+
+            <div>
+              <label for="bot">Bot name</label>
+              <input type="text" id="bot" value="${settings.value.bot}" oninput=${(e) => settings.value.bot = e.target.value} />
+            </div>
+
+            <div>
+              <label for="template">Prompt template</label>
+              <textarea id="template" value="${chatTemplate}" oninput=${(e) => chatTemplate.value = e.target.value} rows="8" cols="60" />
+            </div>
+            
+            <div>
+              <label for="temperature">Temperature</label>
+              <input type="range" id="temperature" min="0.0" max="1.0" step="0.01" value="${temperature.value}" oninput=${(e) => temperature.value = e.target.value} />
+              <span>${temperature}</span>
+            </div>
+
+            <div>
+              <label for="nPredict">Predictions</label>
+              <input type="range" id="nPredict" min="1" max="2048" step="1" value="${nPredict.value}" oninput=${(e) => nPredict.value = e.target.value} />
+              <span>${nPredict}</span>
+            </div>
+            </fieldset>
+
+        </form>
+      `
+
+    }
+
+    function App(props) {
+
+      return html`
+      <div id="container">
+        <header>
+          <h1>llama.cpp</h1>
+        </header>
+                
+        <main>
+          <section class="chat">
+            <${chatStarted.value ? ChatLog : ConfigForm
+        } />
+          </section >
+
+          <section class="chat">
+            <${MessageInput} />
+          </section>
+          
+        </main >
+        <footer>
+          <p>Powered by <a href="https://github.com/ggerganov/llama.cpp">llama.cpp</a> and <a href="https://ggml.ai">ggml.ai</a></p>
+        </footer>
+      </div>
+      `;
+    }
+
+    render(h(App), document.body);
+  </script>
+</head>
+
+<body>
+
+</body>
+
+</html>
\ No newline at end of file
