fix #7 make sample server browser singleton

Author: jperelli

CHANGELOG.md

@@ -1,3 +1,9 @@
+# 3.5.2 (npm unreleased)
+
+Fix sample server issues
+
+ - Fix sample server using too many resources, make headless browser singleton
+
 # 3.5.1
 
 Fix geojson option

lib/lib.js

@@ -4,6 +4,7 @@ const puppeteer = require('puppeteer');
 const path = require('path');
 const child_process = require("child_process");
 
+
 const files = {
   leafletjs: fs.readFileSync(require.resolve('leaflet/dist/leaflet.js'), 'utf8'),
   leafletcss: fs.readFileSync(require.resolve('leaflet/dist/leaflet.css'), 'utf8'),
@@ -16,6 +17,7 @@ const files = {
 const templatestr = fs.readFileSync(path.join(__dirname, 'template.html'), 'utf8')
 const template = Handlebars.compile(templatestr);
 
+
 function replacefiles(str) {
   const ff = Object.entries(files)
   let res = str
@@ -24,6 +26,32 @@ function replacefiles(str) {
   return res
 }
 
+class Browser {
+  /// browser singleton
+  constructor() {
+    this.browser = null;
+  }
+  async launch() {
+    return puppeteer.launch({
+      args: ["--no-sandbox", "--disable-setuid-sandbox"]
+    });
+  }
+  async getBrowser() {
+    if (!this.browser || !this.browser.isConnected()) {
+      // console.log('NEW BROWSER')
+      this.browser = await this.launch()
+    }
+    return this.browser
+  }
+  async getPage() {
+    const browser = await this.getBrowser()
+      // console.log("NEW PAGE");
+    return await browser.newPage()
+  }
+}
+const browser = new Browser();
+
+
 module.exports = function(options) {
   return new Promise(function(resolve, reject) {
     options = options || {};
@@ -50,64 +78,69 @@ module.exports = function(options) {
     }
 
     (async () => {
-      const browser = await puppeteer.launch({
-        args: ['--no-sandbox', '--disable-setuid-sandbox']
-      });
-      const page = await browser.newPage();
-      page.on('error', function (err) { reject(err.toString()) })
-      page.on('pageerror', function (err) { reject(err.toString()) })
-      page.on('console', function (msg, type) {
-        if (msg.type === 'error') {
-          reject(JSON.stringify(msg))
-        }
-      })
-      await page.setViewport({
-        width: Number(options.width),
-        height: Number(options.height)
-      });
-      await page.setContent(html, { waitUntil: 'networkidle0' });
+      const page = await browser.getPage();
+      try {
+        page.on('error', function (err) { reject(err.toString()) })
+        page.on('pageerror', function (err) { reject(err.toString()) })
+        page.on('console', function (msg) {
+          if (msg.type === 'error') {
+            reject(JSON.stringify(msg))
+          }
+        })
+        await page.setViewport({
+          width: Number(options.width),
+          height: Number(options.height)
+        });
+        await page.setContent(html, { waitUntil: 'networkidle0', timeout: 20000 });
 
-      let imageBinary = await page.screenshot({
-        type: options.type || 'png',
-        quality: options.type === 'jpeg' ? Number(options.quality || 100) : undefined,
-        fullPage: true
-      });
+        let imageBinary = await page.screenshot({
+          type: options.type || 'png',
+          quality: options.type === 'jpeg' ? Number(options.quality || 100) : undefined,
+          fullPage: true
+        });
 
-      if (options.imagemin) {
-        const imagemin = require("imagemin");
-        const imageminJpegtran = require("imagemin-jpegtran");
-        const imageminOptipng = require("imagemin-optipng");
-        const plugins = []
-        if (options.type === 'jpeg') {
-          plugins.push(imageminJpegtran());
-        } else {
-          plugins.push(imageminOptipng());
-        }
-        (async () => {
-          resolve(await imagemin.buffer(
-            imageBinary,
-            {
-              plugins,
-            }
-          ))
-        })();
-      } else {
-        if (options.oxipng) {
-          const child = child_process.spawn('/root/.cargo/bin/oxipng', ['-']);
-          child.stdin.on('error', function() {});
-          child.stdin.write(imageBinary);
-          child.stdin.end();
-          let newimg = [];
-          child.stdout.on('data', data => newimg.push(data));
-          child.on('close', () => resolve(Buffer.concat(newimg)));
-          child.on('error', e => reject(e.toString()));
+        if (options.imagemin) {
+          const imagemin = require("imagemin");
+          const imageminJpegtran = require("imagemin-jpegtran");
+          const imageminOptipng = require("imagemin-optipng");
+          const plugins = []
+          if (options.type === 'jpeg') {
+            plugins.push(imageminJpegtran());
+          } else {
+            plugins.push(imageminOptipng());
+          }
+          (async () => {
+            resolve(await imagemin.buffer(
+              imageBinary,
+              {
+                plugins,
+              }
+            ))
+          })();
         } else {
-          resolve(imageBinary);
+          if (options.oxipng) {
+            const child = child_process.spawn('/root/.cargo/bin/oxipng', ['-']);
+            child.stdin.on('error', function() {});
+            child.stdin.write(imageBinary);
+            child.stdin.end();
+            let newimg = [];
+            child.stdout.on('data', data => newimg.push(data));
+            child.on('close', () => resolve(Buffer.concat(newimg)));
+            child.on('error', e => reject(e.toString()));
+          } else {
+            resolve(imageBinary);
+          }
         }
-      }
 
-      browser.close();
+      }
+      catch(e) {
+        page.close();
+        // console.log("PAGE CLOSED with err" + e);
+        throw(e);
+      }
+      page.close();
+      // console.log("PAGE CLOSED ok");
 
-    })()
+    })().catch(reject)
   });
 };