fix: 补充 terrain layer.json 缓存路由

app/services/terrain/controller.js

@@ -65,3 +65,26 @@ module.exports.cache = async (req, res, next) => {
     if (err) return next(err)
   })
 }
+
+module.exports.layer = async (req, res, next) => {
+  const { v = 'DEFAULE' } = req.params
+  const object = `layer.json`
+  const uri = `https://data.mars3d.cn/terrain/${object}`
+  const src = path.resolve(`./data/cache/terrain/${v}/${object}`)
+
+  try {
+    if (!fs.existsSync(src)) {
+      await downloadFile(uri, src)
+    }
+  } catch (_) {
+    try {
+      if (fs.existsSync(src)) {
+        fs.rmSync(src)
+      }
+    } catch (__) {}
+  }
+
+  res.sendFile(src, function (err) {
+    if (err) return next(err)
+  })
+}

app/services/terrain/index.js

@@ -2,5 +2,6 @@ const router = require('express').Router()
 const terrain = require('./controller')
 
 router.get('/terrain/cache/:x/:y/:z', terrain.cache)
+router.get('/terrain/cache/layer.json', terrain.layer)
 
 module.exports = router