better cache filenames, layer_columns uses schema

layer_columns.js

@@ -13,6 +13,7 @@ const sql = (params) => {
       relnamespace = pg_namespace.oid AND
       attnum >= 1 AND
       relname = '${params.table}' 
+      ${params.schema?` AND nspname= '${params.schema}'`:''}
     `
 }
 
@@ -40,6 +41,19 @@ module.exports = function (app, pool) {
  *         description: table not found or not accessible
  */
   app.get('/data/layer_columns/:table', async (req, res)=> {
+    let tableName, schemaName;
+    const table = req.params.table;
+    if (table) {
+      const parts = table.split('.');
+      if (parts.length === 1) {
+        tableName = parts[0];
+        schemaName = null;
+      } else {
+        schemaName = parts[0];
+        tableName = parts[1];
+      }
+      req.params.table = tableName;
+      req.params.schema = schemaName;
       const sqlString = sql(req.params, req.query);
       try {
         const result = await pool.query(sqlString);
@@ -60,5 +74,9 @@ module.exports = function (app, pool) {
         }
         res.status(status).json({error:err.message})
       }
-  })
+    } else {
+      res.status(422).json({error:"missing parameter 'table'"})
+    }
+  });
+    
 }
\ No newline at end of file

mvt.js

@@ -2,7 +2,7 @@
 const sqlTableName = require('./utils/sqltablename.js');
 
 const DirCache = require('./utils/dircache.js')
-const cache = new DirCache('./cache/mvt');
+const cache = new DirCache('./cache');
 
 const sm = require('@mapbox/sphericalmercator');
 const merc = new sm({
@@ -10,8 +10,9 @@ const merc = new sm({
 })
 
 let cacheMiddleWare = async(req, res, next) => {
-  const cacheDir = `${req.params.datasource}/${req.params.z}/${req.params.x}/${req.params.y}`;
-  const key = (req.query.geom_column?req.query.geom_column:'geom') + req.query.columns?','+req.query.columns:'';
+  const cacheDir = `${req.params.datasource}/mvt/${req.params.z}/${req.params.x}/${req.params.y}`;
+  const key = ((req.query.geom_column?req.query.geom_column:'geom') + (req.query.columns?','+req.query.columns:''))
+    .replace(/[\W]+/g, '_');
 
   const mvt = await cache.getCachedFile(cacheDir, key);
   if (mvt) {

public/tableinfo.html

@@ -24,7 +24,7 @@
         document.querySelector('#tablename').innerHTML = fullTableName;
         const parts = fullTableName.split('.');
         const tableName = (parts.length > 1) ? parts[1] : parts[0];
-        fetch(`data/layer_columns/${tableName}`).then(response=>{
+        fetch(`data/layer_columns/${fullTableName}`).then(response=>{
             const list = document.querySelector('#columns');
             if (response.ok) {
                 response.json().then(json=> {