o Accept a function for the cache key

naturalatlas · Apr 12, 2016 · 6a91be0 · 6a91be0
1 parent 3625604
commit 6a91be0
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diff --git a/README.md b/README.md
@@ -17,12 +17,20 @@ var lru = require('tilestrata-lru');
 // set total size limit of cache
 server.layer('mylayer').route('tile.pbf')
     .use(/* some provider */)
-    .use(lru({size: '20mb' ttl: 30})); // ttl in seconds
+    .use(lru({size: '20mb', ttl: 30})); // ttl in seconds
 
 // or set a total number of items
 server.layer('mylayer').route('tile.pbf')
     .use(/* some provider */)
     .use(lru({size: 20, ttl: 30}));
+
+// set a function for the cache key
+server.layer('mylayer').route('tile.pbf')
+    .use(/* some provider */)
+    .use(lru({key: function(req) {
+        var compressed = /gzip|deflate/.test(req.headers['accept-encoding']) ? 1 : 0;
+        return req.z+','+req.x+','+req.y+','+req.layer+','+req.filename+','+compressed;
+    }}));
 ```
 
 ## Contributing

diff --git a/index.js b/index.js
@@ -1,13 +1,13 @@
 var SyncCache = require('active-cache/sync');
 var filesizeParser = require('filesize-parser');
 
-function key(req) {
-	return req.z+','+req.x+','+req.y+','+req.layer+','+req.filename+','+req.headers['accept-encoding'];
-}
-
 module.exports = function(opts) {
 	opts = opts || {};
 
+	var key = opts.key || function(req) {
+		return req.z+','+req.x+','+req.y+','+req.layer+','+req.filename;
+	};
+
 	var lruopts = {max: 6};
 	if (typeof opts.size === 'string') {
 		lruopts.max = filesizeParser(opts.size);