From 2d71e844a2f15257b9447142ba3912fece06e835 Mon Sep 17 00:00:00 2001
From: Thaddee Tyl <thaddee.tyl@gmail.com>
Date: Wed, 5 Apr 2017 13:23:18 +0200
Subject: [PATCH] Store raster badges in the LRU cache

In ef1a5159, the switch to using imagemagick made a faulty use of the library by
listening for an 'end' event that is never raised. As a result, the cache was
never populated.

In d985f81f, a fix that takes care of the fact that the previously mentioned
dead code relies on a non-existent variable caused it to kill the server when a
raster badge is requested twice, as what it stored in the cache was the pipe
transmitting chunks, not the chunks themselves, and the pipe (a Socket object)
cannot be subsequently sent through a pipe. The following error occured instead:

    events.js:163
          throw er; // Unhandled 'error' event
          ^

    TypeError: Invalid non-string/buffer chunk
        at chunkInvalid (_stream_readable.js:395:10)
        at readableAddChunk (_stream_readable.js:150:12)
        at DataStream.Readable.push (_stream_readable.js:136:10)
        at DataStream._read (/home/m/shields/lib/svg-to-img.js:45:21)
        at DataStream.Readable.read (_stream_readable.js:350:10)
        at resume_ (_stream_readable.js:739:12)
        at _combinedTickCallback (internal/process/next_tick.js:80:11)
        at process._tickDomainCallback (internal/process/next_tick.js:128:9)
---
 lib/svg-to-img.js | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/lib/svg-to-img.js b/lib/svg-to-img.js
index dff94f9..7d7e975 100644
--- a/lib/svg-to-img.js
+++ b/lib/svg-to-img.js
@@ -20,13 +20,10 @@ module.exports = function (svg, format, out, cb) {
   .background(format === 'jpg' ? '#FFFFFF' : 'none')
   .flatten()
   .stream(format, function (err, stdout, stderr) {
-    if (err) { console.error(err); }
-
-    stdout.on('end', function () {
-      imgCache.set(cacheIndex, [stdout]);
-      cb && cb();
-    });
-
+    if (err) { console.error(err); return; }
+    var chunks = [];
+    stdout.on('data', function(chunk) { chunks.push(chunk); });
+    stdout.on('end', function() { imgCache.set(cacheIndex, chunks); });
     stdout.pipe(out);
   });
 };
@@ -42,9 +39,9 @@ function DataStream(data) {
 util.inherits(DataStream, Readable);
 DataStream.prototype._read = function() {
   while (this.i < this.data.length) {
-    var stop = this.push(this.data[this.i]);
+    var keepPushing = this.push(this.data[this.i]);
     this.i++;
-    if (stop) { return; }
+    if (!keepPushing) { return; }
   }
   this.push(null);
 };