1 files changed, 105 insertions, 0 deletions
diff --git a/node_modules/koa-range/index.js b/node_modules/koa-range/index.js
new file mode 100644
index 00000000..94451f4c
--- /dev/null
+++ b/node_modules/koa-range/index.js
@@ -0,0 +1,105 @@
+
+var util = require('util');
+var slice = require('stream-slice').slice;
+var Stream = require('stream');
+
+module.exports = async function (ctx, next) {
+  var range = ctx.header.range;
+  ctx.set('Accept-Ranges', 'bytes');
+
+  if (!range) {
+    return next();
+  }
+
+  var ranges = rangeParse(range);
+
+  if (!ranges || ranges.length == 0) {
+    ctx.status = 416;
+    return;
+  }
+
+  if (ctx.method == 'PUT') {
+    ctx.status = 400;
+    return;
+  }
+
+  await next();
+
+  if (ctx.method != 'GET' ||
+     ctx.body == null) {
+    return;
+  }
+
+  var first = ranges[0];
+  var rawBody = ctx.body;
+  var len = rawBody.length;
+
+  // avoid multi ranges
+  var firstRange = ranges[0];
+  var start = firstRange[0];
+  var end = firstRange[1];
+
+  if (!Buffer.isBuffer(rawBody)) {
+    if (rawBody instanceof Stream.Readable) {
+      len = ctx.length || '*';
+      rawBody = rawBody.pipe(slice(start, end + 1));
+    } else if (typeof rawBody !== 'string') {
+      rawBody = new Buffer(JSON.stringify(rawBody));
+      len = rawBody.length;
+    } else {
+      rawBody = new Buffer(rawBody);
+      len = rawBody.length;
+    }
+  }
+
+  //Adjust infinite end
+  if (end === Infinity) {
+    if (Number.isInteger(len)) {
+      end = len - 1;
+    } else {
+      // FIXME(Calle Svensson): If we don't know how much we can return, we do a normal HTTP 200 repsonse
+      ctx.status = 200;
+      return;
+    }
+  }
+
+  var args = [start, end+1].filter(function(item) {
+    return typeof item == 'number';
+  });
+
+  ctx.set('Content-Range', rangeContentGenerator(start, end, len));
+  ctx.status = 206;
+
+  if (rawBody instanceof Stream) {
+    ctx.body = rawBody;
+  } else {
+    ctx.body = rawBody.slice.apply(rawBody, args);
+  }
+
+  if (len !== '*') {
+    ctx.length = end - start + 1;
+  }
+};
+
+function rangeParse(str) {
+  var token = str.split('=');
+  if (!token || token.length != 2 || token[0] != 'bytes') {
+    return null;
+  }
+  return token[1].split(',')
+    .map(function(range) {
+      return range.split('-').map(function(value) {
+        if (value === '') {
+          return Infinity;
+        }
+        return Number(value);
+      });
+    })
+    .filter(function(range) {
+      return !isNaN(range[0]) && !isNaN(range[1]) && range[0] <= range[1];
+    });
+}
+
+function rangeContentGenerator(start, end, length) {
+  return util.format('bytes %d-%d/%s', start, end, length);
+}