Support range based HTTP queries for the HTTP file server

[s-ludwig]

To support resuming of downloads and fix certain issues on some browsers, the Accept-Ranges and related headers should be supported by the HTTP file server module.

See also http://forum.dlang.org/post/[email protected]

[UplinkCoder]

That would really be a useful addition

[yebblies]

diff --git a/source/vibe/http/fileserver.d b/source/vibe/http/fileserver.d
index e3c4f48..71b45a8 100644
--- a/source/vibe/http/fileserver.d
+++ b/source/vibe/http/fileserver.d
@@ -13,6 +13,7 @@ import vibe.http.server;
 import vibe.inet.message;
 import vibe.inet.mimetypes;
 import vibe.inet.url;
+import vibe.stream.counting;

 import std.conv;
 import std.datetime;
@@ -311,7 +312,23 @@ private void sendFileImpl(scope HTTPServerRequest req, scope HTTPServerResponse
    if ("Content-Encoding" in res.headers && isCompressedFormat(mimetype))
        res.headers.remove("Content-Encoding");
    res.headers["Content-Type"] = mimetype;
-   res.headers["Content-Length"] = to!string(dirent.size);
+
+    res.headers.addField("Accept-Ranges", "bytes");
+    ulong rangeStart = 0;
+    ulong rangeEnd = 0;
+    if (auto prange = "Range" in req.headers)
+    {
+        auto range = (*prange).chompPrefix("bytes=");
+        auto s = range.split("-");
+        rangeStart = s[0].to!ulong();
+        rangeEnd = s[1].length ? s[1].to!ulong() : dirent.size;
+        res.headers["Content-Length"] = to!string(rangeEnd - rangeStart + 1);
+        res.headers["Content-Range"] = "bytes %s-%s/%s".format(rangeStart, rangeEnd, dirent.size);
+    }
+    else
+    {
+        res.headers["Content-Length"] = to!string(dirent.size);
+    }

    // check for already encoded file if configured
    string encodedFilepath;
@@ -366,6 +383,13 @@ private void sendFileImpl(scope HTTPServerRequest req, scope HTTPServerResponse
    }
    scope(exit) fil.close();

+    if ("Range" in req.headers)
+    {
+        fil.seek(rangeStart);
+        res.bodyWriter.write(new LimitedInputStream(fil, rangeEnd - rangeStart + 1));
+        return;
+    }
+
    if (pce && !encodedFilepath.length)
        res.bodyWriter.write(fil);
    else res.writeRawBody(fil);

[s-ludwig]

Thanks, Daniel! I'll add some code to detect multi-ranges and integrate this on master.

[etcimon]

status code should be 206 and response should use writeRawBody if there's an encoding