Large payloads

source/droid/gateway/compression.d

@@ -0,0 +1,55 @@
+module droid.gateway.compression;
+
+import droid.exception;
+import std.zlib,
+       std.stdio,
+       std.conv : to;
+
+enum CompressionType : string {
+    NONE        = "",
+    ZLIB        = "zlib",
+    ZLIB_STREAM = "zlib-stream"
+}
+
+class Decompressor {
+    string read(ubyte[] data) {
+        throw new DroidException("Compression type not supported!");
+    }
+}
+
+class ZLib : Decompressor {
+    override string read(ubyte[] data) {
+        return to!string(new UnCompress(HeaderFormat.deflate).uncompress(data));
+    }
+}
+
+class ZLibStream : Decompressor {
+    const ubyte[] ZLIB_SUFFIX = [0x0, 0x0, 0xFF, 0xFF];
+    UnCompress decompressor;
+
+    ubyte[] buffer;
+
+    this() {
+        decompressor = new UnCompress(HeaderFormat.deflate);
+    }
+
+    /*
+     * Reads a zlib stream from the websocket
+     * This will append the data to a buffer,
+     * returning nothing if the data is not a full zlib frame
+     * otherwise, returning the decompressed string.
+     */
+    override string read(ubyte[] data) {
+        buffer ~= data;
+
+        if (data[$-4..$] != ZLIB_SUFFIX) {
+            return "";
+        }
+
+        string decompressed = to!string(decompressor.uncompress(buffer));
+        decompressor.flush();
+        buffer = null;
+
+        return decompressed;
+    }
+}

source/droid/gateway/gateway.d

@@ -6,7 +6,9 @@ import core.time,
        std.stdio,
        std.typecons,
        std.random,
-       std.experimental.logger;
+       std.experimental.logger,
+       std.array,
+       std.zlib;
 
 import vibe.core.core,
        vibe.http.common,
@@ -19,7 +21,8 @@ import droid.exception,
        droid.api,
        droid.gateway.opcode,
        droid.gateway.packet,
-       droid.data.event_type;
+       droid.data.event_type,
+       droid.gateway.compression;
 
 final class Gateway
 {
@@ -32,7 +35,9 @@ final class Gateway
 
     private immutable OpcodeHandlerMap OPCODE_MAPPING;
 
-    private immutable string gatewayUrl_;
+    private string gatewayUrl_;
+    private immutable CompressionType compressionType = CompressionType.ZLIB_STREAM;
+    private Decompressor decompressor = null;
 
     private API api_;
     private WebSocket ws_;
@@ -61,6 +66,21 @@ final class Gateway
 
     void connect(in bool blocking = true, in bool reconnecting = false)
     {
+        if (compressionType != CompressionType.NONE) {
+            switch (compressionType) {
+                case CompressionType.ZLIB_STREAM:
+                    gatewayUrl_ = gatewayUrl_ ~ "&compress=" ~ compressionType;
+                    decompressor = new ZLibStream();
+                    break;
+                case CompressionType.ZLIB:
+                    decompressor = new ZLib();
+                    break;
+                default:
+                    throw new DroidException("Compression type not supported!");
+
+            }
+        }
+
         if (!tryConnect(gatewayUrl_)) {
             logger_.tracef("Could not connect to given gateway url %s, using API", gatewayUrl_);
             tryConnect(api_.getGatewayUrl(), true);
@@ -101,6 +121,7 @@ final class Gateway
 
         opcodeIdentifyHandle(Json([
             "token": Json(api_.token),
+            "compress": Json(compressionType == CompressionType.ZLIB),
             "properties": Json([
                 "$os": Json(osName),
                 "$browser": Json("droid"),
@@ -136,7 +157,23 @@ final class Gateway
         assert(ws_ && ws_.connected);
 
         while (ws_.waitForData()) {
-            const packet = parseMessage(ws_.receiveText());
+            auto data = "";
+
+            if (decompressor) {
+                // TODO: This may be meh.
+                try {
+                    data = decompressor.read(ws_.receiveBinary());
+                } catch (WebSocketException e) {
+                    // The data isn't compressed or something went wrong, Yeet it to text!
+                    data = ws_.receiveText();
+                }
+            } else
+                data = ws_.receiveText();
+
+            // The data isn't complete (not a full zlib message, or something borked)
+            if (data == "") return;
+
+            const packet = parseMessage(data);
 
             auto opcodeHandler = packet.opcode in OPCODE_MAPPING;
             if (opcodeHandler) {

source/droid/gateway/package.d

@@ -4,4 +4,5 @@ public {
     import droid.gateway.opcode;
     import droid.gateway.packet;
     import droid.gateway.gateway;
+    import droid.gateway.compression;
 }