Add abstraction Payload to use in Publish

Author: spuun

spec/io_spec.cr

@@ -84,7 +84,7 @@ describe MQTT::Protocol::IO do
     mio = IO::Memory.new
     io = MQTT::Protocol::IO.new(mio)
 
-    io.write_bytes_raw bytes
+    io.write bytes
     mio.rewind
 
     res = Bytes.new(3)

spec/packets_spec.cr

@@ -254,13 +254,13 @@ describe MQTT::Protocol::Packet do
           io = MQTT::Protocol::IO.new(mio)
 
           topic = "a/b/c"
-          payload = "foobar and barfoo".to_slice
+          payload = MQTT::Protocol::Payload.new("foobar and barfoo".to_slice)
           remaining_length = topic.bytesize + payload.size + 2 # 2 = sizeof topic len
 
           io.write_byte 0b00110000u8
           io.write_remaining_length remaining_length
           io.write_string topic
-          io.write_bytes_raw payload
+          io.write_bytes payload
 
           mio.rewind
 
@@ -282,7 +282,7 @@ describe MQTT::Protocol::Packet do
           io.write_byte 0b00111000u8
           io.write_remaining_length remaining_length
           io.write_string topic
-          io.write_bytes_raw payload
+          io.write payload
 
           mio.rewind
 
@@ -302,7 +302,7 @@ describe MQTT::Protocol::Packet do
           io.write_byte 0b00111000u8
           io.write_remaining_length remaining_length
           io.write_string topic
-          io.write_bytes_raw payload
+          io.write payload
 
           mio.rewind
 
@@ -318,7 +318,7 @@ describe MQTT::Protocol::Packet do
           io = MQTT::Protocol::IO.new(mio)
 
           topic = "a/b/c"
-          payload = "foobar and barfoo".to_slice
+          payload = MQTT::Protocol::Payload.new("foobar and barfoo".to_slice)
           packet_id = 100u16
           publish = MQTT::Protocol::Publish.new(topic, payload, packet_id, false, 1, false)
           publish.to_io(io)
@@ -335,7 +335,7 @@ describe MQTT::Protocol::Packet do
 
         it "raises error if dup is set for QoS 0 messages" do
           topic = "a/b/c"
-          payload = "foobar and barfoo".to_slice
+          payload = MQTT::Protocol::Payload.new("foobar and barfoo".to_slice)
           packet_id = 100u16
           expect_raises(ArgumentError) do
             MQTT::Protocol::Publish.new(topic, payload, packet_id, true, 0, false)
@@ -347,7 +347,7 @@ describe MQTT::Protocol::Packet do
           io = MQTT::Protocol::IO.new(mio)
 
           topic = "a/b/c"
-          payload = "foobar and barfoo".to_slice
+          payload = MQTT::Protocol::Payload.new("foobar and barfoo".to_slice)
           packet_id = 100u16
           publish = MQTT::Protocol::Publish.new(topic, payload, packet_id, false, 0, false)
           publish.to_io(io)
@@ -365,7 +365,7 @@ describe MQTT::Protocol::Packet do
       describe "#initialize" do
         it "raises an error if QoS is 3" do
           topic = "a/b/c"
-          payload = "foobar and barfoo".to_slice
+          payload = MQTT::Protocol::Payload.new("foobar and barfoo".to_slice)
           packet_id = 100u16
           expect_raises(ArgumentError) do
             MQTT::Protocol::Publish.new(topic, payload, packet_id, false, 3, false)
@@ -375,7 +375,7 @@ describe MQTT::Protocol::Packet do
         describe "with wildcard in topic" do
           it "should raise ArguementError" do
             topic = "a/#"
-            payload = "foobar and barfoo".to_slice
+            payload = MQTT::Protocol::Payload.new("foobar and barfoo".to_slice)
             packet_id = 100u16
 
             expect_raises(ArgumentError) do

spec/payload_spec.cr

@@ -0,0 +1,77 @@
+require "./spec_helper"
+
+describe MQTT::Protocol::Payload do
+  it ".new(Bytes) returns a BytesPayload" do
+    obj = MQTT::Protocol::Payload.new("foo".to_slice)
+    obj.should be_a(MQTT::Protocol::BytesPayload)
+  end
+
+  it ".new(IO) returns a IOPayload" do
+    io = IO::Memory.new
+    io.write "foo".to_slice
+    obj = MQTT::Protocol::Payload.new(io, 3)
+    obj.should be_a(MQTT::Protocol::IOPayload)
+  end
+
+  describe "#==" do
+    it "should return true for two BytePayload with same bytes" do
+      one = MQTT::Protocol::BytesPayload.new("foo".to_slice)
+      two = MQTT::Protocol::BytesPayload.new("foo".to_slice)
+
+      (one == two).should be_true
+    end
+
+    it "should return false for two BytePayload with different bytes" do
+      one = MQTT::Protocol::BytesPayload.new("foo".to_slice)
+      two = MQTT::Protocol::BytesPayload.new("bar".to_slice)
+
+      (one == two).should be_false
+    end
+
+    it "should return true for two IOPayload with same content" do
+      io_one = IO::Memory.new("foo".to_slice)
+      io_two = IO::Memory.new("foo".to_slice)
+
+      io_one.rewind
+      io_two.rewind
+
+      one = MQTT::Protocol::IOPayload.new(io_one, 3)
+      two = MQTT::Protocol::IOPayload.new(io_two, 3)
+
+      (one == two).should be_true
+    end
+
+    it "should return false for two IOPayload with different content" do
+      io_one = IO::Memory.new("foo".to_slice)
+      io_two = IO::Memory.new("bar".to_slice)
+
+      io_one.rewind
+      io_two.rewind
+
+      one = MQTT::Protocol::IOPayload.new(io_one, 3)
+      two = MQTT::Protocol::IOPayload.new(io_two, 3)
+
+      (one == two).should be_false
+    end
+
+    it "should return true for one BytesPayload and one IOPayload with same content" do
+      io_two = IO::Memory.new("foo".to_slice)
+      io_two.rewind
+
+      one = MQTT::Protocol::BytesPayload.new("foo".to_slice)
+      two = MQTT::Protocol::IOPayload.new(io_two, 3)
+
+      (one == two).should be_true
+    end
+
+    it "should return false for one BytesPayload and one IOPayload with different content" do
+      io_two = IO::Memory.new("bar".to_slice)
+      io_two.rewind
+
+      one = MQTT::Protocol::BytesPayload.new("foo".to_slice)
+      two = MQTT::Protocol::IOPayload.new(io_two, 3)
+
+      (one == two).should be_false
+    end
+  end
+end

src/mqtt/protocol/io.cr

@@ -68,6 +68,7 @@ module MQTT
         @io.write bytes
       end
 
+      @[Deprecated("Use write_bytes instead")]
       def write_bytes_raw(bytes : Bytes)
         @io.write bytes
       end

src/mqtt/protocol/packets/publish.cr

@@ -1,3 +1,4 @@
+require "../payload"
 require "./packets"
 
 module MQTT
@@ -8,7 +9,7 @@ module MQTT
       getter topic, payload, qos, packet_id, remaining_length
       getter? dup, retain
 
-      def initialize(@topic : String, @payload : Bytes, @packet_id : UInt16?, @dup : Bool, @qos : UInt8, @retain : Bool)
+      def initialize(@topic : String, @payload : Payload, @packet_id : UInt16?, @dup : Bool, @qos : UInt8, @retain : Bool)
         raise ArgumentError.new("QoS must be 0, 1 or 2") if @qos > 2
         raise ArgumentError.new("Topic cannot contain wildcard") if @topic.matches?(/[#+]/)
         raise ArgumentError.new("Topic must be between atleast 1 char long") if @topic.size < 1
@@ -19,6 +20,19 @@ module MQTT
         @remaining_length += 2 if qos.positive? # packet_id
       end
 
+      @[Deprecated("Use Payload instead of Bytes for @payload")]
+      def initialize(@topic : String, payload : Bytes, @packet_id : UInt16?, @dup : Bool, @qos : UInt8, @retain : Bool)
+        raise ArgumentError.new("QoS must be 0, 1 or 2") if @qos > 2
+        raise ArgumentError.new("Topic cannot contain wildcard") if @topic.matches?(/[#+]/)
+        raise ArgumentError.new("Topic must be between atleast 1 char long") if @topic.size < 1
+        raise ArgumentError.new("Topic cannot be larger than 65535 bytes") if @topic.bytesize > 65535
+        raise ArgumentError.new("DUP must be 0 for QoS 0 messages") if dup? && qos.zero?
+        @payload = BytesPayload.new(payload)
+        @remaining_length = 0
+        @remaining_length += (2 + topic.bytesize) + payload.bytesize
+        @remaining_length += 2 if qos.positive? # packet_id
+      end
+
       def self.from_io(io : MQTT::Protocol::IO, flags : Flags, remaining_length : UInt32)
         dup = flags.bit(3) > 0
         retain = flags.bit(0) > 0
@@ -32,7 +46,7 @@ module MQTT
         else
           decode_assert dup == false, "DUP must be 0 for QoS 0 messages"
         end
-        payload = io.read_bytes(remaining_length.to_u16)
+        payload = IOPayload.new(io, remaining_length.to_i32)
         self.new(topic, payload, packet_id, dup, qos, retain)
       rescue ex : ArgumentError
         raise MQTT::Protocol::Error::PacketDecode.new(ex.message)
@@ -47,7 +61,7 @@ module MQTT
         io.write_remaining_length remaining_length
         io.write_string topic
         io.write_int packet_id.not_nil! if qos.positive?
-        io.write_bytes_raw(payload)
+        io.write_bytes payload
       end
     end
   end

src/mqtt/protocol/payload.cr

@@ -0,0 +1,82 @@
+require "./io"
+
+module MQTT
+  module Protocol
+    abstract struct Payload
+      def self.new(bytes : Bytes)
+        BytesPayload.new(bytes)
+      end
+
+      def self.new(io : ::IO, bytesize : Int32)
+        IOPayload.new(MQTT::Protocol::IO.new(io), bytesize)
+      end
+
+      def self.new(io : MQTT::Protocol::IO, bytesize : Int32)
+        IOPayload.new(io, bytesize)
+      end
+
+      def size
+        bytesize
+      end
+
+      abstract def bytesize : Int32
+      abstract def to_slice : Bytes
+      abstract def to_io(io, format : ::IO::ByteFormat = IO::ByteFormat::SystemEndian)
+
+      def ==(other)
+        return false unless other.is_a?(Payload)
+        to_slice == other.to_slice
+      end
+    end
+
+    struct BytesPayload < Payload
+      def initialize(@bytes : Bytes)
+      end
+
+      def bytesize : Int32
+        @bytes.bytesize
+      end
+
+      def to_slice : Bytes
+        @bytes
+      end
+
+      def to_io(io, format : ::IO::ByteFormat = IO::ByteFormat::SystemEndian)
+        io.write @bytes
+      end
+    end
+
+    struct IOPayload < Payload
+      getter bytesize : Int32
+
+      @data : Bytes? = nil
+
+      def initialize(@io : MQTT::Protocol::IO, @bytesize : Int32)
+      end
+
+      def initialize(io : ::IO, @bytesize : Int32)
+        @io = MQTT::Protocol::IO.new(io)
+      end
+
+      def to_slice : Bytes
+        if peeked = @io.peek.try &.[0, bytesize]?
+          return peeked
+        end
+        return @data || begin
+          data = Bytes.new(bytesize)
+          @io.read(data)
+          data
+        end
+      end
+
+      def to_io(io, format : ::IO::ByteFormat = IO::ByteFormat::SystemEndian)
+        if data = @data
+          io.write data
+        else
+          copied = ::IO.copy(@io, io, bytesize)
+          raise "Failed to copy payload" if copied != bytesize
+        end
+      end
+    end
+  end
+end