Simplify message compression

lib/protocol/grpc/body/readable.rb

@@ -117,26 +117,20 @@ def read_exactly(n)
 				def decompress(data)
 					case @encoding
 					when "gzip"
-						# Gzip format: zlib stream with gzip header (RFC 1952)
-						# Use MAX_WBITS + 32 to handle gzip header and CRC
-						inflater = Zlib::Inflate.new(Zlib::MAX_WBITS + 32)
-						result = inflater.inflate(data)
-						inflater.close
-						result
+						begin
+							Zlib.gunzip(data)
+						rescue => error
+							raise Error.new(Status::INTERNAL, "Failed to decompress message: #{error.message}")
+						end
 					when "deflate"
-						# Zlib format (RFC 1950) - default window bits handle zlib header
-						# This matches HTTP's "deflate" content-encoding
-						inflater = Zlib::Inflate.new
-						result = inflater.inflate(data)
-						inflater.close
-						result
+						begin
+							Zlib::Inflate.inflate(data)
+						rescue => error
+							raise Error.new(Status::INTERNAL, "Failed to decompress message: #{error.message}")
+						end
 					else
 						raise Error.new(Status::UNIMPLEMENTED, "Unsupported compression encoding: #{@encoding.inspect}")
 					end
-				rescue Error
-					raise
-				rescue StandardError => error
-					raise Error.new(Status::INTERNAL, "Failed to decompress message: #{error.message}")
 				end
 			end
 		end

lib/protocol/grpc/body/writable.rb

@@ -6,7 +6,6 @@
 require "protocol/http"
 require "protocol/http/body/writable"
 require "zlib"
-require "stringio"
 
 require_relative "../error"
 require_relative "../status"
@@ -89,21 +88,20 @@ def write(message, compressed: nil)
 				def compress(data)
 					case @encoding
 					when "gzip"
-						# Use GzipWriter for proper gzip format (includes headers, CRC)
-						io = StringIO.new
-						gz = Zlib::GzipWriter.new(io, @level)
-						gz.write(data)
-						gz.close
-						io.string
+						begin
+							Zlib.gzip(data, level: @level)
+						rescue => error
+							raise Error.new(Status::INTERNAL, "Failed to compress message: #{error.message}")
+						end
 					when "deflate"
-						# Use zlib format (RFC 1950) for HTTP compatibility
-						# This matches HTTP's "deflate" content-encoding
-						Zlib::Deflate.deflate(data, @level)
+						begin
+							Zlib::Deflate.deflate(data, @level)
+						rescue => error
+							raise Error.new(Status::INTERNAL, "Failed to compress message: #{error.message}")
+						end
 					else
-						raise ArgumentError, "Unsupported compression encoding: #{@encoding.inspect}"
+						raise Error.new(Status::INTERNAL, "Unsupported compression encoding: #{@encoding.inspect}")
 					end
-				rescue StandardError => error
-					raise Error.new(Status::INTERNAL, "Failed to compress message: #{error.message}")
 				end
 			end
 		end

test/protocol/grpc/body/readable.rb

@@ -227,12 +227,23 @@ def source_body.read
 			end
 		end
 
-		it "raises a gRPC error for invalid compressed data" do
+		it "raises a gRPC error for invalid gzip data" do
 			body = subject.new(source_body, encoding: "gzip")
 			write_data("invalid", compressed: true)
 
 			expect{body.read}.to raise_exception(Protocol::GRPC::Error) do |error|
 				expect(error.status_code).to be == Protocol::GRPC::Status::INTERNAL
+				expect(error.message).to be =~ /Failed to decompress message/
+			end
+		end
+
+		it "raises a gRPC error for invalid deflate data" do
+			body = subject.new(source_body, encoding: "deflate")
+			write_data("invalid", compressed: true)
+
+			expect{body.read}.to raise_exception(Protocol::GRPC::Error) do |error|
+				expect(error.status_code).to be == Protocol::GRPC::Status::INTERNAL
+				expect(error.message).to be =~ /Failed to decompress message/
 			end
 		end
 	end

test/protocol/grpc/body/writable.rb

@@ -213,6 +213,17 @@ def message.encode
 			expect(compressed).to be == 0
 		end
 
+		it "compresses messages using gzip" do
+			body = subject.new(encoding: "gzip")
+			message = message_class.new(value: "Hello")
+			body.write(message)
+			body.close_write
+
+			framed_data = body.join
+			expect(framed_data.getbyte(0)).to be == 1
+			expect(Zlib.gunzip(framed_data.byteslice(5..))).to be == message.to_proto
+		end
+
 		it "compresses messages using deflate" do
 			body = subject.new(encoding: "deflate")
 			message = message_class.new(value: "Hello")
@@ -234,11 +245,23 @@ def message.encode
 			end
 		end
 
-		it "raises a gRPC error when compression fails" do
-			body = subject.new(encoding: "deflate", level: 100)
+		it "raises a gRPC error when gzip compression fails" do
+			body = subject.new(encoding: "gzip")
+			expect(Zlib).to receive(:gzip).and_raise(Zlib::StreamError, "compression failed")
+
+			expect{body.write("Hello")}.to raise_exception(Protocol::GRPC::Error) do |error|
+				expect(error.status_code).to be == Protocol::GRPC::Status::INTERNAL
+				expect(error.message).to be == "Failed to compress message: compression failed"
+			end
+		end
+
+		it "raises a gRPC error when deflate compression fails" do
+			body = subject.new(encoding: "deflate")
+			expect(Zlib::Deflate).to receive(:deflate).and_raise(Zlib::StreamError, "compression failed")
 
 			expect{body.write("Hello")}.to raise_exception(Protocol::GRPC::Error) do |error|
 				expect(error.status_code).to be == Protocol::GRPC::Status::INTERNAL
+				expect(error.message).to be == "Failed to compress message: compression failed"
 			end
 		end
 	end