testdata and parse impl

go.mod

@@ -1 +1,3 @@
 module mapserver
+
+require github.com/sirupsen/logrus v1.3.0

go.sum

@@ -0,0 +1,11 @@
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.3.0 h1:hI/7Q+DtNZ2kINb6qt/lS+IyXnHQe9e90POfeewL/ME=
+github.com/sirupsen/logrus v1.3.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+golang.org/x/crypto v0.0.0-20180904163835-0709b304e793 h1:u+LnwYTOOW7Ukr/fppxEb1Nwz0AtPflrblfvUudpo+I=
+golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33 h1:I6FyU15t786LL7oL/hn43zqTuEGr4PN7F4XJ1p4E3Y8=
+golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=

mapblockparser/parse.go

@@ -0,0 +1,125 @@
+package mapblockparser
+
+import (
+	"errors"
+	"compress/zlib"
+	"bytes"
+	"io"
+	"strconv"
+	log "github.com/sirupsen/logrus"
+)
+
+type MapBlock struct {
+	Version byte
+	Underground bool
+	Mapdata []byte
+}
+
+func readU16(data []byte, offset int){
+}
+
+func readU32(data []byte, offset int){
+}
+
+type CountedReader struct {
+	reader io.Reader
+	Count int
+}
+
+func (r *CountedReader) Read(p []byte) (int, error){
+	i,err := r.reader.Read(p)
+	r.Count += i
+	return i,err
+}
+
+func (r *CountedReader) ReadByte() (byte, error){
+	r.Count++;
+	return r.reader.ReadByte()
+}
+
+func parseMapdata(mapblock *MapBlock, data []byte) (int, error) {
+	r := bytes.NewReader(data)
+
+	cr := new(CountedReader)
+	cr.reader = r
+
+	z, err := zlib.NewReader(cr)
+	if err != nil {
+		return 0, err
+	}
+
+	defer z.Close()
+
+	buf := new(bytes.Buffer)
+	io.Copy(buf, z)
+
+	if buf.Len() != 16384 {
+		return 0, errors.New("Mapdata length invalid: " + strconv.Itoa(buf.Len()))
+	}
+
+	mapblock.Mapdata = buf.Bytes()
+
+	return cr.Count, nil
+}
+
+func parseMetadata(mapblock *MapBlock, data []byte) (int, error) {
+	r := bytes.NewReader(data)
+
+	cr := new(CountedReader)
+	cr.reader = r
+
+	z, err := zlib.NewReader(cr)
+	if err != nil {
+		return 0, err
+	}
+
+	defer z.Close()
+
+	buf := new(bytes.Buffer)
+	io.Copy(buf, z)
+
+	log.Println("Metadata length ", buf.Len())
+
+	return cr.Count, nil
+}
+
+func Parse(data []byte) (*MapBlock, error) {
+	mapblock := MapBlock{}
+	if len(data) == 0 {
+		return nil, errors.New("no data")
+	}
+
+	log.Println("data-length: ", len(data))
+
+	offset := 0
+
+	// version
+	mapblock.Version = data[0]
+
+	//flags
+	flags := data[1]
+	mapblock.Underground = (flags & 0x01) == 0x01
+
+	//mapdata (blocks)
+	offset = 6
+
+	//metadata
+	count, err := parseMapdata(&mapblock, data[offset:])
+	if err != nil {
+		return nil, err
+	}
+
+	log.Println("Mapdata length: ", count)
+
+	offset += count
+
+	log.Println("New offset: ", offset)
+
+	count, err = parseMetadata(&mapblock, data[offset:])
+	if err != nil {
+		return nil, err
+	}
+
+	return &mapblock, nil
+}
+

mapblockparser/parse_test.go

@@ -0,0 +1,33 @@
+package mapblockparser
+
+import (
+	"testing"
+	"io/ioutil"
+	"strconv"
+	mapblockparser "mapserver/mapblockparser"
+)
+
+func TestParse(t *testing.T){
+	data, err := ioutil.ReadFile("testdata/0.0.0")
+	if err != nil {
+		t.Error(err)
+	}
+
+	mapblock, err := mapblockparser.Parse(data)
+
+	if err != nil {
+		t.Error(err)
+	}
+
+	if mapblock.Version != 28 {
+		t.Error("wrong mapblock version: " + strconv.Itoa(int(mapblock.Version)))
+	}
+
+	if !mapblock.Underground {
+		t.Error("Underground flag")
+	}
+
+	if len(mapblock.Mapdata) != 16384 {
+		t.Error("Mapdata length wrong")
+	}
+}