Add LookupNetwork method

.golangci.toml

@@ -0,0 +1,30 @@
+[run]
+  deadline = "10m"
+  tests = true
+
+[linters]
+  disable-all = true
+  enable = [
+    "deadcode",
+    "depguard",
+    "errcheck",
+    "goconst",
+    "gocyclo",
+    "gocritic",
+    "gofmt",
+    "golint",
+    "gosec",
+    "gosimple",
+    "ineffassign",
+    "maligned",
+    "misspell",
+    "nakedret",
+    "staticcheck",
+    "structcheck",
+    "typecheck",
+    "unconvert",
+    "unparam",
+    "varcheck",
+    "vet",
+    "vetshadow",
+  ]

.travis.yml

@@ -17,12 +17,15 @@ matrix:
   allow_failures:
     - go: tip
 
-before_install:
-  - "if [[ $TRAVIS_GO_VERSION == 1.11 ]]; then go get -u golang.org/x/lint/golint; fi"
-
 install:
   - go get -v -t ./...
 
+before_script:
+  - |
+    if [[ $TRAVIS_GO_VERSION == 1.12 && $(arch) != 'ppc64le' ]]; then
+      curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin
+    fi
+
 script:
   - |
     if [ $(arch) == "ppc64le" ]; then
@@ -36,7 +39,9 @@ script:
     else
       go test -race -v -tags appengine
     fi
-  - "if [[ $TRAVIS_GO_VERSION == 1.11 ]]; then go vet ./...; fi"
-  - "if [[ $TRAVIS_GO_VERSION == 1.11 ]]; then golint .; fi"
+  - |
+    if [[ $TRAVIS_GO_VERSION == 1.12 && $(arch) != 'ppc64le' ]]; then
+      golangci-lint run
+    fi
 
 sudo: false

decoder.go

@@ -27,8 +27,10 @@ const (
 	_Uint64
 	_Uint128
 	_Slice
-	_Container
-	_Marker
+	// We don't use the next two. They are placeholders. See the spec
+	// for more details.
+	_Container // nolint: deadcode, varcheck
+	_Marker    // nolint: deadcode, varcheck
 	_Bool
 	_Float32
 )
@@ -159,10 +161,8 @@ func (d *decoder) unmarshalBool(size uint, offset uint, result reflect.Value) (u
 	if size > 1 {
 		return 0, newInvalidDatabaseError("the MaxMind DB file's data section contains bad data (bool size of %v)", size)
 	}
-	value, newOffset, err := d.decodeBool(size, offset)
-	if err != nil {
-		return 0, err
-	}
+	value, newOffset := d.decodeBool(size, offset)
+
 	switch result.Kind() {
 	case reflect.Bool:
 		result.SetBool(value)
@@ -207,10 +207,8 @@ func (d *decoder) indirect(result reflect.Value) reflect.Value {
 var sliceType = reflect.TypeOf([]byte{})
 
 func (d *decoder) unmarshalBytes(size uint, offset uint, result reflect.Value) (uint, error) {
-	value, newOffset, err := d.decodeBytes(size, offset)
-	if err != nil {
-		return 0, err
-	}
+	value, newOffset := d.decodeBytes(size, offset)
+
 	switch result.Kind() {
 	case reflect.Slice:
 		if result.Type() == sliceType {
@@ -230,10 +228,7 @@ func (d *decoder) unmarshalFloat32(size uint, offset uint, result reflect.Value)
 	if size != 4 {
 		return 0, newInvalidDatabaseError("the MaxMind DB file's data section contains bad data (float32 size of %v)", size)
 	}
-	value, newOffset, err := d.decodeFloat32(size, offset)
-	if err != nil {
-		return 0, err
-	}
+	value, newOffset := d.decodeFloat32(size, offset)
 
 	switch result.Kind() {
 	case reflect.Float32, reflect.Float64:
@@ -253,10 +248,8 @@ func (d *decoder) unmarshalFloat64(size uint, offset uint, result reflect.Value)
 	if size != 8 {
 		return 0, newInvalidDatabaseError("the MaxMind DB file's data section contains bad data (float 64 size of %v)", size)
 	}
-	value, newOffset, err := d.decodeFloat64(size, offset)
-	if err != nil {
-		return 0, err
-	}
+	value, newOffset := d.decodeFloat64(size, offset)
+
 	switch result.Kind() {
 	case reflect.Float32, reflect.Float64:
 		if result.OverflowFloat(value) {
@@ -277,10 +270,7 @@ func (d *decoder) unmarshalInt32(size uint, offset uint, result reflect.Value) (
 	if size > 4 {
 		return 0, newInvalidDatabaseError("the MaxMind DB file's data section contains bad data (int32 size of %v)", size)
 	}
-	value, newOffset, err := d.decodeInt(size, offset)
-	if err != nil {
-		return 0, err
-	}
+	value, newOffset := d.decodeInt(size, offset)
 
 	switch result.Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
@@ -360,11 +350,8 @@ func (d *decoder) unmarshalSlice(
 }
 
 func (d *decoder) unmarshalString(size uint, offset uint, result reflect.Value) (uint, error) {
-	value, newOffset, err := d.decodeString(size, offset)
+	value, newOffset := d.decodeString(size, offset)
 
-	if err != nil {
-		return 0, err
-	}
 	switch result.Kind() {
 	case reflect.String:
 		result.SetString(value)
@@ -384,10 +371,7 @@ func (d *decoder) unmarshalUint(size uint, offset uint, result reflect.Value, ui
 		return 0, newInvalidDatabaseError("the MaxMind DB file's data section contains bad data (uint%v size of %v)", uintType, size)
 	}
 
-	value, newOffset, err := d.decodeUint(size, offset)
-	if err != nil {
-		return 0, err
-	}
+	value, newOffset := d.decodeUint(size, offset)
 
 	switch result.Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
@@ -416,10 +400,7 @@ func (d *decoder) unmarshalUint128(size uint, offset uint, result reflect.Value)
 	if size > 16 {
 		return 0, newInvalidDatabaseError("the MaxMind DB file's data section contains bad data (uint128 size of %v)", size)
 	}
-	value, newOffset, err := d.decodeUint128(size, offset)
-	if err != nil {
-		return 0, err
-	}
+	value, newOffset := d.decodeUint128(size, offset)
 
 	switch result.Kind() {
 	case reflect.Struct:
@@ -436,36 +417,36 @@ func (d *decoder) unmarshalUint128(size uint, offset uint, result reflect.Value)
 	return newOffset, newUnmarshalTypeError(value, result.Type())
 }
 
-func (d *decoder) decodeBool(size uint, offset uint) (bool, uint, error) {
-	return size != 0, offset, nil
+func (d *decoder) decodeBool(size uint, offset uint) (bool, uint) {
+	return size != 0, offset
 }
 
-func (d *decoder) decodeBytes(size uint, offset uint) ([]byte, uint, error) {
+func (d *decoder) decodeBytes(size uint, offset uint) ([]byte, uint) {
 	newOffset := offset + size
 	bytes := make([]byte, size)
 	copy(bytes, d.buffer[offset:newOffset])
-	return bytes, newOffset, nil
+	return bytes, newOffset
 }
 
-func (d *decoder) decodeFloat64(size uint, offset uint) (float64, uint, error) {
+func (d *decoder) decodeFloat64(size uint, offset uint) (float64, uint) {
 	newOffset := offset + size
 	bits := binary.BigEndian.Uint64(d.buffer[offset:newOffset])
-	return math.Float64frombits(bits), newOffset, nil
+	return math.Float64frombits(bits), newOffset
 }
 
-func (d *decoder) decodeFloat32(size uint, offset uint) (float32, uint, error) {
+func (d *decoder) decodeFloat32(size uint, offset uint) (float32, uint) {
 	newOffset := offset + size
 	bits := binary.BigEndian.Uint32(d.buffer[offset:newOffset])
-	return math.Float32frombits(bits), newOffset, nil
+	return math.Float32frombits(bits), newOffset
 }
 
-func (d *decoder) decodeInt(size uint, offset uint) (int, uint, error) {
+func (d *decoder) decodeInt(size uint, offset uint) (int, uint) {
 	newOffset := offset + size
 	var val int32
 	for _, b := range d.buffer[offset:newOffset] {
 		val = (val << 8) | int32(b)
 	}
-	return int(val), newOffset, nil
+	return int(val), newOffset
 }
 
 func (d *decoder) decodeMap(
@@ -511,7 +492,7 @@ func (d *decoder) decodePointer(
 	if pointerSize == 4 {
 		prefix = 0
 	} else {
-		prefix = uint(size & 0x7)
+		prefix = size & 0x7
 	}
 	unpacked := uintFromBytes(prefix, pointerBytes)
 
@@ -549,9 +530,9 @@ func (d *decoder) decodeSlice(
 	return offset, nil
 }
 
-func (d *decoder) decodeString(size uint, offset uint) (string, uint, error) {
+func (d *decoder) decodeString(size uint, offset uint) (string, uint) {
 	newOffset := offset + size
-	return string(d.buffer[offset:newOffset]), newOffset, nil
+	return string(d.buffer[offset:newOffset]), newOffset
 }
 
 type fieldsType struct {
@@ -638,23 +619,23 @@ func (d *decoder) decodeStruct(
 	return offset, nil
 }
 
-func (d *decoder) decodeUint(size uint, offset uint) (uint64, uint, error) {
+func (d *decoder) decodeUint(size uint, offset uint) (uint64, uint) {
 	newOffset := offset + size
 	bytes := d.buffer[offset:newOffset]
 
 	var val uint64
 	for _, b := range bytes {
 		val = (val << 8) | uint64(b)
 	}
-	return val, newOffset, nil
+	return val, newOffset
 }
 
-func (d *decoder) decodeUint128(size uint, offset uint) (*big.Int, uint, error) {
+func (d *decoder) decodeUint128(size uint, offset uint) (*big.Int, uint) {
 	newOffset := offset + size
 	val := new(big.Int)
 	val.SetBytes(d.buffer[offset:newOffset])
 
-	return val, newOffset, nil
+	return val, newOffset
 }
 
 func uintFromBytes(prefix uint, uintBytes []byte) uint {

decoder_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestBool(t *testing.T) {
@@ -69,9 +70,9 @@ func TestInt32(t *testing.T) {
 
 func TestMap(t *testing.T) {
 	maps := map[string]interface{}{
-		"e0":                                         map[string]interface{}{},
-		"e142656e43466f6f":                           map[string]interface{}{"en": "Foo"},
-		"e242656e43466f6f427a6843e4baba":             map[string]interface{}{"en": "Foo", "zh": "人"},
+		"e0":                             map[string]interface{}{},
+		"e142656e43466f6f":               map[string]interface{}{"en": "Foo"},
+		"e242656e43466f6f427a6843e4baba": map[string]interface{}{"en": "Foo", "zh": "人"},
 		"e1446e616d65e242656e43466f6f427a6843e4baba": map[string]interface{}{"name": map[string]interface{}{"en": "Foo", "zh": "人"}},
 		"e1496c616e677561676573020442656e427a68":     map[string]interface{}{"languages": []interface{}{"en", "zh"}},
 	}
@@ -205,7 +206,7 @@ func validateDecoding(t *testing.T, tests map[string]interface{}) {
 
 		var result interface{}
 		_, err := d.decode(0, reflect.ValueOf(&result), 0)
-		assert.Nil(t, err)
+		assert.NoError(t, err)
 
 		if !reflect.DeepEqual(result, expected) {
 			// A big case statement would produce nicer errors
@@ -215,8 +216,8 @@ func validateDecoding(t *testing.T, tests map[string]interface{}) {
 }
 
 func TestPointers(t *testing.T) {
-	bytes, err := ioutil.ReadFile("test-data/test-data/maps-with-pointers.raw")
-	assert.Nil(t, err)
+	bytes, err := ioutil.ReadFile(testFile("maps-with-pointers.raw"))
+	require.NoError(t, err)
 	d := decoder{bytes}
 
 	expected := map[uint]map[string]string{
@@ -231,7 +232,7 @@ func TestPointers(t *testing.T) {
 	for offset, expectedValue := range expected {
 		var actual map[string]string
 		_, err := d.decode(offset, reflect.ValueOf(&actual), 0)
-		assert.Nil(t, err)
+		assert.NoError(t, err)
 		if !reflect.DeepEqual(actual, expectedValue) {
 			t.Errorf("Decode for pointer at %d failed", offset)
 		}

node.go

@@ -0,0 +1,42 @@
+package maxminddb
+
+type nodeReader interface {
+	readLeft(uint) uint
+	readRight(uint) uint
+}
+
+type nodeReader24 struct {
+	buffer []byte
+}
+
+func (n nodeReader24) readLeft(nodeNumber uint) uint {
+	return (uint(n.buffer[nodeNumber]) << 16) | (uint(n.buffer[nodeNumber+1]) << 8) | uint(n.buffer[nodeNumber+2])
+}
+
+func (n nodeReader24) readRight(nodeNumber uint) uint {
+	return (uint(n.buffer[nodeNumber+3]) << 16) | (uint(n.buffer[nodeNumber+4]) << 8) | uint(n.buffer[nodeNumber+5])
+}
+
+type nodeReader28 struct {
+	buffer []byte
+}
+
+func (n nodeReader28) readLeft(nodeNumber uint) uint {
+	return ((uint(n.buffer[nodeNumber+3]) & 0xF0) << 20) | (uint(n.buffer[nodeNumber]) << 16) | (uint(n.buffer[nodeNumber+1]) << 8) | uint(n.buffer[nodeNumber+2])
+}
+
+func (n nodeReader28) readRight(nodeNumber uint) uint {
+	return ((uint(n.buffer[nodeNumber+3]) & 0x0F) << 24) | (uint(n.buffer[nodeNumber+4]) << 16) | (uint(n.buffer[nodeNumber+5]) << 8) | uint(n.buffer[nodeNumber+6])
+}
+
+type nodeReader32 struct {
+	buffer []byte
+}
+
+func (n nodeReader32) readLeft(nodeNumber uint) uint {
+	return (uint(n.buffer[nodeNumber]) << 24) | (uint(n.buffer[nodeNumber+1]) << 16) | (uint(n.buffer[nodeNumber+2]) << 8) | uint(n.buffer[nodeNumber+3])
+}
+
+func (n nodeReader32) readRight(nodeNumber uint) uint {
+	return (uint(n.buffer[nodeNumber+4]) << 24) | (uint(n.buffer[nodeNumber+5]) << 16) | (uint(n.buffer[nodeNumber+6]) << 8) | uint(n.buffer[nodeNumber+7])
+}