mapping work

lib/common/mapping.go

@@ -1,18 +1,158 @@
 package common
 
 import (
-//	"encoding/binary"
+	"encoding/binary"
-//	"strings"
+	"errors"
+	"sort"
 )
 
 type Mapping []byte
+type MappingValues [][2]String
 
-//65537
+//
+// Returns the values contained in a Mapping in
+// the form of a MappingValues.
+//
+func (mapping Mapping) Values() (map_values MappingValues, errs []error) {
+	// check length and append any errors needed, max: 65537
+	// sanity check no data is missing
 
-func (mapping Mapping) Values() [][2]String {
+	var str String
-	return make([][2]String, 0)
+	var remainder = mapping
+	var err error
+	for {
+		// Read a key, breaking on fatal errors
+		// and appending warnings
+		str, remainder, err = ReadString(remainder)
+		key_str := str
+		if err != nil {
+			errs = append(errs, err)
+			if stopValueRead(err) {
+				return
+			}
+		}
+		if !beginsWith(remainder, "=") {
+			errs = append(errs, errors.New("mapping format violation, expected ="))
+			return
+		}
+		remainder = remainder[1:]
+
+		// Read a value, breaking on fatal errors
+		// and appending warnings
+		str, remainder, err = ReadString(remainder)
+		val_str := str
+		if err != nil {
+			errs = append(errs, err)
+			if stopValueRead(err) {
+				return
+			}
+		}
+		if !beginsWith(remainder, ";") {
+			errs = append(errs, errors.New("mapping format violation, expected ;"))
+			return
+		}
+		remainder = remainder[1:]
+
+		// Append the key-value pair and break
+		// if there is no more data to read
+		map_values = append(map_values, [2]String{key_str, val_str})
+		if len(remainder) == 0 {
+			break
+		}
+	}
+	return
 }
 
-func ValuesToMapping(values [][2]String) Mapping {
+//
-	return Mapping{}
+// Returns true if two keys in a mapping are identical
+//
+func (mapping Mapping) HasDuplicateKeys() bool {
+	return false
+}
+
+//
+// ValuesToMapping takes a MappingValue struct and
+// returns a Mapping.  The values are sorted in the
+// order defined in mappingOrder.
+//
+func ValuesToMapping(values MappingValues) Mapping {
+	var mapping Mapping
+	mappingOrder(values)
+	for _, kv_pair := range values {
+		key_string := String(kv_pair[0])
+		key_value := String(kv_pair[1])
+		mapping = append(append(mapping, key_string...), key_value...)
+	}
+	map_len := len(mapping)
+	len_bytes := make([]byte, 2)
+	binary.BigEndian.PutUint16(len_bytes, uint16(map_len))
+	mapping = append(len_bytes, mapping...)
+	return mapping
+}
+
+//
+// This function takes a map of unformatted strings
+// and returns a Mapping.
+//
+func GoMapToMapping(gomap map[string]string) (mapping Mapping, err error) {
+	map_vals := MappingValues{}
+	for k, v := range gomap {
+		key_str, kerr := ToI2PString(k)
+		if kerr != nil {
+			err = kerr
+			return
+		}
+		val_str, verr := ToI2PString(v)
+		if verr != nil {
+			err = verr
+			return
+		}
+		map_vals = append(
+			map_vals,
+			[2]String{key_str, val_str},
+		)
+	}
+	mapping = ValuesToMapping(map_vals)
+	return
+}
+
+type ByValue MappingValues
+
+func (set ByValue) Len() int      { return len(set) }
+func (set ByValue) Swap(i, j int) { set[i], set[j] = set[j], set[i] }
+func (set ByValue) Less(i, j int) bool {
+	data1, _ := set[i][1].Data()
+	data2, _ := set[j][1].Data()
+	return data1 < data2
+}
+
+type ByKey MappingValues
+
+func (set ByKey) Len() int      { return len(set) }
+func (set ByKey) Swap(i, j int) { set[i], set[j] = set[j], set[i] }
+func (set ByKey) Less(i, j int) bool {
+	data1, _ := set[i][0].Data()
+	data2, _ := set[j][0].Data()
+	return data1 < data2
+}
+
+//
+// I2P Mappings require consistent order for
+// for cryptographic signing, and sorting
+// by keys.  When new Mappings are created,
+// they are stable sorted first by values
+// than by keys to ensure a consistent order.
+//
+func mappingOrder(values MappingValues) {
+	sort.Stable(ByValue(values))
+	sort.Stable(ByKey(values))
+}
+
+func stopValueRead(err error) bool {
+	return err.Error() == "error parsing string: zero length"
+}
+
+func beginsWith(bytes []byte, str string) bool {
+	return len(bytes) != 0 &&
+		string(bytes[0]) == str
 }

lib/common/mapping_test.go

@@ -1,38 +1,5 @@
 package common
 
 import (
-	"testing"
+//"testing"
 )
-
-func TestValuesReturnsCorrectValues(t *testing.T) {
-	//	bytes := []byte{}
-
-}
-
-func TextValuesReportsMappingTooBig() {
-
-}
-
-func TestValuesReportsStringErrorsWhenStringZeroLen(t *testing.T) {
-
-}
-
-func TestValuesReportsStringErrorsWhenStringExtraData(t *testing.T) {
-
-}
-
-func TestValuesReportsStringErrorsWhenStringMissingData(t *testing.T) {
-
-}
-
-func TestValuesReportsStringErrorsWhenStringLengthNoData(t *testing.T) {
-
-}
-
-func TestValuesToMappingCreatesCorrectFormat(t *testing.T) {
-
-}
-
-func TestValuesToMappingReportsStringTooLongError(t *testing.T) {
-
-}