Refactor to check against checksum for uniqueness.

bemasher · Jul 9, 2015 · 34b9eb6 · 34b9eb6
1 parent dbdbcae
commit 34b9eb6
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Showing 5 changed files with 27 additions and 17 deletions.
diff --git a/idm/idm.go b/idm/idm.go
@@ -163,9 +163,10 @@ func (idm IDM) MeterType() uint8 {
 	return idm.ERTType
 }
 
-func (idm IDM) MeterValue() uint32 {
-	// don't know yet
-	return 0
+func (idm IDM) Checksum() []byte {
+	checksum := make([]byte, 2)
+	binary.BigEndian.PutUint16(checksum, idm.PacketCRC)
+	return checksum
 }
 
 func (idm IDM) String() string {

diff --git a/parse/parse.go b/parse/parse.go
@@ -50,7 +50,7 @@ type Message interface {
 	MsgType() string
 	MeterID() uint32
 	MeterType() uint8
-	MeterValue() uint32
+	Checksum() []byte
 }
 
 type LogMessage struct {

diff --git a/r900/r900.go b/r900/r900.go
@@ -222,6 +222,7 @@ func (p Parser) Parse(indices []int) (msgs []parse.Message) {
 		r900.Unkn3 = uint8(unkn3)
 		r900.Leak = uint8(leak)
 		r900.LeakNow = uint8(leaknow)
+		copy(r900.checksum[:], symbols[:16])
 
 		msgs = append(msgs, r900)
 	}
@@ -238,7 +239,7 @@ type R900 struct {
 	Unkn3       uint8  `xml:",attr"` // 2 bits
 	Leak        uint8  `xml:",attr"` // 4 bits, day bins of leak
 	LeakNow     uint8  `xml:",attr"` // 2 bits, leak past 24h hi/lo
-
+	checksum    [5]byte
 }
 
 func (r900 R900) MsgType() string {
@@ -253,8 +254,8 @@ func (r900 R900) MeterType() uint8 {
 	return r900.Unkn1
 }
 
-func (r900 R900) MeterValue() uint32 {
-	return r900.Consumption
+func (r900 R900) Checksum() []byte {
+	return r900.checksum[:]
 }
 
 func (r900 R900) String() string {

diff --git a/recv.go b/recv.go
@@ -17,6 +17,7 @@
 package main
 
 import (
+	"bytes"
 	"encoding/xml"
 	"flag"
 	"fmt"
@@ -36,7 +37,6 @@ import (
 )
 
 var rcvr Receiver
-var lastValue map[uint]uint32
 
 type Receiver struct {
 	rtltcp.SDR
@@ -127,7 +127,7 @@ func (rcvr *Receiver) Run() {
 	}()
 
 	block := make([]byte, rcvr.p.Cfg().BlockSize2)
-	lastValue = make(map[uint]uint32)
+	checksumHistory := make(map[uint][]byte)
 
 	start := time.Now()
 	for {
@@ -157,10 +157,15 @@ func (rcvr *Receiver) Run() {
 					continue
 				}
 				if *unique {
-					if val, ok := lastValue[uint(pkt.MeterID())]; ok && val == pkt.MeterValue() {
+					checksum := pkt.Checksum()
+					mid := uint(pkt.MeterID())
+
+					if val, ok := checksumHistory[mid]; ok && bytes.Compare(val, checksum) == 0 {
 						continue
 					}
-					lastValue[uint(pkt.MeterID())] = pkt.MeterValue()
+
+					checksumHistory[mid] = make([]byte, len(checksum))
+					copy(checksumHistory[mid], checksum)
 				}
 
 				var msg parse.LogMessage

diff --git a/scm/scm.go b/scm/scm.go
@@ -17,6 +17,7 @@
 package scm
 
 import (
+	"encoding/binary"
 	"fmt"
 	"strconv"
 
@@ -97,7 +98,7 @@ type SCM struct {
 	TamperPhy   uint8  `xml:",attr"`
 	TamperEnc   uint8  `xml:",attr"`
 	Consumption uint32 `xml:",attr"`
-	Checksum    uint16 `xml:",attr"`
+	ChecksumVal uint16 `xml:"Checksum,attr"`
 }
 
 func NewSCM(data parse.Data) (scm SCM) {
@@ -113,7 +114,7 @@ func NewSCM(data parse.Data) (scm SCM) {
 	scm.TamperPhy = uint8(tamperphy)
 	scm.TamperEnc = uint8(tamperenc)
 	scm.Consumption = uint32(consumption)
-	scm.Checksum = uint16(checksum)
+	scm.ChecksumVal = uint16(checksum)
 
 	return
 }
@@ -130,13 +131,15 @@ func (scm SCM) MeterType() uint8 {
 	return scm.Type
 }
 
-func (scm SCM) MeterValue() uint32 {
-	return scm.Consumption
+func (scm SCM) Checksum() []byte {
+	checksum := make([]byte, 2)
+	binary.BigEndian.PutUint16(checksum, scm.ChecksumVal)
+	return checksum
 }
 
 func (scm SCM) String() string {
 	return fmt.Sprintf("{ID:%8d Type:%2d Tamper:{Phy:%02X Enc:%02X} Consumption:%8d CRC:0x%04X}",
-		scm.ID, scm.Type, scm.TamperPhy, scm.TamperEnc, scm.Consumption, scm.Checksum,
+		scm.ID, scm.Type, scm.TamperPhy, scm.TamperEnc, scm.Consumption, scm.ChecksumVal,
 	)
 }
 
@@ -146,7 +149,7 @@ func (scm SCM) Record() (r []string) {
 	r = append(r, "0x"+strconv.FormatUint(uint64(scm.TamperPhy), 16))
 	r = append(r, "0x"+strconv.FormatUint(uint64(scm.TamperEnc), 16))
 	r = append(r, strconv.FormatUint(uint64(scm.Consumption), 10))
-	r = append(r, "0x"+strconv.FormatUint(uint64(scm.Checksum), 16))
+	r = append(r, "0x"+strconv.FormatUint(uint64(scm.ChecksumVal), 16))
 
 	return
 }