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
 }