wp

enc/time_delta.go

@@ -1,7 +1,6 @@
 package enc
 
 import (
-	"fmt"
 	"io"
 	"log"
 
@@ -92,11 +91,11 @@ func (s *TimeDeltaCompressor) restore(payloadSize int) {
 
 func (s *TimeDeltaCompressor) Evaluate(tmp []byte, timestamp uint32) qb.TimeEvaluationReport {
 	var (
-		delta        = timestamp - s.lastUnixtime
 		rewindOffset int
 		i            int
 	)
 	if s.pos < len(s.buf) {
+		delta := timestamp - s.lastUnixtime
 		if s.lastDelta > 0 {
 			h := s.buf[s.pos]
 			if h < 128 {
@@ -108,36 +107,36 @@ func (s *TimeDeltaCompressor) Evaluate(tmp []byte, timestamp uint32) qb.TimeEval
 					rewindOffset = 1 // перезапис h
 				} else {
 					// endSeries
-					n, _ := bin.PutVarUint64(tmp, uint64(delta))
-					i += n
 					tmp[i] = 128 // start new literal (length=1)
 					i++
+					n, _ := bin.PutVarUint64(tmp[i:], uint64(delta))
+					i += n
 				}
 			} else {
 				// literal
 				if delta != s.lastDelta {
 					if h < 255 {
 						// incrementLiteral
-						n, _ := bin.PutVarUint64(tmp, uint64(delta))
-						i += n
 						tmp[i] = h + 1
 						i++
+						n, _ := bin.PutVarUint64(tmp[i:], uint64(delta))
+						i += n
 						rewindOffset = 1 // перезапис h
 					} else {
 						// endSeries
-						n, _ := bin.PutVarUint64(tmp, uint64(delta))
-						i += n
 						tmp[i] = 128 // start new literal (length=1)
 						i++
+						n, _ := bin.PutVarUint64(tmp[i:], uint64(delta))
+						i += n
 					}
 				} else {
 					// startRun
 					if h > 128 {
-						tmp[i] = h - 1 // зменшую довжину попередньої серії на 1
+						tmp[i] = 0 // start new run (length=2)
 						i++
 						n, _ := bin.PutVarUint64(tmp[i:], uint64(delta))
 						i += n
-						tmp[i] = 0 // start new run (length=2)
+						tmp[i] = h - 1 // зменшую довжину попередньої серії на 1
 						i++
 						rewindOffset = 1 + n // перезапис пари delta/h
 					} else {
@@ -148,11 +147,10 @@ func (s *TimeDeltaCompressor) Evaluate(tmp []byte, timestamp uint32) qb.TimeEval
 				}
 			}
 		} else {
-			// add 1st delta
-			n, _ := bin.PutVarUint64(tmp, uint64(delta))
-			i += n
 			tmp[i] = 128 // start new literal (length=1)
 			i++
+			n, _ := bin.PutVarUint64(tmp[i:], uint64(delta))
+			i += n
 		}
 	} else {
 		bin.PutUint32(tmp, timestamp) // 1st timestamp (since)
@@ -167,16 +165,16 @@ func (s *TimeDeltaCompressor) Evaluate(tmp []byte, timestamp uint32) qb.TimeEval
 }
 
 func (s *TimeDeltaCompressor) Append(rewindOffset int, change []byte, timestamp uint32) {
-	if s.pos < len(s.buf) {
-		i := s.pos + rewindOffset - 1 // -1, because s.pos always points to h byte
-		for _, b := range change {
-			s.buf[i] = b
-			i--
-		}
+	// fmt.Printf("----\nchange: % x\n", change)
+	// fmt.Printf("rewindOffset: %d\n", rewindOffset)
+	// fmt.Printf("pos: %d\n", s.pos)
+	// fmt.Printf("buf: %d\n", len(s.buf))
+
+	if s.lastUnixtime > 0 {
 		s.lastDelta = timestamp - s.lastUnixtime
-	} else {
-		copy(s.buf[len(s.buf)-4:], change) // 4b since
 	}
+	idx := s.pos - len(change) + rewindOffset
+	copy(s.buf[idx:], change)
 	s.pos -= len(change) - rewindOffset
 	s.lastUnixtime = timestamp
 }
@@ -199,6 +197,10 @@ func (s *TimeDeltaCompressor) getState() qb.TimeDeltaCapturedState {
 			bound = s.pos // only since encoded
 		}
 		state.Payload = s.buf[bound:]
+		// fmt.Printf("% x\n", s.buf)
+		// fmt.Printf("% x\n", s.buf[bound:])
+		// fmt.Printf("h: % x\n", state.H)
+		// fmt.Printf("lastDelta: %d\n", s.lastDelta)
 	}
 	return state
 }
@@ -213,7 +215,7 @@ func (s *TimeDeltaCompressor) ForgetCapturedState() {
 }
 
 func (s *TimeDeltaCompressor) Tail(offset int) []byte {
-	fmt.Println("time tail:", s.pos, len(s.buf), offset)
+	//fmt.Println("time tail:", s.pos, len(s.buf), offset)
 	return s.buf[s.pos : len(s.buf)-offset]
 }