refactor(varenc): 🎨 Simplify bit length manipulation logic in varint …

…encoding and decoding for better readability
weaviate · Dec 3, 2024 · c6c0041 · c6c0041
1 parent a1a6d44
commit c6c0041
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Showing 2 changed files with 11 additions and 20 deletions.
diff --git a/adapters/repos/db/lsmkv/compaction_integration_test.go b/adapters/repos/db/lsmkv/compaction_integration_test.go
@@ -395,7 +395,7 @@ func TestCompaction(t *testing.T) {
 		{
 			name: "compactionInvertedStrategy",
 			f: func(ctx context.Context, t *testing.T, opts []BucketOption) {
-				compactionInvertedStrategy(ctx, t, opts, 8627, 8627)
+				compactionInvertedStrategy(ctx, t, opts, 8629, 8629)
 			},
 			opts: []BucketOption{
 				WithStrategy(StrategyInverted),
@@ -404,7 +404,7 @@ func TestCompaction(t *testing.T) {
 		{
 			name: "compactionInvertedStrategy_KeepTombstones",
 			f: func(ctx context.Context, t *testing.T, opts []BucketOption) {
-				compactionInvertedStrategy(ctx, t, opts, 8931, 8931)
+				compactionInvertedStrategy(ctx, t, opts, 8933, 8933)
 			},
 			opts: []BucketOption{
 				WithStrategy(StrategyInverted),

diff --git a/adapters/repos/db/lsmkv/varenc/varint.go b/adapters/repos/db/lsmkv/varenc/varint.go
@@ -25,19 +25,19 @@ func decodeReusable(deltas []uint64, packed []byte, deltaDiff bool) {
 	deltas[0] = binary.BigEndian.Uint64(packed[0:8])
 
 	// Read bitsNeeded (6 bits starting from bit 2 of packed[8])
-	bitsNeeded := int((packed[8] >> 2) & 0x3F)
+	bitsNeeded := int((packed[8]))
 	if bitsNeeded == 0 || bitsNeeded > 64 {
 		// Handle invalid bitsNeeded
 		return
 	}
 
-	// Starting bit position after reading bitsNeeded
-	bitPos := 6
-	bytePos := 8 // Start from packed[8]
+	// Set up the buffer to the beginning of next byte
+	bytePos := 9
 
 	// Initialize the bit buffer with the remaining bits in packed[8], if any
-	bitsLeft := 8 - bitPos
-	bitBuffer := uint64(packed[bytePos] & ((1 << bitsLeft) - 1))
+
+	bitBuffer := uint64(packed[bytePos])
+	bitsLeft := 8
 
 	bytePos++
 
@@ -89,18 +89,9 @@ func encodeReusable(deltas []uint64, packed []byte, deltaDiff bool) int {
 
 	bitsToStore := uint64(bitsNeeded)
 
-	currentByte |= byte((bitsToStore>>(5-bitPos))&1) << (7 - bitPos)
-	bitPos++
-	currentByte |= byte((bitsToStore>>(5-bitPos))&1) << (7 - bitPos)
-	bitPos++
-	currentByte |= byte((bitsToStore>>(5-bitPos))&1) << (7 - bitPos)
-	bitPos++
-	currentByte |= byte((bitsToStore>>(5-bitPos))&1) << (7 - bitPos)
-	bitPos++
-	currentByte |= byte((bitsToStore>>(5-bitPos))&1) << (7 - bitPos)
-	bitPos++
-	currentByte |= byte((bitsToStore>>(5-bitPos))&1) << (7 - bitPos)
-	bitPos++
+	packed[currentByteIndex] = byte(bitsToStore)
+	currentByteIndex++
+	bitPos = 0
 
 	for i, delta := range deltas[1:] {
 		if deltaDiff {