leveldb: updates per PR comments

wader · Dec 6, 2023 · fe1099b · fe1099b
1 parent 2df0f0f
commit fe1099b
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Showing 4 changed files with 12 additions and 14 deletions.
diff --git a/format/format.go b/format/format.go
@@ -126,8 +126,8 @@ var (
 	JSON                = &decode.Group{Name: "json"}
 	JSONL               = &decode.Group{Name: "jsonl"}
 	LevelDB_Descriptor  = &decode.Group{Name: "leveldb_descriptor"}
-	LDB                 = &decode.Group{Name: "leveldb_table"}
-	LOG                 = &decode.Group{Name: "leveldb_log"}
+	LevelDB_LDB         = &decode.Group{Name: "leveldb_table"}
+	LevelDB_LOG         = &decode.Group{Name: "leveldb_log"}
 	LuaJIT              = &decode.Group{Name: "luajit"}
 	MachO               = &decode.Group{Name: "macho"}
 	MachO_Fat           = &decode.Group{Name: "macho_fat"}

diff --git a/format/leveldb/leveldb_descriptor.go b/format/leveldb/leveldb_descriptor.go
@@ -23,7 +23,6 @@ func init() {
 		format.LevelDB_Descriptor,
 		&decode.Format{
 			Description: "LevelDB Descriptor",
-			Groups:      []*decode.Group{format.Probe},
 			DecodeFn:    ldbDescriptorDecode,
 		})
 	interp.RegisterFS(leveldbDescriptorFS)
@@ -70,10 +69,7 @@ func ldbDescriptorDecode(d *decode.D) any {
 // List of sorted tables for each level involving key ranges and other metadata.
 func readManifest(d *decode.D) {
 	d.FieldArray("tags", func(d *decode.D) {
-		for {
-			if d.End() {
-				break
-			}
+		for !d.End() {
 			d.FieldStruct("tag", func(d *decode.D) {
 				tag := d.FieldULEB128("key", tagTypes)
 				switch tag {

diff --git a/format/leveldb/leveldb_log.go b/format/leveldb/leveldb_log.go
@@ -21,10 +21,9 @@ var leveldbLogFS embed.FS
 
 func init() {
 	interp.RegisterFormat(
-		format.LOG,
+		format.LevelDB_LOG,
 		&decode.Format{
 			Description: "LevelDB Log",
-			Groups:      []*decode.Group{format.Probe},
 			DecodeFn:    ldbLogDecode,
 		})
 	interp.RegisterFS(leveldbLogFS)

diff --git a/format/leveldb/leveldb_table.go b/format/leveldb/leveldb_table.go
@@ -26,7 +26,7 @@ var leveldbFS embed.FS
 
 func init() {
 	interp.RegisterFormat(
-		format.LDB,
+		format.LevelDB_LDB,
 		&decode.Format{
 			Description: "LevelDB Table",
 			Groups:      []*decode.Group{format.Probe},
@@ -82,9 +82,13 @@ func ldbTableDecode(d *decode.D) any {
 	var metaIndexOffset int64
 	var metaIndexSize int64
 
-	d.SeekAbs(d.Len() - footerEncodedLength)
 	d.FieldStruct("footer", func(d *decode.D) {
-		handleLength := d.LimitedFn(footerEncodedLength, func(d *decode.D) {
+		// check for magic number and fail fast if it isn't there
+		d.SeekAbs(d.Len() - magicNumberLength)
+		d.FieldU64("magic_number", d.UintAssert(tableMagicNumber), scalar.UintHex)
+
+		d.SeekAbs(d.Len() - footerEncodedLength)
+		d.LimitedFn(footerEncodedLength-magicNumberLength, func(d *decode.D) {
 			d.FieldStruct("metaindex_handle", func(d *decode.D) {
 				metaIndexOffset = int64(d.FieldULEB128("offset"))
 				metaIndexSize = int64(d.FieldULEB128("size"))
@@ -93,9 +97,8 @@ func ldbTableDecode(d *decode.D) any {
 				indexOffset = int64(d.FieldULEB128("offset"))
 				indexSize = int64(d.FieldULEB128("size"))
 			})
+			d.FieldRawLen("padding", d.BitsLeft())
 		})
-		d.FieldRawLen("padding", footerEncodedLength-handleLength-magicNumberLength)
-		d.FieldU64("magic_number", d.UintAssert(tableMagicNumber), scalar.UintHex)
 	})
 
 	// metaindex