Worked on LevelDB database format support

documentation/LevelDB database format.asciidoc

@@ -76,194 +76,249 @@ For example:
 00000000  4d 41 4e 49 46 45 53 54  2d 30 30 30 30 30 31 0a  |MANIFEST-000001.|
 ....
 
-== Write ahead log file (.ldb)
+== Descriptor file
 
-A write ahead log file consists of:
+The desriptor file is a <<log_file,write ahead log file>> that consist of:
 
-* one or more 32k pages
-** one or more data blocks
+* one or more descriptor records
 
-[cols="1,5",options="header"]
-|===
-| Characteristics | Description
-| Byte order | little-endian
-| Date and time values |
-| Character strings |
-|===
+=== Descriptor record
 
-=== Log block
+A descriptor (VersionEdit) record consists of:
 
-A log block is of variable size and consists of:
+* One or more descriptor values
 
-[cols="1,1,1,5",options="header"]
-|===
-| Offset | Size | Value | Description
-| 0 | 4 | | Checksum +
-Contains a CRC-32
-| 4 | 2 | | Record data size
-| 5 | 1 | | Record type +
-See: <<log_record_types,log record types>>
-| 6 | record data size | | Record data
-|===
+=== Descriptor value
 
-==== [[log_record_types]]Log record types
+A descriptor value consists of:
 
-[cols="1,1,5",options="header"]
-|===
-| Value | Identifier | Description
-| 1 | FULL | Full record
-| 2 | FIRST | First segment of record data
-| 3 | MIDDLE | Intermediate segment of record data
-| 4 | LAST | Last segment of record data
-|===
-
-=== Log record
-
-A log record consists of:
-
-* One or more tagged values
-
-Where each tagged values consists of:
-
-* A <<log_value_tags,value tag>>
+* A <<descriptor_value_tags,value tag>>
 * Value data
 
-==== [[log_value_tags]]Log value tags
+==== [[descriptor_value_tags]]Descriptor value tags
 
 [cols="1,1,5",options="header"]
 |===
 | Value | Identifier | Description
 | 1 | kComparator | Comparator +
-See: <<log_comparator_value,comparator value>>
+See: <<descriptor_comparator_value,comparator value>>
 | 2 | kLogNumber | Log number +
-See: <<log_log_number_value,log number value>>
+See: <<descriptor_log_number_value,log number value>>
 | 3 | kNextFileNumber | Next file number +
-See: <<log_next_file_number_value,next file number value>>
+See: <<descriptor_next_file_number_value,next file number value>>
 | 4 | kLastSequence | Last sequence number +
-See: <<log_last_sequence_number_value,last sequence number value>>
+See: <<descriptor_last_sequence_number_value,last sequence number value>>
 | 5 | kCompactPointer | Compact pointer +
-See: <<log_compact_pointer_value,compact pointer value>>
+See: <<descriptor_compact_pointer_value,compact pointer value>>
 | 6 | kDeletedFile | Deleted file +
-See: <<log_deleted_file_value,deleted file value>>
+See: <<descriptor_deleted_file_value,deleted file value>>
 | 7 | kNewFile | New file +
-See: <<log_new_file_value,new file value>>
+See: <<descriptor_new_file_value,new file value>>
 | 8 | | [yellow-background]*Unknown (was used for large value references)*
 | 9 | kPrevLogNumber | Previous log number +
-See: <<log_previous_log_number_value,previous log number value>>
+See: <<descriptor_previous_log_number_value,previous log number value>>
 |===
 
-==== [[log_comparator_value]]Comparator value
+==== [[descriptor_comparator_value]]Comparator value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 1 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Name string size
 | ... | ... | | Name string +
 Contains an UTF-8 encoded string without end-of-string character
 |===
 
-==== [[log_log_number_value]]Log number value
+==== [[descriptor_log_number_value]]Log number value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 2 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Log number +
 Contains a <<varint64,variable-size integer>>
 |===
 
-==== [[log_next_file_number_value]]Next file number value
+==== [[descriptor_next_file_number_value]]Next file number value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 3 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Next file number +
 Contains a <<varint64,variable-size integer>>
 |===
 
-==== [[log_last_sequence_number_value]]Last sequence number value
+==== [[descriptor_last_sequence_number_value]]Last sequence number value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 4 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Last sequence number +
 Contains a <<varint64,variable-size integer>>
 |===
 
-==== [[log_compact_pointer_value]]Compact pointer value
+==== [[descriptor_compact_pointer_value]]Compact pointer value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 5 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Level +
 Contains a <<varint64,variable-size integer>>
 | ... | ... | | Key +
-Contains a <<log_key_value,key value>>
+Contains a <<log_slice_value,slice value>>
 |===
 
-==== [[log_deleted_file_value]]Deleted file value
+==== [[descriptor_deleted_file_value]]Deleted file value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 6 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Level +
 Contains a <<varint64,variable-size integer>>
 | ... | ... | | Number of files +
 Contains a <<varint64,variable-size integer>>
 |===
 
-==== [[log_new_file_value]]New file value
+==== [[descriptor_new_file_value]]New file value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 7 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Level +
 Contains a <<varint64,variable-size integer>>
 | ... | ... | | Number of files +
 Contains a <<varint64,variable-size integer>>
 | ... | ... | | File size +
 Contains a <<varint64,variable-size integer>>
 | ... | ... | | Smallest record key +
-Contains a <<log_key_value,key value>>
+Contains a <<log_slice_value,slice value>>
 | ... | ... | | Largest record key +
-Contains a <<log_key_value,key value>>
+Contains a <<log_slice_value,slice value>>
 |===
 
-==== [[log_previous_log_number_value]]Previous log number value
+==== [[descriptor_previous_log_number_value]]Previous log number value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | 1 | 9 | Value tag +
 Contains a <<varint64,variable-size integer>> +
-See: <<log_value_tags,value tags>>
+See: <<descriptor_value_tags,value tags>>
 | 1 | ... | | Previous log number +
 Contains a <<varint64,variable-size integer>>
 |===
 
-==== [[log_key_value]]Key value
+== [[log_file]]Write ahead log file (.log)
+
+A write ahead log file consists of:
+
+* one or more 32k pages
+** one or more log blocks
+
+[cols="1,5",options="header"]
+|===
+| Characteristics | Description
+| Byte order | little-endian
+| Date and time values |
+| Character strings |
+|===
+
+=== Log block
+
+A log block is of variable size and consists of:
+
+[cols="1,1,1,5",options="header"]
+|===
+| Offset | Size | Value | Description
+| 0 | 4 | | Checksum +
+Contains a CRC-32
+| 4 | 2 | | Record data size
+| 5 | 1 | | Record type +
+See: <<log_record_types,log record types>>
+| 6 | record data size | | Record data
+|===
+
+==== [[log_record_types]]Log record types
+
+[cols="1,1,5",options="header"]
+|===
+| Value | Identifier | Description
+| 1 | FULL | Full record
+| 2 | FIRST | First segment of record data
+| 3 | MIDDLE | Intermediate segment of record data
+| 4 | LAST | Last segment of record data
+|===
+
+=== Log record
+
+A log (WriteBatch) record consists of:
+
+* value header
+
+==== Log value header
+
+A log header value is 12 byte in size and consists of:
+
+[cols="1,1,1,5",options="header"]
+|===
+| 0 | 8 | | Sequence number
+| 8 | 4 | | [yellow-background]*Unknown (Count?)*
+|===
+
+==== [[log_value_types]]Log value types
+
+[cols="1,1,5",options="header"]
+|===
+| Value | Identifier | Description
+| 0 | kTypeDeletion | Deletion +
+See: <<log_deletion_value,deletion value>>
+| 1 | kTypeValue | Put +
+See: <<log_put_value,put value>>
+|===
+
+==== [[log_slice_value]]Slice value
 
 [cols="1,1,1,5",options="header"]
 |===
 | 0 | ... | | Data size
 | ... | ... | | Data
 |===
 
+==== [[log_deletion_value]]Deletion value
+
+[cols="1,1,1,5",options="header"]
+|===
+| 0 | 1 | 0 | Value type
+| 1 | ... | | Key +
+Contains a <<log_slice_value,slice value>>
+|===
+
+==== [[log_put_value]]Put value
+
+[cols="1,1,1,5",options="header"]
+|===
+| 0 | 1 | 1 | Value type
+| 1 | ... | | Key +
+Contains a <<log_slice_value,slice value>>
+| ... | ... | | Value +
+Contains a <<log_slice_value,slice value>>
+|===
+
 == Sorted tables file (.ldb)
 
-A sorted tables file file consists of:
+A sorted tables file consists of:
 
 * one or more data blocks
 * one or more metadata blocks

dtformats/leveldb.debug.yaml

@@ -15,6 +15,15 @@ attributes:
   description: "Record data"
   format: binary_data
 ---
+data_type_map: leveldb_log_value_header
+attributes:
+- name: sequence_number
+  description: "Sequence number"
+  format: decimal
+- name: count
+  description: "Count"
+  format: decimal
+---
 data_type_map: leveldb_table_footer
 attributes:
 - name: metaindex_block_offset