public final class BlockTreeTermsWriter extends FieldsConsumer
Writes terms dict and index, block-encoding (column stride) each term's metadata for each set of terms between two index terms.
Files:
The .tim file contains the list of terms in each field along with per-term statistics (such as docfreq) and per-term metadata (typically pointers to the postings list for that term in the inverted index).
The .tim is arranged in blocks: with blocks containing a variable number of entries (by default 25-48), where each entry is either a term or a reference to a sub-block.
NOTE: The term dictionary can plug into different postings implementations: the postings writer/reader are actually responsible for encoding and decoding the Postings Metadata and Term Metadata sections.
CodecHeader
Uint64
VInt
length followed by the byte[]VInt
VLong
CodecFooter
Notes:
CodecHeader
storing the version information
for the BlockTree implementation.FieldInfos
. (.fnm)The .tip file contains an index into the term dictionary, so that it can be accessed randomly. The index is also used to determine when a given term cannot exist on disk (in the .tim file), saving a disk seek.
CodecHeader
Uint64
VLong
FST<byte[]>
CodecFooter
Notes:
BlockTreeTermsReader
Modifier and Type | Field and Description |
---|---|
static int |
DEFAULT_MAX_BLOCK_SIZE
Suggested default value for the
maxItemsInBlock parameter to BlockTreeTermsWriter(SegmentWriteState,PostingsWriterBase,int,int) . |
static int |
DEFAULT_MIN_BLOCK_SIZE
Suggested default value for the
minItemsInBlock parameter to BlockTreeTermsWriter(SegmentWriteState,PostingsWriterBase,int,int) . |
Constructor and Description |
---|
BlockTreeTermsWriter(SegmentWriteState state,
PostingsWriterBase postingsWriter,
int minItemsInBlock,
int maxItemsInBlock)
Create a new writer.
|
Modifier and Type | Method and Description |
---|---|
void |
close() |
static void |
validateSettings(int minItemsInBlock,
int maxItemsInBlock)
Throws
IllegalArgumentException if any of these settings
is invalid. |
void |
write(Fields fields)
Write all fields, terms and postings.
|
merge
public static final int DEFAULT_MIN_BLOCK_SIZE
minItemsInBlock
parameter to BlockTreeTermsWriter(SegmentWriteState,PostingsWriterBase,int,int)
.public static final int DEFAULT_MAX_BLOCK_SIZE
maxItemsInBlock
parameter to BlockTreeTermsWriter(SegmentWriteState,PostingsWriterBase,int,int)
.public BlockTreeTermsWriter(SegmentWriteState state, PostingsWriterBase postingsWriter, int minItemsInBlock, int maxItemsInBlock) throws IOException
IOException
public static void validateSettings(int minItemsInBlock, int maxItemsInBlock)
IllegalArgumentException
if any of these settings
is invalid.public void write(Fields fields) throws IOException
FieldsConsumer
Notes:
write
in class FieldsConsumer
IOException
public void close() throws IOException
close
in interface Closeable
close
in interface AutoCloseable
close
in class FieldsConsumer
IOException
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