I have always had a question "to learn the latest version of lucene data writing related source code, which source code should be read and in what order (what to read first, what to read later)?"
For the Lucene data writing process, it can be divided into the following stages
When learning Lucene's data writing related source code, you can learn and understand in the order of the following stages in order to better grasp the Lucene data writing process. At the same time, you also need to know some related classes and methods, such as DocumentsWriter, SegmentInfo, IndexWriterConfig and other classes and methods.
Document parsing phase: convert the document into a Document object inside Lucene. Analyzer can be used for text analysis and processing, such as word segmentation, filtering, case conversion and other operations.
Document adding cache stage: Add the parsed Document object to the cache in memory, usually called DocumentsWriter.
Index writing phase: DocumentsWriter converts the documents in the cache into segments and writes the segments to disk. If the number of documents in the memory cache reaches a certain threshold, DocumentsWriter will trigger a Segment write.
Segment merging phase: Lucene's index storage structure is composed of multiple segments. When the number of multiple segments reaches a certain threshold, Lucene will perform segment merging operations to optimize index query efficiency and storage space usage.
Index refresh phase: refresh the Segment in memory to disk, and add new Segment information to SegmentInfo.
Index submission phase: When the number of multiple segments reaches a certain threshold or the IndexWriter is closed, Lucene will submit the index to save the index information.
In the specific source code learning, you can follow the steps below
Understand the basic usage and implementation principles of IndexWriter. You can view official documents and related books to understand the basic usage of IndexWriter's constructor, commit method, addDocument method, deleteDocuments method, etc., and have a general understanding of the implementation principle of IndexWriter.
Learn the realization principle of DocumentsWriter. DocumentsWriter is a cache in Lucene memory, which is used to add documents to the cache and convert the documents in the cache to Segment for writing. You can view the source code of DocumentsWriter to understand the implementation principle and main methods of DocumentsWriter.
Learn the implementation principles of Document, Field, Term and other related classes. Document, Field, Term and other classes are the basic units in the Lucene index, and it is necessary to have a deep understanding of their implementation principles and related methods.
Learn the implementation principles of Analyzer, TokenStream and other related classes. Classes such as Analyzer and TokenStream are classes used by Lucene to analyze and process text, and it is necessary to understand their implementation principles and related methods.
Learn the implementation principle and writing process of Segment. Segment is a unit in the Lucene index. It is necessary to understand the implementation principle and writing process of Segment, as well as the implementation principle and process of Segment merging.
Learn the implementation principles of IndexWriterConfig, IndexCommit and other related classes. IndexWriterConfig, IndexCommit and other classes are used by Lucene to configure IndexWriter and manage index submission. It is necessary to understand their implementation principles and related methods.
During the learning process, you can use debugging tools and log output to gain an in-depth understanding of Lucene's data writing process and the implementation details of related classes and methods, so as to better understand and master the source code related to Lucene's data writing. At the same time, it is also necessary to learn and practice in combination with Lucene's official documents, reference books, technical blogs and other resources to deepen the understanding and application of Lucene.
List the source code related to lucene
As you study these classes, you should be aware of their relationships and dependencies to better understand the inner workings of Lucene. At the same time, you should also consult the official Lucene documentation and source code comments to better understand the implementation and usage of these classes.
To learn the latest version of the source code related to Lucene data writing, you can read it in the following order:
IndexWriter class: The IndexWriter class is the main entry point for Lucene to create and update indexes. This class is responsible for writing documents to the index and managing the opening and closing of the index. You can learn its implementation from the constructor of the IndexWriter class.
DocumentsWriter class: The DocumentsWriter class is an inner class of IndexWriter that is responsible for writing documents to an in-memory buffer and flushing them to a single segment on disk when the buffer is full. Study this class to understand how Lucene writes documents to disk.
SegmentWriter class: The SegmentWriter class is an inner class of DocumentsWriter, which is responsible for writing documents to a single segment. Understanding this class provides insight into the inner workings of Lucene indexes.
FieldsWriter class: FieldsWriter class is an inner class of SegmentWriter, which is responsible for writing document fields to disk. Learning this class can give you an in-depth understanding of the field writing process of the Lucene index.
TermsHash class: The TermsHash class is another internal class of DocumentsWriter, which is responsible for writing the terms in the document into the memory hash table. Understanding this class can better understand how Lucene performs word segmentation and lemmatization.
TermVectorsWriter class: The TermVectorsWriter class is an inner class of FieldsWriter that is responsible for writing the document's term vectors to disk. Study this class to understand how Lucene handles term vectors.
Related other classes: In addition to the classes listed above, there are some other classes related to Lucene data writing. For example, the Analyzer class, Document class, and Field class can all be drilled down.
Studying the implementation of these classes provides insight into how Lucene manages and transfers data between memory and disk. When learning these classes, you can consult Lucene official documents and source code comments to better understand the implementation and usage of these classes.
FSDirectory class: FSDirectory class is the class used by Lucene to manage the index directory. When writing documents to the index, the index needs to be written to disk, and the FSDirectory class is the class responsible for managing these index files. You can study this class to understand how Lucene manages index files on disk.
IndexOutput and IndexInput classes: These are the classes that Lucene uses to read and write binary files on disk. When writing a document to the disk, the binary data of the document needs to be written to the disk file, and the IndexOutput class is the class responsible for writing the data to the disk. When reading index files on disk, you need to use the IndexInput class to read the contents of these files.
Codec class: The Codec class is the class used by Lucene to encode and decode the index. Lucene supports multiple codecs, such as the default Lucene70Codec and other custom codecs. Understanding this class can give you an in-depth understanding of Lucene's index encoding and decoding process.
DocValuesWriter and DocValuesConsumer classes: The DocValuesWriter and DocValuesConsumer classes are the classes Lucene uses to write document values to disk. These values can be used for operations such as sorting, aggregation, and filtering. Understanding these classes provides insight into how Lucene handles document values.
NormsWriter and NormsConsumer classes: The NormsWriter and NormsConsumer classes are the classes Lucene uses to write normalization factors to disk. Normalization factors are used to weight fields when searching, understanding these classes can give insight into how Lucene does field weighting.
These classes are mainly related to Lucene's indexing and searching functions, including index creation, reading, submission, search query and result sorting, etc. When learning, you can combine specific application scenarios and choose the corresponding class for in-depth understanding. At the same time, it is also necessary to pay attention to Lucene performance and security issues, and properly configure and use Lucene.
These classes are mainly related to Lucene's search function, including the processing and display of search results, as well as the processing of search conditions.
Realization of filtering, fuzzy search, numerical range search, term range search, prefix search and other functions. If you want to learn the source code related to the latest version of Lucene data writing, you can start with the IndexWriter class, which is the class used by Lucene to write index data. You can first understand the basic usage and implementation principles of the IndexWriter class, and then learn more about related classes and methods, such as DocumentsWriter, Document, Field, Term, SegmentInfo, SegmentInfoPerCommit and other classes and methods.
In the process of learning the IndexWriter class, knowledge of Lucene's index storage structure, index optimization, multi-threaded writing, and data merging can be involved. At the same time, you also need to know some related classes and methods, such as Analyzer, IndexOptions, FieldType, IndexWriterConfig, IndexCommit and other classes and methods. In the learning process, it is recommended to start with simple classes and methods, and gradually go deeper into complex classes and methods, so as to better understand the source code related to Lucene data writing.
LiveDocsFormat class: The LiveDocsFormat class is the class used by Lucene to manage the deletion of documents. When indexing documents, sometimes some documents need to be deleted, and the LiveDocsFormat class is the class responsible for managing these deleted documents. Understanding this class provides insight into how Lucene deletes documents.
MergePolicy and MergeScheduler classes: MergePolicy and MergeScheduler classes are classes used by Lucene to control the merging of index segments. When writing documents to an index, Lucene writes documents into multiple index segments, and when these segments reach a certain size, they need to be merged into larger segments. The MergePolicy and MergeScheduler classes are the classes responsible for managing this process. Understanding these classes provides insight into Lucene's index merge process.
DirectoryReader and SegmentReader classes: DirectoryReader and SegmentReader classes are the classes Lucene uses to read indexes. When searching for documents, data needs to be read from the index, and these classes are responsible for reading the index. Understanding these classes provides insight into how Lucene reads the index.
PostingFormat class: The PostingFormat class is a class used by Lucene to manage term position and frequency information. When writing documents to the index, Lucene will record the position and occurrence frequency of each term in the document, and the PostingFormat class is the class responsible for managing this information. Understanding this class provides insight into how Lucene records term information in documents.
Similarity class: The Similarity class is a class used by Lucene to calculate document similarity. When searching for documents, it is necessary to calculate the similarity between the document and the query, and the Similarity class is the class responsible for calculating the similarity. Understanding this class provides insight into how Lucene calculates document similarity.
FuzzyQuery class: FuzzyQuery class is Lucene's class for fuzzy search. When searching, sometimes you need to consider misspellings or variations of words, and the FuzzyQuery class is the class used to achieve this function.
PhraseQuery class: The PhraseQuery class is Lucene's class for phrase searches. When searching, sometimes it is necessary to match phrases in documents, and the PhraseQuery class is the class used to achieve this function.
QueryParser class: QueryParser class is a class used by Lucene to parse user query statements. When searching, the query statement entered by the user needs to be parsed and converted into a query object that Lucene can understand, and the QueryParser class is the class used to implement this function.
IndexWriterConfig class: IndexWriterConfig class is used by Lucene to configure IndexWriter objects. When creating an IndexWriter object, you need to specify some parameters, and the IndexWriterConfig class is the class used to set these parameters.
Directory class: The Directory class is the class used by Lucene to represent the index storage location. When creating an IndexWriter or IndexSearcher object, you need to specify the index storage location, and the Directory class is the class used to represent this location.
Analyzer class: The Analyzer class is a class used by Lucene to segment and process documents. When writing a document into an index, it is necessary to segment and process the document, and the Analyzer class is the class used to implement this function.
Document class: The Document class is the class that Lucene uses to represent documents. When writing a document into an index, the document needs to be converted into an object that Lucene can understand, and the Document class is the class used to represent this object.
IndexSearcher class: The IndexSearcher class is the class that Lucene uses to search the index. When searching, you need to create an IndexSearcher object and use it to perform the search operation.
BooleanQuery class: The BooleanQuery class is the class used by Lucene to implement Boolean queries. When searching, sometimes it is necessary to combine multiple query conditions for query, and the BooleanQuery class is the class used to realize this function.
TopDocs class: TopDocs class is used by Lucene to store search results. After performing a search operation, a TopDocs object will be returned, which contains a list of documents that meet the query criteria and related document scoring information.
ScoreDoc class: The ScoreDoc class is a class used by Lucene to represent documents and scoring information in search results. In the TopDocs object, each document corresponds to a ScoreDoc object, which contains the number and scoring information of the document.
Explanation class: The Explanation class is the class used by Lucene to explain the scoring results. When searching, scoring is a very important indicator, and the Explanation class is a class used to help us understand the scoring results.
Sort class: The Sort class is the class that Lucene uses to sort the search results. When searching, sometimes it is necessary to sort by a certain field, and the Sort class is the class used to realize this function.
QueryFilter class: The QueryFilter class is the class used by Lucene to implement query filters. When searching, sometimes it is necessary to filter the search results, and the QueryFilter class is the class used to realize this function.
CachingWrapperFilter class: The CachingWrapperFilter class is the class used by Lucene to implement cache filters. When searching, sometimes it is necessary to cache the search results, and the CachingWrapperFilter class is the class used to implement this function.
CustomScoreQuery class: The CustomScoreQuery class is the class used by Lucene to implement custom scoring. When searching, sometimes it is necessary to perform custom scoring according to business needs, and the CustomScoreQuery class is the class used to implement this function.
MultiSearcher class: The MultiSearcher class is the class that Lucene uses to search between multiple indexes. When searching, sometimes it is necessary to search multiple indexes at the same time, and the MultiSearcher class is the class used to realize this function.
FuzzyQuery class: FuzzyQuery class is the class used by Lucene to implement fuzzy query. When searching, sometimes it is necessary to correct typos or fuzzy matching, and the FuzzyQuery class is the class used to implement this function.
PhraseQuery class: The PhraseQuery class is the class used by Lucene to implement phrase queries. When searching, sometimes you need to query phrases in the text, and the PhraseQuery class is the class used to implement this function.
PrefixQuery class: The PrefixQuery class is a class used by Lucene to implement prefix queries. When searching, sometimes you need to query the words starting with a certain prefix in the text, and the PrefixQuery class is the class used to realize this function.
RangeQuery class: The RangeQuery class is the class used by Lucene to implement range queries. When searching, sometimes it is necessary to query the documents whose value of a certain field in the text is within a certain range, and the RangeQuery class is the class used to realize this function.
TermQuery class: TermQuery class is used by Lucene to implement term query. When searching, sometimes you need to query the occurrence of a certain word in the text, and the TermQuery class is the class used to implement this function.
WildcardQuery class: The WildcardQuery class is a class used by Lucene to implement wildcard query. When searching, sometimes you need to query words that meet certain rules in the text, and the WildcardQuery class is the class used to implement this function.
BooleanQuery class: The BooleanQuery class is the class used by Lucene to implement Boolean queries. When searching, sometimes you need to query documents that meet multiple conditions, and the BooleanQuery class is the class used to implement this function. It can combine multiple query conditions, including operations such as AND (intersection), OR (union) and NOT (exclusion).
BoostQuery class: The BoostQuery class is the class used by Lucene to implement query weighting. When searching, sometimes it is necessary to weight certain query conditions to achieve more accurate search results, and the BoostQuery class is the class used to realize this function.
ConstantScoreQuery class: The ConstantScoreQuery class is a class used by Lucene to implement constant score queries. When searching, sometimes it is necessary to combine multiple query conditions and assign the same score to all documents that meet the conditions, and the ConstantScoreQuery class is the class used to implement this function.
DisjunctionMaxQuery class: DisjunctionMaxQuery class is used by Lucene to maximize the query class. When searching, sometimes you need to query the most relevant documents that meet multiple conditions, and the DisjunctionMaxQuery class is the class used to implement this function. It can combine multiple query conditions and find the document with the highest score among them.
MultiPhraseQuery class: The MultiPhraseQuery class is a class used by Lucene to implement multi-phrase queries. When searching, sometimes it is necessary to query documents containing multiple phrases in the text, and the MultiPhraseQuery class is the class used to implement this function.
PayloadScoreQuery class: PayloadScoreQuery class is used by Lucene to implement payload score query. When searching, sometimes it is necessary to calculate the score based on the payload information in the document, and the PayloadScoreQuery class is the class used to implement this function.
SynonymQuery class: The SynonymQuery class is a class used by Lucene to implement synonym query. When searching, sometimes you need to treat some words as synonyms and query them, and the SynonymQuery class is the class used to realize this function.
FunctionScoreQuery class: The FunctionScoreQuery class is a class used by Lucene to implement custom scoring queries. When searching, sometimes it is necessary to calculate the score according to a custom scoring function, and the FunctionScoreQuery class is the class used to realize this function.
TermVectorsReader class: The TermVectorsReader class is a class used by Lucene to read word vectors. When searching, sometimes it is necessary to query and analyze word vectors, and the TermVectorsReader class is the class used to implement this function.
FieldInvertState class: The FieldInvertState class is the class used by Lucene to represent the document field information in the index. When creating an index, the document field needs to be analyzed and stored in the index, and the FieldInvertState class is the class used to represent this information.
IndexCommit class: The IndexCommit class is a class used by Lucene to represent index submission information. When creating an index, the index needs to be submitted for searching, and the IndexCommit class is the class used to represent these submitted information.
Sort class: Sort class is the class used by Lucene to sort search results. When searching, sometimes it is necessary to sort the search results, and the Sort class is the class used to realize this function.
SortField class: The SortField class is the class used by Lucene to represent sorting fields. When sorting search results, you need to specify the sorting fields and sorting methods, and the SortField class is the class used to represent this information.
QueryRescorer class: The QueryRescorer class is the class that Lucene uses to recompute scores in search results. When searching, sometimes it is necessary to reorder the search results according to some specific rules, and the QueryRescorer class is the class used to realize this function.
IndexWriterConfig class: The IndexWriterConfig class is the class used by Lucene to configure the index writer. When creating an index, the index writer needs to be configured to meet different needs, and the IndexWriterConfig class is the class used to implement this function.
DirectoryReader class: The DirectoryReader class is the class used by Lucene to read the index. When searching, it is necessary to read the index to obtain the search results, and the DirectoryReader class is the class used to realize this function.
ParallelCompositeReader class: The ParallelCompositeReader class is a class used by Lucene to combine multiple indexes into one index. When searching, sometimes it is necessary to search multiple indexes at the same time, and the ParallelCompositeReader class is the class used to realize this function.
SegmentInfos class: The SegmentInfos class is the class used by Lucene to represent the segment information in the index. When creating an index, the index needs to be divided into multiple segments for optimization and management, and the SegmentInfos class is the class used to represent the information of these segments.
SegmentReader class: The SegmentReader class is the class used by Lucene to read a segment in the index. When searching, one or more segments in the index need to be read to obtain search results, and the SegmentReader class is the class used to implement this function.
ChecksumIndexInput class: The ChecksumIndexInput class is a class used by Lucene to read index data and verify the checksum. When reading index data, verification is required to ensure the integrity of the data, and the ChecksumIndexInput class is the class used to implement this function.
ChecksumIndexOutput class: The ChecksumIndexOutput class is a class that Lucene uses to write index data and calculate checksums. When writing index data, a checksum needs to be calculated to ensure the integrity of the data, and the ChecksumIndexOutput class is the class used to implement this function.
FilteredQuery class: FilteredQuery class is used by Lucene to filter the search results. When searching, sometimes it is necessary to filter the search results according to some conditions, and the FilteredQuery class is the class used to realize this function.
FuzzyQuery class: The FuzzyQuery class is the class that Lucene uses for fuzzy searches. When searching, sometimes it is necessary to perform fuzzy search to obtain more comprehensive search results, and the FuzzyQuery class is the class used to realize this function.
NumericRangeQuery class: The NumericRangeQuery class is the class used by Lucene for numerical range searches. When searching, sometimes it is necessary to obtain search results based on a certain range of values, and the NumericRangeQuery class is the class used to implement this function.
TermRangeQuery class: The TermRangeQuery class is Lucene's class for term range searches. When searching, sometimes it is necessary to obtain search results based on a certain range of terms, and the TermRangeQuery class is the class used to implement this function.
TopDocs class: The TopDocs class is the class that Lucene uses to represent search results. When searching, it is necessary to obtain search results, process and display them, and the TopDocs class is the class used to represent these search results.
TopFieldDocs class: The TopFieldDocs class is the class used by Lucene to represent search results with sorting fields. When sorting search results, it is necessary to obtain search results with sorting fields, process and display them, and the TopFieldDocs class is the class used to represent these search results.
PrefixQuery class: The PrefixQuery class is the class used by Lucene for prefix search. When searching, sometimes it is necessary to obtain search results according to the prefix of the term, and the PrefixQuery class is the class used to realize this function.
SegmentInfos class: The SegmentInfos class is the class used by Lucene to represent the segment information in the index. When creating an index, the index needs to be divided into multiple segments for optimization and management, and the SegmentInfos class is the class used to represent the information of these segments.
SegmentReader class: The SegmentReader class is the class used by Lucene to read a segment in the index. When searching, one or more segments in the index need to be read to obtain search results, and the SegmentReader class is the class used to implement this function.
ChecksumIndexInput class: The ChecksumIndexInput class is a class used by Lucene to read index data and verify the checksum. When reading index data, verification is required to ensure the integrity of the data, and the ChecksumIndexInput class is the class used to implement this function.
ChecksumIndexOutput class: The ChecksumIndexOutput class is a class that Lucene uses to write index data and calculate checksums. When writing index data, a checksum needs to be calculated to ensure the integrity of the data, and the ChecksumIndexOutput class is the class used to implement this function.
FilteredQuery class: FilteredQuery class is used by Lucene to filter the search results. When searching, sometimes it is necessary to filter the search results according to some conditions, and the FilteredQuery class is the class used to realize this function.
FuzzyQuery class: The FuzzyQuery class is the class that Lucene uses for fuzzy searches. When searching, sometimes it is necessary to perform fuzzy search to obtain more comprehensive search results, and the FuzzyQuery class is the class used to realize this function.
NumericRangeQuery class: The NumericRangeQuery class is the class used by Lucene for numerical range searches. When searching, sometimes it is necessary to obtain search results based on a certain range of values, and the NumericRangeQuery class is the class used to implement this function.
TermRangeQuery class: The TermRangeQuery class is Lucene's class for term range searches. When searching, sometimes it is necessary to obtain search results based on a certain range of terms, and the TermRangeQuery class is the class used to implement this function.
TopDocs class: The TopDocs class is the class that Lucene uses to represent search results. When searching, it is necessary to obtain search results, process and display them, and the TopDocs class is the class used to represent these search results.
TopFieldDocs class: The TopFieldDocs class is the class used by Lucene to represent search results with sorting fields. When sorting search results, it is necessary to obtain search results with sorting fields, process and display them, and the TopFieldDocs class is the class used to represent these search results.
PrefixQuery class: The PrefixQuery class is the class used by Lucene for prefix search. When searching, sometimes it is necessary to obtain search results according to the prefix of the term, and the PrefixQuery class is the class used to realize this function.