Documentation
¶
Index ¶
- Constants
- func CheckEOF(in IndexInput) error
- func CheckFooter(in ChecksumIndexInput) (cs int64, err error)
- func CheckHeader(in DataInput, codec string, minVersion, maxVersion int32) (v int32, err error)
- func CheckHeaderNoMagic(in DataInput, codec string, minVersion, maxVersion int32) (v int32, err error)
- func HeaderLength(codec string) int
- func NewIndexFormatTooNewError(in DataInput, version, minVersion, maxVersion int32) error
- func NewIndexFormatTooOldError(in DataInput, version, minVersion, maxVersion int32) error
- func RetrieveChecksum(in IndexInput) (int64, error)
- func WriteFooter(out IndexOutput) (err error)
- func WriteHeader(out DataOutput, codec string, version int) error
- type ChecksumIndexInput
- type DataInput
- type DataOutput
- type IndexInput
- type IndexOutput
- type PostingsConsumer
- type TermStats
Constants ¶
const CODEC_MAGIC = 0x3fd76c17
Constant to identify the start of a codec header.
const FOOTER_LENGTH = 16
const FOOTER_MAGIC = ^CODEC_MAGIC
Constant to identify the start of a codec footer.
Variables ¶
This section is empty.
Functions ¶
func CheckEOF ¶
func CheckEOF(in IndexInput) error
Checks that the stream is positioned at the end, and returns error if it is not.
func CheckFooter ¶
func CheckFooter(in ChecksumIndexInput) (cs int64, err error)
Validates the codec footer previously written by WriteFooter().
func CheckHeader ¶
func CheckHeaderNoMagic ¶
func RetrieveChecksum ¶
func RetrieveChecksum(in IndexInput) (int64, error)
Returns (but does not validate) the checksum previously written by CheckFooter.
func WriteFooter ¶
func WriteFooter(out IndexOutput) (err error)
Writes a codec footer, which records both a checksum algorithm ID and a checksum. This footer can be parsed and validated with CheckFooter().
CodecFooter --> Magic,AlgorithmID,Checksum
- Magic --> uint32. This identifies the start of the footer. It is always FOOTER_MAGIC.
- AlgorithmID --> uing32. This indicates the checksum algorithm used. Currently this is always 0, for zlib-crc32.
- Checksum --> uint64. The actual checksum value for all previous bytes in the stream, including the bytes from Magic and AlgorithmID.
func WriteHeader ¶
func WriteHeader(out DataOutput, codec string, version int) error
Writes a codc header, which records both a string to identify the file and a version number. This header can be parsed and validated with CheckHeader().
CodecHeader --> Magic,CodecName,Version
Magic --> uint32. This identifies the start of the header. It is always CODEC_MAGIC. CodecName --> string. This is a string to identify this file. Version --> uint32. Records the version of the file.
Note that the length of a codec header depends only upon the name of the codec, so this length can be computed at any time with HeaderLength().
Types ¶
type ChecksumIndexInput ¶
type ChecksumIndexInput interface {
IndexInput
Checksum() int64
}
type IndexInput ¶
type IndexOutput ¶
type PostingsConsumer ¶
type PostingsConsumer interface {
// Adds a new doc in this term. freq will be -1 when term
// frequencies are omitted for the field.
StartDoc(docId, freq int) error
// Add a new position & payload, and start/end offset. A nil
// payload means no payload; a non-nil payload with zero length
// also means no payload. Caller may reuse the BytesRef for the
// payload between calls (method must fully consume the payload).
// startOffset and endOffset will be -1 when offsets are not indexed.
AddPosition(position int, payload []byte, startOffset, endOffset int) error
// Called when we are done adding positions & payloads for each doc.
FinishDoc() error
}
Abstract API that consumes postings for an individual term.
The lifecycle is:
- PostingsConsumer is returned for each term by TermsConsumer.startTerm().
- startDoc() is called for each document where the term occurs, specifying id and term frequency for that document.
- If positions are enabled for the field, then addPosition() will be called for each occurrence in the document.
- finishDoc() is called when the producer is done adding positions to the document.
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