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var (
// ErrInvalidDocumentType is returned when methods like Put, Get or Next
// are passed a dst or src argument of invalid type.
ErrInvalidDocumentType = errors.New("search: invalid document type")
// ErrNoSuchDocument is returned when no document was found for a given ID.
ErrNoSuchDocument = errors.New("search: no such document")
// ErrTooManyDocuments is returned when the user passes too many documents to
// PutMulti or DeleteMulti.
ErrTooManyDocuments = fmt.Errorf("search: too many documents given to put or delete (max is %d)", maxDocumentsPerPutDelete)
)
Done is returned when a query iteration has completed.
var Done = errors.New("search: query has no more results")
func LoadStruct ¶
func LoadStruct(dst interface{}, f []Field) error
LoadStruct loads the fields from f to dst. dst must be a struct pointer.
func SaveStruct ¶
func SaveStruct(src interface{}) ([]Field, error)
SaveStruct returns the fields from src as a slice of Field. src must be a struct pointer.
type Atom ¶
Atom is a document field whose contents are indexed as a single indivisible string.
type Atom string
type Cursor ¶
Cursor represents an iterator's position.
The string value of a cursor is web-safe. It can be saved and restored for later use.
type Cursor string
type DocumentMetadata ¶
DocumentMetadata is a struct containing information describing a given document.
type DocumentMetadata struct {
// Rank is an integer specifying the order the document will be returned in
// search results. If zero, the rank will be set to the number of seconds since
// 2011-01-01 00:00:00 UTC when being Put into an index.
Rank int
// Facets is the set of facets for this document.
Facets []Facet
}
type ErrFacetMismatch ¶
ErrFacetMismatch is returned when a facet is to be loaded into a different type than the one it was stored from, or when a field is missing or unexported in the destination struct. StructType is the type of the struct pointed to by the destination argument passed to Iterator.Next.
type ErrFacetMismatch struct {
StructType reflect.Type
FacetName string
Reason string
}
func (*ErrFacetMismatch) Error ¶
func (e *ErrFacetMismatch) Error() string
type ErrFieldMismatch ¶
ErrFieldMismatch is returned when a field is to be loaded into a different than the one it was stored from, or when a field is missing or unexported in the destination struct.
type ErrFieldMismatch struct {
FieldName string
Reason string
}
func (*ErrFieldMismatch) Error ¶
func (e *ErrFieldMismatch) Error() string
type Facet ¶
Facet is a name/value pair which is used to add categorical information to a document.
type Facet struct {
// Name is the facet name. A valid facet name matches /[A-Za-z][A-Za-z0-9_]*/.
// A facet name cannot be longer than 500 characters.
Name string
// Value is the facet value.
//
// When being used in documents (for example, in
// DocumentMetadata.Facets), the valid types are:
// - search.Atom,
// - float64.
//
// When being used in SearchOptions.Refinements or being returned
// in FacetResult, the valid types are:
// - search.Atom,
// - search.Range.
Value interface{}
}
type FacetResult ¶
FacetResult represents the number of times a particular facet and value appeared in the documents matching a search request.
type FacetResult struct {
Facet
// Count is the number of times this specific facet and value appeared in the
// matching documents.
Count int
}
type FacetSearchOption ¶
FacetSearchOption controls what facet information is returned in search results.
type FacetSearchOption interface {
// contains filtered or unexported methods
}
func AutoFacetDiscovery ¶
func AutoFacetDiscovery(facetLimit, valueLimit int) FacetSearchOption
AutoFacetDiscovery returns a FacetSearchOption which enables automatic facet discovery for the search. Automatic facet discovery looks for the facets which appear the most often in the aggregate in the matched documents.
The maximum number of facets returned is controlled by facetLimit, and the maximum number of values per facet by facetLimit. A limit of zero indicates a default limit should be used.
func FacetDiscovery ¶
func FacetDiscovery(name string, value ...interface{}) FacetSearchOption
FacetDiscovery returns a FacetSearchOption which selects a facet to be returned with the search results. By default, the most frequently occurring values for that facet will be returned. However, you can also specify a list of particular Atoms or specific Ranges to return.
func FacetDocumentDepth ¶
func FacetDocumentDepth(depth int) FacetSearchOption
FacetDocumentDepth returns a FacetSearchOption which controls the number of documents to be evaluated with preparing facet results.
type Field ¶
Field is a name/value pair. A search index's document can be loaded and saved as a sequence of Fields.
type Field struct {
// Name is the field name. A valid field name matches /[A-Za-z][A-Za-z0-9_]*/.
Name string
// Value is the field value. The valid types are:
// - string,
// - search.Atom,
// - search.HTML,
// - time.Time (stored with millisecond precision),
// - float64,
// - GeoPoint.
Value interface{}
// Language is a two-letter ISO 639-1 code for the field's language,
// defaulting to "en" if nothing is specified. It may only be specified for
// fields of type string and search.HTML.
Language string
// Derived marks fields that were calculated as a result of a
// FieldExpression provided to Search. This field is ignored when saving a
// document.
Derived bool
}
type FieldExpression ¶
FieldExpression defines a custom expression to evaluate for each result.
type FieldExpression struct {
// Name is the name to use for the computed field.
Name string
// Expr is evaluated to provide a custom content snippet for each document.
// See https://cloud.google.com/appengine/docs/go/search/options for
// the supported expression syntax.
Expr string
}
type FieldList ¶
FieldList converts a []Field to implement FieldLoadSaver.
type FieldList []Field
func (*FieldList) Load ¶
func (l *FieldList) Load(f []Field, _ *DocumentMetadata) error
Load loads all of the provided fields into l. It does not first reset *l to an empty slice.
func (*FieldList) Save ¶
func (l *FieldList) Save() ([]Field, *DocumentMetadata, error)
Save returns all of l's fields as a slice of Fields.
type FieldLoadSaver ¶
FieldLoadSaver can be converted from and to a slice of Fields with additional document metadata.
type FieldLoadSaver interface {
Load([]Field, *DocumentMetadata) error
Save() ([]Field, *DocumentMetadata, error)
}
type HTML ¶
HTML is a document field whose contents are indexed as HTML. Only text nodes are indexed: "foo<b>bar" will be treated as "foobar".
type HTML string
type Index ¶
Index is an index of documents.
type Index struct {
// contains filtered or unexported fields
}
func Open ¶
func Open(name string) (*Index, error)
Open opens the index with the given name. The index is created if it does not already exist.
The name is a human-readable ASCII string. It must contain no whitespace characters and not start with "!".
func (*Index) Delete ¶
func (x *Index) Delete(c context.Context, id string) error
Delete deletes a document from the index.
func (*Index) DeleteMulti ¶
func (x *Index) DeleteMulti(c context.Context, ids []string) error
DeleteMulti deletes multiple documents from the index.
The returned error may be an instance of appengine.MultiError, in which case it will be the same size as srcs and the individual errors inside will correspond with the items in srcs.
func (*Index) Get ¶
func (x *Index) Get(c context.Context, id string, dst interface{}) error
Get loads the document with the given ID into dst.
The ID is a human-readable ASCII string. It must be non-empty, contain no whitespace characters and not start with "!".
dst must be a non-nil struct pointer or implement the FieldLoadSaver interface.
ErrFieldMismatch is returned when a field is to be loaded into a different type than the one it was stored from, or when a field is missing or unexported in the destination struct. ErrFieldMismatch is only returned if dst is a struct pointer. It is up to the callee to decide whether this error is fatal, recoverable, or ignorable.
func (*Index) List ¶
func (x *Index) List(c context.Context, opts *ListOptions) *Iterator
List lists all of the documents in an index. The documents are returned in increasing ID order.
func (*Index) Put ¶
func (x *Index) Put(c context.Context, id string, src interface{}) (string, error)
Put saves src to the index. If id is empty, a new ID is allocated by the service and returned. If id is not empty, any existing index entry for that ID is replaced.
The ID is a human-readable ASCII string. It must contain no whitespace characters and not start with "!".
src must be a non-nil struct pointer or implement the FieldLoadSaver interface.
func (*Index) PutMulti ¶
func (x *Index) PutMulti(c context.Context, ids []string, srcs []interface{}) ([]string, error)
PutMulti is like Put, but is more efficient for adding multiple documents to the index at once.
Up to 200 documents can be added at once. ErrTooManyDocuments is returned if you try to add more.
ids can either be an empty slice (which means new IDs will be allocated for each of the documents added) or a slice the same size as srcs.
The error may be an instance of appengine.MultiError, in which case it will be the same size as srcs and the individual errors inside will correspond with the items in srcs.
func (*Index) Search ¶
func (x *Index) Search(c context.Context, query string, opts *SearchOptions) *Iterator
Search searches the index for the given query.
type Iterator ¶
Iterator is the result of searching an index for a query or listing an index.
type Iterator struct {
// contains filtered or unexported fields
}
func (*Iterator) Count ¶
func (t *Iterator) Count() int
Count returns an approximation of the number of documents matched by the query. It is only valid to call for iterators returned by Search.
func (*Iterator) Cursor ¶
func (t *Iterator) Cursor() Cursor
Cursor returns the cursor associated with the current document (that is, the document most recently returned by a call to Next).
Passing this cursor in a future call to Search will cause those results to commence with the first document after the current document.
func (*Iterator) Facets ¶
func (t *Iterator) Facets() ([][]FacetResult, error)
Facets returns the facets found within the search results, if any facets were requested in the SearchOptions.
func (*Iterator) Next ¶
func (t *Iterator) Next(dst interface{}) (string, error)
Next returns the ID of the next result. When there are no more results, Done is returned as the error.
dst must be a non-nil struct pointer, implement the FieldLoadSaver interface, or be a nil interface value. If a non-nil dst is provided, it will be filled with the indexed fields. dst is ignored if this iterator was created with an IDsOnly option.
type ListOptions ¶
ListOptions are the options for listing documents in an index. Passing a nil *ListOptions is equivalent to using the default values.
type ListOptions struct {
// StartID is the inclusive lower bound for the ID of the returned
// documents. The zero value means all documents will be returned.
StartID string
// Limit is the maximum number of documents to return. The zero value
// indicates no limit.
Limit int
// IDsOnly indicates that only document IDs should be returned for the list
// operation; no document fields are populated.
IDsOnly bool
}
type Range ¶
Range represents a numeric range with inclusive start and exclusive end. Start may be specified as math.Inf(-1) to indicate there is no minimum value, and End may similarly be specified as math.Inf(1); at least one of Start or End must be a finite number.
type Range struct {
Start, End float64
}
func AtLeast ¶
func AtLeast(min float64) Range
AtLeast returns a Range matching any value greater than, or equal to, min.
func LessThan ¶
func LessThan(max float64) Range
LessThan returns a Range matching any value less than max.
type Scorer ¶
A Scorer defines how a document is scored.
type Scorer interface {
// contains filtered or unexported methods
}
var (
// MatchScorer assigns a score based on term frequency in a document.
MatchScorer Scorer = enumScorer{pb.ScorerSpec_MATCH_SCORER}
// RescoringMatchScorer assigns a score based on the quality of the query
// match. It is similar to a MatchScorer but uses a more complex scoring
// algorithm based on match term frequency and other factors like field type.
// Please be aware that this algorithm is continually refined and can change
// over time without notice. This means that the ordering of search results
// that use this scorer can also change without notice.
RescoringMatchScorer Scorer = enumScorer{pb.ScorerSpec_RESCORING_MATCH_SCORER}
)
type SearchOptions ¶
SearchOptions are the options for searching an index. Passing a nil *SearchOptions is equivalent to using the default values.
type SearchOptions struct {
// Limit is the maximum number of documents to return. The zero value
// indicates no limit.
Limit int
// IDsOnly indicates that only document IDs should be returned for the search
// operation; no document fields are populated.
IDsOnly bool
// Sort controls the ordering of search results.
Sort *SortOptions
// Fields specifies which document fields to include in the results. If omitted,
// all document fields are returned. No more than 100 fields may be specified.
Fields []string
// Expressions specifies additional computed fields to add to each returned
// document.
Expressions []FieldExpression
// Facets controls what facet information is returned for these search results.
// If no options are specified, no facet results will be returned.
Facets []FacetSearchOption
// Refinements filters the returned documents by requiring them to contain facets
// with specific values. Refinements are applied in conjunction for facets with
// different names, and in disjunction otherwise.
Refinements []Facet
// Cursor causes the results to commence with the first document after
// the document associated with the cursor.
Cursor Cursor
// Offset specifies the number of documents to skip over before returning results.
// When specified, Cursor must be nil.
Offset int
// CountAccuracy specifies the maximum result count that can be expected to
// be accurate. If zero, the count accuracy defaults to 20.
CountAccuracy int
}
type SortExpression ¶
SortExpression defines a single dimension for sorting a document.
type SortExpression struct {
// Expr is evaluated to provide a sorting value for each document.
// See https://cloud.google.com/appengine/docs/go/search/options for
// the supported expression syntax.
Expr string
// Reverse causes the documents to be sorted in ascending order.
Reverse bool
// The default value to use when no field is present or the expresion
// cannot be calculated for a document. For text sorts, Default must
// be of type string; for numeric sorts, float64.
Default interface{}
}
type SortOptions ¶
SortOptions control the ordering and scoring of search results.
type SortOptions struct {
// Expressions is a slice of expressions representing a multi-dimensional
// sort.
Expressions []SortExpression
// Scorer, when specified, will cause the documents to be scored according to
// search term frequency.
Scorer Scorer
// Limit is the maximum number of objects to score and/or sort. Limit cannot
// be more than 10,000. The zero value indicates a default limit.
Limit int
}