query

Documentation

Index

• func MergeResultStreams(ctx context.Context, args QueryArgs, vshardResults []*ResultStream, ...)
• func MergeResultStreamsUnique(ctx context.Context, args QueryArgs, pkeyFields []string, ...)
• type Query
• type QueryArgs
• type QueryType
• type Result
  • func MergeAggregateResult(args QueryArgs, numResults int, results chan *Result) *Result
  • func MergeResult(primaryIndexFields []string, numResults int, results chan *Result) *Result
  • func (r *Result) Err() error
  • func (r *Result) Project(fields []string)
  • func (r *Result) Sort(keys []string, reverseList []bool)
• type ResultStream
  • func (r *ResultStream) AddTransformation(t ResultStreamItemTransformation) error
  • func (r *ResultStream) Close() error
  • func (r *ResultStream) Err() error
  • func (r *ResultStream) Recv() (record.Record, error)
• type ResultStreamItemTransformation

Functions

func MergeResultStreams

func MergeResultStreams(ctx context.Context, args QueryArgs, vshardResults []*ResultStream, resultStream stream.ServerStream)

TODO: take context MergeResultStreams is responsible to (1) merge result streams and (2) maintain sort order (if sorted) from the streams (each stream is assumed to be in-order already)

func MergeResultStreamsUnique

func MergeResultStreamsUnique(ctx context.Context, args QueryArgs, pkeyFields []string, vshardResults []*ResultStream, resultStream stream.ServerStream)

MergeResultStreams is responsible to (1) merge result streams uniquely based on pkey and (2) maintain sort order (if sorted) from the streams (each stream is assumed to be in-order already)

Types

type Query

type Query struct {
	Type QueryType
	Args QueryArgs
}

Query is the struct which contains the entire query to run, this includes both the function to run and the args associated

type QueryArgs

type QueryArgs struct {
	// Shared options
	DB            string `json:"db"`
	Collection    string `json:"collection"`
	ShardInstance string `json:"shard_instance,omitempty"`

	// Fields defines a list of fields for Projections
	Fields []string `json:"fields"`

	// TODO: rename?
	AggregationFields map[string][]aggregation.AggregationType `json:"aggregation_fields"`

	// Sort + SortReverse control the ordering of results
	Sort []string `json:"sort"`
	// TODO: change to ints?
	SortReverse []bool `json:"sort_reverse"`

	// Limit is how many records will be returned in the result
	Limit uint64 `json:"limit"`

	// TODO: name skip?
	// TODO: if offset is set without a sort, then it is meaningless -- we need to error out
	// Offset controls the offset for returning results. This will exclude `Offset`
	// number of records from the "front" of the results
	Offset uint64 `json:"offset"`

	// Record types (TODO: record struct)
	PKey    record.Record   `json:"pkey"`
	Record  record.Record   `json:"record,omitempty"`
	Records []record.Record `json:"records,omitempty"`

	// TODO struct?
	// RecordOp is a map of operations to apply to the record (incr, decr, etc.)
	RecordOp map[string]interface{} `json:"record_op"`

	// TODO; type for the filter itself
	// Filter is the conditions to match data on
	Filter interface{} `json:"filter"`

	// Join defines what data we should pull in addition to the record defined in `Collection`
	Join interface{} `json:"join"`
}

TODO: add meta TODO: func to validate the mix of arguments

type QueryType

type QueryType string

TODO: method to know if it is stream or not QueryType is the list of all query functions dataman supports

const (
	Get        QueryType = "get"
	Set        QueryType = "set"
	Insert     QueryType = "insert"
	InsertMany QueryType = "insert_many"
	Update     QueryType = "update"
	Delete     QueryType = "delete"
	Filter     QueryType = "filter"
	Aggregate  QueryType = "aggregate"

	// Stream types: responses that will return a stream of results
	FilterStream QueryType = "filter_stream"
)

type Result

type Result struct {
	Return []record.Record `json:"return"`
	Errors []string        `json:"errors,omitempty"`
	// TODO: pointer to the right thing
	ValidationError interface{}            `json:"validation_error,omitempty"`
	Meta            map[string]interface{} `json:"meta,omitempty"`
}

Encapsulate a result from the datastore

func MergeAggregateResult

func MergeAggregateResult(args QueryArgs, numResults int, results chan *Result) *Result

Merge multiple aggregation results together

func MergeResult

func MergeResult(primaryIndexFields []string, numResults int, results chan *Result) *Result

Merge multiple results together

func (*Result) Err

func (r *Result) Err() error

func (*Result) Project

func (r *Result) Project(fields []string)

func (*Result) Sort

func (r *Result) Sort(keys []string, reverseList []bool)

type ResultStream

type ResultStream struct {
	// ClientStream -- this is the actual data that is coming back from the DB
	Stream stream.ClientStream `json:"-"`
	// TODO: do we need?
	Errors []string `json:"errors,omitempty"`
	// TODO: does this make sens in the result itself?
	Meta map[string]interface{} `json:"meta,omitempty"`
	// contains filtered or unexported fields
}

Encapsulate a streaming result from the datastore

func (*ResultStream) AddTransformation

func (r *ResultStream) AddTransformation(t ResultStreamItemTransformation) error

func (*ResultStream) Close

func (r *ResultStream) Close() error

func (*ResultStream) Err

func (r *ResultStream) Err() error

func (*ResultStream) Recv

func (r *ResultStream) Recv() (record.Record, error)

type ResultStreamItemTransformation

type ResultStreamItemTransformation func(record.Record) (record.Record, error)

Function to transform a given record argument *must* be a pointer, otherwise you are passed a copy which you cannot replace directly