Documentation
¶
Index ¶
- Constants
- Variables
- func CompareValues(v1, v2 Value) int
- func Register(reg Registration)
- func ValuesEqual(v1, v2 Value) bool
- type BatchInserter
- type Bool
- type Bytes
- type Database
- type Delete
- type DocIterator
- type DocWriter
- type Document
- type FieldFilter
- type FilterOp
- type Float
- type Index
- type IndexType
- type Int
- type Key
- type OpenFunc
- type Options
- type Query
- type Registration
- type String
- type Strings
- type Time
- type Traits
- type Update
- type Value
Constants ¶
const ( Equal = FilterOp(iota + 1) NotEqual GT GTE LT LTE Regexp )
const ( IndexAny = IndexType(iota) StringExact // exact match for string values (usually a hash index) )
Variables ¶
var ErrNotFound = errors.New("not found")
Functions ¶
func CompareValues ¶
CompareValues return 0 if values are equal, positive value if first value sorts after second, and negative otherwise.
func ValuesEqual ¶
ValuesEqual returns true if values are strictly equal.
Types ¶
type BatchInserter ¶
BatchInserter is an optional interface for databases that can insert documents in batches.
type Bytes ¶
type Bytes []byte
Bytes is a raw binary data.
Some databases has no type to represent binary data. In this case base64 representation can be used and package will take care of converting it.
type Database ¶
type Database interface {
// Insert creates a document with a given key in a given collection.
// Key can be nil meaning that implementation should generate a unique key for the item.
// It returns the key that was generated, or the same key that was passed to it.
Insert(ctx context.Context, col string, key Key, d Document) (Key, error)
// FindByKey finds a document by it's Key. It returns ErrNotFound if document not exists.
FindByKey(ctx context.Context, col string, key Key) (Document, error)
// Query starts construction of a new query for a specified collection.
Query(col string) Query
// Update starts construction of document update request for a specified document and collection.
Update(col string, key Key) Update
// Delete starts construction of document delete request.
Delete(col string) Delete
// EnsureIndex creates or updates indexes on the collection to match it's arguments.
// It should create collection if it not exists. Primary index is guaranteed to be of StringExact type.
EnsureIndex(ctx context.Context, col string, primary Index, secondary []Index) error
// Close closes the database connection.
Close() error
}
Database is a minimal interface for NoSQL database implementations.
type Delete ¶
type Delete interface {
// WithFields adds specified filters to select document for deletion.
WithFields(filters ...FieldFilter) Delete
// Keys limits a set of documents to delete to ones with keys specified.
// Delete still uses provided filters, thus it will not delete objects with these keys if they do not pass filters.
Keys(keys ...Key) Delete
// Do executes batch delete.
Do(ctx context.Context) error
}
Update is a batch delete request builder.
type DocIterator ¶
type DocIterator interface {
// Next advances an iterator to the next document.
Next(ctx context.Context) bool
// Err returns a last encountered error.
Err() error
// Close frees all resources associated with iterator.
Close() error
// Key returns a key of current document.
Key() Key
// Doc returns current document.
Doc() Document
}
DocIterator is an iterator over a list of documents.
type DocWriter ¶
type DocWriter interface {
// WriteDoc prepares document to be written. Write becomes valid only after Flush.
WriteDoc(ctx context.Context, key Key, d Document) error
// Flush waits for all writes to complete.
Flush(ctx context.Context) error
// Keys returns a list of already inserted documents.
// Might be less then a number of written documents until Flush is called.
Keys() []Key
// Close closes writer and discards any unflushed documents.
Close() error
}
DocWriter is an interface for writing documents in streaming manner.
func BatchInsert ¶
BatchInsert returns a streaming writer for database or emulates it if database has no support for batch inserts.
type FieldFilter ¶
type FieldFilter struct {
Path []string // path is a path to specific field in the document
Filter FilterOp // comparison operation
Value Value // value that will be compared with field of the document
}
FieldFilter represents a single field comparison operation.
func (FieldFilter) Matches ¶
func (f FieldFilter) Matches(doc Document) bool
type Float ¶
type Float float64
Float is an floating point value.
Some databases might not distinguish Int value from Float. In this case the package will take care of converting it to a correct type.
type Int ¶
type Int int64
Int is an int value.
Some databases might not distinguish Int value from Float. In this case implementation will take care of converting it to a correct type.
type Key ¶
type Key []string
Key is a set of values that describe primary key of document.
type OpenFunc ¶
OpenFunc is a function for opening a database given a address and the database name.
type Query ¶
type Query interface {
// WithFields adds specified filters to the query.
WithFields(filters ...FieldFilter) Query
// Limit limits a maximal number of results returned.
Limit(n int) Query
// Count executes query and returns a number of items that matches it.
Count(ctx context.Context) (int64, error)
// One executes query and returns first document from it.
One(ctx context.Context) (Document, error)
// Iterate starts an iteration over query results.
Iterate(ctx context.Context) DocIterator
}
Query is a query builder object.
type Registration ¶
type Registration struct {
base.Registration
New, Open OpenFunc
Traits Traits
}
Registration is an information about the database driver.
func ByName ¶
func ByName(name string) *Registration
ByName returns a registered database driver by it's name.
type Time ¶
Time is a timestamp value.
Some databases has no type to represent time values. In this case string/json representation can be used and package will take care of converting it.
type Update ¶
type Update interface {
// Inc increments document field with a given amount. Will also increment upserted document.
Inc(field string, dn int) Update
// Upsert sets a document that will be inserted in case original object does not exists already.
// It should omit fields used by Inc - they will be added automatically.
Upsert(d Document) Update
// Do executes update request.
Do(ctx context.Context) error
}
Update is an update request builder.
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