idb

package
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 Go to latest Published: Feb 22, 2023 License: Apache-2.0 Imports: 8 Imported by: 6

Documentation

Rendered for js/wasm

Overview

Package idb is a low-level driver that provides type-safe bindings to IndexedDB in Wasm programs. The primary focus is to align with the IndexedDB spec, followed by ease of use.

To get started, get the global indexedDB instance with idb.Global(). See below for examples.

Example 
//go:build js && wasm
// +build js,wasm

// nolint:errcheck
package main

import (
	"context"
	"syscall/js"

	"github.com/hack-pad/go-indexeddb/idb"
)

var (
	Books = []string{
		"Hitchhiker's Guide to the Galaxy",
		"Leaves of Grass",
		"The Great Gatsby",
		"The Hobbit",
	}
)

func main() {
	// Create the 'library' database, then create a 'books' object store during setup.
	// The setup func can also upgrade the database from older versions.
	ctx := context.Background()
	openRequest, _ := idb.Global().Open(ctx, "library", 1, func(db *idb.Database, oldVersion, newVersion uint) error {
		db.CreateObjectStore("books", idb.ObjectStoreOptions{})
		return nil
	})
	db, _ := openRequest.Await(ctx)

	{ // Store some books in the library database.
		txn, _ := db.Transaction(idb.TransactionReadWrite, "books")
		store, _ := txn.ObjectStore("books")
		for _, bookTitle := range Books {
			store.Add(js.ValueOf(bookTitle))
		}
		txn.Await(ctx)
	}

	{ // Iterate through the books and print their titles.
		txn, _ := db.Transaction(idb.TransactionReadOnly, "books")
		store, _ := txn.ObjectStore("books")
		cursorRequest, _ := store.OpenCursor(idb.CursorNext)
		cursorRequest.Iter(ctx, func(cursor *idb.CursorWithValue) error {
			value, _ := cursor.Value()
			println(value.String())
			return nil
		})
	}
}

Output:

Index

Examples

Constants

This section is empty.

Variables

View Source 
var (
	// ErrCursorStopIter stops iteration when returned from a CursorRequest.Iter() handler
	ErrCursorStopIter = errors.New("stop cursor iteration")
)

Functions

This section is empty.

Types

type AckRequest 

type AckRequest struct {
	*Request
}

AckRequest is a Request that doesn't retrieve a value, only used to detect errors.

func (*AckRequest) Await 

func (a *AckRequest) Await(ctx context.Context) error

Await waits for success or failure, then returns the results.

func (*AckRequest) Result 

func (a *AckRequest) Result()

Result is a no-op. This kind of request does not retrieve any data in the result.

type ArrayRequest 

type ArrayRequest struct {
	*Request
}

ArrayRequest is a Request that retrieves an array of js.Values

func (*ArrayRequest) Await 

func (a *ArrayRequest) Await(ctx context.Context) ([]js.Value, error)

Await waits for success or failure, then returns the results.

func (*ArrayRequest) Result 

func (a *ArrayRequest) Result() ([]js.Value, error)

Result returns the result of the request. If the request failed and the result is not available, an error is returned.

type Cursor 

type Cursor struct {
	// contains filtered or unexported fields
}

Cursor represents a cursor for traversing or iterating over multiple records in a Database

func (*Cursor) Advance 

func (c *Cursor) Advance(count uint) error

Advance sets the number of times a cursor should move its position forward.

func (*Cursor) Continue 

func (c *Cursor) Continue() error

Continue advances the cursor to the next position along its direction.

func (*Cursor) ContinueKey 

func (c *Cursor) ContinueKey(key js.Value) error

ContinueKey advances the cursor to the next position along its direction.

func (*Cursor) ContinuePrimaryKey 

func (c *Cursor) ContinuePrimaryKey(key, primaryKey js.Value) error

ContinuePrimaryKey sets the cursor to the given index key and primary key given as arguments. Returns an error if the source is not an index.

func (*Cursor) Delete 

func (c *Cursor) Delete() (*AckRequest, error)

Delete returns an AckRequest, and, in a separate thread, deletes the record at the cursor's position, without changing the cursor's position. This can be used to delete specific records.

func (*Cursor) Direction 

func (c *Cursor) Direction() (CursorDirection, error)

Direction returns the direction of traversal of the cursor

func (*Cursor) Key 

func (c *Cursor) Key() (js.Value, error)

Key returns the key for the record at the cursor's position. If the cursor is outside its range, this is set to undefined.

func (*Cursor) PrimaryKey 

func (c *Cursor) PrimaryKey() (js.Value, error)

PrimaryKey returns the cursor's current effective primary key. If the cursor is currently being iterated or has iterated outside its range, this is set to undefined.

func (*Cursor) Request 

func (c *Cursor) Request() (*Request, error)

Request returns the Request that was used to obtain the cursor.

func (*Cursor) Source 

func (c *Cursor) Source() (objectStore *ObjectStore, index *Index, err error)

Source returns the ObjectStore or Index that the cursor is iterating

func (*Cursor) Update 

func (c *Cursor) Update(value js.Value) (*Request, error)

Update returns a Request, and, in a separate thread, updates the value at the current position of the cursor in the object store. This can be used to update specific records.

type CursorDirection 

type CursorDirection int

CursorDirection is the direction of traversal of the cursor 

const (
	// CursorNext direction causes the cursor to be opened at the start of the source.
	CursorNext CursorDirection = iota
	// CursorNextUnique direction causes the cursor to be opened at the start of the source. For every key with duplicate values, only the first record is yielded.
	CursorNextUnique
	// CursorPrevious direction causes the cursor to be opened at the end of the source.
	CursorPrevious
	// CursorPreviousUnique direction causes the cursor to be opened at the end of the source. For every key with duplicate values, only the first record is yielded.
	CursorPreviousUnique
)

func (CursorDirection) String 

func (d CursorDirection) String() string

type CursorRequest 

type CursorRequest struct {
	*Request
}

CursorRequest is a Request that retrieves a Cursor

func (*CursorRequest) Await 

func (c *CursorRequest) Await(ctx context.Context) (*Cursor, error)

Await waits for success or failure, then returns the results.

func (*CursorRequest) Iter 

func (c *CursorRequest) Iter(ctx context.Context, iter func(*Cursor) error) error

Iter invokes the callback when the request succeeds for each cursor iteration

func (*CursorRequest) Result 

func (c *CursorRequest) Result() (*Cursor, error)

Result returns the result of the request. If the request failed and the result is not available, an error is returned.

type CursorWithValue 

type CursorWithValue struct {
	*Cursor
}

CursorWithValue represents a cursor for traversing or iterating over multiple records in a database. It is the same as the Cursor, except that it includes the value property.

func (*CursorWithValue) Value 

func (c *CursorWithValue) Value() (js.Value, error)

Value returns the value of the current cursor

type CursorWithValueRequest 

type CursorWithValueRequest struct {
	*Request
}

CursorWithValueRequest is a Request that retrieves a CursorWithValue

func (*CursorWithValueRequest) Await 

func (c *CursorWithValueRequest) Await(ctx context.Context) (*CursorWithValue, error)

Await waits for success or failure, then returns the results.

func (*CursorWithValueRequest) Iter 

func (c *CursorWithValueRequest) Iter(ctx context.Context, iter func(*CursorWithValue) error) error

Iter invokes the callback when the request succeeds for each cursor iteration

func (*CursorWithValueRequest) Result 

func (c *CursorWithValueRequest) Result() (*CursorWithValue, error)

Result returns the result of the request. If the request failed and the result is not available, an error is returned.

type DOMException added in v0.3.2 

type DOMException struct {
	// contains filtered or unexported fields
}

DOMException is a JavaScript DOMException with a standard name. Use errors.Is() to compare by name.

func NewDOMException added in v0.3.2 

func NewDOMException(name string) DOMException

NewDOMException returns a new DOMException with the given name. Only useful for errors.Is() comparisons with errors returned from idb.

func (DOMException) Error added in v0.3.2 

func (e DOMException) Error() string

func (DOMException) Is added in v0.3.2 

func (e DOMException) Is(target error) bool

Is returns true target is a DOMException and matches this DOMException's name. Use 'errors.Is()' to call it.

type Database 

type Database struct {
	// contains filtered or unexported fields
}

Database provides a connection to a database. You can use a Database object to open a transaction on your database then create, manipulate, and delete objects (data) in that database.

func (*Database) Close 

func (db *Database) Close() error

Close closes the connection to a database.

func (*Database) CreateObjectStore 

func (db *Database) CreateObjectStore(name string, options ObjectStoreOptions) (*ObjectStore, error)

CreateObjectStore creates and returns a new object store or index.

func (*Database) DeleteObjectStore 

func (db *Database) DeleteObjectStore(name string) error

DeleteObjectStore destroys the object store with the given name in the connected database, along with any indexes that reference it.

func (*Database) Name 

func (db *Database) Name() (string, error)

Name returns the name of the connected database.

func (*Database) ObjectStoreNames 

func (db *Database) ObjectStoreNames() ([]string, error)

ObjectStoreNames returns a list of the names of the object stores currently in the connected database.

func (*Database) Transaction 

func (db *Database) Transaction(mode TransactionMode, objectStoreName string, objectStoreNames ...string) (_ *Transaction, err error)

Transaction returns a transaction object containing the Transaction.ObjectStore() method, which you can use to access your object store.

func (*Database) TransactionWithOptions 

func (db *Database) TransactionWithOptions(options TransactionOptions, objectStoreName string, objectStoreNames ...string) (*Transaction, error)

TransactionWithOptions returns a transaction object containing the Transaction.ObjectStore() method, which you can use to access your object store.

func (*Database) Version 

func (db *Database) Version() (uint, error)

Version returns the version of the connected database.

type Factory 

type Factory struct {
	// contains filtered or unexported fields
}

Factory lets applications asynchronously access the indexed databases. A typical program will call Global() to access window.indexedDB.

func Global 

func Global() *Factory

Global returns the global IndexedDB instance. Can be called multiple times, will always return the same result (or error if one occurs).

func WrapFactory 

func WrapFactory(jsFactory js.Value) (*Factory, error)

WrapFactory wraps the given IDBFactory object

func (*Factory) CompareKeys 

func (f *Factory) CompareKeys(a, b js.Value) (int, error)

CompareKeys compares two keys and returns a result indicating which one is greater in value.

func (*Factory) DeleteDatabase 

func (f *Factory) DeleteDatabase(name string) (*AckRequest, error)

DeleteDatabase requests the deletion of a database.

func (*Factory) Open 

func (f *Factory) Open(upgradeCtx context.Context, name string, version uint, upgrader Upgrader) (*OpenDBRequest, error)

Open requests to open a connection to a database.

type Index 

type Index struct {
	// contains filtered or unexported fields
}

Index provides asynchronous access to an index in a database. An index is a kind of object store for looking up records in another object store, called the referenced object store. You use this to retrieve data.

func (*Index) Count 

func (i *Index) Count() (*UintRequest, error)

Count returns a UintRequest, and, in a separate thread, returns the total number of records in the index.

func (*Index) CountKey 

func (i *Index) CountKey(key js.Value) (*UintRequest, error)

CountKey returns a UintRequest, and, in a separate thread, returns the total number of records that match the provided key.

func (*Index) CountRange 

func (i *Index) CountRange(keyRange *KeyRange) (*UintRequest, error)

CountRange returns a UintRequest, and, in a separate thread, returns the total number of records that match the provided KeyRange.

func (*Index) Get 

func (i *Index) Get(key js.Value) (*Request, error)

Get returns a Request, and, in a separate thread, returns objects selected by the specified key. This is for retrieving specific records from an index.

func (*Index) GetAllKeys 

func (i *Index) GetAllKeys() (*ArrayRequest, error)

GetAllKeys returns an ArrayRequest that retrieves record keys for all objects in the index.

func (*Index) GetAllKeysRange 

func (i *Index) GetAllKeysRange(query *KeyRange, maxCount uint) (*ArrayRequest, error)

GetAllKeysRange returns an ArrayRequest that retrieves record keys for all objects in the index matching the specified query. If maxCount is 0, retrieves all objects matching the query.

func (*Index) GetKey 

func (i *Index) GetKey(value js.Value) (*Request, error)

GetKey returns a Request, and, in a separate thread retrieves and returns the record key for the object matching the specified parameter.

func (*Index) KeyPath 

func (i *Index) KeyPath() (js.Value, error)

KeyPath returns the key path of this index. If js.Null(), this index is not auto-populated.

func (*Index) MultiEntry 

func (i *Index) MultiEntry() (bool, error)

MultiEntry affects how the index behaves when the result of evaluating the index's key path yields an array. If true, there is one record in the index for each item in an array of keys. If false, then there is one record for each key that is an array.

func (*Index) Name 

func (i *Index) Name() (string, error)

Name returns the name of this index

func (*Index) ObjectStore 

func (i *Index) ObjectStore() (*ObjectStore, error)

ObjectStore returns the object store referenced by this index.

func (*Index) OpenCursor 

func (i *Index) OpenCursor(direction CursorDirection) (*CursorWithValueRequest, error)

OpenCursor returns a CursorWithValueRequest, and, in a separate thread, returns a new CursorWithValue. Used for iterating through an index by primary key with a cursor.

func (*Index) OpenCursorKey 

func (i *Index) OpenCursorKey(key js.Value, direction CursorDirection) (*CursorWithValueRequest, error)

OpenCursorKey is the same as OpenCursor, but opens a cursor over the given key instead.

func (*Index) OpenCursorRange 

func (i *Index) OpenCursorRange(keyRange *KeyRange, direction CursorDirection) (*CursorWithValueRequest, error)

OpenCursorRange is the same as OpenCursor, but opens a cursor over the given range instead.

func (*Index) OpenKeyCursor 

func (i *Index) OpenKeyCursor(direction CursorDirection) (*CursorRequest, error)

OpenKeyCursor returns a CursorRequest, and, in a separate thread, returns a new Cursor. Used for iterating through all keys in an object store.

func (*Index) OpenKeyCursorKey 

func (i *Index) OpenKeyCursorKey(key js.Value, direction CursorDirection) (*CursorRequest, error)

OpenKeyCursorKey is the same as OpenKeyCursor, but opens a cursor over the given key instead.

func (*Index) OpenKeyCursorRange 

func (i *Index) OpenKeyCursorRange(keyRange *KeyRange, direction CursorDirection) (*CursorRequest, error)

OpenKeyCursorRange is the same as OpenKeyCursor, but opens a cursor over the given key range instead.

func (*Index) Unique 

func (i *Index) Unique() (bool, error)

Unique indicates this index does not allow duplicate values for a key.

type IndexOptions 

type IndexOptions struct {
	// Unique disallows duplicate values for a single key.
	Unique bool
	// MultiEntry adds an entry in the index for each array element when the keyPath resolves to an Array. If false, adds one single entry containing the Array.
	MultiEntry bool
}

IndexOptions contains all options used to create an Index

type KeyRange 

type KeyRange struct {
	// contains filtered or unexported fields
}

KeyRange represents a continuous interval over some data type that is used for keys. Records can be retrieved from ObjectStore and Index objects using keys or a range of keys.

func NewKeyRangeBound 

func NewKeyRangeBound(lower, upper js.Value, lowerOpen, upperOpen bool) (*KeyRange, error)

NewKeyRangeBound creates a new key range with the specified upper and lower bounds. The bounds can be open (that is, the bounds exclude the endpoint values) or closed (that is, the bounds include the endpoint values).

func NewKeyRangeLowerBound 

func NewKeyRangeLowerBound(lower js.Value, open bool) (*KeyRange, error)

NewKeyRangeLowerBound creates a new key range with only a lower bound.

func NewKeyRangeOnly 

func NewKeyRangeOnly(only js.Value) (*KeyRange, error)

NewKeyRangeOnly creates a new key range containing a single value.

func NewKeyRangeUpperBound 

func NewKeyRangeUpperBound(upper js.Value, open bool) (*KeyRange, error)

NewKeyRangeUpperBound creates a new key range with only an upper bound.

func (*KeyRange) Includes 

func (k *KeyRange) Includes(key js.Value) (bool, error)

Includes returns a boolean indicating whether a specified key is inside the key range.

func (*KeyRange) Lower 

func (k *KeyRange) Lower() (js.Value, error)

Lower returns the lower bound of the key range.

func (*KeyRange) LowerOpen 

func (k *KeyRange) LowerOpen() (bool, error)

LowerOpen returns false if the lower-bound value is included in the key range.

func (*KeyRange) Upper 

func (k *KeyRange) Upper() (js.Value, error)

Upper returns the upper bound of the key range.

func (*KeyRange) UpperOpen 

func (k *KeyRange) UpperOpen() (bool, error)

UpperOpen returns false if the upper-bound value is included in the key range.

type ObjectStore 

type ObjectStore struct {
	// contains filtered or unexported fields
}

ObjectStore represents an object store in a database. Records within an object store are sorted according to their keys. This sorting enables fast insertion, look-up, and ordered retrieval.

func (*ObjectStore) Add 

func (o *ObjectStore) Add(value js.Value) (*AckRequest, error)

Add returns an AckRequest, and, in a separate thread, creates a structured clone of the value, and stores the cloned value in the object store. This is for adding new records to an object store.

func (*ObjectStore) AddKey 

func (o *ObjectStore) AddKey(key, value js.Value) (*AckRequest, error)

AddKey is the same as Add, but includes the key to use to identify the record.

func (*ObjectStore) AutoIncrement 

func (o *ObjectStore) AutoIncrement() (bool, error)

AutoIncrement returns the value of the auto increment flag for this object store.

func (*ObjectStore) Clear 

func (o *ObjectStore) Clear() (*AckRequest, error)

Clear returns an AckRequest, then clears this object store in a separate thread. This is for deleting all current records out of an object store.

func (*ObjectStore) Count 

func (o *ObjectStore) Count() (*UintRequest, error)

Count returns a UintRequest, and, in a separate thread, returns the total number of records in the store.

func (*ObjectStore) CountKey 

func (o *ObjectStore) CountKey(key js.Value) (*UintRequest, error)

CountKey returns a UintRequest, and, in a separate thread, returns the total number of records that match the provided key.

func (*ObjectStore) CountRange 

func (o *ObjectStore) CountRange(keyRange *KeyRange) (*UintRequest, error)

CountRange returns a UintRequest, and, in a separate thread, returns the total number of records that match the provided KeyRange.

func (*ObjectStore) CreateIndex 

func (o *ObjectStore) CreateIndex(name string, keyPath js.Value, options IndexOptions) (*Index, error)

CreateIndex creates a new index during a version upgrade, returning a new Index object in the connected database.

func (*ObjectStore) Delete 

func (o *ObjectStore) Delete(key js.Value) (*AckRequest, error)

Delete returns an AckRequest, and, in a separate thread, deletes the store object selected by the specified key. This is for deleting individual records out of an object store.

func (*ObjectStore) DeleteIndex 

func (o *ObjectStore) DeleteIndex(name string) error

DeleteIndex destroys the specified index in the connected database, used during a version upgrade.

func (*ObjectStore) Get 

func (o *ObjectStore) Get(key js.Value) (*Request, error)

Get returns a Request, and, in a separate thread, returns the objects selected by the specified key. This is for retrieving specific records from an object store.

func (*ObjectStore) GetAllKeys 

func (o *ObjectStore) GetAllKeys() (*ArrayRequest, error)

GetAllKeys returns an ArrayRequest that retrieves record keys for all objects in the object store.

func (*ObjectStore) GetAllKeysRange 

func (o *ObjectStore) GetAllKeysRange(query *KeyRange, maxCount uint) (*ArrayRequest, error)

GetAllKeysRange returns an ArrayRequest that retrieves record keys for all objects in the object store matching the specified query. If maxCount is 0, retrieves all objects matching the query.

func (*ObjectStore) GetKey 

func (o *ObjectStore) GetKey(value js.Value) (*Request, error)

GetKey returns a Request, and, in a separate thread retrieves and returns the record key for the object matching the specified parameter.

func (*ObjectStore) Index 

func (o *ObjectStore) Index(name string) (*Index, error)

Index opens an index from this object store after which it can, for example, be used to return a sequence of records sorted by that index using a cursor.

func (*ObjectStore) IndexNames 

func (o *ObjectStore) IndexNames() ([]string, error)

IndexNames returns a list of the names of indexes on objects in this object store.

func (*ObjectStore) KeyPath 

func (o *ObjectStore) KeyPath() (js.Value, error)

KeyPath returns the key path of this object store. If this returns js.Null(), the application must provide a key for each modification operation.

func (*ObjectStore) Name 

func (o *ObjectStore) Name() (string, error)

Name returns the name of this object store.

func (*ObjectStore) OpenCursor 

func (o *ObjectStore) OpenCursor(direction CursorDirection) (*CursorWithValueRequest, error)

OpenCursor returns a CursorWithValueRequest, and, in a separate thread, returns a new CursorWithValue. Used for iterating through an object store by primary key with a cursor.

func (*ObjectStore) OpenCursorKey 

func (o *ObjectStore) OpenCursorKey(key js.Value, direction CursorDirection) (*CursorWithValueRequest, error)

OpenCursorKey is the same as OpenCursor, but opens a cursor over the given key instead.

func (*ObjectStore) OpenCursorRange 

func (o *ObjectStore) OpenCursorRange(keyRange *KeyRange, direction CursorDirection) (*CursorWithValueRequest, error)

OpenCursorRange is the same as OpenCursor, but opens a cursor over the given range instead.

func (*ObjectStore) OpenKeyCursor 

func (o *ObjectStore) OpenKeyCursor(direction CursorDirection) (*CursorRequest, error)

OpenKeyCursor returns a CursorRequest, and, in a separate thread, returns a new Cursor. Used for iterating through all keys in an object store.

func (*ObjectStore) OpenKeyCursorKey 

func (o *ObjectStore) OpenKeyCursorKey(key js.Value, direction CursorDirection) (*CursorRequest, error)

OpenKeyCursorKey is the same as OpenKeyCursor, but opens a cursor over the given key instead.

func (*ObjectStore) OpenKeyCursorRange 

func (o *ObjectStore) OpenKeyCursorRange(keyRange *KeyRange, direction CursorDirection) (*CursorRequest, error)

OpenKeyCursorRange is the same as OpenKeyCursor, but opens a cursor over the given key range instead.

func (*ObjectStore) Put 

func (o *ObjectStore) Put(value js.Value) (*Request, error)

Put returns a Request, and, in a separate thread, creates a structured clone of the value, and stores the cloned value in the object store. This is for updating existing records in an object store when the transaction's mode is readwrite.

func (*ObjectStore) PutKey 

func (o *ObjectStore) PutKey(key, value js.Value) (*Request, error)

PutKey is the same as Put, but includes the key to use to identify the record.

func (*ObjectStore) Transaction 

func (o *ObjectStore) Transaction() (*Transaction, error)

Transaction returns the Transaction object to which this object store belongs.

type ObjectStoreOptions 

type ObjectStoreOptions struct {
	KeyPath       js.Value
	AutoIncrement bool
}

ObjectStoreOptions contains all available options for creating an ObjectStore

type OpenDBRequest 

type OpenDBRequest struct {
	*Request
}

OpenDBRequest provides access to the results of requests to open or delete databases (performed using Factory.open and Factory.DeleteDatabase).

func (*OpenDBRequest) Await 

func (o *OpenDBRequest) Await(ctx context.Context) (*Database, error)

Await waits for success or failure, then returns the results.

func (*OpenDBRequest) Result 

func (o *OpenDBRequest) Result() (*Database, error)

Result returns the result of the request. If the request failed and the result is not available, an error is returned.

type Request 

type Request struct {
	// contains filtered or unexported fields
}

Request provides access to results of asynchronous requests to databases and database objects using event listeners. Each reading and writing operation on a database is done using a request.

func (*Request) Await 

func (r *Request) Await(ctx context.Context) (js.Value, error)

Await waits for success or failure, then returns the results.

func (*Request) Err 

func (r *Request) Err() (err error)

Err returns an error in the event of an unsuccessful request, indicating what went wrong.

func (*Request) Listen 

func (r *Request) Listen(ctx context.Context, success, failed func()) error

Listen invokes the success callback when the request succeeds and failed when it fails.

func (*Request) ListenError 

func (r *Request) ListenError(ctx context.Context, failed func()) error

ListenError invokes the callback when the request fails

func (*Request) ListenSuccess 

func (r *Request) ListenSuccess(ctx context.Context, success func()) error

ListenSuccess invokes the callback when the request succeeds

func (*Request) ReadyState 

func (r *Request) ReadyState() (string, error)

ReadyState returns the state of the request. Every request starts in the pending state. The state changes to done when the request completes successfully or when an error occurs.

func (*Request) Result 

func (r *Request) Result() (js.Value, error)

Result returns the result of the request. If the request failed and the result is not available, an error is returned.

func (*Request) Source 

func (r *Request) Source() (objectStore *ObjectStore, index *Index, err error)

Source returns the source of the request, such as an Index or an ObjectStore. If no source exists (such as when calling Factory.Open), it returns nil for both.

func (*Request) Transaction 

func (r *Request) Transaction() (*Transaction, error)

Transaction returns the transaction for the request. This can return nil for certain requests, for example those returned from Factory.Open unless an upgrade is needed. (You're just connecting to a database, so there is no transaction to return).

type Transaction 

type Transaction struct {
	// contains filtered or unexported fields
}

Transaction provides a static, asynchronous transaction on a database. All reading and writing of data is done within transactions. You use Database to start transactions, Transaction to set the mode of the transaction (e.g. is it TransactionReadOnly or TransactionReadWrite), and you access an ObjectStore to make a request. You can also use a Transaction object to abort transactions.

func (*Transaction) Abort 

func (t *Transaction) Abort() error

Abort rolls back all the changes to objects in the database associated with this transaction.

func (*Transaction) Await 

func (t *Transaction) Await(ctx context.Context) error

Await waits for success or failure, then returns the results.

func (*Transaction) Commit 

func (t *Transaction) Commit() error

Commit for an active transaction, commits the transaction. Note that this doesn't normally have to be called — a transaction will automatically commit when all outstanding requests have been satisfied and no new requests have been made. Commit() can be used to start the commit process without waiting for events from outstanding requests to be dispatched.

func (*Transaction) Database 

func (t *Transaction) Database() (*Database, error)

Database returns the database connection with which this transaction is associated.

func (*Transaction) Durability 

func (t *Transaction) Durability() (TransactionDurability, error)

Durability returns the durability hint the transaction was created with.

func (*Transaction) Err 

func (t *Transaction) Err() error

Err returns an error indicating the type of error that occurred when there is an unsuccessful transaction. Returns nil if the transaction is not finished, is finished and successfully committed, or was aborted with Transaction.Abort().

func (*Transaction) Mode 

func (t *Transaction) Mode() (TransactionMode, error)

Mode returns the mode for isolating access to data in the object stores that are in the scope of the transaction. The default value is TransactionReadOnly.

func (*Transaction) ObjectStore 

func (t *Transaction) ObjectStore(name string) (*ObjectStore, error)

ObjectStore returns an ObjectStore representing an object store that is part of the scope of this transaction.

func (*Transaction) ObjectStoreNames 

func (t *Transaction) ObjectStoreNames() ([]string, error)

ObjectStoreNames returns a list of the names of ObjectStores associated with the transaction.

type TransactionDurability 

type TransactionDurability int

TransactionDurability is a hint to the user agent of whether to prioritize performance or durability when committing a transaction. 

const (
	// DurabilityDefault indicates the user agent should use its default durability behavior for the storage bucket. This is the default for transactions if not otherwise specified.
	DurabilityDefault TransactionDurability = iota
	// DurabilityRelaxed indicates the user agent may consider that the transaction has successfully committed as soon as all outstanding changes have been written to the operating system, without subsequent verification.
	DurabilityRelaxed
	// DurabilityStrict indicates the user agent may consider that the transaction has successfully committed only after verifying all outstanding changes have been successfully written to a persistent storage medium.
	DurabilityStrict
)

func (TransactionDurability) String 

func (d TransactionDurability) String() string

type TransactionMode 

type TransactionMode int

TransactionMode defines the mode for isolating access to data in the transaction's current object stores. 

const (
	// TransactionReadOnly allows data to be read but not changed.
	TransactionReadOnly TransactionMode = iota
	// TransactionReadWrite allows reading and writing of data in existing data stores to be changed.
	TransactionReadWrite
)

func (TransactionMode) String 

func (m TransactionMode) String() string

type TransactionOptions 

type TransactionOptions struct {
	Mode       TransactionMode
	Durability TransactionDurability
}

TransactionOptions contains all available options for creating and starting a Transaction

type UintRequest 

type UintRequest struct {
	*Request
}

UintRequest is a Request that retrieves a uint result

func (*UintRequest) Await 

func (u *UintRequest) Await(ctx context.Context) (uint, error)

Await waits for success or failure, then returns the results.

func (*UintRequest) Result 

func (u *UintRequest) Result() (uint, error)

Result returns the result of the request. If the request failed and the result is not available, an error is returned.

type Upgrader 

type Upgrader func(db *Database, oldVersion, newVersion uint) error

Upgrader is a function that can upgrade the given database from an old version to a new one.

Source Files

View all Source files

Directories

Path Synopsis
internal
assert
Package assert contains small assertion test functions to assist in writing clean tests.
 Package assert contains small assertion test functions to assist in writing clean tests.
jscache
Package jscache caches expensive JavaScript results, like string encoding
 Package jscache caches expensive JavaScript results, like string encoding

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