IReadableObjectStore
Direct Subclass:
Indirect Subclass:
Direct Implemented:
Indirect Implemented:
This interface represents an object store (roughly corresponding to a table in a relational database). It stores key-value pairs where the key is generally considered to be a string and the value is any object. The key is the entry's primary key. Other keys within the object may be accessed by indices as offered by the store.
Member Summary
| Public Members | ||
| public get |
connected: boolean |
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| public get abstract |
A map of index names to indices. |
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Method Summary
| Public Methods | ||
| public abstract |
async close(): Promise Closes the object store and potential connections. |
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| public abstract |
Returns the count of entries in the given range. |
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| public abstract |
decode(value: *, key: string): * Method called to decode a single value. |
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| public abstract |
encode(value: *): * Method called to encode a single value. |
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| public abstract |
async get(key: string, options: RetrievalConfig): Promise<*> Returns a promise of the object stored under the given primary key. |
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| public abstract |
Returns the index of the given name. |
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| public abstract |
isSynchronous(): boolean Checks whether an object store implements the ISynchronousObjectStore interface. |
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| public abstract |
Iterates over the keys in a given range and direction. |
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| public abstract |
Returns a promise of a set of keys fulfilling the given query. |
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| public abstract |
Returns a promise of the key being maximal for the given range. |
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| public abstract |
Returns a promise of the object whose primary key is maximal for the given range. |
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| public abstract |
Returns a promise of the key being minimal for the given range. |
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| public abstract |
Returns a promise of the object whose primary key is minimal for the given range. |
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| public abstract |
async truncate(): Promise Empties the object store. |
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| public abstract |
valueStream(callback: function(value: *, key: string): boolean, ascending: boolean, query: KeyRange): Promise Iterates over the keys and values in a given range and direction. |
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| public abstract |
Returns a promise of an array of objects whose primary keys fulfill the given query. |
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| Protected Methods | ||
| protected abstract |
async _apply(tx: Transaction): Promise Internally applies a transaction to the store's state. This needs to be done in batch (as a db level transaction), i.e., either the full state is updated or no changes are applied. |
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Public Members
public get connected: boolean source
Public Methods
public abstract async close(): Promise source
Closes the object store and potential connections.
Return:
| Promise | The promise resolves after closing the object store. |
public abstract async count(query: KeyRange): Promise<number> source
Returns the count of entries in the given range. If the optional query is not given, it returns the count of entries in the object store. If the query is of type KeyRange, it returns the count of entries within the given range.
Params:
| Name | Type | Attribute | Description |
| query | KeyRange |
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Return:
| Promise<number> |
public abstract decode(value: *, key: string): * source
Method called to decode a single value.
Params:
| Name | Type | Attribute | Description |
| value | * | Value to be decoded. |
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| key | string | Key corresponding to the value. |
Return:
| * | The decoded value. |
public abstract encode(value: *): * source
Method called to encode a single value.
Params:
| Name | Type | Attribute | Description |
| value | * | Value to be encoded. |
Return:
| * | The encoded value. |
public abstract async get(key: string, options: RetrievalConfig): Promise<*> source
Returns a promise of the object stored under the given primary key. Resolves to undefined if the key is not present in the object store.
Params:
| Name | Type | Attribute | Description |
| key | string | The primary key to look for. |
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| options | RetrievalConfig |
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Advanced retrieval options. |
Return:
| Promise<*> | A promise of the object stored under the given key, or undefined if not present. |
public abstract index(indexName: string): IIndex source
Returns the index of the given name. If the index does not exist, it returns undefined.
Params:
| Name | Type | Attribute | Description |
| indexName | string | The name of the requested index. |
public abstract isSynchronous(): boolean source
Checks whether an object store implements the ISynchronousObjectStore interface.
Return:
| boolean | The transaction object. |
public abstract keyStream(callback: function(key: string): boolean, ascending: boolean, query: KeyRange): Promise source
Iterates over the keys in a given range and direction. The callback is called for each primary key fulfilling the query until it returns false and stops the iteration.
Params:
| Name | Type | Attribute | Description |
| callback | function(key: string): boolean | A predicate called for each key until returning false. |
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| ascending | boolean | Determines the direction of traversal. |
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| query | KeyRange | An optional KeyRange to narrow down the iteration space. |
Return:
| Promise | The promise resolves after all elements have been streamed. |
public abstract async keys(query: Query | KeyRange, limit: number): Promise<Set<string>> source
Returns a promise of a set of keys fulfilling the given query. If the optional query is not given, it returns all keys in the object store. If the query is of type KeyRange, it returns all keys of the object store being within this range. If the query is of type Query, it returns all keys fulfilling the query.
Return:
| Promise<Set<string>> | A promise of the set of keys relevant to the query. |
public abstract async maxKey(query: KeyRange): Promise<string> source
Returns a promise of the key being maximal for the given range. If the optional query is not given, it returns the maximal key. If the query is of type KeyRange, it returns the key being maximal for the given range.
Params:
| Name | Type | Attribute | Description |
| query | KeyRange |
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Optional query to check keys against. |
Return:
| Promise<string> | A promise of the key relevant to the query. |
public abstract async maxValue(query: KeyRange): Promise<*> source
Returns a promise of the object whose primary key is maximal for the given range. If the optional query is not given, it returns the object whose key is maximal. If the query is of type KeyRange, it returns the object whose primary key is maximal for the given range.
Params:
| Name | Type | Attribute | Description |
| query | KeyRange |
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Optional query to check keys against. |
Return:
| Promise<*> | A promise of the object relevant to the query. |
public abstract async minKey(query: KeyRange): Promise<string> source
Returns a promise of the key being minimal for the given range. If the optional query is not given, it returns the minimal key. If the query is of type KeyRange, it returns the key being minimal for the given range.
Params:
| Name | Type | Attribute | Description |
| query | KeyRange |
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Optional query to check keys against. |
Return:
| Promise<string> | A promise of the key relevant to the query. |
public abstract async minValue(query: KeyRange): Promise<*> source
Returns a promise of the object whose primary key is minimal for the given range. If the optional query is not given, it returns the object whose key is minimal. If the query is of type KeyRange, it returns the object whose primary key is minimal for the given range.
Params:
| Name | Type | Attribute | Description |
| query | KeyRange |
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Optional query to check keys against. |
Return:
| Promise<*> | A promise of the object relevant to the query. |
public abstract async truncate(): Promise source
Empties the object store.
Return:
| Promise | The promise resolves after emptying the object store. |
public abstract valueStream(callback: function(value: *, key: string): boolean, ascending: boolean, query: KeyRange): Promise source
Iterates over the keys and values in a given range and direction. The callback is called for each value and primary key fulfilling the query until it returns false and stops the iteration.
Params:
| Name | Type | Attribute | Description |
| callback | function(value: *, key: string): boolean | A predicate called for each value and key until returning false. |
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| ascending | boolean | Determines the direction of traversal. |
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| query | KeyRange | An optional KeyRange to narrow down the iteration space. |
Return:
| Promise | The promise resolved after all elements have been streamed. |
public abstract async values(query: Query | KeyRange, limit: number): Promise<Array<*>> source
Returns a promise of an array of objects whose primary keys fulfill the given query. If the optional query is not given, it returns all objects in the object store. If the query is of type KeyRange, it returns all objects whose primary keys are within this range. If the query is of type Query, it returns all objects whose primary keys fulfill the query.
Return:
| Promise<Array<*>> | A promise of the array of objects relevant to the query. |
Protected Methods
protected abstract async _apply(tx: Transaction): Promise source
Internally applies a transaction to the store's state. This needs to be done in batch (as a db level transaction), i.e., either the full state is updated or no changes are applied.
Params:
| Name | Type | Attribute | Description |
| tx | Transaction | The transaction to apply. |
Return:
| Promise | The promise resolves after applying the transaction. |