List API reference for Momento Cache
This page details the Momento API methods for the list collection data types.
List methods
ListFetch
Gets a list item from a cache, with optional slices.
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | The name of the list item to be retrieved. |
startIndex | Number | The starting inclusive element of the list to fetch. Default is 0. This argument is optional. |
endIndex | Number | The ending exclusive element of the list to fetch. Default is end of list. This argument is optional. |
Method response object
The response object for ListFetch returns three possible options, a cache hit, miss, or an error.
- Hit
- valueListBytes(): bytes[]
- valueListString(): string[]
- toString(): string - Display a truncated valueListString(). See truncation.
- Miss
- Error
See response objects for specific information.
ListConcatenateBack
Appends the supplied list to the end of an existing list item.
Example:
If you have [1, 2, 3] and listConcatenateBack [4, 5, 6] you will have [1, 2, 3, 4, 5, 6].
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list item to be set. |
values | String[] | bytes[] | Values to be added as elements to the list item. |
ttl | CollectionTTL object | TTL for the list item in cache. This TTL takes precedence over the TTL used when initializing a cache client connection object. |
truncateFrontToSize | Number | See truncate to size. |
Method response object
- Success
listLength()
: number - the new length of the listtoString()
: string - add the listLength
- Error
See response objects for specific information.
ListConcatenateFront
Appends the supplied list to the front of an existing list item.
Example:
If you have [1, 2, 3] and listConcatenateFront [4, 5, 6] you will have [4, 5, 6, 1, 2, 3].
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list item to be set. |
values | String[] | bytes[] | Values to be added as elements to the list item. |
ttl | CollectionTTL object | TTL for the list item in cache. This TTL takes precedence over the TTL used when initializing a cache client. |
truncateBackToSize | Number | See truncate to size. |
Method response object
- Success
listLength()
: number - the new length of the list itemtoString()
: string - add the listLength
- Error
See response objects for specific information.
ListLength
Get the length of an existing list item
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list item to be checked. |
Method response object
- Hit
length()
: numbertoString()
: include the length
- Miss
- Error
See response objects for specific information.
ListPopBack
Remove and return the last element from a list item.
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list item to be retreived. |
Method response object
- Hit
valueString()
: stringvalueBytes()
: bytestoString()
: truncated valueString()
- Miss
- Error
See response objects for specific information.
ListPopFront
Remove and return the first element from a list item.
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list item to be retreived. |
Method response object
- Hit
valueString()
: stringvalueBytes()
: bytestoString()
: truncated valueString()
- Miss
- Error
See response objects for specific information.
ListPushBack
Push a value to the end of a list item. This is exactly like passing just one value to ListConcatenateBack.
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list to be set. |
value | String | bytes | Value to be added. |
ttl | CollectionTTL object | TTL for the list item in cache. This TTL takes precedence over the TTL used when initializing a cache connection client. |
truncateBackToSize | Number | See truncate to size. |
Method response object
- Success
listLength()
: number - the new length of the list itemtoString()
: string - add the listLength
- Error
See response objects for specific information.
ListPushFront
Push a value to the beginning of a list item. Just like ListPushBack, but to the front.
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list to be set. |
value | String | bytes | Value to be added to the list item by the operation. |
ttl | CollectionTTL object | TTL for the list item in cache. This TTL takes precedence over the TTL used when initializing a cache connection client. |
truncateBackToSize | Number | See truncate to size. |
Method response object
- Success
listLength()
: number - the new length of the listtoString()
: string - add the listLength
- Error
See response objects for specific information.
ListRemoveValue
Remove all elements in a list item equal to a particular value.
Examples
- If you have the list
['up', 'up', 'down', 'down', 'left', 'right']
and remove ‘up’ the list will be['down', 'down', 'left', 'right']
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list item to be set. |
value | String | bytes | Value to be added to the list item by the operation. |
Method response object
Responses
- Success - even if the value does not exist
- Error
See response objects for specific information.
ListRetain
Retains only slice of the list where the start is inclusive and the end is exclusive. The items outside of this range will be dropped from the list.
Example: For the specified list, start at index 4 (the startIndex) and keep the next five elements, end at index 10 (the endIndex). Discard all other elements in the list. In this example, elements at position 0-3 and 9 or higher are dropped.
Name | Type | Description |
---|---|---|
cacheName | String | Name of the cache. |
listName | String | Name of the list item to be set. |
startIndex | Number | The starting inclusive element of the list to retain. Default is 0. |
endIndex | Number | The ending exclusive element of the list to retain. Default is end of list. |
ttl | CollectionTTL object | TTL for the list item in cache. This TTL takes precedence over the TTL used when initializing a cache connection client. |
Method response object
Responses
- Success - even if the value does not exist
- Error
See response objects for specific information.
Truncate to size
ListConcatenate and ListPush type API calls all have truncation options. If after adding their elements the list exceeds this size, this list will be truncated.
Example: If the list is
[1, 2, 3]
and you ListConcatenateBack[4, 5, 6]
withtruncateFrontToSize: 5
the list will be truncated to[2, 3, 4, 5, 6]
and the response ListLength will be 5.Example: If the list is
[1, 2, 3]
and you ListConcatenateBack[4, 5, 6]
withtruncateFrontToSize: 10
the list will not be truncated. It will be[1, 2, 3, 4, 5, 6]