Class Cache

Cache

A reference to a particular cache.

This class allows you to insert, retrieve, and remove items from a cache. This can be particularly useful when you want frequent access to an expensive or slow resource. For example, say you have an RSS feed at example.com that takes 20 seconds to fetch, but you want to speed up access on an average request. 

function getRssFeed() {
  var cache = CacheService.getScriptCache();
  var cached = cache.get("rss-feed-contents");
  if (cached != null) {
    return cached;
  }
  var result = UrlFetchApp.fetch("http://example.com/my-slow-rss-feed.xml"); // takes 20 seconds
  var contents = result.getContentText();
  cache.put("rss-feed-contents", contents, 1500); // cache for 25 minutes
  return contents;
}
 You'll still need to wait the 20 seconds if the item is not in the cache, but subsequent calls will be very fast until the item expires out of the cache in 25 minutes.

Methods

MethodReturn typeBrief description
get(key)StringGets the cached value for the given key, or null if none is found.
getAll(keys)ObjectReturns a JavaScript Object containing all key/value pairs found in the cache for an array of keys.
put(key, value)voidAdds a key/value pair to the cache.
put(key, value, expirationInSeconds)voidAdds a key/value pair to the cache, with an expiration time (in seconds).
putAll(values)voidAdds a set of key/value pairs to the cache.
putAll(values, expirationInSeconds)voidAdds a set of key/value pairs to the cache, with an expiration time (in seconds).
remove(key)voidRemoves an entry from the cache using the given key.
removeAll(keys)voidRemoves a set of entries from the cache.

Detailed documentation

get(key)

Gets the cached value for the given key, or null if none is found. 

// Gets the value from the cache for the key 'foo'.
var value = cache.get('foo');

Parameters

NameTypeDescription
keyStringthe key to look up in the cache

Return

String — the cached value, or null if none was found

getAll(keys)

Returns a JavaScript Object containing all key/value pairs found in the cache for an array of keys. 

// Gets a set of values from the cache
var values = cache.getAll(['foo', 'x', 'missing']);
// If there were values in the cache for 'foo' and 'x' but not 'missing', then 'values' would
// be: {'foo': 'somevalue', 'x': 'othervalue'}

Parameters

NameTypeDescription
keysString[]the keys to lookup

Return

Object — a JavaScript Object containing the key/value pairs for all keys found in the cache

See also

put(key, value)

Adds a key/value pair to the cache.

The maximum length of a key is 250 characters. The maximum amount of data that can be stored per key is 100KB. The value will expire from the cache after 600 seconds (10 minutes).

The cap for cached items is 1,000. If more than 1,000 items are written, the cache stores the 900 items farthest from expiration. This limit might change. 

// Puts the value 'bar' into the cache using the key 'foo'
cache.put('foo', 'bar');

Parameters

NameTypeDescription
keyStringthe key to store the value under
valueStringthe value to be cached

put(key, value, expirationInSeconds)

Adds a key/value pair to the cache, with an expiration time (in seconds).

The maximum length of a key is 250 characters. The maximum amount of data that can be stored per key is 100KB. The specified expiration time is only a suggestion; cached data may be removed before this time if a lot of data is cached.

The cap for cached items is 1,000. If more than 1,000 items are written, the cache stores the 900 items farthest from expiration. This limit might change. 

// Puts the value 'bar' into the cache using the key 'foo', but only for the next 20 seconds.
cache.put('foo', 'bar', 20);

Parameters

NameTypeDescription
keyStringthe key to store the value under
valueStringthe value to be cached
expirationInSecondsIntegerthe maximum time the value remains in the cache, in seconds. The minimum is 1 second and the maximum is 21600 seconds (6 hours).

putAll(values)

Adds a set of key/value pairs to the cache.

Similar to repeated calls to "put", but more efficient as it only makes one call to the memcache server to set all values. The maximum length of a key is 250 characters. The maximum amount of data that can be stored per key is 100KB. The values will expire from the cache after 600 seconds (10 minutes).

The cap for cached items is 1,000. If more than 1,000 items are written, the cache stores the 900 items farthest from expiration. This limit might change. 

// Puts a set of values into the cache with the keys 'foo', 'x', and 'key'.
var values = {
  'foo': 'bar',
  'x':'y',
  'key': 'value'
};
cache.putAll(values);

Parameters

NameTypeDescription
valuesObjecta JavaScript Object containing string keys and values

See also

putAll(values, expirationInSeconds)

Adds a set of key/value pairs to the cache, with an expiration time (in seconds).

Similar to repeated calls to "put", but more efficient as it only makes one call to the memcache server to set all values. The maximum length of a key is 250 characters. The maximum amount of data that can be stored per key is 100KB. The specified expiration time is only a suggestion; cached data may be removed before this time if a lot of data is cached.

The cap for cached items is 1,000. If more than 1,000 items are written, the cache stores the 900 items farthest from expiration. This limit might change. 

// Puts a set of values into the cache with the keys 'foo', 'x', and 'key'.
var values = {
  'foo': 'bar',
  'x':'y',
  'key': 'value'
};
cache.putAll(values, 20);

Parameters

NameTypeDescription
valuesObjectA JavaScript Object containing string keys and values
expirationInSecondsIntegerThe maximum time the value remains in the cache, in seconds The minimum allowed expiration is 1 second, and the maximum allowed expiration is 21600 seconds (6 hours). The default expiration is 600 seconds (10 minutes).

See also

remove(key)

Removes an entry from the cache using the given key. 

// Removes any cache entries for 'foo'
cache.remove('foo');

Parameters

NameTypeDescription
keyStringthe key to remove from the cache

removeAll(keys)

Removes a set of entries from the cache. 

// Removes entries from the cache with keys 'foo' and 'x'
cache.removeAll(['foo', 'x']);

Parameters

NameTypeDescription
keysString[]the array of keys to remove