Salesforce Platform Cache

Hello devs,

Platform Cache is a Salesforce feature, which allows you to provide faster performance and better reliablity. Frequently used data are stored in memory layer, so it can be easily accessed by your applications without additional SOQL or API request.

What is Cache?

Cache is a temporary storage, that keeps frequently using data. It makes your application really fast, because instead of retrieving data you have them at hand. In short, Cache is used to reduce the average time to access data from database/API requests.

Real life example:
Let\’s assume that you like milk. You keep it in your fridge (cache), which is easily accessible. However, if you run out of milk (data), what you need to do? Buy a cow or go shopping (database/API request).

Platform Cache

The Platform Cache API lets you store and retrieve data that’s tied to Salesforce sessions or shared across your org. Put, retrieve, or remove cache values by using the Session, Org, SessionPartition, and OrgPartition classes in the Cache namespace. ~ Salesforce

What we can cache?

• Static data as object metadata or user profile
• Apex list of sObjects, String, Integers, etc.
• Apex Sets, Maps.
• Records or sObject results of SOQL query
• API callouts data

Types

We can highlight two types of Platform Cache namely, Org and Sassion Cache.

Org Cache

Stores data that any user in an org reuses. For example, the contents of navigation bars that dynamically display menu items based on user profile are reused. Unlike session cache, org cache is accessible across sessions, requests, and org users and profiles. Org cache expires when its specified time-to-live (ttlsecs value) is reached. ~ Salesforce

Session Cache

Stores data for individual user sessions. For example, in an app that finds customers within specified territories, the calculations that run while users browse different locations on a map are reused. Session cache lives alongside a user session. The maximum life of a session is eight hours. Session cache expires when its specified time-to-live (ttlsecs value) is reached or when the session expires after eight hours, whichever comes first. ~ Salesforce

Create Platform Cache Step by Step

1. Go to Setup > Platform Cache (under Custom Code) > Click New Platform Cache Partition
2. Define Partition Label and Name.
3. Default Partition allows you to write following code:

   // Instead of it:
   Cache.Session.put('local.partitionA.userFirstName', 'myDataToStoreString');
   // You can do this:
   Cache.Session.put('userFirstName', 'myDataToStoreString');
   // userFirstName (key) will be saved with 'myDataToStoreString' (value) to partition marked as default.
   // We can have only one default partition.

4. Session Cache Allocation here we can define storage size for Session Cache. If we will leave it as 0 we won’t be able to put values in there.
5. Org Cache Allocation here we can define storage size for Org Cache. If we will leave it as 0 we won’t be able to put values in there.

Code

public with sharing class PlatformCacheService {
    // fullCacheName - NAMESPACE_PREFIX.PARTITION_NAME.YOUR_KEY
    // partitionName - NAMESPACE_PREFIX.PARTITION_NAM
    // cacheKey - YOUR_KEY

    //Org

    public static void putToOrgCache(String fullCacheName, Object value) {
        Cache.Org.put(fullCacheName, value);
    }

    public static Object getOrgCache(String fullCacheName) {
        return Cache.Org.get(fullCacheName);
    }

    public static void putToOrgByPartitionClass(String partitionName, String cacheKey, Object value) {
        Cache.OrgPartition orgPartition = Cache.Org.getPartition(partitionName);
        orgPartition.put(cacheKey, value);
    }

    public static Object getOrgByPartitionClass(String partitionName, String cacheKey) {
        Cache.OrgPartition orgPartition = Cache.Org.getPartition(partitionName);
        return orgPartition.get(cacheKey);
    }

    //Session

    public static void putToSessionCache(String fullCacheName, Object value) {
        Cache.Session.put(fullCacheName, value);
    }

    public static Object getSessionCache(String fullCacheName) {
        return Cache.Session.get(fullCacheName);
    }

    public static void putToSessionByPartitionClass(String partitionName, String cacheKey, Object value) {
        Cache.SessionPartition orgPartition = Cache.Session.getPartition(partitionName);
        orgPartition.put(cacheKey, value);
    }

    public static Object getSessionByPartitionClass(String partitionName, String cacheKey) {
        Cache.SessionPartition orgPartition = Cache.Session.getPartition(partitionName);
        return orgPartition.get(cacheKey);
    }

    // Use Case

    public static String orgCacheExample() {
        String namespace = 'local';
        String partitionName = 'partitionName';
        String key = 'cacheKey';
        String value = 'valueToCache';

        String fullCacheName = namespace + partitionName + key;

        String myCachedValue = (String) Cache.Org.get(fullCacheName);

        if (myCachedValue == null) {
            Cache.Org.put(fullCacheName, value);
            myCachedValue = value;
        }

        return myCachedValue;
    }

    public static String sessionCacheExample() {
        String namespace = 'local';
        String partitionName = 'partitionName';
        String key = 'cacheKey';
        String value = 'valueToCache';

        String fullCacheName = namespace + partitionName + key;

        String myCachedValue = (String) Cache.Session.get(fullCacheName);

        if (myCachedValue == null) {
            Cache.Session.put(fullCacheName, value);
            myCachedValue = value;
        }

        return myCachedValue;
    }
}

You might wonder why I didn\’t use profilePartition.contains(UserInfo.getProfileId())?

Avoid calling the contains(key) method followed by the get(key) method. If you intend to use the key value, simply call the get(key) method and make sure that the value is not equal to null. ~ Salesforce

Cache.CacheBuilder Interface

A Platform Cache best practice is to ensure that your Apex code handles cache misses by testing for cache requests that return null. You can write this code yourself. Or, you can use the Cache.CacheBuilder interface, which makes it easy to safely store and retrieve values to a session or org cache. ~ Salesforce

From:

public static String getCurrentUserProfileName() {

    Cache.OrgPartition profilePartition = Cache.Org.getPartition('local.ProfileData'); // ProfileData is my partition name

    String userProfileName = (String) profilePartition.get(UserInfo.getProfileId());

    if (String.isBlank(userProfileName)) {
        Profile currentUserProfile = [ SELECT Id, Name
                                       FROM Profile
                                       WHERE Id = :UserInfo.getProfileId() ];
        userProfileName = currentUserProfile.Name;
        profilePartition.put(UserInfo.getProfileId(), userProfileName, 86400);
    }

    return userProfileName;
}

// Use
String currenUserProfile = getCurrentUserProfileName();

To:

public class ProfileInfoCache implements Cache.CacheBuilder {
    public Object doLoad(String profileId) {
        return (Profile)[ SELECT Id, Name
                          FROM Profile
                          WHERE Id = :profileId ];
    }
}
// Use
Profile currenUserProfileDetails = (Profile) Cache.Org.get(ProfileInfoCache.class, UserInfo.getProfileId());
String currenUserProfile = currenUserProfileDetails.Name;

Note!

• When you run get Cache.Org.get(ProfileInfoCache.class, UserInfo.getProfileId());, Salesforce is trying to find cached data by unique key and if there is no data, fire doLoad() method, caches retrives data, and then returns it.
• The doLoad(String var) method must take a String parameter, even if you do not use the parameter in the method’s code.
• The class that implements CacheBuilder must be non-static.
• The doLoad(String var) method can return any value, including null. If a null value is returned, it is delivered directly to the CacheBuilder consumer and not cached.

Summary

• Cache isn’t persisted. There’s no guarantee against data loss. We should always check if data in cache exists and if not, retrieve data from database.
• Cache misses can happen.
• Partitions must adhere to the limits within Salesforce.
• Data in the cache isn’t encrypted.
• Some or all cache is invalidated when you modify an Apex class in your org.
• No saving order. Two different transactions have a race, and the winner’s data will be saved.

Use cases

• Reused throughout a session
• Reduce number of SOQL statements
• Static (not rapidly changing)
• Public transit schedule
• Company shuttle bus schedule
• Tab headers that all users see
• A static navigation bar that appears on every page of your app
• A user’s shopping cart that you want to persist during a session
• Daily snapshots of exchange rates (rates fluctuate during a day)
• User Profile Name data
• Expensive to compute or retrieve
• Total sales over the past week
• Total volunteering hours company employees did as a whole
• Top sales ranking

Best Practices

• Ensure that your code handles cache misses by testing cache requests that return null.
• To help improve performance, perform cache operations on a list of keys rather than on individual keys.
• It’s more efficient to cache a few large items than to cache many small items separately.
• Avoid calling the contains(key) method followed by the get(key) method.
• Clear the cache only when necessary.

Limitations

• When the cache partition limit is reached, keys are evicted until the cache is reduced to 100% capacity. Platform Cache uses least recently used (LRU) algorithm to evict keys from the cache.

Repository

Github

Was it helpful? Check out our other great posts here.

References

• Salesforce Developer – Platform Cache
• Salesforce Trainlhead – Platform Cache
• Salesforce Developer Blog
• OrgPartition Class
• Org Class
• Session Class
• SessionPartition Class