Vellum

Requirements

• Swift 5.0 or higher
• iOS 9.3 or higher

Installation

Cocoapods

Vellum is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'Vellum'

Swift Package Manager

First, create a Package.swift file and add this github url. It should look like:

dependencies: [
    .package(url: "https://github.com/nayanda1/Vellum.git", from: "1.2.0")
]

Then run swift build to build the dependency before you use it

Author

Nayanda Haberty, [email protected]

License

Vellum is available under the MIT license. See the LICENSE file for more info.

Storage Algorithm

Vellum is using LRU Algorithm. It contains 2 type of storage which is Memory Storage and Disk Storage. Both size can be assigned manually.

Store Data

1. Store data to Memory Storage
2. If Memory Storage is is full, it will remove the most oldest accessed data from memory until the space is enough for new data
3. Data stored to the memory
4. Store data to Disk Storage
5. If Disk Storage is is full, it will remove the most oldest accessed data from memory until the space is enough for new data
6. Data stored to the disk

Getting Data

1. Find data from the Memory Storage
2. If the data is exist, it will return the data and the step ended
3. If the data is not exist in the memory, it will try to find data from Disk Storage
4. If the data is exist, it will store the data to the Memory Storage for future faster use and return the data and the step ended
5. If the data is not exist, it will return nil

Usage Example

Basic Usage

All you need to do is just get the ArchiveManager from factory and store your object which implement Archivable and Codable or using typealias ArchiveCodable which is the same:

let archives = try! ArchivesFactory.shared.archives(
    for: MyArchivable.self,
    trySetMaxMemorySize: 10.megaByte, 
    trySetMaxDiskSize: 20.megaByte
)

// will insert object
archives.record(myObject)

let object = archives.access(archiveWithKey: "object_key")

Archivable

Archivable actually is just a protocol which have methods to convert object to data or vice versa. Archivable make sure the object have keys too:

class User: Archivable {
    
    var primaryKey: String { userName }
    var userName: String = ""
    var fullName: String = ""
    var age: Int = 0
    
    func archive() throws -> Data {
        // do something to convert the object to Data
    }
    
    static func deArchive(fromData data: Data) throws -> Archivable {
        // do something to convert the data to object
    }
}

ArchiveCodable

If your object are Codable, just add Archivable or or using typealias ArchiveCodable which is the same, your object will have those methods automatically. You just need to add primaryKey property you want as primary key as long as the value is String:

struct User: Codable, Archivable {
    var primaryKey: String { userName }
    var userName: String
    var fullName: String
    var age: Int
}

ArchiveManager

To get ArchiveManager, you can use ArchivesFactory. You can assign the maximum size in byte for memory size and disk size. But keep in mind, the size will only applicable on the first creation of the ArchiveManager, If the cache manager already created, then the memory size and disk size is ignored. If you don't assign the memory size or disk size, it will use the default value which are 1 mega byte for memory and 2 mega byte disk size:

let archives = try! ArchivesFactory.shared.archives(
    for: User.self, 
    trySetMaxMemorySize: 10.kiloByte, 
    trySetMaxDiskSize: 20.kiloByte
)

// or not explicit
let sameArchives: ArchiveManager<User> = try! ArchivesFactory.shared.archives( 
    trySetMaxMemorySize: 10.kiloByte, 
    trySetMaxDiskSize: 20.kiloByte
)

the ArchiveManager have some usable methods and property which are:

• var maxSize: Int { get } to get maximum size of the cache
• var currentSize: Int { get } to get current used size of the cache
• func latestAccessedTime(for key: String) -> Date? to get the latest time the object with same key accessed
• func deleteAllInvalidateArchives(invalidateTimeInterval: TimeInterval) to remove all object older than time interval
• func record(_ object: Archive) to insert object
• func update(_ object: Archive) to update existing object, or insert if have none
• func access(archiveWithKey key: String) -> Archive? to get object with given key
• func accessAll(limitedBy limit: Int) -> [Archive] to get all object limited by limit
• func accessAll() -> [Archive] to get all object stored in cache
• func delete(archiveWithKey key: String) to delete object with given key
• func deleteAll() to remove all object from cache
• func process(queries: [Query<Archive>]) -> [Archive] to process query. This will be disucessed later

Query

You can do a query from cache. there are 3 types of query which are:

• QueryFinder to find the object/results by its properties
• QuerySorter to sort the results by its properties
• QueryLimiter to limit the results by limit

All Query can be combined and will executed sequentially:

let results = userCache.findWhere { archive in
    archive.userName(.contains("premium"))
        .fullName(.isNotEqual(nil))
}
.getResults()

The code above will find all user in cache which its userName contains "premium" and its fullName is not nill. The results is array of User

let results = userCache.sorted { by in 
    by.age(.ascending)
        .fullName(.descending)
}
.getResults()

The code above will get all user in cache and sorted it by its age ascendingly and then its fullName descendingly. The results is sorted array of User

You can add the limit too

let results = userCache.sorted { by in 
    by.age(.ascending)
        .fullName(.descending)
}
.limitResults(by: 10)
.getResults()

The code above will limit the results maximum just 10

You can even combine the query if you want:

let results = userCache.findWhere { archive in
    archive.userName(.contains("premium"))
        .fullName(.isNotEqual(nil))
}
.sorted { by in 
    by.age(.ascending)
        .fullName(.descending)
}
.limitResults(by: 10)
.getResults()

The code above will find all user in cache which its userName contains "premium" and its fullName is not nill, then sort it by its age ascendingly and then its fullName descendingly. The results are limited by 10.

here are the list of finder that can be used with QueryFinder:

• contains(string: ) match if string property contains given string
• matches(regex: ) match if string property matches with given regex
• contains(with: ) match if collection property is contains given element
• contains(atLeastOne: ) match if collection property contains at least one of given element
• contains(all: ) match if collection property contains all given element
• countEqual(with: ) match if collection property count equal with given number
• countGreater(than: ) match if collection property count greater than given number
• countLess(than: ) match if collection property count less than given number
• countGreaterOrEqual(with: ) match if collection property count greater than or equal with given number
• countLessOrEqual(with: ) match if collection property count greater than or equal with given number
• isEqual(with: ) match if property equal with given value
• isNotEqual(with: ) match if property not equal with given value
• greater(than: ) match if property greater than given value
• less(than: ) match if property less than given value
• greaterOrEqual(with: ) match if property greater than or equal with given value
• lessOrEqual(with: ) match if property less than or equal with given value

if you want to validate manually, you can just use isValid(_ validator: (Property) -> Bool):

let results = userCache.findWhere { archive in
    archive.userName(.isValid { $0.contains("premium") })
}
.getResults()

Property Wrapper

You could use Archived property wrapper to wrapped any property so if it assigned it will automatically store those property into ArchiveManager:

@Archived var user: User?

if you want the property have initial value based on the given primary key, just pass the key:

@Archived(initialPrimaryKey: "some") var user: User?

Code above will try to get user with given key at first property load.