Memory usage during encryption

Examples of observed memory usage for common operations of a wrapped app.

Observed examples of memory usage

Note: Use these examples as guidelines only.

Table 1. Read operation (decryption) memory usage observations
APIs used	App memory usage without wrapper	Total memory usage with wrapper
NSData `- initWithContentsOfFile:` NSData`+ dataWithContentsOfFile:` NSData`+ dataWithContentsOfURL:`	100 MB	approximately 100 MB
NSData `- initWithContentsOfFile:` NSData`+ dataWithContentsOfFile:` NSData`+ dataWithContentsOfURL:`	10 MB	approximately 10 MB
NSData `- initWithContentsOfFile:options:error:` NSFileHAndle`- readDataOfLength:` NSInputStream`- read:maxLength:`	100 MB	200 MB
NSData `- initWithContentsOfFile:options:error:` NSFileHAndle`- readDataOfLength:` NSInputStream`- read:maxLength:`	10 MB	20 MB

MaaS360AppWrapUtility `CGPDFDocumentCreateWithURL:theURL`	16 KB chunk size	Double the chunk size or 32 KB

AVPlayer `- initWithPlayerItem:`	256 KB chunk size	Double the chunk size or 512 KB

Note: Chunk sizes, including how much they accumulate in memory and their release rate, depend on the native API.

Table 2. Write operation (encryption) memory usage observations
APIs used	App memory usage without wrapper	Total memory usage with wrapper
Any	100 MB	200 MB
Any	10 MB	20 MB

Note: The memory that is used by the MaaS360® app wrapper is transient and released after the read or write operation completes and is returned back to the caller.