[TRINIDAD-2032] perf: save memory by sharing selector objects in filesystemstylecache

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0-beta-2
• Component/s: Skinning
• Assignee: Jeanne Waldman
• Reporter: Jeanne Waldman
• Created: 09/Feb/11 01:47
• Updated: 02/Mar/11 23:46
• Resolved: 02/Mar/11 23:45

Description

We can save memory if we store Selectors in a <Selector, Selector> map at the
FileSystemStyleCache level, and reuse where we can.

The implementation will be similar to what we did in TRINIDAD-2025 where we reused
Style objects. Selector objects are only 16 bytes each, but each
FileSystemStyleCache$StylesImpl instance creates about 4500 of them for our complicated skin.

Before Selector sharing:
FSSC$Entry about 335K each of retained size.
FSSC$StylesImpl about 214K each of retained size

run a page in 3 diff browsers, and we have 13402 Selector objects, total 214K
retained size

After Selector sharing:
FSSC$Entry about 263K each of retained size.
FSSC$StylesImpl about 142K each of retained size
run a page in 3 diff browsers, and we have 4533 Selector objects using 72.5K
Retained Size