topic "Global Value Cache"; [i448;a25;kKO9;2 $$1,0#37138531426314131252341829483380:class] [l288;2 $$2,2#27521748481378242620020725143825:desc] [0 $$3,0#96390100711032703541132217272105:end] [H6;0 $$4,0#05600065144404261032431302351956:begin] [i448;a25;kKO9;2 $$5,0#37138531426314131252341829483370:item] [l288;a4;*@5;1 $$6,6#70004532496200323422659154056402:requirement] [l288;i1121;b17;O9;~~~.1408;2 $$7,0#10431211400427159095818037425705:param] [i448;b42;O9;2 $$8,8#61672508125594000341940100500538:tparam] [b42;2 $$9,9#13035079074754324216151401829390:normal] [2 $$0,0#00000000000000000000000000000000:Default] [{_}%EN-US [ {{10000@(113.42.0) [s0; [*@7;4 Global Value Cache]]}}&] [s0; &] [s0; Global Value Cache is a centralized mechanism to cache data. Items in the cache are of Value type. Global Value Cache adjusts its size based on current system memory consumption.&] [s0;* &] [ {{10000F(128)G(128)@1 [s0; [* Function List]]}}&] [s3; &] [s5;:Upp`:`:MakeValue`(Upp`:`:ValueMaker`&`): [_^Upp`:`:Value^ Value]_[* MakeValue]([_^Upp`:`:ValueMaker^ V alueMaker][@(0.0.255) `&]_[*@3 m])&] [s2; Requests a Value. The Value is defined by instance of class derived from ValueMaker, which is class with two virtual methods:&] [s2; &] [s2; virtual String [* Key]() const;&] [s2; virtual int [* Make](Value`& object) const;&] [s2; &] [s2; [* Key] should return unique identifier for Value requested with ValueMaker derived class. Note that the type of ValueMaker derived class becomes a part of the key, so it is not necessary to add any info about the ValueMaker into the key. [* Make] then creates the corresponding Value and returns the approximate memory consumption needed to store that Value. [* MakeValue] first checks whether Value corresponding to given ValueMaker and Key are in the cache, if yes then it returns Value from the cache, otherwise calls ValueMaker`::Make to obtain the Value and stores it to the cache. Note that this function allows full reentrancy (from various threads as well as recursive calls (through Make method) in single thread&] [s3; &] [s4;%- &] [s5;:Upp`:`:IsValueCacheActive`(`):%- [@(0.0.255) bool]_[* IsValueCacheActive]()&] [s2; Returns true if it is still possible to use Value Cache. This special function is intended to solve destruction conflicts at the program exit.&] [s3;%- &] [s4;%- &] [s5;:Upp`:`:AdjustValueCache`(`):%- [@(0.0.255) void]_[* AdjustValueCache]()&] [s2; Adjusts cache limits based on system memory available. Maximum cache size is set to available`_memory / 1024, maximum cached values count is set to available`_memory / 1024 / 200. Note that CtrlCore (U`+`+ GUI) normally calls this function after processing every GUI event.&] [s3;%- &] [s4;%- &] [s5;:Upp`:`:ShrinkValueCache`(`):%- [@(0.0.255) void]_[* ShrinkValueCache]()&] [s2; Maintains the size of cache based on limit computed in the last AdjustValueCache call or setup with SetupValueCache.&] [s3;%- &] [s4;%- &] [s5;:Upp`:`:SetupValueCache`(int`,int`):%- [@(0.0.255) void] [* SetupValueCache]([@(0.0.255) i nt] [*@3 maxsize], [@(0.0.255) int] [*@3 maxcount])&] [s2; Sets cache limits `- [%-*@3 maxsize] in bytes and [%-*@3 maxcount] of cached values. If [%-*@3 maxsize] is zero, calls AdjustValueCache and any further calls to AdjustValueCache adjust it. If [%-*@3 maxsize] is greater than zero, limits are fixed to [%-*@3 maxsize][%- and ][%-*@3 maxcount].&] [s3; &] [s4;%- &] [s5;:Upp`:`:ValueCacheRemove`(P`):%- [@(0.0.255) template]_<[@(0.0.255) class]_[*@4 P]>_[@(0.0.255) i nt]_[* ValueCacheRemove]([*@4 P]_[*@3 what])&] [s2; Removes all Values from the cache that satisfy [%-*@3 what] predicate.&] [s3; &] [s4;%- &] [s5;:Upp`:`:ValueCacheRemoveOne`(P`):%- [@(0.0.255) template]_<[@(0.0.255) class]_[*@4 P]>_ [@(0.0.255) int]_[* ValueCacheRemoveOne]([*@4 P]_[*@3 what])&] [s2; Removes one Value from the cache that satisfy [%-*@3 what] predicate (simply removes the first one that it finds).&] [s3; &] [s4;%- &] [s5;:Upp`:`:ValueCacheAdjustSize`(P`):%- [@(0.0.255) template]_<[@(0.0.255) class]_[*@4 P]> _[@(0.0.255) void]_[* ValueCacheAdjustSize]([*@4 P]_[*@3 getsize])&] [s2; Adjusts size information. [%-*@3 getsize] should return the memory size needed to store Value passed as parameter or it can return negative number to signal that the size has not changed. This is very specific function basically only needed to support PaintOnly Images.&] [s0; ]]