Implementation of the iOS cache cleanup idea

Last Update:2015-09-14 Source: Internet

Author: User

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first, talk about a few knowledge points about file management before you talk about cache Cleanup.the first part of the file management several common methodsCompare the contents of a two file/*-contentsequalatpath:andpath:does not take to account data stored in the resource fork or filesystem extended attrib Utes.*/-(BOOL) contentsequalatpath: (nsstring *) path1 andpath: (nsstring *) path2; Whether the files in the two paths exist/* The following methods is of limited utility. Attempting to predicate behavior based in the current state of the filesystem or a particular file on the filesystem is En Couraging odd behavior in the face of filesystem race Conditions. It's far better to attempt an operation (like loading a file or creating a Directory) and handle the error gracefully than It is-to-try-to-figure out ahead of time whether the operation would succeed.*/-(BOOL) fileexistsatpath: (nsstring *) path; Three removal of file contents in a path /* These methods replace their non-error returning counterparts BELOW. See the Nsfilemanagerdelegate protocol below for methods that is dispatched to the Nsfilemanager instance ' s Delegate.*/-(BOOL) removeitematpath: (nsstring *) path error: (nserror * *) Error Four read data from a file /* These methods is provided here for Compatibility. The corresponding methods on NSData which return nserrors should is regarded as the primary method of creating a file from An nsdata or retrieving the contents of a, file as an Nsdata.*/-(nsdata *) contentsatpath: (nsstring *) path; Five remove the cache file contents from the cache path, The return value is an array, receive the array /* Subpathsatpath:returns An Nsarray of all contents and subpaths recursively from the provided path. This is very expensive to compute for deep filesystem hierarchies, and should probably is Avoided.*/-(nsarray *) subpathsatpath: (nsstring *) path; Six based on the file name stitching path -(nsstring *) stringbyappendingpathcomponent: (nsstring *) str; VII calculates the size of the file in the path according to the path Long long size=[filemanager attributesofitematpath:p ath error:Nil ]. FileSize; the second part of the text description of the cache cleanup idea The first step is to get the cache file path that needs to be cleaned nsstring* filePath =[nssearchpathfordirectoriesindomains(nscachesdirectory , Nsuserdomainmask, YES) lastobject]; The second step is to create the file Manager nsfilemanager *filemanager=[nsfilemanager defaultmanager];The third step is to determine if the file contents in the cache file path exist if ([filemanager fileexistsatpath:p ath])Fourth step through the cache path, get all the files in the path array nsarray *childerfiles = [filemanager subpathsatpath:p ath];The fifth step iterates through the array, stitching the array nsstring *absolutepath=[path stringbyappendingpathcomponent: fileName]; Sixth step calculating File size Long long size=[filemanager attributesofitematpath:p ath error:Nil ]. FileSize; the third part of the cache cleaning ideas Flowchart Implementation of the iOS cache cleanup idea

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Implementation of the iOS cache cleanup idea

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