ios - Performance issues while parsing dates -


i having performance issues in ios app while transforming dates come in 2013-12-19 00:00:00.000000 format medium style date (dec 25, 2014) , double value (epoch). according xcode profiler 2 functions process (bellow) taking approximately 60% of execution time

i know how improve code or if there more efficient way need.

static func getmediumdate(datestring: string) -> (nsstring)? {      // the: yyyy-mm-dd     let shordate = datestring[datestring.startindex..<datestring.startindex.advancedby(10)]      let dateformatter = nsdateformatter()     dateformatter.locale = nslocale(localeidentifier: "en_us")     dateformatter.dateformat = "yyyy-mm-dd"      let stringformatter = nsdateformatter()     stringformatter.locale = nslocale(localeidentifier: "en_us")     stringformatter.dateformat = "yyyy-mm-dd"     stringformatter.datestyle = .mediumstyle      let newdate = dateformatter.datefromstring(shordate)      if (newdate != nil){         return stringformatter.stringfromdate(newdate!)     }else{         return nil     } }  static func getsortdate(datestring:string) -> double{      // the: yyyy-mm-dd     let shordate = datestring[datestring.startindex..<datestring.startindex.advancedby(10)]      let dateformatter = nsdateformatter()     dateformatter.locale = nslocale(localeidentifier: "en_us")     dateformatter.dateformat = "yyyy-mm-dd"      let newdate = dateformatter.datefromstring(shordate)      let value = newdate?.timeintervalsince1970      if value < dbl_min{         return 0     }else if value > dbl_max{         return dbl_max     }else if value != nil{         return value!     }else{         return 0     } }

nsdateformatter notoriously slow. should create once, cache , reuse same instance rather creating new instance every time.

for example, can following:

extension nsdateformatter {     private static let standarddateformatter: nsdateformatter = {         let dateformatter = nsdateformatter()         dateformatter.locale = nslocale(localeidentifier: "en_us")         dateformatter.dateformat = "yyyy-mm-dd"         return dateformatter     }() }

Comments

Post a Comment

Popular posts from this blog

jOOQ update returning clause with Oracle -

according http://www.jooq.org/doc/3.8/manual/sql-building/sql-statements/update-statement/ jooq doesn't support returning clause in update statements databases except firebird , postgres. does know, still correct oracle jooq? according oracle's documentation, oracle db supports returning clase delete, insert, or update statements. incorrect manual you're right - manual wrong , should fixed: https://github.com/jooq/jooq/issues/5470 single row update returning jooq 3.8 added support single row update .. returning statements. internally, uses callablestatement , pl/sql block of form: begin update "my_table" set "my_table"."column" = 'xyz' "my_table"."id" = 1 returning "my_table"."id", "my_table"."column" ?, ?; ? := sql%rowcount; end; the relevant issue is: https://github.com/jooq/jooq/issues/5190 multi row update returning a...
Read more

java - Warning equals/hashCode on @Data annotation lombok with inheritance -

i have entity inherits other. on other hand, i'm using lombok project reduce boilerplate code, put @data annotation. annotation @data inheritance produces next warning: generating equals/hashcode implementation without call superclass, though class not extend java.lang.object. if intentional, add '@equalsandhashcode(callsuper=false)' type. is advisable add annotation @equalsandhashcode (callsuper = true) or @equalsandhashcode (callsuper = false) ? if not added, 1 callsuper=false or callsuper=true ? the default value false . 1 if don't specify , ignore warning. yes, recommended add @equalsandhashcode annotation on @data annotated classes extend else object. cannot tell if need true or false , depends on class hierarchy, , need examined on case-by-case basis. however, project or package, can configure in lombok.config call super methods if not direct subclass of object. lombok.equalsandhashcode.callsuper = call for configuration system ...
Read more

java - BasicPathUsageException: Cannot join to attribute of basic type -

i using java 8 jpa (hibernate 5.2.1). have clause works perfectly, until introduce clause make use foreign key table values too. i getting following error: basicpathusageexception: cannot join attribute of basic type i think problem related fact have join table, , not sure how create join using join table. employee - employee_category - category model (employee.java): @manytomany(cascade = cascadetype.all, fetch=fetchtype.eager) @jointable ( name="employee_category", joincolumns={ @joincolumn(name="emp_id", referencedcolumnname="id") }, inversejoincolumns={ @joincolumn(name="cat_id", referencedcolumnname="id") } ) private set<category> categories; model (category.java): @id private string id; jpa when introduce following code, fails error above (i think problem new piece of code): join<t, category> category = from.join("id"); predicates.add(criteriabuilder.like(category....
Read more