Hadoop is basically 3 things, a FS (Hadoop Distributed File System), a computation framework (MapReduce) and a management bridge (Yet Another Resource Negotiator). HDFS allows you store huge amounts of data in a distributed (provides faster read/write access) and redundant (provides better availability) manner. And MapReduce allows you to process this huge data in a … Read more
I do not know what Git Extensions does with it specifically, but git rebase has an option to automatically squash or fixup commits with squash! or fixup! prefixes, respectively: –autosquash, –no-autosquash When the commit log message begins with “squash! …” (or “fixup! …”), and there is a commit whose title begins with the same …, … Read more
Source: MSDN IsNullOrWhiteSpace is a convenience method that is similar to the following code, except that it offers superior performance: return String.IsNullOrEmpty(value) || value.Trim().Length == 0; White-space characters are defined by the Unicode standard. The IsNullOrWhiteSpace method interprets any character that returns a value of true when it is passed to the Char.IsWhiteSpace method as … Read more
Unlike a List<> … A HashSet is a List with no duplicate members. Because a HashSet is constrained to contain only unique entries, the internal structure is optimised for searching (compared with a list) – it is considerably faster Adding to a HashSet returns a boolean – false if addition fails due to already existing … Read more
My own favorites are these two: compare image1 image2 -compose src diff.png compare image1 image2 -compose src diff.pdf The only difference between the 2 commands above: the first one shows the visual difference between the two images as a PNG file, the second one as a PDF. The resulting diff file displays all pixels which … Read more
rev4: A very eloquent comment by user Sammaron has noted that, perhaps, this answer previously confused top-down and bottom-up. While originally this answer (rev3) and other answers said that “bottom-up is memoization” (“assume the subproblems”), it may be the inverse (that is, “top-down” may be “assume the subproblems” and “bottom-up” may be “compose the subproblems”). … Read more
This approach will work ONLY when the total duration is less than 24 hours: var now = “04/09/2013 15:00:00”; var then = “04/09/2013 14:20:30″; moment.utc(moment(now,”DD/MM/YYYY HH:mm:ss”).diff(moment(then,”DD/MM/YYYY HH:mm:ss”))).format(“HH:mm:ss”) // outputs: “00:39:30” If you have 24 hours or more, the hours will reset to zero with the above approach, so it is not ideal. If you want … Read more
Relevant article on Programming.Guide: Dynamic programming vs memoization vs tabulation What is difference between memoization and dynamic programming? Memoization is a term describing an optimization technique where you cache previously computed results, and return the cached result when the same computation is needed again. Dynamic programming is a technique for solving problems of recursive nature, … Read more
It uses the C# 4.0 dynamic feature. It achieves the same goal as viewdata and should be avoided in favor of using strongly typed view models (the same way as viewdata should be avoided). So basically it replaces magic strings: ViewData[“Foo”] with magic properties: ViewBag.Foo for which you have no compile time safety. I continue … Read more
I found the best way to do this is with ChronoUnit. long minutes = ChronoUnit.MINUTES.between(fromDate, toDate); long hours = ChronoUnit.HOURS.between(fromDate, toDate); Additional documentation is here: https://docs.oracle.com/javase/tutorial/datetime/iso/period.html