| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
| #include<string> | |
| #include<vector> | |
| class UnionFind { | |
| public: | |
| UnionFind(vector<vector<char>>& grid) { | |
| m = grid.size(); | |
| n = grid[0].size(); | |
| count = 0; | |
| { |
| # version 2.5.0 | |
| $wget https://github.com/google/protobuf/releases/download/v2.5.0/protobuf-2.5.0.tar.bz2 | |
| $tar xvf protobuf-2.5.0.tar.bz2 | |
| $cd protobuf-2.5.0 | |
| $./configure CC=clang CXX=clang++ CXXFLAGS='-std=c++11 -stdlib=libc++ -O3 -g' LDFLAGS='-stdlib=libc++' LIBS="-lc++ -lc++abi" | |
| $make -j 4 | |
| $sudo make install | |
| $protoc --version | |
| # version 2.4.1 |
| import com.twitter.util.Eval | |
| object EvalDemo { | |
| def main(args: Array[String]): Unit = { | |
| val eval = new Eval | |
| eval.compile( | |
| """ | |
| |object Env { | |
| | val a = 5 | |
| |} |
| import com.twitter.util.Eval | |
| object InterpolationDemo { | |
| case class Indicator(basetime: String, key: String, value: Double) | |
| case class ExprImplicit(basetime: String, data: Map[String, Double]) | |
| implicit class IndicatorExpressionHelper(val sc: StringContext) extends AnyVal { | |
| def indicator(args: Any*)(implicit default: ExprImplicit): Indicator = { |
| object RDD { | |
| implicit def rddToPairRDDFunctions[K, V](rdd: RDD[(K, V)]): PairRDDFunctions[K, V] = { | |
| new PairRDDFunctions(rdd) | |
| } | |
| } | |
| class RDD[T] { | |
| def filter(): Unit = { | |
| println("filter") |
| import org.junit.Assert._ | |
| import org.junit._ | |
| // junit 4 | |
| object UsingJUnit { | |
| @BeforeClass | |
| def beforeClass(): Unit = { | |
| println("before class") | |
| } |
| #!/usr/bin/env python2.7 | |
| # encoding: utf-8 | |
| """ | |
| @brief: 一个类型转换为自定义类型 json 的脚本，支持类型的嵌套 | |
| 例如：string 变为 {"metadata":{"chineseName":null,"desc":null},"name":"simple_string","nullable":true,"type":"string"} | |
| @author: icejoywoo | |
| @date: 2018/8/27 | |
| """ |
| import java.util.regex.Pattern; | |
| /** | |
| * 字符通用工具类 | |
| * | |
| * @author <a href="http://www.micmiu.com">Michael Sun</a>; | |
| */ | |
| public class CharUtil { | |
| /** |
"For comprehension" is a another syntaxe to use map, flatMap and withFilter (or filter) methods.
yield keyword is used to aggregate values in the resulting structure.
This composition can be used on any type implementing this methods, like List, Option, Future...