Mercurial > lbo > hg > localmr
view src/record_types.rs @ 68:edbfc8c3ff56
Add shortcut function to quickly create Records
author | Lewin Bormann <lbo@spheniscida.de> |
---|---|
date | Sat, 06 Feb 2016 17:07:59 +0000 |
parents | 33f3fcc22c02 |
children | 98b6d1e37f6a |
line wrap: on
line source
use std::cmp::{Eq, PartialEq, Ordering, PartialOrd}; use std::collections::LinkedList; /// A (key,value) pair. #[derive(Clone, PartialEq, Eq)] pub struct Record { pub key: String, pub value: String, } /// Shortcut for creating a record. pub fn mk_rcrd(k: &str, v: &str) -> Record { Record { key: String::from(k), value: String::from(v) } } impl PartialOrd for Record { fn partial_cmp(&self, other: &Record) -> Option<Ordering> { Some(match self.key.cmp(&other.key) { Ordering::Equal => self.value.cmp(&other.value), o => o, }) } } impl Ord for Record { fn cmp(&self, other: &Record) -> Ordering { match self.key.cmp(&other.key) { Ordering::Equal => self.value.cmp(&other.value), o => o, } } } /// A (key,[value]) pair; typicall used as input to a reducer function. /// Can be easily iterated over, e.g. in a `for` loop. pub struct MultiRecord { key: String, values: Vec<String>, } impl MultiRecord { pub fn new(key: String, values: Vec<String>) -> MultiRecord { MultiRecord { key: key, values: values, } } /// Retrieves the key of the record. pub fn key<'a>(&'a self) -> &'a String { &self.key } } impl PartialEq for MultiRecord { fn eq(&self, other: &MultiRecord) -> bool { self.key == other.key } } impl PartialOrd for MultiRecord { fn partial_cmp(&self, other: &MultiRecord) -> Option<Ordering> { Some(self.key.cmp(&other.key)) } } use std::vec; impl IntoIterator for MultiRecord { type Item = String; type IntoIter = vec::IntoIter<String>; /// Allows iterating over all the values. fn into_iter(self) -> Self::IntoIter { self.values.into_iter() } } /// Emitter type used in the mapper phase; used to emit (key,value) pairs. pub struct MEmitter { r: LinkedList<Record>, } impl MEmitter { pub fn new() -> MEmitter { MEmitter { r: LinkedList::new() } } pub fn emit(&mut self, key: String, val: String) { self.r.push_back(Record { key: key, value: val, }) } pub fn _get(self) -> LinkedList<Record> { self.r } } /// Emitter used in the reducer phase; used to emit values. pub struct REmitter { r: LinkedList<String>, } impl REmitter { pub fn new() -> REmitter { REmitter { r: LinkedList::new() } } pub fn emit(&mut self, val: String) { self.r.push_back(val) } pub fn _get(self) -> LinkedList<String> { self.r } }