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// MIT License // Copyright (c) 2016 Jerome Froelich // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // The above copyright notice and this permission notice shall be included in all // copies or substantial portions of the Software. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE // SOFTWARE. //! A crate for time series compression based upon Facebook's white paper //! [Gorilla: A Fast, Scalable, In-Memory Time Series Database](http://www.vldb.org/pvldb/vol8/p1816-teller.pdf). //! `tsz` provides functionality for compressing a stream of `DataPoint`s, which are composed of a //! time and value, into bytes, and decompressing a stream of bytes into `DataPoint`s. //! //! ## Example //! //! Below is a simple example of how to interact with `tsz` to encode and decode `DataPoint`s. //! //! ```rust,no_run //! extern crate tsz; //! //! use std::vec::Vec; //! use tsz::{DataPoint, Encode, Decode, StdEncoder, StdDecoder}; //! use tsz::stream::{BufferedReader, BufferedWriter}; //! use tsz::decode::Error; //! //! const DATA: &'static str = "1482892270,1.76 //! 1482892280,7.78 //! 1482892288,7.95 //! 1482892292,5.53 //! 1482892310,4.41 //! 1482892323,5.30 //! 1482892334,5.30 //! 1482892341,2.92 //! 1482892350,0.73 //! 1482892360,-1.33 //! 1482892370,-1.78 //! 1482892390,-12.45 //! 1482892401,-34.76 //! 1482892490,78.9 //! 1482892500,335.67 //! 1482892800,12908.12 //! "; //! //! fn main() { //! let w = BufferedWriter::new(); //! //! // 1482892260 is the Unix timestamp of the start of the stream //! let mut encoder = StdEncoder::new(1482892260, w); //! //! let mut actual_datapoints = Vec::new(); //! //! for line in DATA.lines() { //! let substrings: Vec<&str> = line.split(",").collect(); //! let t = substrings[0].parse::<u64>().unwrap(); //! let v = substrings[1].parse::<f64>().unwrap(); //! let dp = DataPoint::new(t, v); //! actual_datapoints.push(dp); //! } //! //! for dp in &actual_datapoints { //! encoder.encode(*dp); //! } //! //! let bytes = encoder.close(); //! let r = BufferedReader::new(bytes); //! let mut decoder = StdDecoder::new(r); //! //! let mut expected_datapoints = Vec::new(); //! //! let mut done = false; //! loop { //! if done { //! break; //! } //! //! match decoder.next() { //! Ok(dp) => expected_datapoints.push(dp), //! Err(err) => { //! if err == Error::EndOfStream { //! done = true; //! } else { //! panic!("Received an error from decoder: {:?}", err); //! } //! } //! }; //! } //! //! println!("actual datapoints: {:?}", actual_datapoints); //! println!("expected datapoints: {:?}", expected_datapoints); //! } //! ``` /// Bit /// /// An enum used to represent a single bit, can be either `Zero` or `One`. #[derive(Debug, PartialEq)] pub enum Bit { Zero, One, } impl Bit { /// Convert a bit to u64, so `Zero` becomes 0 and `One` becomes 1. pub fn to_u64(self) -> u64 { match self { Bit::Zero => 0, Bit::One => 1, } } } /// DataPoint /// /// Struct used to represent a single datapoint. Consists of a time and value. #[derive(Debug, PartialEq, Copy)] pub struct DataPoint { time: u64, value: f64, } impl Clone for DataPoint { fn clone(&self) -> DataPoint { *self } } impl DataPoint { // Create a new DataPoint from a time and value. pub fn new(time: u64, value: f64) -> Self { DataPoint { time: time, value: value, } } } pub mod stream; pub mod encode; pub use self::encode::Encode; pub use self::encode::std_encoder::StdEncoder; pub mod decode; pub use self::decode::Decode; pub use self::decode::std_decoder::StdDecoder; #[cfg(test)] mod tests { use std::vec::Vec; use super::{DataPoint, Encode, Decode, StdEncoder, StdDecoder}; use super::stream::{BufferedReader, BufferedWriter}; use super::decode::Error; const DATA: &'static str = "1482892270,1.76 1482892280,7.78 1482892288,7.95 1482892292,5.53 1482892310,4.41 1482892323,5.30 1482892334,5.30 1482892341,2.92 1482892350,0.73 1482892360,-1.33 1482892370,-1.78 1482892390,-12.45 1482892401,-34.76 1482892490,78.9 1482892500,335.67 1482892800,12908.12 "; #[test] fn integration_test() { let w = BufferedWriter::new(); let mut encoder = StdEncoder::new(1482892260, w); let mut original_datapoints = Vec::new(); for line in DATA.lines() { let substrings: Vec<&str> = line.split(",").collect(); let t = substrings[0].parse::<u64>().unwrap(); let v = substrings[1].parse::<f64>().unwrap(); let dp = DataPoint::new(t, v); original_datapoints.push(dp); } for dp in &original_datapoints { encoder.encode(*dp); } let bytes = encoder.close(); let r = BufferedReader::new(bytes); let mut decoder = StdDecoder::new(r); let mut new_datapoints = Vec::new(); let mut done = false; loop { if done { break; } match decoder.next() { Ok(dp) => new_datapoints.push(dp), Err(err) => { if err == Error::EndOfStream { done = true; } else { panic!("Received an error from decoder: {:?}", err); } } }; } assert_eq!(original_datapoints, new_datapoints); } }