Add aging algorithm

src/config.rs

@@ -1 +1,36 @@
-pub const DB_PATH: &str = "_ZO_DBPATH";
+use crate::error::AppError;
+use crate::types::Rank;
+use failure::{bail, ResultExt};
+use std::env;
+use std::ffi::OsString;
+
+pub const ZO_DATA: &str = "_ZO_DATA";
+pub const ZO_MAXAGE: &str = "_ZO_MAXAGE";
+
+pub fn get_zo_data() -> Result<OsString, failure::Error> {
+    let path = match env::var_os(ZO_DATA) {
+        Some(path) => path,
+        None => {
+            let mut path = dirs::home_dir().ok_or_else(|| AppError::GetHomeDirError)?;
+            path.push(".zo");
+            path.into_os_string()
+        }
+    };
+    Ok(path)
+}
+
+pub fn get_zo_maxage() -> Result<Rank, failure::Error> {
+    if let Some(maxage_osstr) = env::var_os(ZO_MAXAGE) {
+        match maxage_osstr.to_str() {
+            Some(maxage_str) => {
+                let maxage = maxage_str
+                    .parse::<Rank>()
+                    .with_context(|_| AppError::EnvError(ZO_MAXAGE.to_owned()))?;
+                Ok(maxage)
+            }
+            None => bail!(AppError::EnvError(ZO_MAXAGE.to_owned())),
+        }
+    } else {
+        Ok(5000.0)
+    }
+}

src/db.rs

@@ -1,13 +1,14 @@
+use crate::config::get_zo_maxage;
 use crate::dir::Dir;
 use crate::error::AppError;
-use crate::types::Timestamp;
+use crate::types::{Rank, Timestamp};
 use failure::ResultExt;
+use fs2::FileExt;
 use serde::{Deserialize, Serialize};
 use std::fs::File;
 use std::io::{self, BufReader, BufWriter};
 use std::io::{Read, Write};
 use std::path::Path;
-use fs2::FileExt;
 
 #[derive(Debug, Default, Deserialize, Serialize)]
 pub struct DB {
@@ -21,7 +22,8 @@ impl DB {
     pub fn open<P: AsRef<Path>>(path: P) -> Result<DB, failure::Error> {
         match File::open(path) {
             Ok(file) => {
-                file.lock_shared().with_context(|_| AppError::FileLockError)?;
+                file.lock_shared()
+                    .with_context(|_| AppError::FileLockError)?;
                 let rd = BufReader::new(file);
                 let db = DB::read_from(rd).with_context(|_| AppError::DBReadError)?;
                 Ok(db)
@@ -36,7 +38,8 @@ impl DB {
     pub fn save<P: AsRef<Path>>(&mut self, path: P) -> Result<(), failure::Error> {
         if self.modified {
             let file = File::create(path).with_context(|_| AppError::FileOpenError)?;
-            file.lock_exclusive().with_context(|_| AppError::FileLockError)?;
+            file.lock_exclusive()
+                .with_context(|_| AppError::FileLockError)?;
             let wr = BufWriter::new(file);
             self.write_into(wr)
                 .with_context(|_| AppError::DBWriteError)?;
@@ -64,15 +67,27 @@ impl DB {
             None => self.dirs.push(Dir {
                 path: path_str.to_owned(),
                 last_accessed: now,
-                rank: 1,
+                rank: 1.0,
             }),
             Some(dir) => {
                 dir.last_accessed = now;
-                dir.rank += 1;
+                dir.rank += 1.0;
             }
         };
 
+        let max_age = get_zo_maxage()?;
+        let sum_age = self.dirs.iter().map(|dir| dir.rank).sum::<Rank>();
+
+        if sum_age > max_age {
+            let factor = max_age / sum_age;
+            for dir in &mut self.dirs {
+                dir.rank *= factor;
+            }
+        }
+
+        self.dirs.retain(|dir| dir.rank >= 1.0);
         self.modified = true;
+
         Ok(())
     }
 
@@ -85,7 +100,7 @@ impl DB {
                 .iter()
                 .enumerate()
                 .filter(|(_, dir)| dir.is_match(keywords))
-                .max_by_key(|(_, dir)| dir.get_frecency(now))?;
+                .max_by_key(|(_, dir)| dir.get_frecency(now) as i64)?;
 
             if dir.is_dir() {
                 return Some(dir.to_owned());

src/dir.rs

@@ -49,13 +49,13 @@ impl Dir {
 
         let duration = now - self.last_accessed;
         if duration < HOUR {
-            self.rank * 4
+            self.rank * 4.0
         } else if duration < DAY {
-            self.rank * 2
+            self.rank * 2.0
         } else if duration < WEEK {
-            self.rank / 2
+            self.rank / 2.0
         } else {
-            self.rank / 4
+            self.rank / 4.0
         }
     }
 }

src/error.rs

@@ -29,4 +29,7 @@ pub enum AppError {
     GetCurrentDirError,
     #[fail(display = "could not access path")]
     PathAccessError,
+
+    #[fail(display = "could not decode ${} in env", 0)]
+    EnvError(String),
 }

src/main.rs

@@ -5,45 +5,50 @@ mod error;
 mod types;
 mod util;
 
+use crate::config::get_zo_data;
 use crate::db::DB;
 use crate::error::AppError;
 use crate::types::Timestamp;
-use crate::util::{fzf_helper, get_current_time, get_db_path, process_query};
+use crate::util::{fzf_helper, get_current_time};
 use clap::{app_from_crate, crate_authors, crate_description, crate_name, crate_version};
 use clap::{App, Arg, SubCommand};
 use failure::ResultExt;
 use std::env;
 use std::path::Path;
 
-fn zoxide_query(
-    db: &mut DB,
-    keywords: &[String],
-    now: Timestamp,
-) -> Result<Option<String>, failure::Error> {
-    if let [path] = keywords {
-        if Path::new(&path).is_dir() {
-            return Ok(Some(path.to_owned()));
+fn zoxide_query(db: &mut DB, mut keywords: Vec<String>, now: Timestamp) -> Option<String> {
+    if let [path] = keywords.as_slice() {
+        if Path::new(path).is_dir() {
+            return Some(path.to_owned());
         }
     }
 
-    if let Some(dir) = db.query(keywords, now) {
-        return Ok(Some(dir.path));
+    for keyword in &mut keywords {
+        keyword.make_ascii_lowercase();
     }
 
-    Ok(None)
+    if let Some(dir) = db.query(&keywords, now) {
+        return Some(dir.path);
+    }
+
+    None
 }
 
 fn zoxide_query_interactive(
     db: &mut DB,
-    keywords: &[String],
+    mut keywords: Vec<String>,
     now: Timestamp,
 ) -> Result<Option<String>, failure::Error> {
     db.remove_invalid();
 
+    for keyword in &mut keywords {
+        keyword.make_ascii_lowercase();
+    }
+
     let dirs = db
         .dirs
         .iter()
-        .filter(|dir| dir.is_match(keywords))
+        .filter(|dir| dir.is_match(&keywords))
         .cloned()
         .collect();
 
@@ -85,17 +90,25 @@ fn zoxide_app() -> App<'static, 'static> {
 fn zoxide() -> Result<(), failure::Error> {
     let matches = zoxide_app().get_matches();
 
-    let db_path = get_db_path()?;
+    let db_path = get_zo_data()?;
     let mut db = DB::open(&db_path)?;
 
     if let Some(matches) = matches.subcommand_matches("query") {
         let now = get_current_time()?;
-        let keywords = process_query(matches.values_of("KEYWORD").unwrap_or_default());
+
+        let keywords = matches
+            .values_of_os("KEYWORD")
+            .unwrap_or_default()
+            .map(|keyword| match keyword.to_str() {
+                Some(keyword) => Ok(keyword.to_owned()),
+                None => Err(AppError::UnicodeError),
+            })
+            .collect::<Result<Vec<String>, _>>()?;
 
         let path_opt = if matches.is_present("interactive") {
-            zoxide_query_interactive(&mut db, &keywords, now)
+            zoxide_query_interactive(&mut db, keywords, now)
         } else {
-            zoxide_query(&mut db, &keywords, now)
+            Ok(zoxide_query(&mut db, keywords, now))
         }?;
 
         if let Some(path) = path_opt {

src/types.rs

@@ -1,3 +1,3 @@
 // TODO: convert these to newtypes
-pub use i32 as Rank;
+pub use f64 as Rank;
 pub use i64 as Timestamp; // use a signed integer so subtraction can be performed on it

src/util.rs

@@ -1,10 +1,7 @@
-use crate::config::DB_PATH;
 use crate::dir::Dir;
 use crate::error::AppError;
 use crate::types::Timestamp;
 use failure::ResultExt;
-use std::env;
-use std::ffi::OsString;
 use std::io::{Read, Write};
 use std::process::{Command, Stdio};
 use std::time::SystemTime;
@@ -18,22 +15,6 @@ pub fn get_current_time() -> Result<Timestamp, failure::Error> {
     Ok(current_time as Timestamp)
 }
 
-pub fn get_db_path() -> Result<OsString, failure::Error> {
-    let path = match env::var_os(DB_PATH) {
-        Some(path) => path,
-        None => {
-            let mut path = dirs::home_dir().ok_or_else(|| AppError::GetHomeDirError)?;
-            path.push(".zo");
-            path.into_os_string()
-        }
-    };
-    Ok(path)
-}
-
-pub fn process_query<'a, I: Iterator<Item = &'a str>>(keywords: I) -> Vec<String> {
-    keywords.map(|keyword| keyword.to_ascii_lowercase()).collect()
-}
-
 pub fn fzf_helper(now: Timestamp, mut dirs: Vec<Dir>) -> Result<Option<String>, failure::Error> {
     let fzf = Command::new("fzf")
         .arg("-n2..")
@@ -48,16 +29,17 @@ pub fn fzf_helper(now: Timestamp, mut dirs: Vec<Dir>) -> Result<Option<String>,
         dir.rank = dir.get_frecency(now);
     }
 
-    dirs.sort_by_key(|dir| std::cmp::Reverse(dir.rank));
+    dirs.sort_by_key(|dir| std::cmp::Reverse(dir.rank as i64));
 
     for dir in dirs.iter() {
         // ensure that frecency fits in 4 characters
-        let mut frecency = dir.rank;
-        if frecency < 0 {
-            frecency = 0;
-        } else if frecency > 9999 {
-            frecency = 9999;
-        }
+        let frecency = if dir.rank > 9999.0 {
+            9999
+        } else if dir.rank > 0.0 {
+            dir.rank as i32
+        } else {
+            0
+        };
 
         writeln!(fzf_stdin, "{:>4}        {}", frecency, dir.path)
             .with_context(|_| AppError::FzfIoError)?;