minimal implementation of shada

currently only writes the header when closing

Cargo.lock

@@ -122,6 +122,12 @@ version = "3.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0d261e256854913907f67ed06efbc3338dfe6179796deefc1ff763fc1aee5535"
 
+[[package]]
+name = "byteorder"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
+
 [[package]]
 name = "bytes"
 version = "1.4.0"
@@ -1445,6 +1451,7 @@ dependencies = [
  "open",
  "pulldown-cmark",
  "same-file",
+ "rmp-serde",
  "serde",
  "serde_json",
  "signal-hook",
@@ -1876,6 +1883,12 @@ dependencies = [
  "windows-sys 0.45.0",
 ]
 
+[[package]]
+name = "paste"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"
+
 [[package]]
 name = "pathdiff"
 version = "0.2.1"
@@ -2050,6 +2063,28 @@ version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c08c74e62047bb2de4ff487b251e4a92e24f48745648451635cec7d591162d9f"
 
+[[package]]
+name = "rmp"
+version = "0.8.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f9860a6cc38ed1da53456442089b4dfa35e7cedaa326df63017af88385e6b20"
+dependencies = [
+ "byteorder",
+ "num-traits",
+ "paste",
+]
+
+[[package]]
+name = "rmp-serde"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bffea85eea980d8a74453e5d02a8d93028f3c34725de143085a844ebe953258a"
+dependencies = [
+ "byteorder",
+ "rmp",
+ "serde",
+]
+
 [[package]]
 name = "ropey"
 version = "1.6.1"

helix-loader/src/lib.rs

@@ -15,6 +15,8 @@ static CONFIG_FILE: once_cell::sync::OnceCell<PathBuf> = once_cell::sync::OnceCe
 
 static LOG_FILE: once_cell::sync::OnceCell<PathBuf> = once_cell::sync::OnceCell::new();
 
+static SHADA_FILE: once_cell::sync::OnceCell<PathBuf> = once_cell::sync::OnceCell::new();
+
 pub fn initialize_config_file(specified_file: Option<PathBuf>) {
     let config_file = specified_file.unwrap_or_else(default_config_file);
     ensure_parent_dir(&config_file);
@@ -27,6 +29,12 @@ pub fn initialize_log_file(specified_file: Option<PathBuf>) {
     LOG_FILE.set(log_file).ok();
 }
 
+pub fn initialize_shada_file(specified_file: Option<PathBuf>) {
+    let shada_file = specified_file.unwrap_or_else(default_shada_file);
+    ensure_parent_dir(&shada_file);
+    SHADA_FILE.set(shada_file).ok();
+}
+
 /// A list of runtime directories from highest to lowest priority
 ///
 /// The priority is:
@@ -132,6 +140,14 @@ pub fn cache_dir() -> PathBuf {
     path
 }
 
+pub fn state_dir() -> PathBuf {
+    // TODO: allow env var override
+    let strategy = choose_base_strategy().expect("Unable to find the state directory!");
+    let mut path = strategy.state_dir().unwrap();
+    path.push("helix");
+    path
+}
+
 pub fn config_file() -> PathBuf {
     CONFIG_FILE.get().map(|path| path.to_path_buf()).unwrap()
 }
@@ -140,6 +156,10 @@ pub fn log_file() -> PathBuf {
     LOG_FILE.get().map(|path| path.to_path_buf()).unwrap()
 }
 
+pub fn shada_file() -> PathBuf {
+    SHADA_FILE.get().map(|path| path.to_path_buf()).unwrap()
+}
+
 pub fn workspace_config_file() -> PathBuf {
     find_workspace().0.join(".helix").join("config.toml")
 }
@@ -152,6 +172,10 @@ pub fn default_log_file() -> PathBuf {
     cache_dir().join("helix.log")
 }
 
+pub fn default_shada_file() -> PathBuf {
+    state_dir().join("helix.shada")
+}
+
 /// Merge two TOML documents, merging values from `right` onto `left`
 ///
 /// When an array exists in both `left` and `right`, `right`'s array is

helix-term/Cargo.toml

@@ -68,6 +68,9 @@ toml = "0.8"
 serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 
+# shada
+rmp-serde = "1.1.2"
+
 # ripgrep for global search
 grep-regex = "0.1.12"
 grep-searcher = "0.1.13"

helix-term/src/application.rs

@@ -27,6 +27,7 @@ use crate::{
     handlers,
     job::Jobs,
     keymap::Keymaps,
+    shada,
     ui::{self, overlay::overlaid},
 };
 
@@ -1254,6 +1255,8 @@ impl Application {
             ));
         }
 
+        shada::write_shada_file();
+
         errs
     }
 }

helix-term/src/args.rs

@@ -16,6 +16,7 @@ pub struct Args {
     pub verbosity: u64,
     pub log_file: Option<PathBuf>,
     pub config_file: Option<PathBuf>,
+    pub shada_file: Option<PathBuf>,
     pub files: Vec<(PathBuf, Position)>,
     pub working_directory: Option<PathBuf>,
 }
@@ -61,6 +62,10 @@ impl Args {
                     Some(path) => args.log_file = Some(path.into()),
                     None => anyhow::bail!("--log must specify a path to write"),
                 },
+                "--shada" => match argv.next().as_deref() {
+                    Some(path) => args.shada_file = Some(path.into()),
+                    None => anyhow::bail!("--shada must specify a path to write"),
+                },
                 "-w" | "--working-dir" => match argv.next().as_deref() {
                     Some(path) => {
                         args.working_directory = if Path::new(path).is_dir() {

helix-term/src/lib.rs

@@ -10,6 +10,7 @@ pub mod events;
 pub mod health;
 pub mod job;
 pub mod keymap;
+pub mod shada;
 pub mod ui;
 
 use std::path::Path;

helix-term/src/main.rs

@@ -63,6 +63,7 @@ FLAGS:
     -v                             Increases logging verbosity each use for up to 3 times
     --log <file>                   Specifies a file to use for logging
                                    (default file: {})
+    --shada <file>                 Specifies a file to use for shared data
     -V, --version                  Prints version information
     --vsplit                       Splits all given files vertically into different windows
     --hsplit                       Splits all given files horizontally into different windows
@@ -80,6 +81,7 @@ FLAGS:
 
     helix_loader::initialize_config_file(args.config_file.clone());
     helix_loader::initialize_log_file(args.log_file.clone());
+    helix_loader::initialize_shada_file(args.shada_file.clone());
 
     // Help has a higher priority and should be handled separately.
     if args.display_help {

helix-term/src/shada.rs

@@ -0,0 +1,75 @@
+use helix_loader::{shada_file, VERSION_AND_GIT_HASH};
+use helix_view::view::ViewPosition;
+use rmp_serde::Serializer;
+use serde::{Deserialize, Serialize};
+use std::{
+    fs::File,
+    time::{SystemTime, UNIX_EPOCH},
+};
+
+// TODO: should this be non-exhaustive?
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename = "H")]
+struct Header {
+    generator: String,
+    version: String,
+    encoding: String,
+    max_kbyte: u32,
+    pid: u32,
+}
+
+// TODO: should this be non-exhaustive?
+#[derive(Debug, Deserialize, Serialize)]
+struct FilePosition {
+    path: String,
+    position: ViewPosition,
+}
+
+// TODO: should this be non-exhaustive?
+#[derive(Debug, Deserialize, Serialize)]
+enum EntryData {
+    Header(Header),
+    FilePosition(FilePosition),
+}
+
+// TODO: should this be non-exhaustive?
+#[derive(Debug, Deserialize, Serialize)]
+struct Entry {
+    timestamp: u64,
+    data: EntryData,
+}
+
+fn timestamp_now() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}
+
+fn generate_header() -> Entry {
+    Entry {
+        timestamp: timestamp_now(),
+        data: EntryData::Header(Header {
+            generator: "helix".to_string(),
+            version: VERSION_AND_GIT_HASH.to_string(),
+            // TODO: is this necessary? helix doesn't seem to expose an option
+            // for internal encoding like nvim does
+            encoding: "utf-8".to_string(),
+            max_kbyte: 100,
+            pid: std::process::id(),
+        }),
+    }
+}
+
+pub fn write_shada_file() {
+    // TODO: merge existing file if exists
+
+    // TODO: do something about this unwrap
+    let shada_file = File::create(shada_file()).unwrap();
+    let mut serializer = Serializer::new(shada_file);
+
+    let header = generate_header();
+
+    // TODO: do something about this unwrap
+    header.serialize(&mut serializer).unwrap();
+}

helix-view/src/view.rs

@@ -18,6 +18,8 @@ use helix_core::{
     VisualOffsetError::{PosAfterMaxRow, PosBeforeAnchorRow},
 };
 
+use serde::{Deserialize, Serialize};
+
 use std::{
     collections::{HashMap, VecDeque},
     fmt,
@@ -118,7 +120,7 @@ impl JumpList {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Copy, Default)]
+#[derive(Clone, Debug, PartialEq, Eq, Copy, Default, Serialize, Deserialize)]
 pub struct ViewPosition {
     pub anchor: usize,
     pub horizontal_offset: usize,