1 files changed, 1154 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..3a8e5f9
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,1154 @@
+use std::{
+    collections::{HashMap, VecDeque},
+    fmt::Display,
+    fs::File,
+    io::{BufWriter, Read as _, Write},
+    os::unix::fs::MetadataExt,
+    path::{Path, PathBuf},
+    str::FromStr,
+    sync::{Arc, Mutex},
+    time::SystemTime,
+};
+
+use clap::{Args, Parser, Subcommand};
+use sha2::Digest;
+use slotmap::SlotMap;
+
+const BLOB_STORE_HIERARCHY_DEPTH: usize = 4;
+
+#[derive(Debug)]
+pub struct InvalidBlobId;
+
+impl Display for InvalidBlobId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "invalid blob id")
+    }
+}
+
+impl std::error::Error for InvalidBlobId {}
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct BlobId([u8; 32]);
+
+impl BlobId {
+    pub fn hash(&self, data: &[u8]) -> BlobId {
+        let mut hasher = sha2::Sha256::default();
+        hasher.write_all(data).unwrap();
+        Self(hasher.finalize().try_into().unwrap())
+    }
+
+    pub fn as_bytes(&self) -> &[u8; 32] {
+        &self.0
+    }
+}
+
+impl Display for BlobId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        hex::display(&self.0).fmt(f)
+    }
+}
+
+impl FromStr for BlobId {
+    type Err = InvalidBlobId;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let decoded = hex::decode(s).map_err(|_| InvalidBlobId)?;
+        Ok(Self(decoded.try_into().map_err(|_| InvalidBlobId)?))
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct BlobStore(PathBuf);
+
+impl BlobStore {
+    pub fn new(path: impl Into<PathBuf>) -> Self {
+        Self(path.into())
+    }
+}
+
+pub fn blob_path(store: &BlobStore, blob_id: &BlobId) -> PathBuf {
+    let encoded = hex::encode(blob_id.as_bytes());
+    let mut path = store.0.clone();
+    for depth in 0..BLOB_STORE_HIERARCHY_DEPTH {
+        let base_idx = depth * 2;
+        path.push(&encoded[base_idx..base_idx + 2]);
+    }
+    path.push(encoded);
+    path
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum ImportMode {
+    Move,
+    Copy,
+    HardLink,
+}
+
+pub fn blob_import_file(
+    store: &BlobStore,
+    mode: ImportMode,
+    blob_id: &BlobId,
+    file_path: &Path,
+) -> std::io::Result<()> {
+    let blob_path = blob_path(store, blob_id);
+    if blob_path.exists() {
+        return Ok(());
+    }
+
+    if let Some(parent) = blob_path.parent() {
+        std::fs::create_dir_all(parent)?;
+    }
+    match mode {
+        ImportMode::Move => {
+            std::fs::rename(file_path, blob_path)?;
+        }
+        ImportMode::Copy => {
+            todo!()
+        }
+        ImportMode::HardLink => match std::fs::hard_link(file_path, blob_path) {
+            Ok(()) => {}
+            Err(err) => {
+                if err.kind() != std::io::ErrorKind::AlreadyExists {
+                    panic!("{err}");
+                }
+            }
+        },
+    }
+    Ok(())
+}
+
+pub fn blob_hash_file(file_path: &Path) -> std::io::Result<BlobId> {
+    let mut file = std::fs::File::open(file_path)?;
+    let mut buf = vec![0u8; 1 * 1024 * 1024];
+    let mut hasher = sha2::Sha256::default();
+    loop {
+        let n = file.read(&mut buf)?;
+        if n == 0 {
+            break;
+        }
+        hasher.write_all(&buf[..n])?;
+    }
+    Ok(BlobId(hasher.finalize().try_into().unwrap()))
+}
+
+pub fn blob_size(store: &BlobStore, blob_id: &BlobId) -> std::io::Result<u64> {
+    let blob_path = blob_path(store, blob_id);
+    Ok(blob_path.metadata()?.size())
+}
+
+const OPERATION_KIND_CREATE_FILE: &'static str = "create_file";
+const OPERATION_KIND_CREATE_DIR: &'static str = "create_dir";
+const OPERATION_KIND_REMOVE: &'static str = "remove";
+const OPERATION_KIND_RENAME: &'static str = "rename";
+
+#[derive(Debug)]
+pub struct InvalidOperation;
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Operation {
+    pub header: OperationHeader,
+    pub data: OperationData,
+}
+
+impl FromStr for Operation {
+    type Err = InvalidOperation;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let err = || InvalidOperation;
+        let mut iter = s.split('\t');
+
+        let timestamp_str = iter.next().ok_or_else(err)?;
+        let revision_str = iter.next().ok_or_else(err)?;
+        let email_str = iter.next().ok_or_else(err)?;
+        let kind_str = iter.next().ok_or_else(err)?;
+
+        let timestamp = timestamp_str.parse().map_err(|_| err())?;
+        let revision = revision_str.parse().map_err(|_| err())?;
+        let email = email_str.to_string();
+        let data = match kind_str {
+            OPERATION_KIND_CREATE_FILE => {
+                let path_str = iter.next().ok_or_else(err)?;
+                let blob_str = iter.next().ok_or_else(err)?;
+                let size_str = iter.next().ok_or_else(err)?;
+
+                let path = path_str.parse().map_err(|_| err())?;
+                let blob = blob_str.parse().map_err(|_| err())?;
+                let size = size_str.parse().map_err(|_| err())?;
+
+                OperationData::CreateFile(OperationCreateFile { path, blob, size })
+            }
+            OPERATION_KIND_CREATE_DIR => {
+                let path_str = iter.next().ok_or_else(err)?;
+
+                let path = path_str.parse().map_err(|_| err())?;
+
+                OperationData::CreateDir(OperationCreateDir { path })
+            }
+            OPERATION_KIND_RENAME => {
+                let old_str = iter.next().ok_or_else(err)?;
+                let new_str = iter.next().ok_or_else(err)?;
+
+                let old = old_str.parse().map_err(|_| err())?;
+                let new = new_str.parse().map_err(|_| err())?;
+
+                OperationData::Rename(OperationRename { old, new })
+            }
+            OPERATION_KIND_REMOVE => {
+                let path_str = iter.next().ok_or_else(err)?;
+
+                let path = path_str.parse().map_err(|_| err())?;
+
+                OperationData::Remove(OperationRemove { path })
+            }
+            _ => return Err(err()),
+        };
+
+        Ok(Self {
+            header: OperationHeader {
+                timestamp,
+                revision,
+                email,
+            },
+            data,
+        })
+    }
+}
+
+impl Display for Operation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}\t{}\t{}\t",
+            self.header.timestamp, self.header.revision, self.header.email
+        )?;
+        match &self.data {
+            OperationData::CreateFile(data) => write!(
+                f,
+                "{}\t{}\t{}\t{}",
+                OPERATION_KIND_CREATE_FILE, data.path, data.blob, data.size
+            ),
+            OperationData::CreateDir(data) => {
+                write!(f, "{}\t{}", OPERATION_KIND_CREATE_DIR, data.path)
+            }
+            OperationData::Remove(data) => write!(f, "{}\t{}", OPERATION_KIND_REMOVE, data.path),
+            OperationData::Rename(data) => {
+                write!(f, "{}\t{}\t{}", OPERATION_KIND_RENAME, data.old, data.new)
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct OperationHeader {
+    pub timestamp: u64,
+    pub revision: u64,
+    pub email: String,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum OperationData {
+    CreateFile(OperationCreateFile),
+    CreateDir(OperationCreateDir),
+    Remove(OperationRemove),
+    Rename(OperationRename),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct OperationCreateFile {
+    pub path: DrivePath,
+    pub blob: BlobId,
+    pub size: u64,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct OperationCreateDir {
+    pub path: DrivePath,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct OperationRemove {
+    pub path: DrivePath,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct OperationRename {
+    pub old: DrivePath,
+    pub new: DrivePath,
+}
+
+#[derive(Debug)]
+pub struct InvalidDrivePath(String);
+
+impl std::fmt::Display for InvalidDrivePath {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "invalid path: {}", self.0)
+    }
+}
+
+impl std::error::Error for InvalidDrivePath {}
+
+#[derive(Debug, Default, Clone, PartialEq, Eq, Hash)]
+pub struct DrivePath(Vec<DrivePathComponent>);
+
+impl Display for DrivePath {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if self.is_root() {
+            f.write_str("/")?;
+        } else {
+            for comp in self.components() {
+                f.write_str("/")?;
+                comp.fmt(f)?;
+            }
+        }
+        Ok(())
+    }
+}
+
+impl DrivePath {
+    pub fn is_root(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    pub fn push(&self, component: DrivePathComponent) -> DrivePath {
+        let mut components = self.0.clone();
+        components.push(component);
+        Self(components)
+    }
+
+    pub fn components(&self) -> &[DrivePathComponent] {
+        self.0.as_slice()
+    }
+
+    pub fn parent(&self) -> DrivePath {
+        if self.0.is_empty() {
+            Self(Default::default())
+        } else {
+            let slice = self.0.as_slice();
+            Self(slice[..slice.len() - 1].to_owned())
+        }
+    }
+
+    pub fn last(&self) -> Option<DrivePathComponent> {
+        self.0.last().cloned()
+    }
+
+    pub fn split(&self) -> Option<(DrivePath, DrivePathComponent)> {
+        if self.0.is_empty() {
+            None
+        } else {
+            Some((
+                Self(self.0[..self.0.len() - 1].to_owned()),
+                self.0[self.0.len() - 1].clone(),
+            ))
+        }
+    }
+}
+
+impl FromStr for DrivePath {
+    type Err = InvalidDrivePath;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut components = Vec::default();
+        for unchecked_component in s.trim().trim_matches('/').split('/') {
+            match unchecked_component.parse() {
+                Ok(component) => components.push(component),
+                Err(err) => {
+                    return Err(InvalidDrivePath(format!(
+                        "path contained invalid component '{unchecked_component}': {err}"
+                    )));
+                }
+            };
+        }
+        Ok(Self(components))
+    }
+}
+
+#[derive(Debug)]
+pub struct InvalidDrivePathComponent(&'static str);
+
+impl Display for InvalidDrivePathComponent {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl InvalidDrivePathComponent {
+    pub const fn new(msg: &'static str) -> Self {
+        Self(msg)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct DrivePathComponent(String);
+
+impl Display for DrivePathComponent {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl DrivePathComponent {
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+impl FromStr for DrivePathComponent {
+    type Err = InvalidDrivePathComponent;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if s.is_empty() {
+            return Err(InvalidDrivePathComponent::new(
+                "path component cannot be empty",
+            ));
+        }
+
+        if s.contains('\t') {
+            return Err(InvalidDrivePathComponent::new(
+                "path component cannot contain tabs",
+            ));
+        }
+
+        if s == "." || s == ".." {
+            return Err(InvalidDrivePathComponent::new(
+                "path component cannot be '.' or '..'",
+            ));
+        }
+
+        if s.contains('/') {
+            return Err(InvalidDrivePathComponent::new(
+                "path component cannot contain '/'",
+            ));
+        }
+
+        if s.len() > 256 {
+            return Err(InvalidDrivePathComponent::new("path component is too long"));
+        }
+
+        Ok(Self(s.to_string()))
+    }
+}
+
+#[derive(Debug)]
+pub struct FsError(String);
+
+impl From<String> for FsError {
+    fn from(value: String) -> Self {
+        Self(value)
+    }
+}
+
+impl From<&str> for FsError {
+    fn from(value: &str) -> Self {
+        Self(value.to_string())
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum FsNodeKind {
+    File,
+    Directory,
+}
+
+pub struct FsNode {
+    pub kind: FsNodeKind,
+    pub author: String,
+    pub lastmod: u64,
+    pub children: HashMap<DrivePathComponent, FsNodeId>,
+    pub blob: BlobId,
+    pub size: u64,
+}
+
+slotmap::new_key_type! { pub struct FsNodeId; }
+
+pub struct Fs {
+    pub root: FsNodeId,
+    pub nodes: SlotMap<FsNodeId, FsNode>,
+}
+
+impl Default for Fs {
+    fn default() -> Self {
+        let mut nodes: SlotMap<FsNodeId, FsNode> = Default::default();
+        let root = nodes.insert(FsNode {
+            kind: FsNodeKind::Directory,
+            author: "system".to_string(),
+            lastmod: 0,
+            children: Default::default(),
+            blob: Default::default(),
+            size: 0,
+        });
+        Self { root, nodes }
+    }
+}
+
+pub fn apply(fs: &mut Fs, op: &Operation) -> Result<(), FsError> {
+    match &op.data {
+        OperationData::CreateFile(data) => apply_create_file(fs, &op.header, &data),
+        OperationData::CreateDir(data) => apply_create_dir(fs, &op.header, &data),
+        OperationData::Remove(data) => apply_remove(fs, &op.header, &data),
+        OperationData::Rename(data) => apply_rename(fs, &op.header, &data),
+    }
+}
+
+pub fn apply_create_file(
+    fs: &mut Fs,
+    header: &OperationHeader,
+    data: &OperationCreateFile,
+) -> Result<(), FsError> {
+    if data.path.is_root() {
+        return Err(FsError::from("cannot create file at root"));
+    }
+
+    let mut parent_id = fs.root;
+    for comp in data.path.parent().components() {
+        let node = &mut fs.nodes[parent_id];
+        if node.kind != FsNodeKind::Directory {
+            return Err(FsError::from("cannot create file under another file"));
+        }
+        parent_id = match node.children.get(comp) {
+            Some(id) => *id,
+            None => {
+                let id = fs.nodes.insert(FsNode {
+                    kind: FsNodeKind::Directory,
+                    author: header.email.clone(),
+                    lastmod: header.timestamp,
+                    children: Default::default(),
+                    blob: Default::default(),
+                    size: 0,
+                });
+                fs.nodes[parent_id].children.insert(comp.clone(), id);
+                id
+            }
+        };
+    }
+
+    let name = data.path.last().unwrap();
+    let parent = &mut fs.nodes[parent_id];
+
+    if parent.kind != FsNodeKind::Directory {
+        return Err(FsError::from("cannot create file under another file"));
+    }
+
+    match parent.children.get(&name).copied() {
+        Some(node_id) => {
+            let node = &mut fs.nodes[node_id];
+            if node.kind == FsNodeKind::Directory {
+                return Err(FsError::from(
+                    "node at path already exists but is a directory",
+                ));
+            }
+            node.author = header.email.clone();
+            node.lastmod = header.timestamp;
+            node.blob = data.blob.clone();
+        }
+        None => {
+            let id = fs.nodes.insert(FsNode {
+                kind: FsNodeKind::File,
+                author: header.email.clone(),
+                lastmod: header.timestamp,
+                children: Default::default(),
+                blob: data.blob.clone(),
+                size: data.size,
+            });
+            fs.nodes[parent_id].children.insert(name, id);
+        }
+    }
+    Ok(())
+}
+
+pub fn apply_create_dir(
+    fs: &mut Fs,
+    header: &OperationHeader,
+    data: &OperationCreateDir,
+) -> Result<(), FsError> {
+    let (parent, name) = data
+        .path
+        .split()
+        .ok_or_else(|| FsError::from("cannot recreate root directory"))?;
+
+    let mut parent_id = fs.root;
+    for comp in parent.components() {
+        let node = &fs.nodes[parent_id];
+        parent_id = match node.children.get(comp) {
+            Some(&child_id) => {
+                let child = &fs.nodes[child_id];
+                if child.kind == FsNodeKind::File {
+                    return Err(FsError::from("cannot create directory under file"));
+                }
+                child_id
+            }
+            None => {
+                let id = fs.nodes.insert(FsNode {
+                    kind: FsNodeKind::Directory,
+                    author: header.email.clone(),
+                    lastmod: header.timestamp,
+                    children: Default::default(),
+                    blob: Default::default(),
+                    size: 0,
+                });
+                fs.nodes[parent_id].children.insert(comp.clone(), id);
+                id
+            }
+        };
+    }
+
+    let parent = &fs.nodes[parent_id];
+    match parent.children.get(&name).copied() {
+        Some(child_id) => {
+            let child = &fs.nodes[child_id];
+            if child.kind != FsNodeKind::Directory {
+                return Err(FsError::from(
+                    "cannot create directory, the given path is already a file",
+                ));
+            }
+        }
+        None => {
+            let id = fs.nodes.insert(FsNode {
+                kind: FsNodeKind::Directory,
+                author: header.email.clone(),
+                lastmod: header.timestamp,
+                children: Default::default(),
+                blob: Default::default(),
+                size: 0,
+            });
+
+            let parent = &mut fs.nodes[parent_id];
+            parent.children.insert(name, id);
+        }
+    }
+
+    Ok(())
+}
+
+pub fn apply_remove(
+    fs: &mut Fs,
+    _header: &OperationHeader,
+    data: &OperationRemove,
+) -> Result<(), FsError> {
+    let (parent, name) = data
+        .path
+        .split()
+        .ok_or_else(|| FsError::from("cannot remove root directory"))?;
+
+    let parent_id = match find_node(fs, &parent) {
+        Some(id) => id,
+        None => return Ok(()),
+    };
+
+    let parent = &mut fs.nodes[parent_id];
+    parent.children.remove(&name);
+
+    Ok(())
+}
+
+fn find_node(fs: &Fs, path: &DrivePath) -> Option<FsNodeId> {
+    let mut node_id = fs.root;
+    for comp in path.components() {
+        let node = &fs.nodes[node_id];
+        node_id = *node.children.get(comp)?;
+    }
+    Some(node_id)
+}
+
+pub fn apply_rename(
+    fs: &mut Fs,
+    _header: &OperationHeader,
+    data: &OperationRename,
+) -> Result<(), FsError> {
+    let (old_parent, old_name) = data
+        .old
+        .split()
+        .ok_or_else(|| FsError::from("cannot move root directory"))?;
+
+    let (new_parent, new_name) = data
+        .new
+        .split()
+        .ok_or_else(|| FsError::from("move destination cannot be root directory"))?;
+
+    let old_parent_id = find_node(fs, &old_parent).unwrap();
+    let old_parent = &mut fs.nodes[old_parent_id];
+    let node_id = old_parent.children.remove(&old_name).unwrap();
+
+    let new_parent_id = find_node(fs, &new_parent).unwrap();
+    let new_parent = &mut fs.nodes[new_parent_id];
+    new_parent.children.insert(new_name, node_id);
+
+    Ok(())
+}
+
+#[derive(Debug, Parser)]
+struct Cli {
+    #[clap(subcommand)]
+    cmd: Cmd,
+}
+
+#[derive(Debug, Parser)]
+struct CliCommon {
+    #[clap(long, default_value = "./", env = "FCTDRIVE_PATH")]
+    drive: PathBuf,
+}
+
+#[derive(Debug, Subcommand)]
+enum Cmd {
+    CreateFile(CreateFileArgs),
+    CreateDir(CreateDirArgs),
+    Remove(RemoveArgs),
+    Rename(RenameArgs),
+    Ls(LsArgs),
+    Import(ImportArgs),
+    Blob(BlobArgs),
+}
+
+#[derive(Debug, Args)]
+struct CreateFileArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    #[clap(long)]
+    timestamp: Option<u64>,
+
+    #[clap(long)]
+    email: String,
+
+    #[clap(long)]
+    path: DrivePath,
+
+    #[clap(long)]
+    file: std::path::PathBuf,
+}
+
+#[derive(Debug, Args)]
+struct CreateDirArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    #[clap(long)]
+    timestamp: Option<u64>,
+
+    #[clap(long)]
+    email: String,
+
+    #[clap(long)]
+    path: DrivePath,
+}
+
+#[derive(Debug, Args)]
+struct RemoveArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    #[clap(long)]
+    timestamp: Option<u64>,
+
+    #[clap(long)]
+    email: String,
+
+    #[clap(long)]
+    path: DrivePath,
+}
+
+#[derive(Debug, Args)]
+struct RenameArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    #[clap(long)]
+    timestamp: Option<u64>,
+
+    #[clap(long)]
+    email: String,
+
+    #[clap(long)]
+    old: DrivePath,
+
+    #[clap(long)]
+    new: DrivePath,
+}
+
+#[derive(Debug, Args)]
+struct LsArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    #[clap(short, long)]
+    recursive: bool,
+
+    path: Option<DrivePath>,
+}
+
+#[derive(Debug, Args)]
+struct ImportArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    #[clap(long)]
+    timestamp: Option<u64>,
+
+    #[clap(long)]
+    email: String,
+
+    path: PathBuf,
+}
+
+#[derive(Debug, Args)]
+struct BlobArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    blob_id: BlobId,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    match cli.cmd {
+        Cmd::CreateFile(args) => cmd_create_file(args),
+        Cmd::CreateDir(args) => cmd_create_dir(args),
+        Cmd::Remove(args) => cmd_remove(args),
+        Cmd::Rename(args) => cmd_rename(args),
+        Cmd::Ls(args) => cmd_ls(args),
+        Cmd::Import(args) => cmd_import(args),
+        Cmd::Blob(args) => cmd_blob(args),
+    }
+}
+
+fn cmd_create_file(args: CreateFileArgs) {
+    let store = common_create_blob_store(&args.common);
+    let file_blob_id = blob_hash_file(&args.file).unwrap();
+    let file_blob_size = blob_size(&store, &file_blob_id).unwrap();
+
+    let _lock = common_write_lock(&args.common);
+    let mut fs = Fs::default();
+    let mut ops = common_read_log_file(&args.common);
+    ops.iter().for_each(|op| apply(&mut fs, op).unwrap());
+
+    let timestamp = args.timestamp.unwrap_or_else(get_timestamp);
+    let revision = get_next_revision(&ops);
+    blob_import_file(&store, ImportMode::HardLink, &file_blob_id, &args.file).unwrap();
+
+    let new_op = Operation {
+        header: OperationHeader {
+            timestamp,
+            revision,
+            email: args.email,
+        },
+        data: OperationData::CreateFile(OperationCreateFile {
+            path: args.path,
+            blob: file_blob_id,
+            size: file_blob_size,
+        }),
+    };
+    apply(&mut fs, &new_op).unwrap();
+    ops.push(new_op);
+    common_write_log_file(&args.common, &ops);
+}
+
+fn cmd_create_dir(args: CreateDirArgs) {
+    let _lock = common_write_lock(&args.common);
+    let mut fs = Fs::default();
+    let mut ops = common_read_log_file(&args.common);
+    ops.iter().for_each(|op| apply(&mut fs, op).unwrap());
+
+    let timestamp = args.timestamp.unwrap_or_else(get_timestamp);
+    let revision = get_next_revision(&ops);
+
+    let new_op = Operation {
+        header: OperationHeader {
+            timestamp,
+            revision,
+            email: args.email,
+        },
+        data: OperationData::CreateDir(OperationCreateDir { path: args.path }),
+    };
+    apply(&mut fs, &new_op).unwrap();
+    ops.push(new_op);
+    common_write_log_file(&args.common, &ops);
+}
+
+fn cmd_remove(args: RemoveArgs) {
+    let _lock = common_write_lock(&args.common);
+    let mut fs = Fs::default();
+    let mut ops = common_read_log_file(&args.common);
+    ops.iter().for_each(|op| apply(&mut fs, op).unwrap());
+
+    let timestamp = args.timestamp.unwrap_or_else(get_timestamp);
+    let revision = get_next_revision(&ops);
+
+    let new_op = Operation {
+        header: OperationHeader {
+            timestamp,
+            revision,
+            email: args.email,
+        },
+        data: OperationData::Remove(OperationRemove { path: args.path }),
+    };
+    apply(&mut fs, &new_op).unwrap();
+    ops.push(new_op);
+    common_write_log_file(&args.common, &ops);
+}
+
+fn cmd_rename(args: RenameArgs) {
+    let _lock = common_write_lock(&args.common);
+    let mut fs = Fs::default();
+    let mut ops = common_read_log_file(&args.common);
+    ops.iter().for_each(|op| apply(&mut fs, op).unwrap());
+
+    let timestamp = args.timestamp.unwrap_or_else(get_timestamp);
+    let revision = get_next_revision(&ops);
+
+    let new_op = Operation {
+        header: OperationHeader {
+            timestamp,
+            revision,
+            email: args.email,
+        },
+        data: OperationData::Rename(OperationRename {
+            old: args.old,
+            new: args.new,
+        }),
+    };
+
+    apply(&mut fs, &new_op).unwrap();
+    ops.push(new_op);
+    common_write_log_file(&args.common, &ops);
+}
+
+type FsNodeWriter<'a> = std::io::BufWriter<std::io::StdoutLock<'a>>;
+
+fn cmd_ls(args: LsArgs) {
+    let stdout = std::io::stdout().lock();
+    let mut writer = BufWriter::new(stdout);
+    let mut fs = Fs::default();
+    let ops = common_read_log_file(&args.common);
+    ops.iter().for_each(|op| apply(&mut fs, op).unwrap());
+    let node_id = match args.path {
+        Some(path) => find_node(&fs, &path),
+        None => Some(fs.root),
+    };
+    if let Some(node_id) = node_id {
+        write_node(
+            &mut writer,
+            &fs,
+            node_id,
+            Default::default(),
+            args.recursive,
+            true,
+        );
+    }
+    writer.flush().unwrap();
+    std::process::exit(0);
+}
+
+fn write_node(
+    writer: &mut FsNodeWriter,
+    fs: &Fs,
+    node_id: FsNodeId,
+    path: DrivePath,
+    recursive: bool,
+    recurse: bool,
+) {
+    let node = &fs.nodes[node_id];
+    match node.kind {
+        FsNodeKind::File => {
+            writeln!(
+                writer,
+                "{}\tfile\t{}\t{}\t{}\t{}",
+                path, node.lastmod, node.blob, node.size, node.author
+            )
+            .unwrap();
+        }
+        FsNodeKind::Directory => {
+            writeln!(
+                writer,
+                "{}\tdir\t{}\t-\t-\t{}",
+                path, node.lastmod, node.author
+            )
+            .unwrap();
+            if recursive || recurse {
+                for (child_comp, child_id) in node.children.iter() {
+                    let child_path = path.push(child_comp.clone());
+                    write_node(writer, fs, *child_id, child_path, recursive, false);
+                }
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+struct Queue<T>(Arc<Mutex<VecDeque<T>>>);
+
+impl<T> Default for Queue<T> {
+    fn default() -> Self {
+        Self(Arc::new(Mutex::new(Default::default())))
+    }
+}
+
+impl<T> From<Vec<T>> for Queue<T> {
+    fn from(value: Vec<T>) -> Self {
+        Self(Arc::new(Mutex::new(value.into())))
+    }
+}
+
+impl<T> Queue<T> {
+    pub fn push(&self, v: T) {
+        self.0.lock().unwrap().push_back(v);
+    }
+
+    pub fn pop(&self) -> Option<T> {
+        self.0.lock().unwrap().pop_front()
+    }
+}
+
+fn cmd_import(args: ImportArgs) {
+    let _lock = common_write_lock(&args.common);
+
+    let mut ops = common_read_log_file(&args.common);
+
+    let store = BlobStore::new("blobs");
+    let timestamp = args.timestamp.unwrap_or_else(get_timestamp);
+    let root = args.path.canonicalize().unwrap();
+
+    let files = Queue::from(collect_all_file_paths(&root));
+    let num_threads = std::thread::available_parallelism().unwrap().get();
+    let mut handles = Vec::default();
+    for _ in 0..num_threads {
+        let root = root.clone();
+        let email = args.email.clone();
+        let files = files.clone();
+        let store = store.clone();
+        let handle = std::thread::spawn(move || {
+            let mut ops = Vec::default();
+            while let Some(file) = files.pop() {
+                let rel = file.strip_prefix(&root).unwrap();
+                let drive_path = rel.to_str().unwrap().parse::<DrivePath>().unwrap();
+                let blob_id = blob_hash_file(&file).unwrap();
+                blob_import_file(&store, ImportMode::HardLink, &blob_id, &file).unwrap();
+                let blob_size = blob_size(&store, &blob_id).unwrap();
+                let op = Operation {
+                    header: OperationHeader {
+                        timestamp,
+                        revision: 0,
+                        email: email.clone(),
+                    },
+                    data: OperationData::CreateFile(OperationCreateFile {
+                        path: drive_path,
+                        blob: blob_id,
+                        size: blob_size,
+                    }),
+                };
+                ops.push(op);
+            }
+            ops
+        });
+        handles.push(handle);
+    }
+
+    let mut fs = Fs::default();
+    let mut next_rev = get_next_revision(&ops);
+    for handle in handles {
+        let mut task_ops = handle.join().unwrap();
+        for op in &mut task_ops {
+            op.header.revision = next_rev;
+            next_rev += 1;
+        }
+        ops.extend(task_ops);
+    }
+    ops.iter().for_each(|op| apply(&mut fs, op).unwrap());
+    common_write_log_file(&args.common, &ops);
+}
+
+fn cmd_blob(args: BlobArgs) {
+    let store = common_create_blob_store(&args.common);
+    let path = blob_path(&store, &args.blob_id);
+    println!("{}", path.display());
+}
+
+fn collect_all_file_paths(root: &Path) -> Vec<PathBuf> {
+    let mut queue = vec![root.to_path_buf()];
+    let mut files = vec![];
+    while let Some(path) = queue.pop() {
+        if path.is_dir() {
+            let mut read = path.read_dir().unwrap();
+            while let Some(entry) = read.next() {
+                let entry = entry.unwrap();
+                queue.push(entry.path());
+            }
+        } else {
+            files.push(path);
+        }
+    }
+    files
+}
+
+fn common_create_blob_store(common: &CliCommon) -> BlobStore {
+    BlobStore::new(common.drive.join("blobs"))
+}
+
+fn common_log_file_path(common: &CliCommon) -> PathBuf {
+    common.drive.join("log.txt")
+}
+
+fn common_log_temp_file_path(common: &CliCommon) -> PathBuf {
+    common.drive.join("log.txt.tmp")
+}
+
+fn common_read_log_file(common: &CliCommon) -> Vec<Operation> {
+    let log_file_path = common_log_file_path(common);
+    let mut operations = Vec::default();
+    if std::fs::exists(&log_file_path).unwrap() {
+        let contents = std::fs::read_to_string(&log_file_path).unwrap();
+        for line in contents.lines() {
+            let operation = line.parse().unwrap();
+            operations.push(operation);
+        }
+    }
+    operations
+}
+
+fn common_write_log_file(common: &CliCommon, ops: &[Operation]) {
+    let log_file_path = common_log_file_path(common);
+    let log_temp_file_path = common_log_temp_file_path(common);
+    {
+        let file = File::options()
+            .create(true)
+            .write(true)
+            .truncate(true)
+            .open(&log_temp_file_path)
+            .unwrap();
+        let mut writer = BufWriter::new(file);
+        for op in ops {
+            writeln!(writer, "{op}").unwrap();
+        }
+        writer.flush().unwrap();
+    }
+    std::fs::rename(&log_temp_file_path, &log_file_path).unwrap();
+}
+
+fn common_write_lock_path(common: &CliCommon) -> PathBuf {
+    common.drive.join("write.lock")
+}
+
+fn common_write_lock(common: &CliCommon) -> File {
+    let lock_path = common_write_lock_path(common);
+    let file = std::fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open(lock_path)
+        .unwrap();
+    file.lock().unwrap();
+    file
+}
+
+fn get_timestamp() -> u64 {
+    SystemTime::now()
+        .duration_since(SystemTime::UNIX_EPOCH)
+        .unwrap()
+        .as_secs()
+}
+
+fn get_next_revision(ops: &[Operation]) -> u64 {
+    match ops.last() {
+        Some(op) => op.header.revision + 1,
+        None => 0,
+    }
+}