Merge branch 'lib' into 'main'

Lib

See merge request larswirzenius/summain!1

3 files changed, 110 insertions, 69 deletions

diff --git a/src/bin/summain.rs b/src/bin/summain.rs
new file mode 100644
index 0000000..056bc8b
--- /dev/null
+++ b/src/bin/summain.rs
@@ -0,0 +1,27 @@
+use anyhow::Context;
+use std::fs::symlink_metadata;
+use std::path::{Path, PathBuf};
+use structopt::StructOpt;
+use summain::ManifestEntry;
+
+fn main() -> anyhow::Result<()> {
+    let mut opt = Opt::from_args();
+    opt.pathnames[..].sort();
+    for pathname in opt.pathnames {
+        report(&pathname).with_context(|| format!("{}", pathname.display()))?
+    }
+    Ok(())
+}
+
+#[derive(StructOpt, Debug)]
+struct Opt {
+    #[structopt(parse(from_os_str))]
+    pathnames: Vec<PathBuf>,
+}
+
+fn report(pathname: &Path) -> anyhow::Result<()> {
+    let m = symlink_metadata(pathname)?;
+    let e = ManifestEntry::new(pathname, m);
+    println!("{}", serde_yaml::to_string(&e)?);
+    Ok(())
+}
diff --git a/src/lib.rs b/src/lib.rs
index 8b13789..eacce62 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1 +1,84 @@
+//! File manifests.
+//!
+//! This crate defines the [`ManifestEntry`] struct to represent an
+//! entry in a file manifest. The entry contains data about each file.
+//! A manifest can be produced of some data, and later, a new manifest
+//! can be produced and compared with the original. If the manifests
+//! have changed, the data has changed. If they haven't changed, the
+//! data has probably not changed.
+//!
+//! Such manifests can be used, for example, to verify that data that
+//! has been restored from a backup is the same as what was backed up.
+//!
+//! This crate uses Linux metadata of files.
+//!
+//! ~~~
+//! let m = std::fs::metadata(".").unwrap();
+//! let e = summain::ManifestEntry(m);
+//! println!("{}", serde_yaml::to_string(e).unwrap());
+//! ~~~
+//!
+//! The output is something like:
+//!
+//! ~~~yaml
+//! path: "."
+//! atime: 1606565868
+//! atime_nsec: 824368155
+//! mode: drwxrwxr-x
+//! mtime: 1606565867
+//! mtime_nsec: 500355545
+//! nlink: 6
+//! size: ~
+//! ~~~
 
+use serde::Serialize;
+use std::fs::Metadata;
+use std::os::linux::fs::MetadataExt;
+use std::path::{Path, PathBuf};
+
+/// An entry in a file manifest.
+#[derive(Serialize, Debug)]
+pub struct ManifestEntry {
+    path: PathBuf,
+    atime: i64,
+    atime_nsec: i64,
+    #[serde(with = "mode")]
+    mode: u32,
+    mtime: i64,
+    mtime_nsec: i64,
+    nlink: u64,
+    size: Option<u64>,
+}
+
+impl ManifestEntry {
+    /// Create a new manifest entry.
+    ///
+    /// The pathname of the file and the metadata are passed in by the
+    /// caller. This function doesn't query the system for it.
+    ///
+    /// The structure can be serialized using serde.
+    pub fn new(path: &Path, m: Metadata) -> Self {
+        Self {
+            path: path.to_path_buf(),
+            atime: m.st_atime(),
+            atime_nsec: m.st_atime_nsec(),
+            mode: m.st_mode(),
+            mtime: m.st_mtime(),
+            mtime_nsec: m.st_mtime_nsec(),
+            nlink: m.st_nlink(),
+            size: if m.is_dir() { None } else { Some(m.st_size()) },
+        }
+    }
+}
+
+mod mode {
+    use serde::{self, Serializer};
+
+    pub fn serialize<S>(mode: &u32, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let s = unix_mode::to_string(*mode);
+        serializer.serialize_str(&s)
+    }
+}
diff --git a/src/main.rs b/src/main.rs
deleted file mode 100644
index fd23eb8..0000000
--- a/src/main.rs
+++ /dev/null
@@ -1,69 +0,0 @@
-use anyhow::Context;
-use serde::Serialize;
-use std::fs::symlink_metadata;
-use std::fs::Metadata;
-use std::os::linux::fs::MetadataExt;
-use std::path::{Path, PathBuf};
-use structopt::StructOpt;
-
-fn main() -> anyhow::Result<()> {
-    let mut opt = Opt::from_args();
-    opt.pathnames[..].sort();
-    for pathname in opt.pathnames {
-        report(&pathname).with_context(|| format!("{}", pathname.display()))?
-    }
-    Ok(())
-}
-
-#[derive(StructOpt, Debug)]
-struct Opt {
-    #[structopt(parse(from_os_str))]
-    pathnames: Vec<PathBuf>,
-}
-
-#[derive(Serialize, Debug)]
-struct Entry {
-    path: PathBuf,
-    atime: i64,
-    atime_nsec: i64,
-    #[serde(with = "mode")]
-    mode: u32,
-    mtime: i64,
-    mtime_nsec: i64,
-    nlink: u64,
-    size: Option<u64>,
-}
-
-impl Entry {
-    fn new(path: &Path, m: Metadata) -> Self {
-        Self {
-            path: path.to_path_buf(),
-            atime: m.st_atime(),
-            atime_nsec: m.st_atime_nsec(),
-            mode: m.st_mode(),
-            mtime: m.st_mtime(),
-            mtime_nsec: m.st_mtime_nsec(),
-            nlink: m.st_nlink(),
-            size: if m.is_dir() { None } else { Some(m.st_size()) },
-        }
-    }
-}
-
-fn report(pathname: &Path) -> anyhow::Result<()> {
-    let m = symlink_metadata(pathname)?;
-    let e = Entry::new(pathname, m);
-    println!("{}", serde_yaml::to_string(&e)?);
-    Ok(())
-}
-
-mod mode {
-    use serde::{self, Serializer};
-
-    pub fn serialize<S>(mode: &u32, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        let s = unix_mode::to_string(*mode);
-        serializer.serialize_str(&s)
-    }
-}