From 162e0273652db867f692c139b0f365666b0ee550 Mon Sep 17 00:00:00 2001
From: Nathan Fisher <nfisher.sr@gmail.com>
Date: Mon, 3 Jul 2023 23:37:57 -0400
Subject: [PATCH] Finish `from_path` for `Node`

---
 src/lib.rs | 115 ++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 92 insertions(+), 23 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 03f9a19..8586214 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,12 +4,13 @@ use {
     sha2::Sha256,
     std::{
         array::TryFromSliceError,
+        collections::HashMap,
         fmt, fs,
-        io::{self, BufRead, BufReader, Read, Write},
+        io::{self, BufReader, Read, Write},
         num::TryFromIntError,
         os::unix::fs::MetadataExt,
-        path::PathBuf,
         string::FromUtf8Error,
+        sync::Mutex,
     },
 };
 
@@ -100,6 +101,13 @@ impl Special {
         writer.write_all(&self.minor.to_le_bytes())?;
         Ok(())
     }
+
+    fn from_rdev(rdev: u32) -> Self {
+        Self {
+            major: rdev >> 8,
+            minor: rdev & 0xff,
+        }
+    }
 }
 
 #[derive(Debug)]
@@ -249,7 +257,7 @@ impl FileType {
             0 => {
                 let file = File::read(reader)?;
                 Ok(Self::Normal(file))
-            },
+            }
             1 => {
                 let mut len = [0; 8];
                 reader.read_exact(&mut len)?;
@@ -289,7 +297,7 @@ impl FileType {
             Self::Normal(f) => {
                 writer.write_all(&[0])?;
                 f.write(writer)?;
-            },
+            }
             Self::HardLink(s) => {
                 writer.write_all(&[1])?;
                 let len = s.len() as u64;
@@ -317,7 +325,7 @@ impl FileType {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 enum Kind {
     Normal,
     Dir,
@@ -391,31 +399,92 @@ impl Node {
         Ok(())
     }
 
-    /*pub fn from_path(path: &str) -> Result<Self, Error> {
+    pub fn from_path(
+        path: &str,
+        checksum: Checksum,
+        links: Mutex<HashMap<u64, String>>,
+    ) -> Result<Self, Error> {
         let name = String::from(path);
-        let mut fd = fs::File::open(path)?;
+        let fd = fs::File::open(path)?;
         let meta = fd.metadata()?;
         let mode = meta.mode();
         let uid = meta.uid();
         let gid = meta.gid();
-        let mtime = meta.mtime();
+        let mtime = meta.mtime().try_into()?;
         let mut reader = BufReader::new(fd);
         let ft = meta.file_type();
-        let filetype = if ft.is_dir() {
-            FileType::Directory
-        } else if ft.is_symlink() {
-            let target = fs::read_link(path)?;
-            let target = target
-                .to_str()
-                .ok_or(Error::Other("bad path".to_string()))?
-                .to_string();
-            FileType::SoftLink(target)
-        } else if mode & 0o20000 != 0 {
-            let rdev = meta.rdev();
-            if rdev != 0 {
+        let filetype = 'blk: {
+            if ft.is_dir() {
+                FileType::Directory
+            } else if ft.is_symlink() {
+                let target = fs::read_link(path)?;
+                let target = target
+                    .to_str()
+                    .ok_or(Error::Other("bad path".to_string()))?
+                    .to_string();
+                FileType::SoftLink(target)
+            } else {
+                if meta.nlink() > 1 {
+                    if let Ok(mut list) = links.lock() {
+                        let inode = meta.ino();
+                        if let Some(target) = list.get(&inode).cloned() {
+                            break 'blk FileType::HardLink(target);
+                        } else {
+                            list.insert(inode, name.clone());
+                        }
+                    }
+                }
+                let kind = Kind::from(mode);
+                if kind == Kind::Char {
+                    let device = Special::from_rdev(meta.rdev().try_into()?);
+                    break 'blk FileType::Character(device);
+                } else if kind == Kind::Block {
+                    let device = Special::from_rdev(meta.rdev().try_into()?);
+                    break 'blk FileType::Block(device);
+                } else if kind == Kind::Pipe {
+                    break 'blk FileType::Fifo;
+                } else if kind == Kind::Normal {
+                    let mut len = meta.len();
+                    let mut data = Vec::with_capacity(len.try_into()?);
+                    len = reader.read_to_end(&mut data)?.try_into()?;
+                    let checksum = match checksum {
+                        Checksum::Md5(mut cs) => {
+                            let mut hasher = Md5::new();
+                            hasher.update(&data);
+                            cs = hasher.finalize().into();
+                            Checksum::Md5(cs)
+                        }
+                        Checksum::Sha1(mut cs) => {
+                            let mut hasher = Sha1::new();
+                            hasher.update(&data);
+                            cs = hasher.finalize().into();
+                            Checksum::Sha1(cs)
+                        }
+                        Checksum::Sha256(mut cs) => {
+                            let mut hasher = Sha256::new();
+                            hasher.update(&data);
+                            cs = hasher.finalize().into();
+                            Checksum::Sha256(cs)
+                        }
+                        Checksum::Skip => checksum,
+                    };
+                    break 'blk FileType::Normal(File {
+                        len,
+                        checksum,
+                        data,
+                    });
+                } else {
+                    return Err(Error::UnknownFileType);
+                }
             }
-            todo!()
         };
-        todo!()
-    }*/
+        Ok(Self {
+            name,
+            mode,
+            uid,
+            gid,
+            mtime,
+            filetype,
+        })
+    }
 }