hashing restored

README.md

@@ -132,3 +132,10 @@ Memory: 31731MiB (~32GiB)
     - Tree format output for duplicate file listing
     - GUI
     - Packages for different operating system repositories (currently only installable via cargo) 
+
+## v0.3 checklist
+- [x] parallelization of scanning, processing and formatting
+- [x] reduce cloning values on the heap
+- [ ] add a partial hashing mode
+- [ ] add an option to use a bloom filter for very large filesystems
+- [ ] max file path size should use the last set of duplicates

src/fileinfo.rs

@@ -4,19 +4,19 @@ use memmap2::Mmap;
 use serde::Serialize;
 use std::fs;
 use std::hash::Hasher;
+use std::io::Read;
 use std::{fs::Metadata, path::PathBuf};
 
 #[derive(Debug, Clone, Serialize)]
 pub struct FileInfo {
     pub path: PathBuf,
-    pub hash: Option<String>,
     pub size: u64,
     #[serde(skip)]
     pub filemeta: Metadata,
 }
 
 impl FileInfo {
-    pub fn hash(&self) -> Result<Self> {
+    pub fn hash(&self) -> Result<String> {
         let file = fs::File::open(self.path.clone())?;
         let mapper = unsafe { Mmap::map(&file)? };
         let mut primhasher = GxHasher::default();
@@ -25,10 +25,16 @@ impl FileInfo {
             .chunks(1_000_000)
             .for_each(|chunk| primhasher.write(chunk));
 
-        Ok(Self {
-            hash: Some(primhasher.finish().to_string()),
-            ..self.clone()
-        })
+        Ok(primhasher.finish().to_string())
+    }
+
+    pub fn initial_page_hash(&self) -> Result<String> {
+        let file = fs::File::open(self.path.clone())?;
+        let mapper = unsafe { Mmap::map(&file)? };
+        let mut primhasher = GxHasher::default();
+        primhasher.write(mapper.take(4096).into_inner());
+
+        Ok(primhasher.finish().to_string())
     }
 
     pub fn new(path: PathBuf) -> Result<Self> {
@@ -36,7 +42,6 @@ impl FileInfo {
         Ok(Self {
             path,
             filemeta: filemeta.clone(),
-            hash: None,
             size: filemeta.len(),
         })
     }

src/processor.rs

@@ -33,7 +33,7 @@ impl Processor {
                 if group.len() > 1 {
                     group.into_par_iter().for_each(|file| {
                         hw_store
-                            .entry(file.hash.clone().unwrap_or_default())
+                            .entry(file.hash().expect("hashing file failed."))
                             .and_modify(|fileset| fileset.push(file.clone()))
                             .or_insert_with(|| vec![file]);
                     });