From 927d1bab3d663bee151eb3c7f0b1e1612f98ef03 Mon Sep 17 00:00:00 2001
From: Jon Moroney <darakian@gmail.com>
Date: Mon, 6 Jul 2020 18:10:06 -0700
Subject: [PATCH] Add chunk iter

This PR adds a new struct which breaks a file into chunks
of a given size.
---
 src/lib.rs   | 12 +++++++-----
 src/utils.rs | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 5 deletions(-)
 create mode 100644 src/utils.rs

diff --git a/src/lib.rs b/src/lib.rs
index 1853962..3560e69 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,6 +2,8 @@
 //!
 //! `ddh` is a collection of functions and structs to aid in analysing filesystem directories.
 
+pub mod utils;
+
 use std::hash::{Hasher};
 use std::fs::{self, DirEntry};
 use std::io::{Read};
@@ -56,7 +58,7 @@ impl Fileinfo{
         Fileinfo{full_hash: full_hash, partial_hash: partial_hash, file_length: length, file_paths: vec![path]}
     }
     /// Gets the length of the files in the current collection.
-    /// 
+    ///
     /// # Examples
     /// ```
     /// use std::path::Path;
@@ -70,7 +72,7 @@ impl Fileinfo{
         self.file_length
     }
     /// Gets the hash of the full file if available.
-    /// 
+    ///
     /// # Examples
     /// ```
     /// use std::path::Path;
@@ -87,7 +89,7 @@ impl Fileinfo{
         self.full_hash = hash
     }
     /// Gets the hash of the partially read file if available.
-    /// 
+    ///
     /// # Examples
     /// ```
     /// use std::path::Path;
@@ -104,7 +106,7 @@ impl Fileinfo{
         self.partial_hash = hash
     }
     /// Gets a candidate name. This will be the name of the first file inserted into the collection and so can vary.
-    /// 
+    ///
     /// # Examples
     /// ```
     /// use std::path::Path;
@@ -126,7 +128,7 @@ impl Fileinfo{
         .unwrap()
     }
     /// Gets all paths in the current collection. This can be used to get the names of each file with the string `rsplit("/")` method.
-    /// 
+    ///
     /// # Examples
     /// ```
     /// use std::path::Path;
diff --git a/src/utils.rs b/src/utils.rs
new file mode 100644
index 0000000..cf34a62
--- /dev/null
+++ b/src/utils.rs
@@ -0,0 +1,32 @@
+use std::path::Path;
+use std::fs::File;
+use std::io::{Read, self};
+
+pub struct ChunkIter{
+    f: File,
+    chunk_len: usize,
+}
+
+impl ChunkIter{
+    pub fn new(f: File, len: usize) -> Self{
+        ChunkIter{f: f, chunk_len: len}
+    }
+}
+
+impl Iterator for ChunkIter{
+    type Item = Result<Vec<u8>, io::Error>;
+    fn next(&mut self) -> Option<Result<Vec<u8>, io::Error>>{
+        let mut buffer = Vec::with_capacity(self.chunk_len);
+        match self.f.by_ref()
+            .take(self.chunk_len as u64)
+            .read_to_end(&mut buffer){
+            Ok(i) => {
+                if i == 0 {
+                    return None
+                } else {
+                    Some(Ok(buffer))}
+                },
+            Err(e) => Some(Err(e))
+        }
+    }
+}