diff --git a/src/bin/backup-client.rs b/src/bin/backup-client.rs
index 7682877f..380d8824 100644
--- a/src/bin/backup-client.rs
+++ b/src/bin/backup-client.rs
@@ -2,19 +2,12 @@ extern crate apitest;
 
 use failure::*;
 
-use std::collections::HashMap;
-use std::fs::File;
-use std::io::Read;
-use std::io::ErrorKind;
-use std::io::prelude::*;
-use std::iter::Iterator;
-
+use apitest::tools;
 use apitest::cli::command::*;
 use apitest::api::schema::*;
 use apitest::api::router::*;
 use apitest::backup::chunk_store::*;
-use serde_json::{json, Value};
-use std::path::{Path, PathBuf};
+use serde_json::{Value};
 
 use apitest::config::datastore;
 
@@ -23,71 +16,6 @@ fn required_string_param<'a>(param: &'a Value, name: &str) -> &'a str {
 }
 
 
-// Note: We cannot implement an Iterator, because Iterators cannot
-// return a borrowed buffer ref (we want zero-copy)
-fn file_chunker<C, R>(
-    mut file: R,
-    chunk_size: usize,
-    chunk_cb: C
-) -> Result<(), Error>
-    where C: Fn(usize, &[u8]) -> Result<bool, Error>,
-          R: Read,
-{
-
-    const read_buffer_size: usize = 4*1024*1024; // 4M
-
-    if chunk_size > read_buffer_size { bail!("chunk size too large!"); }
-
-    let mut buf = vec![0u8; read_buffer_size];
-
-    let mut pos = 0;
-    let mut file_pos = 0;
-    loop {
-        let mut eof = false;
-        let mut tmp = &mut buf[..];
-       // try to read large portions, at least chunk_size
-        while pos < chunk_size {
-            match file.read(tmp) {
-                Ok(0) => { eof = true; break; },
-                Ok(n) => {
-                    pos += n;
-                    if pos > chunk_size { break; }
-                    tmp = &mut tmp[n..];
-                }
-                Err(ref e) if e.kind() == ErrorKind::Interrupted => { /* try again */ }
-                Err(e) => bail!("read error - {}", e.to_string()),
-            }
-        }
-        println!("READ {} {}", pos, eof);
-
-        let mut start = 0;
-        while start + chunk_size <= pos {
-            if !(chunk_cb)(file_pos, &buf[start..start+chunk_size])? { break; }
-            file_pos += chunk_size;
-            start += chunk_size;
-        }
-        if eof {
-            if start < pos {
-                (chunk_cb)(file_pos, &buf[start..pos])?;
-                //file_pos += pos - start;
-            }
-            break;
-        } else {
-            let rest = pos - start;
-            if rest > 0 {
-                let ptr = buf.as_mut_ptr();
-                unsafe { std::ptr::copy_nonoverlapping(ptr.add(start), ptr, rest); }
-                pos = rest;
-            } else {
-                pos = 0;
-            }
-        }
-    }
-
-    Ok(())
-
-}
-
 fn backup_file(param: Value, _info: &ApiMethod) -> Result<Value, Error> {
 
     let filename = required_string_param(&param, "filename");
@@ -105,7 +33,7 @@ fn backup_file(param: Value, _info: &ApiMethod) -> Result<Value, Error> {
 
     let file = std::fs::File::open(filename)?;
 
-    file_chunker(file, 64*1024, |pos, chunk| {
+    tools::file_chunker(file, 64*1024, |pos, chunk| {
         println!("CHUNK {} {}", pos, chunk.len());
         Ok(true)
     })?;
diff --git a/src/tools.rs b/src/tools.rs
index 4abafeec..4e32d1aa 100644
--- a/src/tools.rs
+++ b/src/tools.rs
@@ -5,6 +5,8 @@ use nix::sys::stat;
 use std::fs::File;
 use std::io::Write;
 use std::path::Path;
+use std::io::Read;
+use std::io::ErrorKind;
 
 pub fn file_set_contents<P: AsRef<Path>>(
     path: P,
@@ -50,3 +52,68 @@ pub fn file_set_contents<P: AsRef<Path>>(
 
     Ok(())
 }
+
+// Note: We cannot implement an Iterator, because Iterators cannot
+// return a borrowed buffer ref (we want zero-copy)
+pub fn file_chunker<C, R>(
+    mut file: R,
+    chunk_size: usize,
+    chunk_cb: C
+) -> Result<(), Error>
+    where C: Fn(usize, &[u8]) -> Result<bool, Error>,
+          R: Read,
+{
+
+    const READ_BUFFER_SIZE: usize = 4*1024*1024; // 4M
+
+    if chunk_size > READ_BUFFER_SIZE { bail!("chunk size too large!"); }
+
+    let mut buf = vec![0u8; READ_BUFFER_SIZE];
+
+    let mut pos = 0;
+    let mut file_pos = 0;
+    loop {
+        let mut eof = false;
+        let mut tmp = &mut buf[..];
+       // try to read large portions, at least chunk_size
+        while pos < chunk_size {
+            match file.read(tmp) {
+                Ok(0) => { eof = true; break; },
+                Ok(n) => {
+                    pos += n;
+                    if pos > chunk_size { break; }
+                    tmp = &mut tmp[n..];
+                }
+                Err(ref e) if e.kind() == ErrorKind::Interrupted => { /* try again */ }
+                Err(e) => bail!("read error - {}", e.to_string()),
+            }
+        }
+        println!("READ {} {}", pos, eof);
+
+        let mut start = 0;
+        while start + chunk_size <= pos {
+            if !(chunk_cb)(file_pos, &buf[start..start+chunk_size])? { break; }
+            file_pos += chunk_size;
+            start += chunk_size;
+        }
+        if eof {
+            if start < pos {
+                (chunk_cb)(file_pos, &buf[start..pos])?;
+                //file_pos += pos - start;
+            }
+            break;
+        } else {
+            let rest = pos - start;
+            if rest > 0 {
+                let ptr = buf.as_mut_ptr();
+                unsafe { std::ptr::copy_nonoverlapping(ptr.add(start), ptr, rest); }
+                pos = rest;
+            } else {
+                pos = 0;
+            }
+        }
+    }
+
+    Ok(())
+
+}