Split up LazyFile for test/prod

libimagstore/src/lazyfile.rs

@@ -1,3 +1,60 @@
+pub use self::fs::LazyFile;
+
+#[cfg(test)]
+mod fs {
+    use error::StoreError as SE;
+    use std::io::Cursor;
+    use std::path::PathBuf;
+
+    /// `LazyFile` type
+    ///
+    /// A lazy file is either absent, but a path to it is available, or it is present.
+    #[derive(Debug)]
+    pub enum LazyFile {
+        Absent(PathBuf),
+        File(Cursor<Vec<u8>>)
+    }
+
+    impl LazyFile {
+
+        /**
+         * Get the mutable file behind a LazyFile object
+         */
+        pub fn get_file_mut(&mut self) -> Result<&mut Cursor<Vec<u8>>, SE> {
+            debug!("Getting lazy file: {:?}", self);
+            let file = match *self {
+                LazyFile::File(ref mut f) => return {
+                    Ok(f)
+                },
+                LazyFile::Absent(ref p) => unreachable!(),
+            };
+            *self = LazyFile::File(file);
+            if let LazyFile::File(ref mut f) = *self {
+                return Ok(f);
+            }
+            unreachable!()
+        }
+
+        /**
+         * Create a file out of this LazyFile object
+         */
+        pub fn create_file(&mut self) -> Result<&mut Cursor<Vec<u8>>, SE> {
+            debug!("Creating lazy file: {:?}", self);
+            let file = match *self {
+                LazyFile::File(ref mut f) => return Ok(f),
+                LazyFile::Absent(ref p) => unreachable!(),
+            };
+            *self = LazyFile::File(file);
+            if let LazyFile::File(ref mut f) = *self {
+                return Ok(f);
+            }
+            unreachable!()
+        }
+    }
+}
+
+#[cfg(not(test))]
+mod fs {
     use error::{MapErrInto, StoreError as SE, StoreErrorKind as SEK};
     use std::io::{Seek, SeekFrom};
     use std::path::{Path, PathBuf};
@@ -56,16 +113,21 @@ impl LazyFile {
         pub fn create_file(&mut self) -> Result<&mut File, SE> {
             debug!("Creating lazy file: {:?}", self);
             let file = match *self {
-            LazyFile::File(ref mut f) => return Ok(f),
+                LazyFile::File(ref mut f) => {
+                    try!(f.set_len(0).map_err_into(SEK::FileError));
+                    return Ok(f)
+                },
                 LazyFile::Absent(ref p) => try!(create_file(p).map_err_into(SEK::FileNotFound)),
             };
             *self = LazyFile::File(file);
             if let LazyFile::File(ref mut f) = *self {
+                try!(f.set_len(0).map_err_into(SEK::FileError));
                 return Ok(f);
             }
             unreachable!()
         }
     }
+}
 
 #[cfg(test)]
 mod test {