refactor (#293)

Author: Byron

Diff for: git-index/src/extension.rs

@@ -10,60 +10,58 @@ fn decode_header(data: &[u8]) -> (Signature, u32, &[u8]) {
     (signature.try_into().unwrap(), read_u32(size), data)
 }
 
-mod end_of_index_entry {
-    use crate::{extension, extension::EndOfIndexEntry, file::header, util::read_u32};
+pub(crate) mod end_of_index_entry {
+    use crate::{extension, extension::Signature, file::header, util::read_u32};
 
-    impl EndOfIndexEntry {
-        pub fn from_bytes(data: &[u8], object_hash: git_hash::Kind) -> Option<Self> {
-            let hash_len = object_hash.len_in_bytes();
-            if data.len() < EndOfIndexEntry::SIZE_WITH_HEADER + hash_len {
-                return None;
-            }
+    pub const SIGNATURE: Signature = *b"EOIE";
+    pub const SIZE: usize = 4 /* offset to extensions */ + git_hash::Kind::Sha1.len_in_bytes();
+    pub const SIZE_WITH_HEADER: usize = crate::extension::MIN_SIZE + SIZE;
 
-            let start_of_eoie = data.len() - EndOfIndexEntry::SIZE_WITH_HEADER - hash_len;
-            let ext_data = &data[start_of_eoie..data.len() - hash_len];
+    pub fn decode(data: &[u8], object_hash: git_hash::Kind) -> Option<usize> {
+        let hash_len = object_hash.len_in_bytes();
+        if data.len() < SIZE_WITH_HEADER + hash_len {
+            return None;
+        }
 
-            let (signature, ext_size, ext_data) = extension::decode_header(ext_data);
-            if signature != EndOfIndexEntry::SIGNATURE || ext_size as usize != EndOfIndexEntry::SIZE {
-                return None;
-            }
+        let start_of_eoie = data.len() - SIZE_WITH_HEADER - hash_len;
+        let ext_data = &data[start_of_eoie..data.len() - hash_len];
 
-            let (offset, checksum) = ext_data.split_at(4);
-            let offset = read_u32(offset) as usize;
-            if offset < header::SIZE || offset > start_of_eoie || checksum.len() != git_hash::Kind::Sha1.len_in_bytes()
-            {
-                return None;
-            }
+        let (signature, ext_size, ext_data) = extension::decode_header(ext_data);
+        if signature != SIGNATURE || ext_size as usize != SIZE {
+            return None;
+        }
 
-            let mut hasher = git_features::hash::hasher(git_hash::Kind::Sha1);
-            let mut last_chunk = None;
-            for (signature, chunk) in
-                extension::Iter::new(&data[offset..data.len() - EndOfIndexEntry::SIZE_WITH_HEADER - hash_len])
-            {
-                hasher.update(&signature);
-                hasher.update(&(chunk.len() as u32).to_be_bytes());
-                last_chunk = Some(chunk);
-            }
+        let (offset, checksum) = ext_data.split_at(4);
+        let offset = read_u32(offset) as usize;
+        if offset < header::SIZE || offset > start_of_eoie || checksum.len() != git_hash::Kind::Sha1.len_in_bytes() {
+            return None;
+        }
 
-            if hasher.digest() != checksum {
-                return None;
-            }
-            // The last-to-this chunk ends where ours starts
-            if last_chunk
-                .map(|s| s.as_ptr_range().end != (&data[start_of_eoie]) as *const _)
-                .unwrap_or(true)
-            {
-                return None;
-            }
-            todo!("euio")
+        let mut hasher = git_features::hash::hasher(git_hash::Kind::Sha1);
+        let mut last_chunk = None;
+        for (signature, chunk) in extension::Iter::new(&data[offset..data.len() - SIZE_WITH_HEADER - hash_len]) {
+            hasher.update(&signature);
+            hasher.update(&(chunk.len() as u32).to_be_bytes());
+            last_chunk = Some(chunk);
         }
+
+        if hasher.digest() != checksum {
+            return None;
+        }
+        // The last-to-this chunk ends where ours starts
+        if last_chunk
+            .map(|s| s.as_ptr_range().end != (&data[start_of_eoie]) as *const _)
+            .unwrap_or(true)
+        {
+            return None;
+        }
+
+        Some(offset)
     }
 }
 
 mod iter {
-    use crate::extension;
-    use crate::extension::Iter;
-    use crate::util::read_u32;
+    use crate::{extension, extension::Iter, util::read_u32};
 
     impl<'a> Iter<'a> {
         pub fn new(data_at_beginning_of_extensions_and_truncated: &'a [u8]) -> Self {
@@ -102,16 +100,3 @@ mod iter {
 pub struct Iter<'a> {
     data: &'a [u8],
 }
-
-pub struct EndOfIndexEntry {
-    /// The offset the the beginning of all extensions, or the end of all entries.
-    offset_to_extensions: u32,
-    /// The SHA1 checksum over the signature and size of all extensions.
-    checksum: git_hash::ObjectId,
-}
-
-impl EndOfIndexEntry {
-    pub const SIGNATURE: Signature = *b"EOIE";
-    pub const SIZE: usize = 4 /* offset to extensions */ + git_hash::Kind::Sha1.len_in_bytes();
-    pub const SIZE_WITH_HEADER: usize = crate::extension::MIN_SIZE + Self::SIZE;
-}

Diff for: git-index/src/file.rs

@@ -42,7 +42,7 @@ pub mod init {
             };
 
             let (version, num_entries, post_header_data) = header::decode(&data, object_hash)?;
-            let start_of_extensions = extension::EndOfIndexEntry::from_bytes(&data, object_hash);
+            let start_of_extensions = extension::end_of_index_entry::decode(&data, object_hash);
 
             Ok(File {
                 state: State { timestamp: mtime },

Diff for: git-index/src/lib.rs

@@ -7,7 +7,7 @@ use filetime::FileTime;
 
 pub mod file;
 
-pub mod extension;
+pub(crate) mod extension;
 
 pub mod init {
     use filetime::FileTime;