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git/src/loose.rs

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// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation: version 2 of the License, dated June 1991.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, see <https://www.gnu.org/licenses/>.
use crate::hash::{HashAlgorithm, ObjectID, GIT_MAX_RAWSZ};
use std::collections::BTreeMap;
use std::convert::TryInto;
use std::io::{self, Write};
/// The type of object stored in the map.
///
/// If this value is `Reserved`, then it is never written to disk and is used primarily to store
/// certain hard-coded objects, like the empty tree, empty blob, or null object ID.
///
/// If this value is `LooseObject`, then this represents a loose object. `Shallow` represents a
/// shallow commit, its parent, or its tree. `Submodule` represents a submodule commit.
#[repr(C)]
#[derive(Debug, Clone, Copy, Ord, PartialOrd, Eq, PartialEq)]
pub enum MapType {
Reserved = 0,
LooseObject = 1,
Shallow = 2,
Submodule = 3,
}
impl MapType {
pub fn from_u32(n: u32) -> Option<MapType> {
match n {
0 => Some(Self::Reserved),
1 => Some(Self::LooseObject),
2 => Some(Self::Shallow),
3 => Some(Self::Submodule),
_ => None,
}
}
}
/// The value of an object stored in a `ObjectMemoryMap`.
///
/// This keeps the object ID to which the key is mapped and its kind together.
struct MappedObject {
oid: ObjectID,
kind: MapType,
}
/// Memory storage for a loose object.
struct ObjectMemoryMap {
to_compat: BTreeMap<ObjectID, MappedObject>,
to_storage: BTreeMap<ObjectID, MappedObject>,
compat: HashAlgorithm,
storage: HashAlgorithm,
}
impl ObjectMemoryMap {
/// Create a new `ObjectMemoryMap`.
///
/// The storage and compatibility `HashAlgorithm` instances are used to store the object IDs in
/// the correct map.
fn new(storage: HashAlgorithm, compat: HashAlgorithm) -> Self {
Self {
to_compat: BTreeMap::new(),
to_storage: BTreeMap::new(),
compat,
storage,
}
}
fn len(&self) -> usize {
self.to_compat.len()
}
/// Write this map to an interface implementing `std::io::Write`.
fn write<W: Write>(&self, wrtr: W) -> io::Result<()> {
const VERSION_NUMBER: u32 = 1;
const NUM_OBJECT_FORMATS: u32 = 2;
const PADDING: [u8; 4] = [0u8; 4];
let mut wrtr = wrtr;
let header_size: u32 = (4 * 5) + (4 + 4 + 8) * NUM_OBJECT_FORMATS + 8;
wrtr.write_all(b"LMAP")?;
wrtr.write_all(&VERSION_NUMBER.to_be_bytes())?;
wrtr.write_all(&header_size.to_be_bytes())?;
wrtr.write_all(&(self.to_compat.len() as u32).to_be_bytes())?;
wrtr.write_all(&NUM_OBJECT_FORMATS.to_be_bytes())?;
let storage_short_len = self.find_short_name_len(&self.to_compat, self.storage);
let compat_short_len = self.find_short_name_len(&self.to_storage, self.compat);
let storage_npadding = Self::required_nul_padding(self.to_compat.len(), storage_short_len);
let compat_npadding = Self::required_nul_padding(self.to_compat.len(), compat_short_len);
let mut offset: u64 = header_size as u64;
for (algo, len, npadding) in &[
(self.storage, storage_short_len, storage_npadding),
(self.compat, compat_short_len, compat_npadding),
] {
wrtr.write_all(&algo.format_id().to_be_bytes())?;
wrtr.write_all(&(*len as u32).to_be_bytes())?;
offset += *npadding;
wrtr.write_all(&offset.to_be_bytes())?;
offset += self.to_compat.len() as u64 * (*len as u64 + algo.raw_len() as u64 + 4);
}
wrtr.write_all(&offset.to_be_bytes())?;
let order_map: BTreeMap<&ObjectID, usize> = self
.to_compat
.keys()
.enumerate()
.map(|(i, oid)| (oid, i))
.collect();
wrtr.write_all(&PADDING[0..storage_npadding as usize])?;
for oid in self.to_compat.keys() {
wrtr.write_all(&oid.as_slice().unwrap()[0..storage_short_len])?;
}
for oid in self.to_compat.keys() {
wrtr.write_all(oid.as_slice().unwrap())?;
}
for meta in self.to_compat.values() {
wrtr.write_all(&(meta.kind as u32).to_be_bytes())?;
}
wrtr.write_all(&PADDING[0..compat_npadding as usize])?;
for oid in self.to_storage.keys() {
wrtr.write_all(&oid.as_slice().unwrap()[0..compat_short_len])?;
}
for meta in self.to_compat.values() {
wrtr.write_all(meta.oid.as_slice().unwrap())?;
}
for meta in self.to_storage.values() {
wrtr.write_all(&(order_map[&meta.oid] as u32).to_be_bytes())?;
}
Ok(())
}
fn required_nul_padding(nitems: usize, short_len: usize) -> u64 {
let shortened_table_len = nitems as u64 * short_len as u64;
let misalignment = shortened_table_len & 3;
// If the value is 0, return 0; otherwise, return the difference from 4.
(4 - misalignment) & 3
}
fn last_matching_offset(a: &ObjectID, b: &ObjectID, algop: HashAlgorithm) -> usize {
for i in 0..=algop.raw_len() {
if a.hash[i] != b.hash[i] {
return i;
}
}
algop.raw_len()
}
fn find_short_name_len(
&self,
map: &BTreeMap<ObjectID, MappedObject>,
algop: HashAlgorithm,
) -> usize {
if map.len() <= 1 {
return 1;
}
let mut len = 1;
let mut iter = map.keys();
let mut cur = match iter.next() {
Some(cur) => cur,
None => return len,
};
for item in iter {
let offset = Self::last_matching_offset(cur, item, algop);
if offset >= len {
len = offset + 1;
}
cur = item;
}
if len > algop.raw_len() {
algop.raw_len()
} else {
len
}
}
}
struct ObjectFormatData {
data_off: usize,
shortened_len: usize,
full_off: usize,
mapping_off: Option<usize>,
}
pub struct MmapedObjectMapIter<'a> {
offset: usize,
algos: Vec<HashAlgorithm>,
source: &'a MmapedObjectMap<'a>,
}
impl<'a> Iterator for MmapedObjectMapIter<'a> {
type Item = Vec<ObjectID>;
fn next(&mut self) -> Option<Self::Item> {
if self.offset >= self.source.nitems {
return None;
}
let offset = self.offset;
self.offset += 1;
let v: Vec<ObjectID> = self
.algos
.iter()
.cloned()
.filter_map(|algo| self.source.oid_from_offset(offset, algo))
.collect();
if v.len() != self.algos.len() {
return None;
}
Some(v)
}
}
#[allow(dead_code)]
pub struct MmapedObjectMap<'a> {
memory: &'a [u8],
nitems: usize,
meta_off: usize,
obj_formats: BTreeMap<HashAlgorithm, ObjectFormatData>,
main_algo: HashAlgorithm,
}
#[derive(Debug)]
#[allow(dead_code)]
enum MmapedParseError {
HeaderTooSmall,
InvalidSignature,
InvalidVersion,
UnknownAlgorithm,
OffsetTooLarge,
TooFewObjectFormats,
UnalignedData,
InvalidTrailerOffset,
}
#[allow(dead_code)]
impl<'a> MmapedObjectMap<'a> {
fn new(
slice: &'a [u8],
hash_algo: HashAlgorithm,
) -> Result<MmapedObjectMap<'a>, MmapedParseError> {
let object_format_header_size = 4 + 4 + 8;
let trailer_offset_size = 8;
let header_size: usize =
4 + 4 + 4 + 4 + 4 + object_format_header_size * 2 + trailer_offset_size;
if slice.len() < header_size {
return Err(MmapedParseError::HeaderTooSmall);
}
if slice[0..4] != *b"LMAP" {
return Err(MmapedParseError::InvalidSignature);
}
if Self::u32_at_offset(slice, 4) != 1 {
return Err(MmapedParseError::InvalidVersion);
}
let _ = Self::u32_at_offset(slice, 8) as usize;
let nitems = Self::u32_at_offset(slice, 12) as usize;
let nobj_formats = Self::u32_at_offset(slice, 16) as usize;
if nobj_formats < 2 {
return Err(MmapedParseError::TooFewObjectFormats);
}
let mut offset = 20;
let mut meta_off = None;
let mut data = BTreeMap::new();
for i in 0..nobj_formats {
if offset + object_format_header_size + trailer_offset_size > slice.len() {
return Err(MmapedParseError::HeaderTooSmall);
}
let format_id = Self::u32_at_offset(slice, offset);
let shortened_len = Self::u32_at_offset(slice, offset + 4) as usize;
let data_off = Self::u64_at_offset(slice, offset + 8);
let algo = HashAlgorithm::from_format_id(format_id)
.ok_or(MmapedParseError::UnknownAlgorithm)?;
let data_off: usize = data_off
.try_into()
.map_err(|_| MmapedParseError::OffsetTooLarge)?;
// Every object format must have these entries.
let shortened_table_len = shortened_len
.checked_mul(nitems)
.ok_or(MmapedParseError::OffsetTooLarge)?;
let full_off = data_off
.checked_add(shortened_table_len)
.ok_or(MmapedParseError::OffsetTooLarge)?;
Self::verify_aligned(full_off)?;
Self::verify_valid(slice, full_off as u64)?;
let full_length = algo
.raw_len()
.checked_mul(nitems)
.ok_or(MmapedParseError::OffsetTooLarge)?;
let off = full_length
.checked_add(full_off)
.ok_or(MmapedParseError::OffsetTooLarge)?;
Self::verify_aligned(off)?;
Self::verify_valid(slice, off as u64)?;
// This is for the metadata for the first object format and for the order mapping for
// other object formats.
let meta_size = nitems
.checked_mul(4)
.ok_or(MmapedParseError::OffsetTooLarge)?;
let meta_end = off
.checked_add(meta_size)
.ok_or(MmapedParseError::OffsetTooLarge)?;
Self::verify_valid(slice, meta_end as u64)?;
let mut mapping_off = None;
if i == 0 {
meta_off = Some(off);
} else {
mapping_off = Some(off);
}
data.insert(
algo,
ObjectFormatData {
data_off,
shortened_len,
full_off,
mapping_off,
},
);
offset += object_format_header_size;
}
let trailer = Self::u64_at_offset(slice, offset);
Self::verify_aligned(trailer as usize)?;
Self::verify_valid(slice, trailer)?;
let end = trailer
.checked_add(hash_algo.raw_len() as u64)
.ok_or(MmapedParseError::OffsetTooLarge)?;
if end != slice.len() as u64 {
return Err(MmapedParseError::InvalidTrailerOffset);
}
match meta_off {
Some(meta_off) => Ok(MmapedObjectMap {
memory: slice,
nitems,
meta_off,
obj_formats: data,
main_algo: hash_algo,
}),
None => Err(MmapedParseError::TooFewObjectFormats),
}
}
fn iter(&self) -> MmapedObjectMapIter<'_> {
let mut algos = Vec::with_capacity(self.obj_formats.len());
algos.push(self.main_algo);
for algo in self.obj_formats.keys().cloned() {
if algo != self.main_algo {
algos.push(algo);
}
}
MmapedObjectMapIter {
offset: 0,
algos,
source: self,
}
}
/// Treats `sl` as if it were a set of slices of `wanted.len()` bytes, and searches for
/// `wanted` within it.
///
/// If found, returns the offset of the subslice in `sl`.
///
/// ```
/// let sl = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
///
/// assert_eq!(MmapedObjectMap::binary_search_slice(sl, &[2, 3]), Some(1));
/// assert_eq!(MmapedObjectMap::binary_search_slice(sl, &[6, 7]), Some(4));
/// assert_eq!(MmapedObjectMap::binary_search_slice(sl, &[1, 2]), None);
/// assert_eq!(MmapedObjectMap::binary_search_slice(sl, &[10, 20]), None);
/// ```
fn binary_search_slice(sl: &[u8], wanted: &[u8]) -> Option<usize> {
let len = wanted.len();
let res = sl.binary_search_by(|item| {
// We would like element_offset, but that is currently nightly only. Instead, do a
// pointer subtraction to find the index.
let index = unsafe { (item as *const u8).offset_from(sl.as_ptr()) } as usize;
// Now we have the index of this object. Round it down to the nearest full-sized
// chunk to find the actual offset where this starts.
let index = index - (index % len);
// Compute the comparison of that value instead, which will provide the expected
// result.
sl[index..index + wanted.len()].cmp(wanted)
});
res.ok().map(|offset| offset / len)
}
/// Look up `oid` in the map in order to convert it to `algo`.
///
/// If this object is in the map, return the offset in the table for the main algorithm.
fn look_up_object(&self, oid: &ObjectID) -> Option<usize> {
let oid_algo = HashAlgorithm::from_u32(oid.algo)?;
let params = self.obj_formats.get(&oid_algo)?;
let short_table =
&self.memory[params.data_off..params.data_off + (params.shortened_len * self.nitems)];
let index = Self::binary_search_slice(
short_table,
&oid.as_slice().unwrap()[0..params.shortened_len],
)?;
match params.mapping_off {
Some(from_off) => {
// oid is in a compatibility algorithm. Find the mapping index.
let mapped = Self::u32_at_offset(self.memory, from_off + index * 4) as usize;
if mapped >= self.nitems {
return None;
}
let oid_offset = params.full_off + mapped * oid_algo.raw_len();
if self.memory[oid_offset..oid_offset + oid_algo.raw_len()]
!= *oid.as_slice().unwrap()
{
return None;
}
Some(mapped)
}
None => {
// oid is in the main algorithm. Find the object ID in the main map to confirm
// it's correct.
let oid_offset = params.full_off + index * oid_algo.raw_len();
if self.memory[oid_offset..oid_offset + oid_algo.raw_len()]
!= *oid.as_slice().unwrap()
{
return None;
}
Some(index)
}
}
}
#[allow(dead_code)]
fn map_object(&self, oid: &ObjectID, algo: HashAlgorithm) -> Option<MappedObject> {
let main = self.look_up_object(oid)?;
let meta = MapType::from_u32(Self::u32_at_offset(self.memory, self.meta_off + (main * 4)))?;
Some(MappedObject {
oid: self.oid_from_offset(main, algo)?,
kind: meta,
})
}
fn map_oid(&self, oid: &ObjectID, algo: HashAlgorithm) -> Option<ObjectID> {
if algo as u32 == oid.algo {
return Some(oid.clone());
}
let main = self.look_up_object(oid)?;
self.oid_from_offset(main, algo)
}
fn oid_from_offset(&self, offset: usize, algo: HashAlgorithm) -> Option<ObjectID> {
let aparams = self.obj_formats.get(&algo)?;
let mut hash = [0u8; GIT_MAX_RAWSZ];
let len = algo.raw_len();
let oid_off = aparams.full_off + (offset * len);
hash[0..len].copy_from_slice(&self.memory[oid_off..oid_off + len]);
Some(ObjectID {
hash,
algo: algo as u32,
})
}
fn u32_at_offset(slice: &[u8], offset: usize) -> u32 {
u32::from_be_bytes(slice[offset..offset + 4].try_into().unwrap())
}
fn u64_at_offset(slice: &[u8], offset: usize) -> u64 {
u64::from_be_bytes(slice[offset..offset + 8].try_into().unwrap())
}
fn verify_aligned(offset: usize) -> Result<(), MmapedParseError> {
if (offset & 3) != 0 {
return Err(MmapedParseError::UnalignedData);
}
Ok(())
}
fn verify_valid(slice: &[u8], offset: u64) -> Result<(), MmapedParseError> {
if offset >= slice.len() as u64 {
return Err(MmapedParseError::OffsetTooLarge);
}
Ok(())
}
}
/// A map for loose and other non-packed object IDs that maps between a storage and compatibility
/// mapping.
///
/// In addition to the in-memory option, there is an optional batched storage, which can be used to
/// write objects to disk in an efficient way.
pub struct ObjectMap {
mem: ObjectMemoryMap,
batch: Option<ObjectMemoryMap>,
}
impl ObjectMap {
/// Create a new `ObjectMap` with the given hash algorithms.
///
/// This initializes the memory map to automatically map the empty tree, empty blob, and null
/// object ID.
pub fn new(storage: HashAlgorithm, compat: HashAlgorithm) -> Self {
let mut map = ObjectMemoryMap::new(storage, compat);
for (main, compat) in &[
(storage.empty_tree(), compat.empty_tree()),
(storage.empty_blob(), compat.empty_blob()),
(storage.null_oid(), compat.null_oid()),
] {
map.to_storage.insert(
(*compat).clone(),
MappedObject {
oid: (*main).clone(),
kind: MapType::Reserved,
},
);
map.to_compat.insert(
(*main).clone(),
MappedObject {
oid: (*compat).clone(),
kind: MapType::Reserved,
},
);
}
Self {
mem: map,
batch: None,
}
}
pub fn hash_algo(&self) -> HashAlgorithm {
self.mem.storage
}
/// Start a batch for efficient writing.
///
/// If there is already a batch started, this does nothing and the existing batch is retained.
pub fn start_batch(&mut self) {
if self.batch.is_none() {
self.batch = Some(ObjectMemoryMap::new(self.mem.storage, self.mem.compat));
}
}
pub fn batch_len(&self) -> Option<usize> {
self.batch.as_ref().map(|b| b.len())
}
/// If a batch exists, write it to the writer.
pub fn finish_batch<W: Write>(&mut self, w: W) -> io::Result<()> {
if let Some(txn) = self.batch.take() {
txn.write(w)?;
}
Ok(())
}
/// If a batch exists, write it to the writer.
pub fn abort_batch(&mut self) {
self.batch = None;
}
/// Return whether there is a batch already started.
///
/// If you just want a batch to exist and don't care whether one has already been started, you
/// may simply call `start_batch` unconditionally.
pub fn has_batch(&self) -> bool {
self.batch.is_some()
}
/// Insert an object into the map.
///
/// If `write` is true and there is a batch started, write the object into the batch as well as
/// into the memory map.
pub fn insert(&mut self, oid1: &ObjectID, oid2: &ObjectID, kind: MapType, write: bool) {
let (compat_oid, storage_oid) =
if HashAlgorithm::from_u32(oid1.algo) == Some(self.mem.compat) {
(oid1, oid2)
} else {
(oid2, oid1)
};
Self::insert_into(&mut self.mem, storage_oid, compat_oid, kind);
if write {
if let Some(ref mut batch) = self.batch {
Self::insert_into(batch, storage_oid, compat_oid, kind);
}
}
}
fn insert_into(
map: &mut ObjectMemoryMap,
storage: &ObjectID,
compat: &ObjectID,
kind: MapType,
) {
map.to_compat.insert(
storage.clone(),
MappedObject {
oid: compat.clone(),
kind,
},
);
map.to_storage.insert(
compat.clone(),
MappedObject {
oid: storage.clone(),
kind,
},
);
}
#[allow(dead_code)]
fn map_object(&self, oid: &ObjectID, algo: HashAlgorithm) -> Option<&MappedObject> {
let map = if algo == self.mem.storage {
&self.mem.to_storage
} else {
&self.mem.to_compat
};
map.get(oid)
}
#[allow(dead_code)]
fn map_oid<'a, 'b: 'a>(
&'b self,
oid: &'a ObjectID,
algo: HashAlgorithm,
) -> Option<&'a ObjectID> {
if algo as u32 == oid.algo {
return Some(oid);
}
let entry = self.map_object(oid, algo);
entry.map(|obj| &obj.oid)
}
}
#[cfg(test)]
mod tests {
use super::{MapType, MmapedObjectMap, ObjectMap, ObjectMemoryMap};
use crate::hash::{CryptoDigest, CryptoHasher, HashAlgorithm, ObjectID};
use std::convert::TryInto;
use std::io::{self, Cursor, Write};
struct TrailingWriter {
curs: Cursor<Vec<u8>>,
hasher: CryptoHasher,
}
impl TrailingWriter {
fn new() -> Self {
Self {
curs: Cursor::new(Vec::new()),
hasher: CryptoHasher::new(HashAlgorithm::SHA256),
}
}
fn finalize(mut self) -> Vec<u8> {
let _ = self.hasher.flush();
let mut v = self.curs.into_inner();
v.extend(self.hasher.into_vec());
v
}
}
impl Write for TrailingWriter {
fn write(&mut self, data: &[u8]) -> io::Result<usize> {
self.hasher.write_all(data)?;
self.curs.write_all(data)?;
Ok(data.len())
}
fn flush(&mut self) -> io::Result<()> {
self.hasher.flush()?;
self.curs.flush()?;
Ok(())
}
}
fn sha1_oid(b: &[u8]) -> ObjectID {
assert_eq!(b.len(), 20);
let mut data = [0u8; 32];
data[0..20].copy_from_slice(b);
ObjectID {
hash: data,
algo: HashAlgorithm::SHA1 as u32,
}
}
fn sha256_oid(b: &[u8]) -> ObjectID {
assert_eq!(b.len(), 32);
ObjectID {
hash: b.try_into().unwrap(),
algo: HashAlgorithm::SHA256 as u32,
}
}
#[allow(clippy::type_complexity)]
fn test_entries() -> &'static [(&'static str, &'static [u8], &'static [u8], MapType, bool)] {
// These are all example blobs containing the content in the first argument.
&[
("abc", b"\xf2\xba\x8f\x84\xab\x5c\x1b\xce\x84\xa7\xb4\x41\xcb\x19\x59\xcf\xc7\x09\x3b\x7f", b"\xc1\xcf\x6e\x46\x50\x77\x93\x0e\x88\xdc\x51\x36\x64\x1d\x40\x2f\x72\xa2\x29\xdd\xd9\x96\xf6\x27\xd6\x0e\x96\x39\xea\xba\x35\xa6", MapType::LooseObject, false),
("def", b"\x0c\x00\x38\x32\xe7\xbf\xa9\xca\x8b\x5c\x20\x35\xc9\xbd\x68\x4a\x5f\x26\x23\xbc", b"\x8a\x90\x17\x26\x48\x4d\xb0\xf2\x27\x9f\x30\x8d\x58\x96\xd9\x6b\xf6\x3a\xd6\xde\x95\x7c\xa3\x8a\xdc\x33\x61\x68\x03\x6e\xf6\x63", MapType::Shallow, true),
("ghi", b"\x45\xa8\x2e\x29\x5c\x52\x47\x31\x14\xc5\x7c\x18\xf4\xf5\x23\x68\xdf\x2a\x3c\xfd", b"\x6e\x47\x4c\x74\xf5\xd7\x78\x14\xc7\xf7\xf0\x7c\x37\x80\x07\x90\x53\x42\xaf\x42\x81\xe6\x86\x8d\x33\x46\x45\x4b\xb8\x63\xab\xc3", MapType::Submodule, false),
("jkl", b"\x45\x32\x8c\x36\xff\x2e\x9b\x9b\x4e\x59\x2c\x84\x7d\x3f\x9a\x7f\xd9\xb3\xe7\x16", b"\xc3\xee\xf7\x54\xa2\x1e\xc6\x9d\x43\x75\xbe\x6f\x18\x47\x89\xa8\x11\x6f\xd9\x66\xfc\x67\xdc\x31\xd2\x11\x15\x42\xc8\xd5\xa0\xaf", MapType::LooseObject, true),
]
}
fn test_map(write_all: bool) -> Box<ObjectMap> {
let mut map = Box::new(ObjectMap::new(HashAlgorithm::SHA256, HashAlgorithm::SHA1));
map.start_batch();
for (_blob_content, sha1, sha256, kind, swap) in test_entries() {
let s256 = sha256_oid(sha256);
let s1 = sha1_oid(sha1);
let write = write_all || (*kind as u32 & 2) == 0;
if *swap {
// Insert the item into the batch arbitrarily based on the type. This tests that
// we can specify either order and we'll do the right thing.
map.insert(&s256, &s1, *kind, write);
} else {
map.insert(&s1, &s256, *kind, write);
}
}
map
}
#[test]
fn can_read_and_write_format() {
for full in &[true, false] {
let mut map = test_map(*full);
let mut wrtr = TrailingWriter::new();
map.finish_batch(&mut wrtr).unwrap();
assert!(!map.has_batch());
let data = wrtr.finalize();
MmapedObjectMap::new(&data, HashAlgorithm::SHA256).unwrap();
}
}
#[test]
fn looks_up_from_mmaped() {
let mut map = test_map(true);
let mut wrtr = TrailingWriter::new();
map.finish_batch(&mut wrtr).unwrap();
assert!(!map.has_batch());
let data = wrtr.finalize();
let entries = test_entries();
let map = MmapedObjectMap::new(&data, HashAlgorithm::SHA256).unwrap();
for (_, sha1, sha256, kind, _) in entries {
let s256 = sha256_oid(sha256);
let s1 = sha1_oid(sha1);
let res = map.map_object(&s256, HashAlgorithm::SHA1).unwrap();
assert_eq!(res.oid, s1);
assert_eq!(res.kind, *kind);
let res = map.map_oid(&s256, HashAlgorithm::SHA1).unwrap();
assert_eq!(res, s1);
let res = map.map_object(&s256, HashAlgorithm::SHA256).unwrap();
assert_eq!(res.oid, s256);
assert_eq!(res.kind, *kind);
let res = map.map_oid(&s256, HashAlgorithm::SHA256).unwrap();
assert_eq!(res, s256);
let res = map.map_object(&s1, HashAlgorithm::SHA256).unwrap();
assert_eq!(res.oid, s256);
assert_eq!(res.kind, *kind);
let res = map.map_oid(&s1, HashAlgorithm::SHA256).unwrap();
assert_eq!(res, s256);
let res = map.map_object(&s1, HashAlgorithm::SHA1).unwrap();
assert_eq!(res.oid, s1);
assert_eq!(res.kind, *kind);
let res = map.map_oid(&s1, HashAlgorithm::SHA1).unwrap();
assert_eq!(res, s1);
}
for octet in &[0x00u8, 0x6d, 0x6e, 0x8a, 0xff] {
let missing_oid = ObjectID {
hash: [*octet; 32],
algo: HashAlgorithm::SHA256 as u32,
};
assert!(map.map_object(&missing_oid, HashAlgorithm::SHA1).is_none());
assert!(map.map_oid(&missing_oid, HashAlgorithm::SHA1).is_none());
assert_eq!(
map.map_oid(&missing_oid, HashAlgorithm::SHA256).unwrap(),
missing_oid
);
}
}
#[test]
fn binary_searches_slices_correctly() {
let sl = &[
0, 1, 2, 15, 14, 13, 18, 10, 2, 20, 20, 20, 21, 21, 0, 21, 21, 1, 21, 21, 21, 21, 21,
22, 22, 23, 24,
];
let expected: &[(&[u8], Option<usize>)] = &[
(&[0, 1, 2], Some(0)),
(&[15, 14, 13], Some(1)),
(&[18, 10, 2], Some(2)),
(&[20, 20, 20], Some(3)),
(&[21, 21, 0], Some(4)),
(&[21, 21, 1], Some(5)),
(&[21, 21, 21], Some(6)),
(&[21, 21, 22], Some(7)),
(&[22, 23, 24], Some(8)),
(&[2, 15, 14], None),
(&[0, 21, 21], None),
(&[21, 21, 23], None),
(&[22, 22, 23], None),
(&[0xff, 0xff, 0xff], None),
(&[0, 0, 0], None),
];
for (wanted, value) in expected {
assert_eq!(MmapedObjectMap::binary_search_slice(sl, wanted), *value);
}
}
#[test]
fn looks_up_oid_correctly() {
let map = test_map(false);
let entries = test_entries();
let s256 = sha256_oid(entries[0].2);
let s1 = sha1_oid(entries[0].1);
let missing_oid = ObjectID {
hash: [0xffu8; 32],
algo: HashAlgorithm::SHA256 as u32,
};
let res = map.map_object(&s256, HashAlgorithm::SHA1).unwrap();
assert_eq!(res.oid, s1);
assert_eq!(res.kind, MapType::LooseObject);
let res = map.map_oid(&s256, HashAlgorithm::SHA1).unwrap();
assert_eq!(*res, s1);
let res = map.map_object(&s1, HashAlgorithm::SHA256).unwrap();
assert_eq!(res.oid, s256);
assert_eq!(res.kind, MapType::LooseObject);
let res = map.map_oid(&s1, HashAlgorithm::SHA256).unwrap();
assert_eq!(*res, s256);
assert!(map.map_object(&missing_oid, HashAlgorithm::SHA1).is_none());
assert!(map.map_oid(&missing_oid, HashAlgorithm::SHA1).is_none());
assert_eq!(
*map.map_oid(&missing_oid, HashAlgorithm::SHA256).unwrap(),
missing_oid
);
}
#[test]
fn looks_up_known_oids_correctly() {
let map = test_map(false);
let funcs: &[&dyn Fn(HashAlgorithm) -> &'static ObjectID] = &[
&|h: HashAlgorithm| h.empty_tree(),
&|h: HashAlgorithm| h.empty_blob(),
&|h: HashAlgorithm| h.null_oid(),
];
for f in funcs {
let s256 = f(HashAlgorithm::SHA256);
let s1 = f(HashAlgorithm::SHA1);
let res = map.map_object(s256, HashAlgorithm::SHA1).unwrap();
assert_eq!(res.oid, *s1);
assert_eq!(res.kind, MapType::Reserved);
let res = map.map_oid(s256, HashAlgorithm::SHA1).unwrap();
assert_eq!(*res, *s1);
let res = map.map_object(s1, HashAlgorithm::SHA256).unwrap();
assert_eq!(res.oid, *s256);
assert_eq!(res.kind, MapType::Reserved);
let res = map.map_oid(s1, HashAlgorithm::SHA256).unwrap();
assert_eq!(*res, *s256);
}
}
#[test]
fn nul_padding() {
assert_eq!(ObjectMemoryMap::required_nul_padding(1, 1), 3);
assert_eq!(ObjectMemoryMap::required_nul_padding(2, 1), 2);
assert_eq!(ObjectMemoryMap::required_nul_padding(3, 1), 1);
assert_eq!(ObjectMemoryMap::required_nul_padding(2, 2), 0);
assert_eq!(ObjectMemoryMap::required_nul_padding(39, 3), 3);
}
}
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