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Fix starting gap index with free sectors #6
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@vaIgarashi
vaIgarashi committed Jul 19, 2020
1 parent 0f20e46 commit a9d3b20
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Showing 2 changed files with 64 additions and 23 deletions.
1 change: 1 addition & 0 deletions Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ readme = "README.md"
byteorder = "1.3"
named-binary-tag = "0.2"
bitvec = "0.17"
log = "0.4.11"

[dev-dependencies]
tempfile = "3.1"
86 changes: 63 additions & 23 deletions src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,7 @@
//! ```
use bitvec::prelude::*;
use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
use log::debug;
use nbt::decode::TagDecodeError;
use nbt::decode::{read_gzip_compound_tag, read_zlib_compound_tag};
use nbt::encode::write_zlib_compound_tag;
Expand Down Expand Up @@ -175,7 +176,7 @@ impl<'a> AnvilChunkProvider<'a> {
}

// TODO: Cache region files.
let mut region = AnvilRegion::new(region_path)?;
let mut region = AnvilRegion::load(region_x, region_z, region_path)?;

region.read_chunk(region_chunk_x, region_chunk_z)
}
Expand Down Expand Up @@ -221,14 +222,18 @@ impl<'a> AnvilChunkProvider<'a> {
let region_path = self.folder_path.join(region_name);

// TODO: Cache region files.
let mut region = AnvilRegion::new(region_path)?;
let mut region = AnvilRegion::load(region_x, region_z, region_path)?;

region.write_chunk(region_chunk_x, region_chunk_z, chunk_compound_tag)
}
}

/// Region represents a 32x32 group of chunks.
struct AnvilRegion {
/// X-axis coordinate.
x: i32,
/// Z-axis coordinate.
z: i32,
/// File in which region are stored.
file: File,
/// Array of chunks metadata.
Expand Down Expand Up @@ -270,7 +275,7 @@ impl AnvilChunkMetadata {
}

impl AnvilRegion {
fn new<P: AsRef<Path>>(path: P) -> Result<Self, io::Error> {
fn load<P: AsRef<Path>>(x: i32, z: i32, path: P) -> Result<Self, io::Error> {
let mut file = OpenOptions::new()
.write(true)
.read(true)
Expand All @@ -287,6 +292,8 @@ impl AnvilRegion {
let used_sectors = Self::used_sectors(total_sectors, &chunks_metadata);

let region = AnvilRegion {
x,
z,
file,
chunks_metadata,
used_sectors,
Expand Down Expand Up @@ -437,12 +444,17 @@ impl AnvilRegion {
let sectors_required = (chunk_length / REGION_SECTOR_BYTES_LENGTH as u32) as u8 + 1;
let metadata = self.get_metadata(chunk_x, chunk_z);

// Can place chunk in the old sectors.
// Chunk still fits in the old place.
if metadata.sectors == sectors_required {
debug!(
"Region x: {}, z: {} chunk x: {}, z: {} with length {} still fits in the old place",
self.x, self.z, chunk_x, chunk_z, chunk_length
);

return Ok(metadata);
}

// Release used sectors.
// Release previously used sectors.
for i in 0..metadata.sectors {
let sector_index = metadata.sector_index as usize + i as usize;
self.used_sectors.set(sector_index, false);
Expand All @@ -455,30 +467,54 @@ impl AnvilRegion {
let mut sectors_free = 0;

for sector_index in 0..total_sectors {
// Sector occupied and we can't place chunk.
if self.used_sectors[sector_index as usize] {
sectors_free = 0;
continue;
}

debug!("Sector {} is free", sector_index);
sectors_free += 1;

// Can put chunk in gap.
if sectors_free == sectors_required {
let put_sector_index = sector_index as u32 - sectors_free as u32;
let put_sector_index = sector_index as u32 - sectors_free as u32 + 1;

// Acquire used sectors.
// Marking new sectors as used.
for i in 0..sectors_free {
let sector_index = put_sector_index as usize + i as usize;
self.used_sectors.set(sector_index, true);
}

return Ok(AnvilChunkMetadata::new(put_sector_index, sectors_free, 0));
debug!(
"Region x: {}, z: {} chunk x: {}, z: {} with {} required sectors \
can be placed in free sectors gap between from {} to {}",
self.x,
self.z,
chunk_x,
chunk_z,
sectors_required,
put_sector_index,
sector_index
);

return Ok(AnvilChunkMetadata::new(
put_sector_index,
sectors_required,
0,
));
}
}

// Extending file because cannot find a place to put chunk data.
let extend_sectors = sectors_required - sectors_free;
let extend_length = (REGION_SECTOR_BYTES_LENGTH * extend_sectors as u16) as u64;

debug!(
"Extending region x: {}, z: {} file for {} bytes to place chunk data",
self.x, self.z, extend_length
);

self.file.set_len(file_length + extend_length)?;

// Mark new sectors as used.
Expand Down Expand Up @@ -533,7 +569,7 @@ mod tests {
#[test]
fn test_empty_header_write() {
let file = NamedTempFile::new().unwrap();
let region = AnvilRegion::new(file.path()).unwrap();
let region = AnvilRegion::load(1, 1, file.path()).unwrap();
let file_length = region.file.metadata().unwrap().len();

assert_eq!(file_length, REGION_HEADER_BYTES_LENGTH);
Expand All @@ -542,7 +578,7 @@ mod tests {
#[test]
fn test_empty_region_init() {
let mut file = NamedTempFile::new().unwrap();
AnvilRegion::new(file.path()).unwrap();
AnvilRegion::load(1, 1, file.path()).unwrap();

let mut vec = Vec::new();
file.read_to_end(&mut vec).unwrap();
Expand All @@ -563,7 +599,7 @@ mod tests {
let path = Path::new("test/region/r.0.0.mca");
assert!(path.exists());

let region = AnvilRegion::new(path).unwrap();
let region = AnvilRegion::load(0, 0, path).unwrap();

for (index, expected_chunk_metadata) in expected_data.iter().enumerate() {
let chunk_metadata = region.chunks_metadata[256 + index];
Expand All @@ -577,7 +613,7 @@ mod tests {
let path = Path::new("test/region/r.0.0.mca");
assert!(path.exists());

let mut region = AnvilRegion::new(path).unwrap();
let mut region = AnvilRegion::load(0, 0, path).unwrap();
let compound_tag = region.read_chunk(15, 3).unwrap();
let level_tag = compound_tag.get_compound_tag("Level").unwrap();

Expand All @@ -590,7 +626,7 @@ mod tests {
let path = Path::new("test/empty_region.mca");
assert!(path.exists());

let mut region = AnvilRegion::new(path).unwrap();
let mut region = AnvilRegion::load(0, 0, path).unwrap();
let load_error = region.read_chunk(0, 0).err().unwrap();

match load_error {
Expand Down Expand Up @@ -647,7 +683,7 @@ mod tests {
#[test]
fn test_update_metadata() {
let mut file = NamedTempFile::new().unwrap();
let mut region = AnvilRegion::new(file.path()).unwrap();
let mut region = AnvilRegion::load(1, 1, file.path()).unwrap();

let mut metadata = AnvilChunkMetadata::new(500, 10, 0);
metadata.update_last_modified_timestamp();
Expand All @@ -665,7 +701,7 @@ mod tests {
#[test]
fn test_write_chunk_with_file_extend() {
let file = NamedTempFile::new().unwrap();
let mut region = AnvilRegion::new(file.path()).unwrap();
let mut region = AnvilRegion::load(1, 1, file.path()).unwrap();

let mut write_compound_tag = CompoundTag::new();
write_compound_tag.insert_bool("test_bool", true);
Expand All @@ -689,7 +725,7 @@ mod tests {
#[test]
fn test_write_chunk_same_sector() {
let file = NamedTempFile::new().unwrap();
let mut region = AnvilRegion::new(file.path()).unwrap();
let mut region = AnvilRegion::load(1, 1, file.path()).unwrap();

let mut write_compound_tag_1 = CompoundTag::new();
write_compound_tag_1.insert_bool("test_bool", true);
Expand Down Expand Up @@ -721,7 +757,7 @@ mod tests {
#[test]
fn test_write_chunk_same_sector_with_file_expand() {
let file = NamedTempFile::new().unwrap();
let mut region = AnvilRegion::new(file.path()).unwrap();
let mut region = AnvilRegion::load(1, 1, file.path()).unwrap();

let mut write_compound_tag_1 = CompoundTag::new();
write_compound_tag_1.insert_bool("test_bool", true);
Expand Down Expand Up @@ -751,34 +787,38 @@ mod tests {
}

#[test]
fn test_write_chunk_with_insert_in_middle() {
fn test_write_chunk_with_insert_in_middle_gap() {
let file = NamedTempFile::new().unwrap();
let mut region = AnvilRegion::new(file.path()).unwrap();
let mut region = AnvilRegion::load(1, 1, file.path()).unwrap();

let mut write_compound_tag = CompoundTag::new();
write_compound_tag.insert_bool("test_bool", true);
write_compound_tag.insert_str("test_str", "test");

for _ in 3..6 {
// First two sectors are occupied by header.
for _ in 0..3 {
region.used_sectors.push(true);
}

region.used_sectors.set(3, false);
region.used_sectors.set(2, false);

let length = REGION_HEADER_BYTES_LENGTH + REGION_SECTOR_BYTES_LENGTH as u64 * 3;
file.as_file().set_len(length).unwrap();

region.write_chunk(15, 15, write_compound_tag).unwrap();

assert!(region.used_sectors.get(4).unwrap());
for i in 0..5 {
assert!(region.used_sectors.get(i).unwrap());
}

assert_eq!(file.as_file().metadata().unwrap().len(), length);
assert_eq!(region.used_sectors.len(), 5);
}

#[test]
fn test_write_chunk_not_enough_gap() {
let file = NamedTempFile::new().unwrap();
let mut region = AnvilRegion::new(file.path()).unwrap();
let mut region = AnvilRegion::load(1, 1, file.path()).unwrap();

let mut write_compound_tag_1 = CompoundTag::new();
write_compound_tag_1.insert_bool("test_bool", true);
Expand Down

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