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Defragmentation in UploadPartCopy: first pass (not pretty but it compiles)

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Alex 2022-04-07 18:38:32 +02:00
parent a4f9f19ac3
commit e5341ca47b
Signed by: lx
GPG key ID: 0E496D15096376BE
1 changed files with 122 additions and 63 deletions
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185
src/api/s3_copy.rs
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@ -1,7 +1,7 @@
use std::sync::Arc;
use std::time::{Duration, SystemTime, UNIX_EPOCH};
use futures::TryFutureExt;
use futures::{stream, StreamExt, TryFutureExt};
use md5::{Digest as Md5Digest, Md5};
use hyper::{Body, Request, Response};
@ -298,77 +298,136 @@ pub async fn handle_upload_part_copy(
// Now, actually copy the blocks
let mut md5hasher = Md5::new();
let mut block = Some(
garage
.block_manager
.rpc_get_block(&blocks_to_copy[0].0)
.await?,
);
// First, create a stream that is able to read the source blocks
// and extract the subrange if necessary.
// The second returned value is an Option<Hash>, that is Some
// if and only if the block returned is a block that already existed
// in the Garage data store (thus we don't need to save it again).
let garage2 = garage.clone();
let source_blocks = stream::iter(blocks_to_copy)
.flat_map(|(block_hash, range_to_copy)| {
let garage3 = garage2.clone();
stream::once(async move {
let data = garage3.block_manager.rpc_get_block(&block_hash).await?;
match range_to_copy {
Some(r) => Ok((data[r].to_vec(), None)),
None => Ok((data, Some(block_hash))),
}
})
})
.peekable();
let mut source_blocks = Box::pin(source_blocks);
// Keep information about the next block we want to insert
let mut current_offset = 0;
for (i, (block_hash, range_to_copy)) in blocks_to_copy.iter().enumerate() {
let (current_block, subrange_hash) = match range_to_copy.clone() {
Some(r) => {
let subrange = block.take().unwrap()[r].to_vec();
let hash = blake2sum(&subrange);
(subrange, hash)
let mut next_block: Option<(Vec<u8>, Option<Hash>)> = None;
// State of the defragmenter
let config_block_size = garage.config.block_size;
let mut defrag_buffer = vec![];
let mut defrag_hash = None;
// We loop a step that does two things concurrently:
// 1. if there is a block to be inserted in next_block, insert it
// 2. grab the next block (it might be composed of several sub-blocks
// to be concatenated to ensure defragmentation)
loop {
let insert_current_block = async {
if let Some((data, existing_block_hash)) = next_block {
md5hasher.update(&data[..]);
let must_upload = existing_block_hash.is_none();
let final_hash = existing_block_hash.unwrap_or_else(|| blake2sum(&data[..]));
let mut version =
Version::new(dest_version_uuid, dest_bucket_id, dest_key.clone(), false);
version.blocks.put(
VersionBlockKey {
part_number,
offset: current_offset,
},
VersionBlock {
hash: final_hash,
size: data.len() as u64,
},
);
current_offset += data.len() as u64;
let block_ref = BlockRef {
block: final_hash,
version: dest_version_uuid,
deleted: false.into(),
};
let garage2 = garage.clone();
futures::try_join!(
// Thing 1: if the block is not exactly a block that existed before,
// we need to insert that data as a new block.
async move {
if must_upload {
garage2.block_manager.rpc_put_block(final_hash, data).await
} else {
Ok(())
}
},
// Thing 2: we need to insert the block in the version
garage.version_table.insert(&version),
// Thing 3: we need to add a block reference
garage.block_ref_table.insert(&block_ref),
)?;
Ok(())
} else {
Ok(())
}
None => (block.take().unwrap(), *block_hash),
};
md5hasher.update(&current_block[..]);
let mut version = Version::new(dest_version_uuid, dest_bucket_id, dest_key.clone(), false);
version.blocks.put(
VersionBlockKey {
part_number,
offset: current_offset,
},
VersionBlock {
hash: subrange_hash,
size: current_block.len() as u64,
},
);
current_offset += current_block.len() as u64;
let block_ref = BlockRef {
block: subrange_hash,
version: dest_version_uuid,
deleted: false.into(),
};
let next_block_hash = blocks_to_copy.get(i + 1).map(|(h, _)| *h);
let get_next_block = async {
loop {
let tmpres: Option<&Result<(Vec<u8>, Option<Hash>), garage_util::error::Error>> =
source_blocks.as_mut().peek().await;
if let Some(res) = tmpres {
let (next_block, _) = match res {
Ok(t) => t,
Err(_) => {
source_blocks.next().await.unwrap()?;
unreachable!()
}
};
let garage2 = garage.clone();
let garage3 = garage.clone();
let is_subrange = range_to_copy.is_some();
let (_, _, _, next_block) = futures::try_join!(
// Thing 1: if we are taking a subrange of the source block,
// we need to insert that subrange as a new block.
async move {
if is_subrange {
garage2
.block_manager
.rpc_put_block(subrange_hash, current_block)
.await
if defrag_buffer.is_empty() {
let (next_block, next_block_hash) = source_blocks.next().await.unwrap()?;
defrag_buffer = next_block;
defrag_hash = next_block_hash;
} else if defrag_buffer.len() + next_block.len() > config_block_size {
return Ok((
std::mem::replace(&mut defrag_buffer, vec![]),
std::mem::replace(&mut defrag_hash, None),
));
} else {
let (next_block, _) = source_blocks.next().await.unwrap()?;
defrag_buffer.extend(next_block);
defrag_hash = None;
}
} else {
Ok(())
return Ok::<_, garage_util::error::Error>((
std::mem::replace(&mut defrag_buffer, vec![]),
std::mem::replace(&mut defrag_hash, None),
));
}
},
// Thing 2: we need to insert the block in the version
garage.version_table.insert(&version),
// Thing 3: we need to add a block reference
garage.block_ref_table.insert(&block_ref),
// Thing 4: we need to prefetch the next block
async move {
match next_block_hash {
Some(h) => Ok(Some(garage3.block_manager.rpc_get_block(&h).await?)),
None => Ok(None),
}
},
)?;
}
};
block = next_block;
let tmp: Result<(_, (Vec<u8>, Option<Hash>)), garage_util::error::Error> = futures::try_join!(
insert_current_block,
// Thing 4: we need to prefetch the next block
get_next_block,
);
let tmp_block = tmp?.1;
if tmp_block.0.is_empty() {
break;
}
next_block = Some(tmp_block);
}
let data_md5sum = md5hasher.finalize();