Merge pull request 'Propose ETag fix' (#23) from bug/etag into master

Reviewed-on: Deuxfleurs/garage#23
This commit is contained in:
Alex 2020-12-06 15:27:58 +01:00
commit 857440f192
5 changed files with 24 additions and 3 deletions

1
Cargo.lock generated
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@ -461,6 +461,7 @@ dependencies = [
"log",
"md-5",
"percent-encoding",
"rand",
"roxmltree",
"sha2",
"tokio",

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@ -27,6 +27,7 @@ md-5 = "0.9.1"
sha2 = "0.8"
hmac = "0.7"
crypto-mac = "0.7"
rand = "0.7"
futures = "0.3"
futures-util = "0.3"

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@ -24,10 +24,13 @@ fn object_headers(
"Content-Type",
version_meta.headers.content_type.to_string(),
)
.header("ETag", version_meta.etag.to_string())
.header("Last-Modified", date_str)
.header("Accept-Ranges", format!("bytes"));
if !version_meta.etag.is_empty() {
resp = resp.header("ETag", format!("\"{}\"", version_meta.etag));
}
for (k, v) in version_meta.headers.other.iter() {
resp = resp.header(k, v.to_string());
}

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@ -428,6 +428,21 @@ pub async fn handle_complete_multipart_upload(
_ => unreachable!(),
};
// ETag calculation: we produce ETags that have the same form as
// those of S3 multipart uploads, but we don't use their actual
// calculation for the first part (we use random bytes). This
// shouldn't impact compatibility as the S3 docs specify that
// the ETag is an opaque value in case of a multipart upload.
// See also: https://teppen.io/2018/06/23/aws_s3_etags/
let num_parts = version.blocks().last().unwrap().part_number
- version.blocks().first().unwrap().part_number
+ 1;
let etag = format!(
"{}-{}",
hex::encode(&rand::random::<[u8; 16]>()[..]),
num_parts
);
// TODO: check that all the parts that they pretend they gave us are indeed there
// TODO: when we read the XML from _req, remember to check the sha256 sum of the payload
// against the signed x-amz-content-sha256
@ -442,7 +457,7 @@ pub async fn handle_complete_multipart_upload(
ObjectVersionMeta {
headers,
size: total_size,
etag: "".to_string(), // TODO
etag: etag,
},
version.blocks()[0].hash,
));

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@ -391,7 +391,8 @@ where
let (old_entry, new_entry) = self.store.transaction(|db| {
let (old_entry, new_entry) = match db.get(&tree_key)? {
Some(prev_bytes) => {
let old_entry = self.decode_entry(&prev_bytes)
let old_entry = self
.decode_entry(&prev_bytes)
.map_err(sled::ConflictableTransactionError::Abort)?;
let mut new_entry = old_entry.clone();
new_entry.merge(&update);