garage/src/k2v-client/src/lib.rs

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use std::collections::BTreeMap;
use std::time::Duration;
use http::header::{ACCEPT, CONTENT_LENGTH, CONTENT_TYPE};
use http::status::StatusCode;
use http::HeaderMap;
use rusoto_core::{ByteStream, DispatchSignedRequest, HttpClient};
use rusoto_credential::AwsCredentials;
use rusoto_signature::region::Region;
use rusoto_signature::signature::SignedRequest;
use serde::de::Error as DeError;
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use tokio::io::AsyncReadExt;
mod error;
pub use error::Error;
const DEFAULT_TIMEOUT: Duration = Duration::from_secs(5);
const DEFAULT_POLL_TIMEOUT: Duration = Duration::from_secs(300);
const SERVICE: &str = "k2v";
const GARAGE_CAUSALITY_TOKEN: &str = "X-Garage-Causality-Token";
/// Client used to query a K2V server.
pub struct K2vClient {
region: Region,
bucket: String,
creds: AwsCredentials,
client: HttpClient,
}
impl K2vClient {
/// Create a new K2V client.
pub fn new(
region: Region,
bucket: String,
creds: AwsCredentials,
user_agent: Option<String>,
) -> Result<Self, Error> {
let mut client = HttpClient::new()?;
if let Some(ua) = user_agent {
client.local_agent_prepend(ua);
} else {
client.local_agent_prepend(format!("k2v/{}", env!("CARGO_PKG_VERSION")));
}
Ok(K2vClient {
region,
bucket,
creds,
client,
})
}
/// Perform a ReadItem request, reading the value(s) stored for a single pk+sk.
pub async fn read_item(
&self,
partition_key: &str,
sort_key: &str,
) -> Result<CausalValue, Error> {
let mut req = SignedRequest::new(
"GET",
SERVICE,
&self.region,
&format!("/{}/{}", self.bucket, partition_key),
);
req.add_param("sort_key", sort_key);
req.add_header(ACCEPT, "application/octet-stream, application/json");
let res = self.dispatch(req, None).await?;
let causality = res
.causality_token
.ok_or_else(|| Error::InvalidResponse("missing causality token".into()))?;
if res.status == StatusCode::NO_CONTENT {
return Ok(CausalValue {
causality,
value: vec![K2vValue::Tombstone],
});
}
match res.content_type.as_deref() {
Some("application/octet-stream") => Ok(CausalValue {
causality,
value: vec![K2vValue::Value(res.body)],
}),
Some("application/json") => {
let value = serde_json::from_slice(&res.body)?;
Ok(CausalValue { causality, value })
}
Some(ct) => Err(Error::InvalidResponse(
format!("invalid content type: {}", ct).into(),
)),
None => Err(Error::InvalidResponse("missing content type".into())),
}
}
/// Perform a PollItem request, waiting for the value(s) stored for a single pk+sk to be
/// updated.
pub async fn poll_item(
&self,
partition_key: &str,
sort_key: &str,
causality: CausalityToken,
timeout: Option<Duration>,
) -> Result<Option<CausalValue>, Error> {
let timeout = timeout.unwrap_or(DEFAULT_POLL_TIMEOUT);
let mut req = SignedRequest::new(
"GET",
SERVICE,
&self.region,
&format!("/{}/{}", self.bucket, partition_key),
);
req.add_param("sort_key", sort_key);
req.add_param("causality_token", &causality.0);
req.add_param("timeout", &timeout.as_secs().to_string());
req.add_header(ACCEPT, "application/octet-stream, application/json");
let res = self.dispatch(req, Some(timeout + DEFAULT_TIMEOUT)).await?;
let causality = res
.causality_token
.ok_or_else(|| Error::InvalidResponse("missing causality token".into()))?;
if res.status == StatusCode::NOT_MODIFIED {
return Ok(None);
}
if res.status == StatusCode::NO_CONTENT {
return Ok(Some(CausalValue {
causality,
value: vec![K2vValue::Tombstone],
}));
}
match res.content_type.as_deref() {
Some("application/octet-stream") => Ok(Some(CausalValue {
causality,
value: vec![K2vValue::Value(res.body)],
})),
Some("application/json") => {
let value = serde_json::from_slice(&res.body)?;
Ok(Some(CausalValue { causality, value }))
}
Some(ct) => Err(Error::InvalidResponse(
format!("invalid content type: {}", ct).into(),
)),
None => Err(Error::InvalidResponse("missing content type".into())),
}
}
/// Perform an InsertItem request, inserting a value for a single pk+sk.
pub async fn insert_item(
&self,
partition_key: &str,
sort_key: &str,
value: Vec<u8>,
causality: Option<CausalityToken>,
) -> Result<(), Error> {
let mut req = SignedRequest::new(
"PUT",
SERVICE,
&self.region,
&format!("/{}/{}", self.bucket, partition_key),
);
req.add_param("sort_key", sort_key);
req.set_payload(Some(value));
if let Some(causality) = causality {
req.add_header(GARAGE_CAUSALITY_TOKEN, &causality.0);
}
self.dispatch(req, None).await?;
Ok(())
}
/// Perform a DeleteItem request, deleting the value(s) stored for a single pk+sk.
pub async fn delete_item(
&self,
partition_key: &str,
sort_key: &str,
causality: CausalityToken,
) -> Result<(), Error> {
let mut req = SignedRequest::new(
"DELETE",
SERVICE,
&self.region,
&format!("/{}/{}", self.bucket, partition_key),
);
req.add_param("sort_key", sort_key);
req.add_header(GARAGE_CAUSALITY_TOKEN, &causality.0);
self.dispatch(req, None).await?;
Ok(())
}
/// Perform a ReadIndex request, listing partition key which have at least one associated
/// sort key, and which matches the filter.
pub async fn read_index(
&self,
filter: Filter<'_>,
) -> Result<PaginatedRange<PartitionInfo>, Error> {
let mut req =
SignedRequest::new("GET", SERVICE, &self.region, &format!("/{}", self.bucket));
filter.insert_params(&mut req);
let res = self.dispatch(req, None).await?;
let resp: ReadIndexResponse = serde_json::from_slice(&res.body)?;
let items = resp
.partition_keys
.into_iter()
.map(|ReadIndexItem { pk, info }| (pk, info))
.collect();
Ok(PaginatedRange {
items,
next_start: resp.next_start,
})
}
/// Perform an InsertBatch request, inserting multiple values at once. Note: this operation is
/// *not* atomic: it is possible for some sub-operations to fails and others to success. In
/// that case, failure is reported.
pub async fn insert_batch(&self, operations: &[BatchInsertOp<'_>]) -> Result<(), Error> {
let mut req =
SignedRequest::new("POST", SERVICE, &self.region, &format!("/{}", self.bucket));
let payload = serde_json::to_vec(operations)?;
req.set_payload(Some(payload));
self.dispatch(req, None).await?;
Ok(())
}
/// Perform a ReadBatch request, reading multiple values or range of values at once.
pub async fn read_batch(
&self,
operations: &[BatchReadOp<'_>],
) -> Result<Vec<PaginatedRange<CausalValue>>, Error> {
let mut req =
SignedRequest::new("POST", SERVICE, &self.region, &format!("/{}", self.bucket));
req.add_param("search", "");
let payload = serde_json::to_vec(operations)?;
req.set_payload(Some(payload));
let res = self.dispatch(req, None).await?;
let resp: Vec<BatchReadResponse> = serde_json::from_slice(&res.body)?;
Ok(resp
.into_iter()
.map(|e| PaginatedRange {
items: e
.items
.into_iter()
.map(|BatchReadItem { sk, ct, v }| {
(
sk,
CausalValue {
causality: ct,
value: v,
},
)
})
.collect(),
next_start: e.next_start,
})
.collect())
}
/// Perform a DeleteBatch request, deleting mutiple values or range of values at once, without
/// providing causality information.
pub async fn delete_batch(&self, operations: &[BatchDeleteOp<'_>]) -> Result<Vec<u64>, Error> {
let mut req =
SignedRequest::new("POST", SERVICE, &self.region, &format!("/{}", self.bucket));
req.add_param("delete", "");
let payload = serde_json::to_vec(operations)?;
req.set_payload(Some(payload));
let res = self.dispatch(req, None).await?;
let resp: Vec<BatchDeleteResponse> = serde_json::from_slice(&res.body)?;
Ok(resp.into_iter().map(|r| r.deleted_items).collect())
}
async fn dispatch(
&self,
mut req: SignedRequest,
timeout: Option<Duration>,
) -> Result<Response, Error> {
req.sign(&self.creds);
let mut res = self
.client
.dispatch(req, Some(timeout.unwrap_or(DEFAULT_TIMEOUT)))
.await?;
let causality_token = res
.headers
.remove(GARAGE_CAUSALITY_TOKEN)
.map(CausalityToken);
let content_type = res.headers.remove(CONTENT_TYPE);
let body = match res.status {
StatusCode::OK => read_body(&mut res.headers, res.body).await?,
StatusCode::NO_CONTENT => Vec::new(),
StatusCode::NOT_FOUND => return Err(Error::NotFound),
StatusCode::NOT_MODIFIED => Vec::new(),
_ => {
return Err(Error::InvalidResponse(
format!("invalid error code: {}", res.status).into(),
))
}
};
Ok(Response {
body,
status: res.status,
causality_token,
content_type,
})
}
}
async fn read_body(headers: &mut HeaderMap<String>, body: ByteStream) -> Result<Vec<u8>, Error> {
let body_len = headers
.get(CONTENT_LENGTH)
.and_then(|h| h.parse().ok())
.unwrap_or(0);
let mut res = Vec::with_capacity(body_len);
body.into_async_read().read_to_end(&mut res).await?;
Ok(res)
}
/// An opaque token used to convey causality between operations.
#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
#[serde(transparent)]
pub struct CausalityToken(String);
impl From<String> for CausalityToken {
fn from(v: String) -> Self {
CausalityToken(v)
}
}
impl From<CausalityToken> for String {
fn from(v: CausalityToken) -> Self {
v.0
}
}
/// A value in K2V. can be either a binary value, or a tombstone.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum K2vValue {
Tombstone,
Value(Vec<u8>),
}
impl From<Vec<u8>> for K2vValue {
fn from(v: Vec<u8>) -> Self {
K2vValue::Value(v)
}
}
impl From<Option<Vec<u8>>> for K2vValue {
fn from(v: Option<Vec<u8>>) -> Self {
match v {
Some(v) => K2vValue::Value(v),
None => K2vValue::Tombstone,
}
}
}
impl<'de> Deserialize<'de> for K2vValue {
fn deserialize<D>(d: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let val: Option<&str> = Option::deserialize(d)?;
Ok(match val {
Some(s) => {
K2vValue::Value(base64::decode(s).map_err(|_| DeError::custom("invalid base64"))?)
}
None => K2vValue::Tombstone,
})
}
}
impl Serialize for K2vValue {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
match self {
K2vValue::Tombstone => serializer.serialize_none(),
K2vValue::Value(v) => {
let b64 = base64::encode(v);
serializer.serialize_str(&b64)
}
}
}
}
/// A set of K2vValue and associated causality information.
#[derive(Debug, Clone, Serialize)]
pub struct CausalValue {
pub causality: CausalityToken,
pub value: Vec<K2vValue>,
}
/// Result of paginated requests.
#[derive(Debug, Clone)]
pub struct PaginatedRange<V> {
pub items: BTreeMap<String, V>,
pub next_start: Option<String>,
}
/// Filter for batch operations.
#[derive(Debug, Default, Clone, Deserialize, Serialize)]
pub struct Filter<'a> {
pub start: Option<&'a str>,
pub end: Option<&'a str>,
pub prefix: Option<&'a str>,
pub limit: Option<u64>,
#[serde(default)]
pub reverse: bool,
}
impl<'a> Filter<'a> {
fn insert_params(&self, req: &mut SignedRequest) {
if let Some(start) = &self.start {
req.add_param("start", start);
}
if let Some(end) = &self.end {
req.add_param("end", end);
}
if let Some(prefix) = &self.prefix {
req.add_param("prefix", prefix);
}
if let Some(limit) = &self.limit {
req.add_param("limit", &limit.to_string());
}
if self.reverse {
req.add_param("reverse", "true");
}
}
}
#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "camelCase")]
struct ReadIndexResponse<'a> {
#[serde(flatten, borrow)]
#[allow(dead_code)]
filter: Filter<'a>,
partition_keys: Vec<ReadIndexItem>,
#[allow(dead_code)]
more: bool,
next_start: Option<String>,
}
#[derive(Debug, Clone, Deserialize)]
struct ReadIndexItem {
pk: String,
#[serde(flatten)]
info: PartitionInfo,
}
/// Information about data stored with a given partition key.
#[derive(Debug, Clone, Deserialize, Serialize)]
pub struct PartitionInfo {
pub entries: u64,
pub conflicts: u64,
pub values: u64,
pub bytes: u64,
}
/// Single sub-operation of an InsertBatch.
#[derive(Debug, Clone, Serialize)]
pub struct BatchInsertOp<'a> {
#[serde(rename = "pk")]
pub partition_key: &'a str,
#[serde(rename = "sk")]
pub sort_key: &'a str,
#[serde(rename = "ct")]
pub causality: Option<CausalityToken>,
#[serde(rename = "v")]
pub value: K2vValue,
}
/// Single sub-operation of a ReadBatch.
#[derive(Debug, Default, Clone, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct BatchReadOp<'a> {
pub partition_key: &'a str,
#[serde(flatten, borrow)]
pub filter: Filter<'a>,
#[serde(default)]
pub single_item: bool,
#[serde(default)]
pub conflicts_only: bool,
#[serde(default)]
pub tombstones: bool,
}
#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "camelCase")]
struct BatchReadResponse<'a> {
#[serde(flatten, borrow)]
#[allow(dead_code)]
op: BatchReadOp<'a>,
items: Vec<BatchReadItem>,
#[allow(dead_code)]
more: bool,
next_start: Option<String>,
}
#[derive(Debug, Clone, Deserialize)]
struct BatchReadItem {
sk: String,
ct: CausalityToken,
v: Vec<K2vValue>,
}
/// Single sub-operation of a DeleteBatch
#[derive(Debug, Clone, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct BatchDeleteOp<'a> {
pub partition_key: &'a str,
pub prefix: Option<&'a str>,
pub start: Option<&'a str>,
pub end: Option<&'a str>,
#[serde(default)]
pub single_item: bool,
}
impl<'a> BatchDeleteOp<'a> {
pub fn new(partition_key: &'a str) -> Self {
BatchDeleteOp {
partition_key,
prefix: None,
start: None,
end: None,
single_item: false,
}
}
}
#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "camelCase")]
struct BatchDeleteResponse<'a> {
#[serde(flatten, borrow)]
#[allow(dead_code)]
filter: BatchDeleteOp<'a>,
deleted_items: u64,
}
struct Response {
body: Vec<u8>,
status: StatusCode,
causality_token: Option<CausalityToken>,
content_type: Option<String>,
}