aboutsummaryrefslogtreecommitdiff
path: root/src/k2v-client/lib.rs
blob: 95974d7a93df36216ef4e72a19522b30ba48ee7f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
use std::collections::BTreeMap;
use std::time::Duration;

use http::header::{ACCEPT, CONTENT_LENGTH, CONTENT_TYPE};
use http::status::StatusCode;
use http::HeaderMap;
use log::{debug, error};

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(),
			s => {
				let err_body = read_body(&mut res.headers, res.body)
					.await
					.unwrap_or_default();
				let err_body_str = std::str::from_utf8(&err_body)
					.map(String::from)
					.unwrap_or_else(|_| base64::encode(&err_body));

				if s.is_client_error() || s.is_server_error() {
					error!("Error response {}: {}", res.status, err_body_str);
					let err = match serde_json::from_slice::<ErrorResponse>(&err_body) {
						Ok(err) => Error::Remote(
							res.status,
							err.code.into(),
							err.message.into(),
							err.path.into(),
						),
						Err(_) => Error::Remote(
							res.status,
							"unknown".into(),
							err_body_str.into(),
							"?".into(),
						),
					};
					return Err(err);
				} else {
					let msg = format!(
						"Unexpected response code {}. Response body: {}",
						res.status, err_body_str
					);
					error!("{}", msg);
					return Err(Error::InvalidResponse(msg.into()));
				}
			}
		};
		debug!(
			"Response body: {}",
			std::str::from_utf8(&body)
				.map(String::from)
				.unwrap_or_else(|_| base64::encode(&body))
		);

		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,
}

#[derive(Deserialize)]
struct ErrorResponse {
	code: String,
	message: String,
	#[allow(dead_code)]
	region: String,
	path: String,
}

struct Response {
	body: Vec<u8>,
	status: StatusCode,
	causality_token: Option<CausalityToken>,
	content_type: Option<String>,
}