aboutsummaryrefslogtreecommitdiff
path: root/src/api/s3_get.rs
blob: 15c0ed0a2a974dccfe10530b5e9ee197688a0b5c (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
//! Function related to GET and HEAD requests
use std::sync::Arc;
use std::time::{Duration, UNIX_EPOCH};

use futures::stream::*;
use hyper::body::Bytes;
use hyper::{Body, Request, Response, StatusCode};

use garage_table::EmptyKey;

use garage_model::garage::Garage;
use garage_model::object_table::*;

use crate::error::*;

fn object_headers(
	version: &ObjectVersion,
	version_meta: &ObjectVersionMeta,
) -> http::response::Builder {
	debug!("Version meta: {:?}", version_meta);

	let date = UNIX_EPOCH + Duration::from_millis(version.timestamp);
	let date_str = httpdate::fmt_http_date(date);

	let mut resp = Response::builder()
		.header(
			"Content-Type",
			version_meta.headers.content_type.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());
	}

	resp
}

fn try_answer_cached(
	version: &ObjectVersion,
	version_meta: &ObjectVersionMeta,
	req: &Request<Body>,
) -> Option<Response<Body>> {
	// <trinity> It is possible, and is even usually the case, [that both If-None-Match and
	// If-Modified-Since] are present in a request. In this situation If-None-Match takes
	// precedence and If-Modified-Since is ignored (as per 6.Precedence from rfc7232). The rational
	// being that etag based matching is more accurate, it has no issue with sub-second precision
	// for instance (in case of very fast updates)
	let cached = if let Some(none_match) = req.headers().get(http::header::IF_NONE_MATCH) {
		let none_match = none_match.to_str().ok()?;
		let expected = format!("\"{}\"", version_meta.etag);
		let found = none_match
			.split(',')
			.map(str::trim)
			.any(|etag| etag == expected || etag == "\"*\"");
		found
	} else if let Some(modified_since) = req.headers().get(http::header::IF_MODIFIED_SINCE) {
		let modified_since = modified_since.to_str().ok()?;
		let client_date = httpdate::parse_http_date(modified_since).ok()?;
		let server_date = UNIX_EPOCH + Duration::from_millis(version.timestamp);
		client_date >= server_date
	} else {
		false
	};

	if cached {
		Some(
			Response::builder()
				.status(StatusCode::NOT_MODIFIED)
				.body(Body::empty())
				.unwrap(),
		)
	} else {
		None
	}
}

/// Handle HEAD request
pub async fn handle_head(
	garage: Arc<Garage>,
	req: &Request<Body>,
	bucket: &str,
	key: &str,
) -> Result<Response<Body>, Error> {
	let object = garage
		.object_table
		.get(&bucket.to_string(), &key.to_string())
		.await?
		.ok_or(Error::NotFound)?;

	let version = object
		.versions()
		.iter()
		.rev()
		.filter(|v| v.is_data())
		.next()
		.ok_or(Error::NotFound)?;

	let version_meta = match &version.state {
		ObjectVersionState::Complete(ObjectVersionData::Inline(meta, _)) => meta,
		ObjectVersionState::Complete(ObjectVersionData::FirstBlock(meta, _)) => meta,
		_ => unreachable!(),
	};

	if let Some(cached) = try_answer_cached(&version, version_meta, req) {
		return Ok(cached);
	}

	let body: Body = Body::empty();
	let response = object_headers(&version, version_meta)
		.header("Content-Length", format!("{}", version_meta.size))
		.status(StatusCode::OK)
		.body(body)
		.unwrap();
	Ok(response)
}

/// Handle GET request
pub async fn handle_get(
	garage: Arc<Garage>,
	req: &Request<Body>,
	bucket: &str,
	key: &str,
) -> Result<Response<Body>, Error> {
	let object = garage
		.object_table
		.get(&bucket.to_string(), &key.to_string())
		.await?
		.ok_or(Error::NotFound)?;

	let last_v = object
		.versions()
		.iter()
		.rev()
		.filter(|v| v.is_complete())
		.next()
		.ok_or(Error::NotFound)?;

	let last_v_data = match &last_v.state {
		ObjectVersionState::Complete(x) => x,
		_ => unreachable!(),
	};
	let last_v_meta = match last_v_data {
		ObjectVersionData::DeleteMarker => return Err(Error::NotFound),
		ObjectVersionData::Inline(meta, _) => meta,
		ObjectVersionData::FirstBlock(meta, _) => meta,
	};

	if let Some(cached) = try_answer_cached(&last_v, last_v_meta, req) {
		return Ok(cached);
	}

	let range = match req.headers().get("range") {
		Some(range) => {
			let range_str = range.to_str()?;
			let mut ranges = http_range::HttpRange::parse(range_str, last_v_meta.size)?;
			if ranges.len() > 1 {
				return Err(Error::BadRequest(format!("Multiple ranges not supported")));
			} else {
				ranges.pop()
			}
		}
		None => None,
	};
	if let Some(range) = range {
		return handle_get_range(
			garage,
			last_v,
			last_v_data,
			last_v_meta,
			range.start,
			range.start + range.length,
		)
		.await;
	}

	let resp_builder = object_headers(&last_v, last_v_meta)
		.header("Content-Length", format!("{}", last_v_meta.size))
		.status(StatusCode::OK);

	match &last_v_data {
		ObjectVersionData::DeleteMarker => unreachable!(),
		ObjectVersionData::Inline(_, bytes) => {
			let body: Body = Body::from(bytes.to_vec());
			Ok(resp_builder.body(body)?)
		}
		ObjectVersionData::FirstBlock(_, first_block_hash) => {
			let read_first_block = garage.block_manager.rpc_get_block(&first_block_hash);
			let get_next_blocks = garage.version_table.get(&last_v.uuid, &EmptyKey);

			let (first_block, version) = futures::try_join!(read_first_block, get_next_blocks)?;
			let version = version.ok_or(Error::NotFound)?;

			let mut blocks = version
				.blocks
				.items()
				.iter()
				.map(|(_, vb)| (vb.hash, None))
				.collect::<Vec<_>>();
			blocks[0].1 = Some(first_block);

			let body_stream = futures::stream::iter(blocks)
				.map(move |(hash, data_opt)| {
					let garage = garage.clone();
					async move {
						if let Some(data) = data_opt {
							Ok(Bytes::from(data))
						} else {
							garage
								.block_manager
								.rpc_get_block(&hash)
								.await
								.map(Bytes::from)
						}
					}
				})
				.buffered(2);

			let body = hyper::body::Body::wrap_stream(body_stream);
			Ok(resp_builder.body(body)?)
		}
	}
}

async fn handle_get_range(
	garage: Arc<Garage>,
	version: &ObjectVersion,
	version_data: &ObjectVersionData,
	version_meta: &ObjectVersionMeta,
	begin: u64,
	end: u64,
) -> Result<Response<Body>, Error> {
	if end > version_meta.size {
		return Err(Error::BadRequest(format!("Range not included in file")));
	}

	let resp_builder = object_headers(version, version_meta)
		.header("Content-Length", format!("{}", end - begin))
		.header(
			"Content-Range",
			format!("bytes {}-{}/{}", begin, end - 1, version_meta.size),
		)
		.status(StatusCode::PARTIAL_CONTENT);

	match &version_data {
		ObjectVersionData::DeleteMarker => unreachable!(),
		ObjectVersionData::Inline(_meta, bytes) => {
			if end as usize <= bytes.len() {
				let body: Body = Body::from(bytes[begin as usize..end as usize].to_vec());
				Ok(resp_builder.body(body)?)
			} else {
				None.ok_or_internal_error(
					"Requested range not present in inline bytes when it should have been",
				)
			}
		}
		ObjectVersionData::FirstBlock(_meta, _first_block_hash) => {
			let version = garage.version_table.get(&version.uuid, &EmptyKey).await?;
			let version = match version {
				Some(v) => v,
				None => return Err(Error::NotFound),
			};

			// We will store here the list of blocks that have an intersection with the requested
			// range, as well as their "true offset", which is their actual offset in the complete
			// file (whereas block.offset designates the offset of the block WITHIN THE PART
			// block.part_number, which is not the same in the case of a multipart upload)
			let mut blocks = Vec::with_capacity(std::cmp::min(
				version.blocks.len(),
				4 + ((end - begin) / std::cmp::max(version.blocks.items()[0].1.size as u64, 1024))
					as usize,
			));
			let mut true_offset = 0;
			for (_, b) in version.blocks.items().iter() {
				if true_offset >= end {
					break;
				}
				// Keep only blocks that have an intersection with the requested range
				if true_offset < end && true_offset + b.size > begin {
					blocks.push((b.clone(), true_offset));
				}
				true_offset += b.size;
			}

			let body_stream = futures::stream::iter(blocks)
				.map(move |(block, true_offset)| {
					let garage = garage.clone();
					async move {
						let data = garage.block_manager.rpc_get_block(&block.hash).await?;
						let data = Bytes::from(data);
						let start_in_block = if true_offset > begin {
							0
						} else {
							begin - true_offset
						};
						let end_in_block = if true_offset + block.size < end {
							block.size
						} else {
							end - true_offset
						};
						Result::<Bytes, Error>::Ok(Bytes::from(
							data.slice(start_in_block as usize..end_in_block as usize),
						))
					}
				})
				.buffered(2);

			let body = hyper::body::Body::wrap_stream(body_stream);
			Ok(resp_builder.body(body)?)
		}
	}
}