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1 //! The data that we will serialize and deserialize.
2 //!
3 //! The dep-graph is serialized as a sequence of NodeInfo, with the dependencies
4 //! specified inline. The total number of nodes and edges are stored as the last
5 //! 16 bytes of the file, so we can find them easily at decoding time.
6 //!
7 //! The serialisation is performed on-demand when each node is emitted. Using this
8 //! scheme, we do not need to keep the current graph in memory.
9 //!
10 //! The deserialization is performed manually, in order to convert from the stored
11 //! sequence of NodeInfos to the different arrays in SerializedDepGraph. Since the
12 //! node and edge count are stored at the end of the file, all the arrays can be
13 //! pre-allocated with the right length.
14 
15 use super::query::DepGraphQuery;
16 use super::{DepKind, DepNode, DepNodeIndex};
17 use rustc_data_structures::fingerprint::Fingerprint;
18 use rustc_data_structures::fx::FxHashMap;
19 use rustc_data_structures::profiling::SelfProfilerRef;
20 use rustc_data_structures::sync::Lock;
21 use rustc_index::{Idx, IndexVec};
22 use rustc_serialize::opaque::{FileEncodeResult, FileEncoder, IntEncodedWithFixedSize, MemDecoder};
23 use rustc_serialize::{Decodable, Decoder, Encodable};
24 use smallvec::SmallVec;
25 
26 // The maximum value of `SerializedDepNodeIndex` leaves the upper two bits
27 // unused so that we can store multiple index types in `CompressedHybridIndex`,
28 // and use those bits to encode which index type it contains.
29 rustc_index::newtype_index! {
30     #[max = 0x7FFF_FFFF]
31     pub struct SerializedDepNodeIndex {}
32 }
33 
34 /// Data for use when recompiling the **current crate**.
35 #[derive(Debug)]
36 pub struct SerializedDepGraph<K: DepKind> {
37     /// The set of all DepNodes in the graph
38     nodes: IndexVec<SerializedDepNodeIndex, DepNode<K>>,
39     /// The set of all Fingerprints in the graph. Each Fingerprint corresponds to
40     /// the DepNode at the same index in the nodes vector.
41     fingerprints: IndexVec<SerializedDepNodeIndex, Fingerprint>,
42     /// For each DepNode, stores the list of edges originating from that
43     /// DepNode. Encoded as a [start, end) pair indexing into edge_list_data,
44     /// which holds the actual DepNodeIndices of the target nodes.
45     edge_list_indices: IndexVec<SerializedDepNodeIndex, (u32, u32)>,
46     /// A flattened list of all edge targets in the graph. Edge sources are
47     /// implicit in edge_list_indices.
48     edge_list_data: Vec<SerializedDepNodeIndex>,
49     /// Reciprocal map to `nodes`.
50     index: FxHashMap<DepNode<K>, SerializedDepNodeIndex>,
51 }
52 
53 impl<K: DepKind> Default for SerializedDepGraph<K> {
default() -> Self54     fn default() -> Self {
55         SerializedDepGraph {
56             nodes: Default::default(),
57             fingerprints: Default::default(),
58             edge_list_indices: Default::default(),
59             edge_list_data: Default::default(),
60             index: Default::default(),
61         }
62     }
63 }
64 
65 impl<K: DepKind> SerializedDepGraph<K> {
66     #[inline]
edge_targets_from(&self, source: SerializedDepNodeIndex) -> &[SerializedDepNodeIndex]67     pub fn edge_targets_from(&self, source: SerializedDepNodeIndex) -> &[SerializedDepNodeIndex] {
68         let targets = self.edge_list_indices[source];
69         &self.edge_list_data[targets.0 as usize..targets.1 as usize]
70     }
71 
72     #[inline]
index_to_node(&self, dep_node_index: SerializedDepNodeIndex) -> DepNode<K>73     pub fn index_to_node(&self, dep_node_index: SerializedDepNodeIndex) -> DepNode<K> {
74         self.nodes[dep_node_index]
75     }
76 
77     #[inline]
node_to_index_opt(&self, dep_node: &DepNode<K>) -> Option<SerializedDepNodeIndex>78     pub fn node_to_index_opt(&self, dep_node: &DepNode<K>) -> Option<SerializedDepNodeIndex> {
79         self.index.get(dep_node).cloned()
80     }
81 
82     #[inline]
fingerprint_by_index(&self, dep_node_index: SerializedDepNodeIndex) -> Fingerprint83     pub fn fingerprint_by_index(&self, dep_node_index: SerializedDepNodeIndex) -> Fingerprint {
84         self.fingerprints[dep_node_index]
85     }
86 
node_count(&self) -> usize87     pub fn node_count(&self) -> usize {
88         self.index.len()
89     }
90 }
91 
92 impl<'a, K: DepKind + Decodable<MemDecoder<'a>>> Decodable<MemDecoder<'a>>
93     for SerializedDepGraph<K>
94 {
95     #[instrument(level = "debug", skip(d))]
decode(d: &mut MemDecoder<'a>) -> SerializedDepGraph<K>96     fn decode(d: &mut MemDecoder<'a>) -> SerializedDepGraph<K> {
97         // The last 16 bytes are the node count and edge count.
98         debug!("position: {:?}", d.position());
99         let (node_count, edge_count) =
100             d.with_position(d.len() - 2 * IntEncodedWithFixedSize::ENCODED_SIZE, |d| {
101                 debug!("position: {:?}", d.position());
102                 let node_count = IntEncodedWithFixedSize::decode(d).0 as usize;
103                 let edge_count = IntEncodedWithFixedSize::decode(d).0 as usize;
104                 (node_count, edge_count)
105             });
106         debug!("position: {:?}", d.position());
107 
108         debug!(?node_count, ?edge_count);
109 
110         let mut nodes = IndexVec::with_capacity(node_count);
111         let mut fingerprints = IndexVec::with_capacity(node_count);
112         let mut edge_list_indices = IndexVec::with_capacity(node_count);
113         let mut edge_list_data = Vec::with_capacity(edge_count);
114 
115         for _index in 0..node_count {
116             let dep_node: DepNode<K> = Decodable::decode(d);
117             let _i: SerializedDepNodeIndex = nodes.push(dep_node);
118             debug_assert_eq!(_i.index(), _index);
119 
120             let fingerprint: Fingerprint = Decodable::decode(d);
121             let _i: SerializedDepNodeIndex = fingerprints.push(fingerprint);
122             debug_assert_eq!(_i.index(), _index);
123 
124             // Deserialize edges -- sequence of DepNodeIndex
125             let len = d.read_usize();
126             let start = edge_list_data.len().try_into().unwrap();
127             for _ in 0..len {
128                 let edge = Decodable::decode(d);
129                 edge_list_data.push(edge);
130             }
131             let end = edge_list_data.len().try_into().unwrap();
132             let _i: SerializedDepNodeIndex = edge_list_indices.push((start, end));
133             debug_assert_eq!(_i.index(), _index);
134         }
135 
136         let index: FxHashMap<_, _> =
137             nodes.iter_enumerated().map(|(idx, &dep_node)| (dep_node, idx)).collect();
138 
139         SerializedDepGraph { nodes, fingerprints, edge_list_indices, edge_list_data, index }
140     }
141 }
142 
143 #[derive(Debug, Encodable, Decodable)]
144 pub struct NodeInfo<K: DepKind> {
145     node: DepNode<K>,
146     fingerprint: Fingerprint,
147     edges: SmallVec<[DepNodeIndex; 8]>,
148 }
149 
150 struct Stat<K: DepKind> {
151     kind: K,
152     node_counter: u64,
153     edge_counter: u64,
154 }
155 
156 struct EncoderState<K: DepKind> {
157     encoder: FileEncoder,
158     total_node_count: usize,
159     total_edge_count: usize,
160     stats: Option<FxHashMap<K, Stat<K>>>,
161 }
162 
163 impl<K: DepKind> EncoderState<K> {
new(encoder: FileEncoder, record_stats: bool) -> Self164     fn new(encoder: FileEncoder, record_stats: bool) -> Self {
165         Self {
166             encoder,
167             total_edge_count: 0,
168             total_node_count: 0,
169             stats: record_stats.then(FxHashMap::default),
170         }
171     }
172 
encode_node( &mut self, node: &NodeInfo<K>, record_graph: &Option<Lock<DepGraphQuery<K>>>, ) -> DepNodeIndex173     fn encode_node(
174         &mut self,
175         node: &NodeInfo<K>,
176         record_graph: &Option<Lock<DepGraphQuery<K>>>,
177     ) -> DepNodeIndex {
178         let index = DepNodeIndex::new(self.total_node_count);
179         self.total_node_count += 1;
180 
181         let edge_count = node.edges.len();
182         self.total_edge_count += edge_count;
183 
184         if let Some(record_graph) = &record_graph {
185             // Do not ICE when a query is called from within `with_query`.
186             if let Some(record_graph) = &mut record_graph.try_lock() {
187                 record_graph.push(index, node.node, &node.edges);
188             }
189         }
190 
191         if let Some(stats) = &mut self.stats {
192             let kind = node.node.kind;
193 
194             let stat = stats.entry(kind).or_insert(Stat { kind, node_counter: 0, edge_counter: 0 });
195             stat.node_counter += 1;
196             stat.edge_counter += edge_count as u64;
197         }
198 
199         let encoder = &mut self.encoder;
200         node.encode(encoder);
201         index
202     }
203 
finish(self, profiler: &SelfProfilerRef) -> FileEncodeResult204     fn finish(self, profiler: &SelfProfilerRef) -> FileEncodeResult {
205         let Self { mut encoder, total_node_count, total_edge_count, stats: _ } = self;
206 
207         let node_count = total_node_count.try_into().unwrap();
208         let edge_count = total_edge_count.try_into().unwrap();
209 
210         debug!(?node_count, ?edge_count);
211         debug!("position: {:?}", encoder.position());
212         IntEncodedWithFixedSize(node_count).encode(&mut encoder);
213         IntEncodedWithFixedSize(edge_count).encode(&mut encoder);
214         debug!("position: {:?}", encoder.position());
215         // Drop the encoder so that nothing is written after the counts.
216         let result = encoder.finish();
217         if let Ok(position) = result {
218             // FIXME(rylev): we hardcode the dep graph file name so we
219             // don't need a dependency on rustc_incremental just for that.
220             profiler.artifact_size("dep_graph", "dep-graph.bin", position as u64);
221         }
222         result
223     }
224 }
225 
226 pub struct GraphEncoder<K: DepKind> {
227     status: Lock<EncoderState<K>>,
228     record_graph: Option<Lock<DepGraphQuery<K>>>,
229 }
230 
231 impl<K: DepKind + Encodable<FileEncoder>> GraphEncoder<K> {
new( encoder: FileEncoder, prev_node_count: usize, record_graph: bool, record_stats: bool, ) -> Self232     pub fn new(
233         encoder: FileEncoder,
234         prev_node_count: usize,
235         record_graph: bool,
236         record_stats: bool,
237     ) -> Self {
238         let record_graph = record_graph.then(|| Lock::new(DepGraphQuery::new(prev_node_count)));
239         let status = Lock::new(EncoderState::new(encoder, record_stats));
240         GraphEncoder { status, record_graph }
241     }
242 
with_query(&self, f: impl Fn(&DepGraphQuery<K>))243     pub(crate) fn with_query(&self, f: impl Fn(&DepGraphQuery<K>)) {
244         if let Some(record_graph) = &self.record_graph {
245             f(&record_graph.lock())
246         }
247     }
248 
print_incremental_info( &self, total_read_count: u64, total_duplicate_read_count: u64, )249     pub(crate) fn print_incremental_info(
250         &self,
251         total_read_count: u64,
252         total_duplicate_read_count: u64,
253     ) {
254         let status = self.status.lock();
255         if let Some(record_stats) = &status.stats {
256             let mut stats: Vec<_> = record_stats.values().collect();
257             stats.sort_by_key(|s| -(s.node_counter as i64));
258 
259             const SEPARATOR: &str = "[incremental] --------------------------------\
260                                      ----------------------------------------------\
261                                      ------------";
262 
263             eprintln!("[incremental]");
264             eprintln!("[incremental] DepGraph Statistics");
265             eprintln!("{SEPARATOR}");
266             eprintln!("[incremental]");
267             eprintln!("[incremental] Total Node Count: {}", status.total_node_count);
268             eprintln!("[incremental] Total Edge Count: {}", status.total_edge_count);
269 
270             if cfg!(debug_assertions) {
271                 eprintln!("[incremental] Total Edge Reads: {total_read_count}");
272                 eprintln!("[incremental] Total Duplicate Edge Reads: {total_duplicate_read_count}");
273             }
274 
275             eprintln!("[incremental]");
276             eprintln!(
277                 "[incremental]  {:<36}| {:<17}| {:<12}| {:<17}|",
278                 "Node Kind", "Node Frequency", "Node Count", "Avg. Edge Count"
279             );
280             eprintln!("{SEPARATOR}");
281 
282             for stat in stats {
283                 let node_kind_ratio =
284                     (100.0 * (stat.node_counter as f64)) / (status.total_node_count as f64);
285                 let node_kind_avg_edges = (stat.edge_counter as f64) / (stat.node_counter as f64);
286 
287                 eprintln!(
288                     "[incremental]  {:<36}|{:>16.1}% |{:>12} |{:>17.1} |",
289                     format!("{:?}", stat.kind),
290                     node_kind_ratio,
291                     stat.node_counter,
292                     node_kind_avg_edges,
293                 );
294             }
295 
296             eprintln!("{SEPARATOR}");
297             eprintln!("[incremental]");
298         }
299     }
300 
send( &self, profiler: &SelfProfilerRef, node: DepNode<K>, fingerprint: Fingerprint, edges: SmallVec<[DepNodeIndex; 8]>, ) -> DepNodeIndex301     pub(crate) fn send(
302         &self,
303         profiler: &SelfProfilerRef,
304         node: DepNode<K>,
305         fingerprint: Fingerprint,
306         edges: SmallVec<[DepNodeIndex; 8]>,
307     ) -> DepNodeIndex {
308         let _prof_timer = profiler.generic_activity("incr_comp_encode_dep_graph");
309         let node = NodeInfo { node, fingerprint, edges };
310         self.status.lock().encode_node(&node, &self.record_graph)
311     }
312 
finish(self, profiler: &SelfProfilerRef) -> FileEncodeResult313     pub fn finish(self, profiler: &SelfProfilerRef) -> FileEncodeResult {
314         let _prof_timer = profiler.generic_activity("incr_comp_encode_dep_graph");
315         self.status.into_inner().finish(profiler)
316     }
317 }
318