jujube_lib/
simple_op_store.rs

1// Copyright 2020 Google LLC
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// https://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::fmt::Debug;
16use std::fs;
17use std::fs::File;
18use std::io::ErrorKind;
19use std::io::Write;
20use std::path::PathBuf;
21
22use blake2::{Blake2b, Digest};
23use protobuf::{Message, ProtobufError};
24use tempfile::{NamedTempFile, PersistError};
25
26use crate::op_store::{
27    OpStore, OpStoreError, OpStoreResult, Operation, OperationId, OperationMetadata, View, ViewId,
28};
29use crate::store::{CommitId, MillisSinceEpoch, Timestamp};
30
31impl From<std::io::Error> for OpStoreError {
32    fn from(err: std::io::Error) -> Self {
33        OpStoreError::Other(err.to_string())
34    }
35}
36
37impl From<PersistError> for OpStoreError {
38    fn from(err: PersistError) -> Self {
39        OpStoreError::Other(err.to_string())
40    }
41}
42
43impl From<ProtobufError> for OpStoreError {
44    fn from(err: ProtobufError) -> Self {
45        OpStoreError::Other(err.to_string())
46    }
47}
48
49#[derive(Debug)]
50pub struct SimpleOpStore {
51    path: PathBuf,
52}
53
54impl SimpleOpStore {
55    pub fn init(store_path: PathBuf) -> Self {
56        fs::create_dir(store_path.join("views")).unwrap();
57        fs::create_dir(store_path.join("operations")).unwrap();
58        Self::load(store_path)
59    }
60
61    pub fn load(store_path: PathBuf) -> Self {
62        SimpleOpStore { path: store_path }
63    }
64
65    fn view_path(&self, id: &ViewId) -> PathBuf {
66        self.path.join("views").join(id.hex())
67    }
68
69    fn operation_path(&self, id: &OperationId) -> PathBuf {
70        self.path.join("operations").join(id.hex())
71    }
72}
73
74fn not_found_to_store_error(err: std::io::Error) -> OpStoreError {
75    if err.kind() == ErrorKind::NotFound {
76        OpStoreError::NotFound
77    } else {
78        OpStoreError::from(err)
79    }
80}
81
82impl OpStore for SimpleOpStore {
83    fn read_view(&self, id: &ViewId) -> OpStoreResult<View> {
84        let path = self.view_path(&id);
85        let mut file = File::open(path).map_err(not_found_to_store_error)?;
86
87        let proto: crate::protos::op_store::View = protobuf::parse_from_reader(&mut file)?;
88        Ok(view_from_proto(&proto))
89    }
90
91    fn write_view(&self, view: &View) -> OpStoreResult<ViewId> {
92        let temp_file = NamedTempFile::new_in(&self.path)?;
93
94        let proto = view_to_proto(view);
95        let mut proto_bytes: Vec<u8> = Vec::new();
96        proto.write_to_writer(&mut proto_bytes)?;
97
98        temp_file.as_file().write_all(&proto_bytes)?;
99
100        let id = ViewId(Blake2b::digest(&proto_bytes).to_vec());
101
102        temp_file.persist(self.view_path(&id))?;
103        Ok(id)
104    }
105
106    fn read_operation(&self, id: &OperationId) -> OpStoreResult<Operation> {
107        let path = self.operation_path(&id);
108        let mut file = File::open(path).map_err(not_found_to_store_error)?;
109
110        let proto: crate::protos::op_store::Operation = protobuf::parse_from_reader(&mut file)?;
111        Ok(operation_from_proto(&proto))
112    }
113
114    fn write_operation(&self, operation: &Operation) -> OpStoreResult<OperationId> {
115        let temp_file = NamedTempFile::new_in(&self.path)?;
116
117        let proto = operation_to_proto(operation);
118        let mut proto_bytes: Vec<u8> = Vec::new();
119        proto.write_to_writer(&mut proto_bytes)?;
120
121        temp_file.as_file().write_all(&proto_bytes)?;
122
123        let id = OperationId(Blake2b::digest(&proto_bytes).to_vec());
124
125        temp_file.persist(self.operation_path(&id))?;
126        Ok(id)
127    }
128}
129
130fn timestamp_to_proto(timestamp: &Timestamp) -> crate::protos::op_store::Timestamp {
131    let mut proto = crate::protos::op_store::Timestamp::new();
132    proto.set_millis_since_epoch(timestamp.timestamp.0);
133    proto.set_tz_offset(timestamp.tz_offset);
134    proto
135}
136
137fn timestamp_from_proto(proto: &crate::protos::op_store::Timestamp) -> Timestamp {
138    Timestamp {
139        timestamp: MillisSinceEpoch(proto.millis_since_epoch),
140        tz_offset: proto.tz_offset,
141    }
142}
143
144fn operation_metadata_to_proto(
145    metadata: &OperationMetadata,
146) -> crate::protos::op_store::OperationMetadata {
147    let mut proto = crate::protos::op_store::OperationMetadata::new();
148    proto.set_start_time(timestamp_to_proto(&metadata.start_time));
149    proto.set_end_time(timestamp_to_proto(&metadata.end_time));
150    proto.set_description(metadata.description.clone());
151    proto.set_hostname(metadata.hostname.clone());
152    proto.set_username(metadata.username.clone());
153    proto
154}
155
156fn operation_metadata_from_proto(
157    proto: &crate::protos::op_store::OperationMetadata,
158) -> OperationMetadata {
159    let start_time = timestamp_from_proto(proto.get_start_time());
160    let end_time = timestamp_from_proto(proto.get_end_time());
161    let description = proto.get_description().to_owned();
162    let hostname = proto.get_hostname().to_owned();
163    let username = proto.get_username().to_owned();
164    OperationMetadata {
165        start_time,
166        end_time,
167        description,
168        hostname,
169        username,
170    }
171}
172
173fn operation_to_proto(operation: &Operation) -> crate::protos::op_store::Operation {
174    let mut proto = crate::protos::op_store::Operation::new();
175    proto.set_view_id(operation.view_id.0.clone());
176    for parent in &operation.parents {
177        proto.parents.push(parent.0.clone());
178    }
179    proto.set_metadata(operation_metadata_to_proto(&operation.metadata));
180    proto
181}
182
183fn operation_from_proto(proto: &crate::protos::op_store::Operation) -> Operation {
184    let operation_id_from_proto = |parent: &Vec<u8>| OperationId(parent.clone());
185    let parents = proto.parents.iter().map(operation_id_from_proto).collect();
186    let view_id = ViewId(proto.view_id.to_vec());
187    let metadata = operation_metadata_from_proto(proto.get_metadata());
188    Operation {
189        view_id,
190        parents,
191        metadata,
192    }
193}
194
195fn view_to_proto(view: &View) -> crate::protos::op_store::View {
196    let mut proto = crate::protos::op_store::View::new();
197    proto.checkout = view.checkout.0.clone();
198    for head_id in &view.head_ids {
199        proto.head_ids.push(head_id.0.clone());
200    }
201    proto
202}
203
204fn view_from_proto(proto: &crate::protos::op_store::View) -> View {
205    let mut view = View::new(CommitId(proto.checkout.clone()));
206    for head_id_bytes in proto.head_ids.iter() {
207        view.head_ids.insert(CommitId(head_id_bytes.to_vec()));
208    }
209    view
210}
jujube_lib/simple_op_store.rs

jujube_lib/
simple_op_store.rs
