1 /*
2 * Licensed under the Apache License, Version 2.0 (the "License");
3 * you may not use this file except in compliance with the License.
4 * You may obtain a copy of the License at
5 *
6 * http://www.apache.org/licenses/LICENSE-2.0
7 *
8 * Unless required by applicable law or agreed to in writing, software
9 * distributed under the License is distributed on an "AS IS" BASIS,
10 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 * See the License for the specific language governing permissions and
12 * limitations under the License.
13 */
14
15 package de.softwareforge.testing.postgres.embedded;
16
17 import static com.google.common.base.Preconditions.checkState;
18
19 import jakarta.annotation.Nonnull;
20 import jakarta.annotation.Nullable;
21 import java.io.IOException;
22 import java.io.InputStream;
23
24 import com.google.common.hash.Hashing;
25 import com.google.common.hash.HashingInputStream;
26 import com.google.common.io.BaseEncoding;
27 import com.google.common.io.ByteStreams;
28
29 /**
30 * Locates a native binary on the Filesystem. If necessary, it should download the binary first from the network.
31 * <p>
32 * Implementations of this class <b>must</b> implement {@link Object#hashCode()} and {@link Object#equals(Object)} and <i>should</i> implement
33 * {@link Object#toString()}.
34 *
35 * @since 3.0
36 */
37 @SuppressWarnings("PMD.ImplicitFunctionalInterface")
38 public interface NativeBinaryLocator {
39
40 String INSTALL_DIRECTORY_PREFIX = "bin-";
41
42 /**
43 * Returns an input stream from which the contents of the binary archive can be read.
44 *
45 * @return An input stream. May return null.
46 * @throws IOException If the archive could not be located or read.
47 */
48 @Nullable
49 InputStream getInputStream() throws IOException;
50
51 /**
52 * Returns a string identifier that represents the archive returned. This identifier should be stable (same value for the same archive), even across
53 * multiple JVM invocations. The value must only contain characters that can be used as a legal file name.
54 * <p>
55 * The default implementation needs to read the full archive contents and is relatively slow. Implementations of this interface can override this method to
56 * provide a faster way to create a stable identifier based on the specific implementation.
57 * <p>
58 * The default implementation hashes the archive contents and uses it to return a stable file name.
59 *
60 * @return A stable indentifier that can be used as a file name.
61 * @throws IOException If the stream could not be read.
62 */
63 @Nonnull
64 @SuppressWarnings("NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE") // false positive
65 default String getIdentifier() throws IOException {
66 try (InputStream installationArchive = getInputStream()) {
67 checkState(installationArchive != null, "Locator '%s' did not find a suitable archive to unpack!", toString());
68 try (HashingInputStream hashStream = new HashingInputStream(Hashing.murmur3_128(), installationArchive)) {
69 ByteStreams.exhaust(hashStream);
70 return INSTALL_DIRECTORY_PREFIX + BaseEncoding.base16().encode(hashStream.hash().asBytes());
71 }
72 }
73 }
74 }