From c625f61bfc2192861ca5cf7808f143c16ddff881 Mon Sep 17 00:00:00 2001
From: Simon Barner <barner@fortiss.org>
Date: Fri, 13 Oct 2023 16:59:07 +0200
Subject: [PATCH] Fix computeGitObjectHash() to compute the same object has as
Git
* Renamed from computeGitHash()
Issue-Ref: 4310
Issue-Url: https://git.fortiss.org/af3/af3/-/issues/4310
Signed-off-by: Simon Barner <barner@fortiss.org>
---
.../tooling/ext/quality/storage/.ratings | 2 +-
.../ext/quality/storage/CSVFileWriter.java | 52 +++++++++++--------
2 files changed, 31 insertions(+), 23 deletions(-)
diff --git a/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/.ratings b/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/.ratings
index 1af854e96..a7cf9548b 100644
--- a/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/.ratings
+++ b/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/.ratings
@@ -1,2 +1,2 @@
-CSVFileWriter.java a779fce240c25aae1b72dfd11d27b74b0b21d599 RED
+CSVFileWriter.java 0cae6203edc159cec0d3f68c61f4b04a3c61eecd RED
ModelQualityStorageManager.java 8293f17743bdc85e2595eae99b978ed868bd029b RED
diff --git a/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/CSVFileWriter.java b/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/CSVFileWriter.java
index a779fce24..0cae6203e 100644
--- a/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/CSVFileWriter.java
+++ b/org.fortiss.tooling.ext.quality/src/org/fortiss/tooling/ext/quality/storage/CSVFileWriter.java
@@ -15,18 +15,14 @@
+--------------------------------------------------------------------------*/
package org.fortiss.tooling.ext.quality.storage;
-import static java.lang.Integer.toHexString;
-
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
-import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
-import java.nio.file.Paths;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.time.LocalDateTime;
@@ -102,7 +98,7 @@ public class CSVFileWriter {
// Add topLevelElement.doSave(new NullProgressMonitor());
Path modelFile = new File(ModelQualityStorageManager.MODEL_PROJECT_DIR,
topLevelElement.getSaveableName()).toPath();
- String projectHash = computeGitHash(modelFile);
+ String projectHash = computeGitObjectHash(modelFile);
List<String> allKeys = new ArrayList<>();
boolean createNewIndex = true;
@@ -216,27 +212,39 @@ public class CSVFileWriter {
}
/**
- * Function to generate the hash for the model in order to later on match versions of the file
- * project with saved metrics (assuming both are under version control using Git).
+ * Return the Git object hash for the contents of the given file:
+ * <p>
+ * {@code SHA-1("blob <size>\0"+<contents>).asHexString()}.
*/
- private static String computeGitHash(Path filePath)
+ private static String computeGitObjectHash(Path filePath)
throws NoSuchAlgorithmException, IOException {
- String fileAsString = new String(Files.readAllBytes(Paths.get(filePath.toString())));
- MessageDigest digest = MessageDigest.getInstance("SHA-1");
- byte[] hash = digest.digest(fileAsString.getBytes(StandardCharsets.UTF_8));
- return bytesToHex(hash);
- }
- /** Switching from bytes to Hex notation. */
- private static String bytesToHex(byte[] hash) {
- StringBuilder hexString = new StringBuilder(2 * hash.length);
- for(byte b : hash) {
- String hex = toHexString(0xff & b);
- if(hex.length() == 1) {
- hexString.append('0');
+ try(BufferedReader reader = new BufferedReader(new FileReader(filePath.toString()))) {
+ // Read file line-wise with UNIX line endings
+ StringBuilder inputBuilder = new StringBuilder();
+ do {
+ String line = reader.readLine();
+ if(line == null) {
+ break;
+ }
+ inputBuilder.append(line);
+ inputBuilder.append("\n");
+ } while(true);
+
+ // Construct pre-image (input to hash function) according to Git specification
+ String fileContents = inputBuilder.toString();
+ int n = fileContents.length();
+ String preImage = "blob " + n + "\0" + fileContents;
+
+ // Compute hash and convert it to a hex string
+ MessageDigest sha1 = MessageDigest.getInstance("SHA-1");
+ byte[] digest = sha1.digest(preImage.getBytes());
+
+ StringBuilder resultBuilder = new StringBuilder();
+ for(byte b : digest) {
+ resultBuilder.append(String.format("%02x", b & 0xff));
}
- hexString.append(hex);
+ return resultBuilder.toString();
}
- return hexString.toString();
}
}
--
GitLab