feat: 项目整体命名修改cache-schema-checker

src/main/java/com/codechecker/cache/git/GitDiffScanner.java

@@ -0,0 +1,117 @@
+package com.codechecker.cache.git;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 基于 git 命令的差异扫描与双版本文件内容读取。
+ *
+ * <p>通过 {@code git diff --name-only} 获取变更的 .java 文件，通过 {@code git show sha:path}
+ * 读取指定提交下的文件内容，避免检出两个完整 worktree。</p>
+ */
+public class GitDiffScanner {
+
+    private final Path repoRoot;
+
+    public GitDiffScanner(Path repoRoot) {
+        this.repoRoot = repoRoot;
+    }
+
+    /**
+     * 返回 old..new 之间变更的 Java 文件路径（相对仓库根，使用 / 分隔）。
+     */
+    public List<String> changedJavaFiles(String oldSha, String newSha) throws GitException {
+        List<String> lines = runLines(
+                "git", "diff", "--name-only", "--diff-filter=ACMR", oldSha, newSha, "--", "*.java");
+        List<String> result = new ArrayList<>();
+        for (String line : lines) {
+            String trimmed = line.trim();
+            if (!trimmed.isEmpty() && trimmed.endsWith(".java")) {
+                result.add(trimmed);
+            }
+        }
+        return result;
+    }
+
+    /**
+     * 读取某提交下指定文件的内容；文件在该提交不存在时返回 null。
+     */
+    public String fileContentAt(String sha, String path) throws GitException {
+        try {
+            ProcessResult pr = run("git", "show", sha + ":" + path);
+            if (pr.exitCode != 0) {
+                return null;
+            }
+            return pr.stdout;
+        } catch (GitException e) {
+            return null;
+        }
+    }
+
+    private List<String> runLines(String... command) throws GitException {
+        ProcessResult pr = run(command);
+        if (pr.exitCode != 0) {
+            throw new GitException("git 命令执行失败(exit=" + pr.exitCode + "): " + String.join(" ", command)
+                    + "\n" + pr.stderr);
+        }
+        List<String> lines = new ArrayList<>();
+        try (BufferedReader reader = new BufferedReader(
+                new InputStreamReader(new java.io.ByteArrayInputStream(
+                        pr.stdout.getBytes(StandardCharsets.UTF_8)), StandardCharsets.UTF_8))) {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                lines.add(line);
+            }
+        } catch (IOException e) {
+            throw new GitException("读取 git 输出失败", e);
+        }
+        return lines;
+    }
+
+    private ProcessResult run(String... command) throws GitException {
+        ProcessBuilder pb = new ProcessBuilder(command);
+        pb.directory(repoRoot.toFile());
+        pb.redirectErrorStream(false);
+        try {
+            Process process = pb.start();
+            String stdout = readStream(process.getInputStream());
+            String stderr = readStream(process.getErrorStream());
+            int exit = process.waitFor();
+            return new ProcessResult(exit, stdout, stderr);
+        } catch (IOException e) {
+            throw new GitException("无法启动 git 进程: " + String.join(" ", command), e);
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new GitException("git 进程被中断", e);
+        }
+    }
+
+    private static String readStream(InputStream in) throws IOException {
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+        byte[] chunk = new byte[8192];
+        int read;
+        while ((read = in.read(chunk)) != -1) {
+            buffer.write(chunk, 0, read);
+        }
+        return new String(buffer.toByteArray(), StandardCharsets.UTF_8);
+    }
+
+    private static final class ProcessResult {
+        final int exitCode;
+        final String stdout;
+        final String stderr;
+
+        ProcessResult(int exitCode, String stdout, String stderr) {
+            this.exitCode = exitCode;
+            this.stdout = stdout;
+            this.stderr = stderr;
+        }
+    }
+}