public void service()

in src/main/java/com/googlesource/gerrit/plugins/imagare/ImageServlet.java [97:208]
104 lines of code
25 McCabe index (conditional complexity)

  public void service(HttpServletRequest req, HttpServletResponse res) throws IOException {
    if (!"GET".equals(req.getMethod()) && !"HEAD".equals(req.getMethod())) {
      CacheHeaders.setNotCacheable(res);
      res.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
      return;
    }

    ResourceKey key = ResourceKey.fromPath(getEncodedPath(req));
    ProjectState state = projectCache.get(key.project);
    if (state == null || key.file == null) {
      notFound(res);
      return;
    }

    MimeType mimeType = fileTypeRegistry.getMimeType(key.file, (byte[]) null);
    if (!("image".equals(mimeType.getMediaType()) && fileTypeRegistry.isSafeInline(mimeType))) {
      notFound(res);
      return;
    }

    try {
      ProjectState projectState = projectCache.get(key.project);
      String rev = key.revision;
      if (rev == null || Constants.HEAD.equals(rev)) {
        rev = getHead.get().apply(new ProjectResource(projectState, self.get()));
      } else {
        if (!ObjectId.isId(rev)) {
          if (!rev.startsWith(Constants.R_REFS)) {
            rev = Constants.R_HEADS + rev;
          }
          PermissionBackend.ForProject perm = permissionBackend.currentUser().project(key.project);
          try {
            perm.ref(rev).check(RefPermission.READ);
          } catch (AuthException e) {
            notFound(res);
            return;
          }
        }
      }
      try (Repository repo = repoManager.openRepository(key.project)) {
        ObjectId revId = repo.resolve(rev != null ? rev : Constants.HEAD);
        if (revId == null) {
          notFound(res);
          return;
        }

        if (ObjectId.isId(rev)) {
          try (RevWalk rw = new RevWalk(repo)) {
            RevCommit commit = rw.parseCommit(repo.resolve(rev));
            if (!commits.canRead(state, repo, commit)) {
              notFound(res);
              return;
            }
          }
        }

        String eTag = null;
        String receivedETag = req.getHeader(HttpHeaders.IF_NONE_MATCH);
        if (receivedETag != null) {
          eTag = computeETag(key.project, revId, key.file);
          if (eTag.equals(receivedETag)) {
            res.sendError(SC_NOT_MODIFIED);
            return;
          }
        }

        if (!"image".equals(mimeType.getMediaType())) {
          notFound(res);
          return;
        }

        try (RevWalk rw = new RevWalk(repo)) {
          RevCommit commit = rw.parseCommit(revId);
          RevTree tree = commit.getTree();
          try (TreeWalk tw = new TreeWalk(repo)) {
            tw.addTree(tree);
            tw.setRecursive(true);
            tw.setFilter(PathFilter.create(key.file));
            if (!tw.next()) {
              notFound(res);
              return;
            }
            ObjectId objectId = tw.getObjectId(0);
            ObjectLoader loader = repo.open(objectId);
            byte[] content = loader.getBytes(Integer.MAX_VALUE);

            mimeType = fileTypeRegistry.getMimeType(key.file, content);
            if (!"image".equals(mimeType.getMediaType())
                || !fileTypeRegistry.isSafeInline(mimeType)) {
              notFound(res);
              return;
            }
            res.setHeader(
                HttpHeaders.ETAG, eTag != null ? eTag : computeETag(key.project, revId, key.file));
            CacheHeaders.setCacheablePrivate(res, 7, TimeUnit.DAYS, false);
            send(req, res, content, mimeType.toString(), commit.getCommitTime());
            return;
          }
        } catch (IOException e) {
          notFound(res);
          return;
        }
      }
    } catch (RepositoryNotFoundException
        | ResourceNotFoundException
        | AuthException
        | RevisionSyntaxException
        | PermissionBackendException e) {
      notFound(res);
      return;
    }
  }