feat(gax): add HTTP/JSON implementation of ResumableUploadClient.startUpload

[whowes]

_{Stack created with GitHub Stacks CLI • Give Feedback 💬}

[gemini-code-assist]

Code Review

This pull request introduces a new low-level resumable upload client framework for HTTP/JSON transport, including the ResumableUploadClient interface, ResumableUploadSession metadata, and StartUploadRequest parameters, along with their corresponding unit tests. Feedback on the implementation suggests simplifying the response header parsing logic in HttpJsonResumableUploadClient by removing an unnecessary instanceof HttpHeaders check that is likely always false.

[gemini-code-assist]

The instanceof HttpHeaders check is likely always false, as HttpJsonMetadata.getHeaders() returns a Map<String, List<String>> which is usually not an HttpHeaders instance at runtime. This logic can be simplified by removing the conditional and always creating a new HttpHeaders object. This makes the code cleaner and removes a potentially dead code path.

        HttpHeaders headers = new HttpHeaders();
        headers.putAll(responseHeaders.getHeaders());

[whowes]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces the HttpJsonResumableUploadClient class and its associated tests to support resumable uploads over HTTP/JSON. The review feedback suggests optimizing the onHeaders method by replacing the heavy HttpHeaders class with a direct, case-insensitive lookup on the raw headers map to avoid reflection and unnecessary allocations. Consequently, the unused import for HttpHeaders should also be removed.

[gemini-code-assist]

With the removal of com.google.api.client.http.HttpHeaders from the onHeaders method, this import is no longer needed and can be removed.

[gemini-code-assist]

Using com.google.api.client.http.HttpHeaders and calling putAll with all response headers is highly inefficient. HttpHeaders is a heavy class that uses reflection to map header keys to class fields. Since we only need to extract a couple of specific headers case-insensitively, we can perform a direct case-insensitive lookup on the raw headers map. This avoids unnecessary object allocation and reflection overhead.

    @Override
    public void onHeaders(HttpJsonMetadata responseHeaders) {
      if (responseHeaders != null && responseHeaders.getHeaders() != null) {
        Map<String, List<String>> headers = responseHeaders.getHeaders();

        String url = getFirstHeader(headers, UPLOAD_URL_HEADER);
        if (Strings.isNullOrEmpty(url)) {
          url = getFirstHeader(headers, "Location");
        }
        if (!Strings.isNullOrEmpty(url)) {
          this.uploadUrl = url;
        }

        String granularityStr = getFirstHeader(headers, UPLOAD_GRANULARITY_HEADER);
        if (!Strings.isNullOrEmpty(granularityStr)) {
          try {
            this.chunkGranularity = Long.parseLong(granularityStr);
          } catch (NumberFormatException ignored) {
            this.chunkGranularity = 1L;
          }
        }
      }
    }

    @Nullable
    private static String getFirstHeader(Map<String, List<String>> headers, String name) {
      for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
        if (entry.getKey().equalsIgnoreCase(name)) {
          List<String> values = entry.getValue();
          return values != null && !values.isEmpty() ? values.get(0) : null;
        }
      }
      return null;
    }

References

1. When annotating a method with @Nullable, verify if any callers pass the returned value directly to APIs that do not accept nulls (such as Guava's ImmutableMap.Builder). If null checks are missing, they should be added or tracked for follow-up work.

[sonarqubecloud]

Quality Gate passed for 'gapic-generator-java-root'

Issues
9 New issues
0 Accepted issues

Measures
0 Security Hotspots
80.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate failed for 'gapic-generator-java-root'

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud