minio oss 分块上传

minio 分块上传

minio是支持分块上传文件的，只是没有前端直传方案，各种client都有支持分段上传但是这个分段的方法是私有的意思就是对用户是隐藏的 当文件大小超过5mb是就会自动选择分块上传

minio也没有提供像七牛云一样的游览器端的sdk，也就是说你的文件需要经过应用转发一遍再由应用转存到minio中而不能直接像七牛云一样使用一次性token直接在前端分块上传文件

Java 代码分析

MinioClient.java 4371 行

/**
   * Executes put object. If size of object data is <= 5MiB, single put object is used
   * else multipart put object is used.
   *
   * @param bucketName
   *          Bucket name.
   * @param objectName
   *          Object name in the bucket.
   * @param size
   *          Size of object data.
   * @param data
   *          Object data.
   */
  private void putObject(String bucketName, String objectName, Long size, Object data,
      Map headerMap, ServerSideEncryption sse,  String contentType)
    throws InvalidBucketNameException, NoSuchAlgorithmException, IOException,
           InvalidKeyException, NoResponseException, XmlPullParserException, ErrorResponseException,
           InternalException, InvalidArgumentException, InsufficientDataException, InvalidResponseException {
    boolean unknownSize = false;

    if (size == null) {
      unknownSize = true;
      size = MAX_OBJECT_SIZE;
    }

    if (headerMap == null) {
      headerMap = new HashMap<>();
    }
    // Add content type if not already set
    // Content Type being passed as argument has higher precedence
    // than the one passed in headerMap if any.
    if (contentType == null) {
      if (headerMap.get("Content-Type") == null) {
        headerMap.put("Content-Type", "application/octet-stream");
      }
    } else {
      headerMap.put("Content-Type", contentType);
    }

    if (sse != null) {
      checkWriteRequestSse(sse);
      headerMap.putAll(sse.headers());
    }


    if (size <= MIN_MULTIPART_SIZE) {
      putObject(bucketName, objectName, data, size.intValue(), headerMap, null, 0);
      return;
    }

    /* Multipart upload 分块上传 */
    int[] rv = calculateMultipartSize(size);
    int partSize = rv[0];
    int partCount = rv[1];
    int lastPartSize = rv[2];
    Part[] totalParts = new Part[partCount];

    // initiate new multipart upload.
    String uploadId = initMultipartUpload(bucketName, objectName, headerMap);

    try {
      int expectedReadSize = partSize;
      for (int partNumber = 1; partNumber <= partCount; partNumber++) {
        if (partNumber == partCount) {
          expectedReadSize = lastPartSize;
        }

        // For unknown sized stream, check available size. 未知大小的数据 一般是直播监控等场景使用
        int availableSize = 0;
        if (unknownSize) {
          // Check whether data is available one byte more than expectedReadSize.
          availableSize = getAvailableSize(data, expectedReadSize + 1);
          // If availableSize is less or equal to expectedReadSize, then we reached last part.
          if (availableSize <= expectedReadSize) {
            // If it is first part, do single put object.
            if (partNumber == 1) {
              putObject(bucketName, objectName, data, availableSize, headerMap, null, 0);
              return;
            }
            expectedReadSize = availableSize;
            partCount = partNumber;
          }
        }

        Map encryptionHeaders = null;
        // In multi-part uploads, set encryption headers in the case of SSE-C.
        if (sse != null && sse.type() == ServerSideEncryption.Type.SSE_C) {
          encryptionHeaders = sse.headers();
        }

        String etag = putObject(bucketName, objectName, data, expectedReadSize, encryptionHeaders,
                                uploadId, partNumber);
        totalParts[partNumber - 1] = new Part(partNumber, etag);
      }
      // All parts have been uploaded, complete the multipart upload. 所有的数据块上传成功就会合并文件
      completeMultipart(bucketName, objectName, uploadId, totalParts);
    } catch (RuntimeException e) {
      abortMultipartUpload(bucketName, objectName, uploadId);
      throw e;
    } catch (Exception e) {
      abortMultipartUpload(bucketName, objectName, uploadId);
      throw e;
    }
  }