public Map<SystemStreamPartition, String> getFileOffsets() {
    LOG.info("Loading initial offsets from the file for side input stores.");
    Map<SystemStreamPartition, String> fileOffsets = new HashMap<>();

    stores.keySet().forEach(storeName -> {
      LOG.debug("Reading local offsets for store: {}", storeName);

      File storeLocation = getStoreLocation(storeName);
      if (isValidSideInputStore(storeName, storeLocation)) {
        try {

          Map<SystemStreamPartition, String> offsets =
              storageManagerUtil.readOffsetFile(storeLocation, storeToSSps.get(storeName), true);
          fileOffsets.putAll(offsets);
        } catch (Exception e) {
          LOG.warn("Failed to load the offset file for side input store:" + storeName, e);
        }
      }
    });

    return fileOffsets;
  }
Gets the side input SSP offsets for all stores from their local offset files.

@return a {@link Map} of {@link SystemStreamPartition} to offset in the offset files.
samza-core/src/main/java/org/apache/samza/storage/TaskSideInputStorageManager.java