Examples with DatasetResponseWithStatusCodeAndHeaders won.protocol.rest.DatasetResponseWithStatusCodeAndHeaders used on opensource projects

Example 6 with DatasetResponseWithStatusCodeAndHeaders

use of won.protocol.rest.DatasetResponseWithStatusCodeAndHeaders in project webofneeds by researchstudio-sat.

the class CachingLinkedDataSource method fetchAndCacheIfAppropriate.

private DatasetResponseWithStatusCodeAndHeaders fetchAndCacheIfAppropriate(final URI resource, final URI requesterWebID, final LinkedDataCacheEntry linkedDataCacheEntry, final HttpHeaders headers) {
    DatasetResponseWithStatusCodeAndHeaders responseData = fetchWithEtagValidation(resource, requesterWebID, linkedDataCacheEntry, headers);
    Date expires = parseCacheControlMaxAgeValue(resource, responseData);
    if (expires == null) {
        expires = parseExpiresHeader(resource, responseData);
        if (expires != null && expires.getTime() == 0) {
            // Don't cache.
            return responseData;
        }
    }
    EnumSet<CacheControlFlag> cacheControlFlags = parseCacheControlHeaderFlags(resource, responseData);
    if (cacheControlFlags.contains(CacheControlFlag.NO_STORE) || cacheControlFlags.contains(CacheControlFlag.NO_CACHE)) {
        // we are not allowed to cache the result
        // make sure it's not in the cache from a previous request
        cache.remove(makeCacheKey(resource, requesterWebID));
        logger.debug("Fetched {}. Will not be cached due to Cache-Control headers sent by server", resource);
        return responseData;
    }
    Date responseDate = parseDateHeader(resource, responseData);
    if (responseDate != null && expires != null) {
        // old way of saying don't cache: Date header >= Expires header
        if (responseDate.equals(expires) || responseDate.after(expires)) {
            // we are not allowed to cache the result
            // make sure it's not in the cache from a previous request
            logger.debug("Fetched {}. Will not be cached due to Expires/Date header combination sent by server", resource);
            cache.remove(makeCacheKey(resource, requesterWebID));
            return responseData;
        }
    }
    // if we don't get a new etag, see if we have a 304 code - then we can use th
    // old etag
    String etag = responseData.getResponseHeaders().getFirst(HttpHeaders.ETAG);
    if (etag == null && responseData.getStatusCode() == HttpStatus.NOT_MODIFIED.value() && linkedDataCacheEntry != null) {
        etag = linkedDataCacheEntry.getEtag();
    }
    // cache the result
    LinkedDataCacheEntry entry = new LinkedDataCacheEntry(etag, expires, writeDatasetToByteArray(responseData.getDataset()), cacheControlFlags, responseData.getResponseHeaders(), responseData.getStatusCode());
    this.cache.put(new Element(makeCacheKey(resource, requesterWebID), entry));
    logger.debug("Fetched and cached {} ", resource);
    if (logger.isDebugEnabled()) {
        logger.debug("cache size: {} elements, in-memory size: {} bytes", cache.getSize(), cache.calculateInMemorySize());
    }
    return responseData;
}