1 files changed, 320 insertions, 0 deletions
diff --git a/mobile/android/thirdparty/ch/boye/httpclientandroidlib/impl/client/cache/CacheValidityPolicy.java b/mobile/android/thirdparty/ch/boye/httpclientandroidlib/impl/client/cache/CacheValidityPolicy.java
new file mode 100644
index 000000000..333dfbbfb
--- /dev/null
+++ b/mobile/android/thirdparty/ch/boye/httpclientandroidlib/impl/client/cache/CacheValidityPolicy.java
@@ -0,0 +1,320 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package ch.boye.httpclientandroidlib.impl.client.cache;
+
+import java.util.Date;
+
+import ch.boye.httpclientandroidlib.Header;
+import ch.boye.httpclientandroidlib.HeaderElement;
+import ch.boye.httpclientandroidlib.HttpRequest;
+import ch.boye.httpclientandroidlib.annotation.Immutable;
+import ch.boye.httpclientandroidlib.client.cache.HeaderConstants;
+import ch.boye.httpclientandroidlib.client.cache.HttpCacheEntry;
+import ch.boye.httpclientandroidlib.client.utils.DateUtils;
+import ch.boye.httpclientandroidlib.protocol.HTTP;
+
+/**
+ * @since 4.1
+ */
+@Immutable
+class CacheValidityPolicy {
+
+    public static final long MAX_AGE = 2147483648L;
+
+    CacheValidityPolicy() {
+        super();
+    }
+
+    public long getCurrentAgeSecs(final HttpCacheEntry entry, final Date now) {
+        return getCorrectedInitialAgeSecs(entry) + getResidentTimeSecs(entry, now);
+    }
+
+    public long getFreshnessLifetimeSecs(final HttpCacheEntry entry) {
+        final long maxage = getMaxAge(entry);
+        if (maxage > -1) {
+            return maxage;
+        }
+
+        final Date dateValue = entry.getDate();
+        if (dateValue == null) {
+            return 0L;
+        }
+
+        final Date expiry = getExpirationDate(entry);
+        if (expiry == null) {
+            return 0;
+        }
+        final long diff = expiry.getTime() - dateValue.getTime();
+        return (diff / 1000);
+    }
+
+    public boolean isResponseFresh(final HttpCacheEntry entry, final Date now) {
+        return (getCurrentAgeSecs(entry, now) < getFreshnessLifetimeSecs(entry));
+    }
+
+    /**
+     * Decides if this response is fresh enough based Last-Modified and Date, if available.
+     * This entry is meant to be used when isResponseFresh returns false.  The algorithm is as follows:
+     *
+     * if last-modified and date are defined, freshness lifetime is coefficient*(date-lastModified),
+     * else freshness lifetime is defaultLifetime
+     *
+     * @param entry the cache entry
+     * @param now what time is it currently (When is right NOW)
+     * @param coefficient Part of the heuristic for cache entry freshness
+     * @param defaultLifetime How long can I assume a cache entry is default TTL
+     * @return {@code true} if the response is fresh
+     */
+    public boolean isResponseHeuristicallyFresh(final HttpCacheEntry entry,
+            final Date now, final float coefficient, final long defaultLifetime) {
+        return (getCurrentAgeSecs(entry, now) < getHeuristicFreshnessLifetimeSecs(entry, coefficient, defaultLifetime));
+    }
+
+    public long getHeuristicFreshnessLifetimeSecs(final HttpCacheEntry entry,
+            final float coefficient, final long defaultLifetime) {
+        final Date dateValue = entry.getDate();
+        final Date lastModifiedValue = getLastModifiedValue(entry);
+
+        if (dateValue != null && lastModifiedValue != null) {
+            final long diff = dateValue.getTime() - lastModifiedValue.getTime();
+            if (diff < 0) {
+                return 0;
+            }
+            return (long)(coefficient * (diff / 1000));
+        }
+
+        return defaultLifetime;
+    }
+
+    public boolean isRevalidatable(final HttpCacheEntry entry) {
+        return entry.getFirstHeader(HeaderConstants.ETAG) != null
+                || entry.getFirstHeader(HeaderConstants.LAST_MODIFIED) != null;
+    }
+
+    public boolean mustRevalidate(final HttpCacheEntry entry) {
+        return hasCacheControlDirective(entry, HeaderConstants.CACHE_CONTROL_MUST_REVALIDATE);
+    }
+
+    public boolean proxyRevalidate(final HttpCacheEntry entry) {
+        return hasCacheControlDirective(entry, HeaderConstants.CACHE_CONTROL_PROXY_REVALIDATE);
+    }
+
+    public boolean mayReturnStaleWhileRevalidating(final HttpCacheEntry entry, final Date now) {
+        for (final Header h : entry.getHeaders(HeaderConstants.CACHE_CONTROL)) {
+            for(final HeaderElement elt : h.getElements()) {
+                if (HeaderConstants.STALE_WHILE_REVALIDATE.equalsIgnoreCase(elt.getName())) {
+                    try {
+                        final int allowedStalenessLifetime = Integer.parseInt(elt.getValue());
+                        if (getStalenessSecs(entry, now) <= allowedStalenessLifetime) {
+                            return true;
+                        }
+                    } catch (final NumberFormatException nfe) {
+                        // skip malformed directive
+                    }
+                }
+            }
+        }
+
+        return false;
+    }
+
+    public boolean mayReturnStaleIfError(final HttpRequest request,
+            final HttpCacheEntry entry, final Date now) {
+        final long stalenessSecs = getStalenessSecs(entry, now);
+        return mayReturnStaleIfError(request.getHeaders(HeaderConstants.CACHE_CONTROL),
+                                     stalenessSecs)
+                || mayReturnStaleIfError(entry.getHeaders(HeaderConstants.CACHE_CONTROL),
+                                         stalenessSecs);
+    }
+
+    private boolean mayReturnStaleIfError(final Header[] headers, final long stalenessSecs) {
+        boolean result = false;
+        for(final Header h : headers) {
+            for(final HeaderElement elt : h.getElements()) {
+                if (HeaderConstants.STALE_IF_ERROR.equals(elt.getName())) {
+                    try {
+                        final int staleIfErrorSecs = Integer.parseInt(elt.getValue());
+                        if (stalenessSecs <= staleIfErrorSecs) {
+                            result = true;
+                            break;
+                        }
+                    } catch (final NumberFormatException nfe) {
+                        // skip malformed directive
+                    }
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * @deprecated (4.3) use {@link HttpCacheEntry#getDate()}.
+     * @param entry
+     * @return the Date of the entry
+     */
+    @Deprecated
+    protected Date getDateValue(final HttpCacheEntry entry) {
+        return entry.getDate();
+    }
+
+    protected Date getLastModifiedValue(final HttpCacheEntry entry) {
+        final Header dateHdr = entry.getFirstHeader(HeaderConstants.LAST_MODIFIED);
+        if (dateHdr == null) {
+            return null;
+        }
+        return DateUtils.parseDate(dateHdr.getValue());
+    }
+
+    protected long getContentLengthValue(final HttpCacheEntry entry) {
+        final Header cl = entry.getFirstHeader(HTTP.CONTENT_LEN);
+        if (cl == null) {
+            return -1;
+        }
+
+        try {
+            return Long.parseLong(cl.getValue());
+        } catch (final NumberFormatException ex) {
+            return -1;
+        }
+    }
+
+    protected boolean hasContentLengthHeader(final HttpCacheEntry entry) {
+        return null != entry.getFirstHeader(HTTP.CONTENT_LEN);
+    }
+
+    /**
+     * This matters for deciding whether the cache entry is valid to serve as a
+     * response. If these values do not match, we might have a partial response
+     *
+     * @param entry The cache entry we are currently working with
+     * @return boolean indicating whether actual length matches Content-Length
+     */
+    protected boolean contentLengthHeaderMatchesActualLength(final HttpCacheEntry entry) {
+        return !hasContentLengthHeader(entry) || getContentLengthValue(entry) == entry.getResource().length();
+    }
+
+    protected long getApparentAgeSecs(final HttpCacheEntry entry) {
+        final Date dateValue = entry.getDate();
+        if (dateValue == null) {
+            return MAX_AGE;
+        }
+        final long diff = entry.getResponseDate().getTime() - dateValue.getTime();
+        if (diff < 0L) {
+            return 0;
+        }
+        return (diff / 1000);
+    }
+
+    protected long getAgeValue(final HttpCacheEntry entry) {
+        long ageValue = 0;
+        for (final Header hdr : entry.getHeaders(HeaderConstants.AGE)) {
+            long hdrAge;
+            try {
+                hdrAge = Long.parseLong(hdr.getValue());
+                if (hdrAge < 0) {
+                    hdrAge = MAX_AGE;
+                }
+            } catch (final NumberFormatException nfe) {
+                hdrAge = MAX_AGE;
+            }
+            ageValue = (hdrAge > ageValue) ? hdrAge : ageValue;
+        }
+        return ageValue;
+    }
+
+    protected long getCorrectedReceivedAgeSecs(final HttpCacheEntry entry) {
+        final long apparentAge = getApparentAgeSecs(entry);
+        final long ageValue = getAgeValue(entry);
+        return (apparentAge > ageValue) ? apparentAge : ageValue;
+    }
+
+    protected long getResponseDelaySecs(final HttpCacheEntry entry) {
+        final long diff = entry.getResponseDate().getTime() - entry.getRequestDate().getTime();
+        return (diff / 1000L);
+    }
+
+    protected long getCorrectedInitialAgeSecs(final HttpCacheEntry entry) {
+        return getCorrectedReceivedAgeSecs(entry) + getResponseDelaySecs(entry);
+    }
+
+    protected long getResidentTimeSecs(final HttpCacheEntry entry, final Date now) {
+        final long diff = now.getTime() - entry.getResponseDate().getTime();
+        return (diff / 1000L);
+    }
+
+    protected long getMaxAge(final HttpCacheEntry entry) {
+        long maxage = -1;
+        for (final Header hdr : entry.getHeaders(HeaderConstants.CACHE_CONTROL)) {
+            for (final HeaderElement elt : hdr.getElements()) {
+                if (HeaderConstants.CACHE_CONTROL_MAX_AGE.equals(elt.getName())
+                        || "s-maxage".equals(elt.getName())) {
+                    try {
+                        final long currMaxAge = Long.parseLong(elt.getValue());
+                        if (maxage == -1 || currMaxAge < maxage) {
+                            maxage = currMaxAge;
+                        }
+                    } catch (final NumberFormatException nfe) {
+                        // be conservative if can't parse
+                        maxage = 0;
+                    }
+                }
+            }
+        }
+        return maxage;
+    }
+
+    protected Date getExpirationDate(final HttpCacheEntry entry) {
+        final Header expiresHeader = entry.getFirstHeader(HeaderConstants.EXPIRES);
+        if (expiresHeader == null) {
+            return null;
+        }
+        return DateUtils.parseDate(expiresHeader.getValue());
+    }
+
+    public boolean hasCacheControlDirective(final HttpCacheEntry entry,
+            final String directive) {
+        for (final Header h : entry.getHeaders(HeaderConstants.CACHE_CONTROL)) {
+            for(final HeaderElement elt : h.getElements()) {
+                if (directive.equalsIgnoreCase(elt.getName())) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    public long getStalenessSecs(final HttpCacheEntry entry, final Date now) {
+        final long age = getCurrentAgeSecs(entry, now);
+        final long freshness = getFreshnessLifetimeSecs(entry);
+        if (age <= freshness) {
+            return 0L;
+        }
+        return (age - freshness);
+    }
+
+
+}