缓存文件时遵循 Cache-Control 设置 (#4462)

HMCLCore/src/main/java/org/jackhuang/hmcl/task/CacheFileTask.java

@@ -17,6 +17,7 @@
  */
 package org.jackhuang.hmcl.task;
 
+import org.jackhuang.hmcl.util.CacheRepository;
 import org.jackhuang.hmcl.util.io.NetworkUtils;
 import org.jetbrains.annotations.NotNull;
 
@@ -51,8 +52,11 @@ public final class CacheFileTask extends FetchTask<Path> {
         // Check cache
         for (URI uri : uris) {
             try {
-                setResult(repository.getCachedRemoteFile(uri));
+                setResult(repository.getCachedRemoteFile(uri, true));
+                LOG.info("Using cached file for " + NetworkUtils.dropQuery(uri));
                 return EnumCheckETag.CACHED;
+            } catch (CacheRepository.CacheExpiredException e) {
+                LOG.info("Cache expired for " + NetworkUtils.dropQuery(uri));
             } catch (IOException ignored) {
             }
         }

HMCLCore/src/main/java/org/jackhuang/hmcl/task/FetchTask.java

@@ -100,6 +100,17 @@ public abstract class FetchTask<T> extends Task<T> {
         int repeat = 0;
         download:
         for (URI uri : uris) {
+            if (checkETag) {
+                // Handle cache
+                try {
+                    Path cache = repository.getCachedRemoteFile(uri, true);
+                    useCachedResult(cache);
+                    LOG.info("Using cached file for " + NetworkUtils.dropQuery(uri));
+                    return;
+                } catch (IOException ignored) {
+                }
+            }
+
             for (int retryTime = 0; retryTime < retry; retryTime++) {
                 if (isCancelled()) {
                     break download;
@@ -113,8 +124,7 @@ public abstract class FetchTask<T> extends Task<T> {
 
                     URLConnection conn = NetworkUtils.createConnection(uri);
 
-                    if (conn instanceof HttpURLConnection) {
+                    if (conn instanceof HttpURLConnection httpConnection) {
-                        var httpConnection = (HttpURLConnection) conn;
                         httpConnection.setRequestProperty("Accept-Encoding", "gzip");
 
                         if (checkETag) repository.injectConnection(httpConnection);
@@ -172,10 +182,12 @@ public abstract class FetchTask<T> extends Task<T> {
                         if (responseCode == HttpURLConnection.HTTP_NOT_MODIFIED) {
                             // Handle cache
                             try {
-                                Path cache = repository.getCachedRemoteFile(NetworkUtils.toURI(conn.getURL()));
+                                Path cache = repository.getCachedRemoteFile(NetworkUtils.toURI(conn.getURL()), false);
                                 useCachedResult(cache);
                                 LOG.info("Using cached file for " + NetworkUtils.dropQuery(uri));
                                 return;
+                            } catch (CacheRepository.CacheExpiredException e) {
+                                LOG.info("Cache expired for " + NetworkUtils.dropQuery(uri));
                             } catch (IOException e) {
                                 LOG.warning("Unable to use cached file, redownload " + NetworkUtils.dropQuery(uri), e);
                                 repository.removeRemoteEntry(conn.getURL().toURI());

HMCLCore/src/main/java/org/jackhuang/hmcl/util/CacheRepository.java

@@ -36,12 +36,15 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 import java.nio.file.attribute.FileTime;
+import java.time.Instant;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.*;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.BiFunction;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.jackhuang.hmcl.util.gson.JsonUtils.*;
@@ -150,7 +153,7 @@ public class CacheRepository {
         return cache;
     }
 
-    public Path getCachedRemoteFile(URI uri) throws IOException {
+    public Path getCachedRemoteFile(URI uri, boolean checkExpires) throws IOException {
         lock.readLock().lock();
         ETagItem eTagItem;
         try {
@@ -160,6 +163,9 @@ public class CacheRepository {
         }
         if (eTagItem == null) throw new IOException("Cannot find the URL");
         if (StringUtils.isBlank(eTagItem.hash) || !fileExists(SHA1, eTagItem.hash)) throw new FileNotFoundException();
+        if (checkExpires && System.currentTimeMillis() > eTagItem.expires)
+            throw new CacheExpiredException(eTagItem.expires);
+
         Path file = getFile(SHA1, eTagItem.hash);
         if (Files.getLastModifiedTime(file).toMillis() != eTagItem.localLastModified) {
             String hash = DigestUtils.digestToString(SHA1, file);
@@ -222,6 +228,8 @@ public class CacheRepository {
         });
     }
 
+    private static final Pattern MAX_AGE = Pattern.compile("(s-maxage|max-age)=(?<time>[0-9]+)");
+
     private Path cacheData(URLConnection connection, ExceptionalSupplier<CacheResult, IOException> cacheSupplier) throws IOException {
         String eTag = connection.getHeaderField("ETag");
         if (StringUtils.isBlank(eTag)) return null;
@@ -231,9 +239,41 @@ public class CacheRepository {
         } catch (IllegalArgumentException e) {
             throw new IOException(e);
         }
+        long expires = 0L;
+
+        expires:
+        try {
+            String cacheControl = connection.getHeaderField("Cache-Control");
+            if (StringUtils.isNotBlank(cacheControl)) {
+                if (cacheControl.contains("no-store"))
+                    return null;
+
+                Matcher matcher = MAX_AGE.matcher(cacheControl);
+                if (matcher.find()) {
+                    long seconds = Long.parseLong(matcher.group("time"));
+                    expires = Instant.now().plusSeconds(seconds).toEpochMilli();
+                    break expires;
+                }
+            }
+
+            String expiresHeader = connection.getHeaderField("Expires");
+            if (StringUtils.isNotBlank(expiresHeader)) {
+                expires = ZonedDateTime.parse(expiresHeader.trim(), DateTimeFormatter.RFC_1123_DATE_TIME)
+                        .toInstant().toEpochMilli();
+            }
+        } catch (Throwable e) {
+            LOG.warning("Failed to parse expires time", e);
+        }
+
         String lastModified = connection.getHeaderField("Last-Modified");
+
         CacheResult cacheResult = cacheSupplier.get();
-        ETagItem eTagItem = new ETagItem(uri.toString(), eTag, cacheResult.hash, Files.getLastModifiedTime(cacheResult.cachedFile).toMillis(), lastModified);
+        ETagItem eTagItem = new ETagItem(uri.toString(),
+                eTag,
+                cacheResult.hash,
+                Files.getLastModifiedTime(cacheResult.cachedFile).toMillis(),
+                lastModified,
+                expires);
         lock.writeLock().lock();
         try {
             index.compute(uri, updateEntity(eTagItem, true));
@@ -336,20 +376,26 @@ public class CacheRepository {
         private final long localLastModified;
         @SerializedName("remote")
         private final String remoteLastModified;
+        private final long expires;
 
         /**
          * For Gson.
          */
         public ETagItem() {
-            this(null, null, null, 0, null);
+            this(null, null, null, 0, null, 0L);
         }
 
-        public ETagItem(String url, String eTag, String hash, long localLastModified, String remoteLastModified) {
+        public ETagItem(String url, String eTag, String hash, long localLastModified, String remoteLastModified, long expires) {
             this.url = url;
             this.eTag = eTag;
             this.hash = hash;
             this.localLastModified = localLastModified;
             this.remoteLastModified = remoteLastModified;
+            this.expires = expires;
+        }
+
+        public long getExpires() {
+            return expires;
         }
 
         public int compareTo(ETagItem other) {
@@ -367,18 +413,18 @@ public class CacheRepository {
         @Override
         public boolean equals(Object o) {
             if (this == o) return true;
-            if (o == null || getClass() != o.getClass()) return false;
+            return o instanceof ETagItem that
-            ETagItem eTagItem = (ETagItem) o;
+                    && localLastModified == that.localLastModified
-            return localLastModified == eTagItem.localLastModified &&
+                    && Objects.equals(url, that.url)
-                    Objects.equals(url, eTagItem.url) &&
+                    && Objects.equals(eTag, that.eTag)
-                    Objects.equals(eTag, eTagItem.eTag) &&
+                    && Objects.equals(hash, that.hash)
-                    Objects.equals(hash, eTagItem.hash) &&
+                    && Objects.equals(remoteLastModified, that.remoteLastModified)
-                    Objects.equals(remoteLastModified, eTagItem.remoteLastModified);
+                    && this.expires == that.expires;
         }
 
         @Override
         public int hashCode() {
-            return Objects.hash(url, eTag, hash, localLastModified, remoteLastModified);
+            return Objects.hash(url, eTag, hash, localLastModified, remoteLastModified, expires);
         }
 
         @Override
@@ -389,6 +435,7 @@ public class CacheRepository {
                     ", hash='" + hash + '\'' +
                     ", localLastModified=" + localLastModified +
                     ", remoteLastModified='" + remoteLastModified + '\'' +
+                    ", expires=" + expires +
                     ']';
         }
     }
@@ -404,4 +451,21 @@ public class CacheRepository {
     }
 
     public static final String SHA1 = "SHA-1";
+
+    public static class CacheExpiredException extends IOException {
+        private final long expires;
+
+        public CacheExpiredException(long expires) {
+            this.expires = expires;
+        }
+
+        public CacheExpiredException(String message, long expires) {
+            super(message);
+            this.expires = expires;
+        }
+
+        public long getExpires() {
+            return expires;
+        }
+    }
 }