Re-create http disk LRU cache after it was deleted (#1020)

Closes #1017
apollographql · Aug 13, 2018 · 7358a79 · 7358a79
1 parent 7983892
commit 7358a79
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Showing 2 changed files with 69 additions and 9 deletions.
diff --git a/...o-http-cache/src/main/java/com/apollographql/apollo/cache/http/DiskLruHttpCacheStore.java b/...o-http-cache/src/main/java/com/apollographql/apollo/cache/http/DiskLruHttpCacheStore.java
@@ -4,10 +4,12 @@
 import com.apollographql.apollo.api.cache.http.HttpCacheRecordEditor;
 import com.apollographql.apollo.api.cache.http.HttpCacheStore;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.io.File;
 import java.io.IOException;
-
-import org.jetbrains.annotations.NotNull;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import okhttp3.internal.cache.DiskLruCache;
 import okhttp3.internal.io.FileSystem;
@@ -20,18 +22,34 @@ public final class DiskLruHttpCacheStore implements HttpCacheStore {
   private static final int ENTRY_BODY = 1;
   private static final int ENTRY_COUNT = 2;
 
-  private final DiskLruCache cache;
+  private final FileSystem fileSystem;
+  private final File directory;
+  private final long maxSize;
+  private DiskLruCache cache;
+  private final ReadWriteLock cacheLock = new ReentrantReadWriteLock();
 
   public DiskLruHttpCacheStore(@NotNull File directory, long maxSize) {
-    this.cache = DiskLruCache.create(FileSystem.SYSTEM, directory, VERSION, ENTRY_COUNT, maxSize);
+    this(FileSystem.SYSTEM, directory, maxSize);
   }
 
   public DiskLruHttpCacheStore(@NotNull FileSystem fileSystem, @NotNull File directory, long maxSize) {
-    this.cache = DiskLruCache.create(fileSystem, directory, VERSION, ENTRY_COUNT, maxSize);
+    this.fileSystem = fileSystem;
+    this.directory = directory;
+    this.maxSize = maxSize;
+
+    cache = createDiskLruCache();
   }
 
   @Override public HttpCacheRecord cacheRecord(@NotNull String cacheKey) throws IOException {
-    final DiskLruCache.Snapshot snapshot = cache.get(cacheKey);
+    final DiskLruCache.Snapshot snapshot;
+
+    cacheLock.readLock().lock();
+    try {
+      snapshot = cache.get(cacheKey);
+    } finally {
+      cacheLock.readLock().unlock();
+    }
+
     if (snapshot == null) {
       return null;
     }
@@ -53,7 +71,15 @@ public DiskLruHttpCacheStore(@NotNull FileSystem fileSystem, @NotNull File direc
   }
 
   @Override public HttpCacheRecordEditor cacheRecordEditor(@NotNull String cacheKey) throws IOException {
-    final DiskLruCache.Editor editor = cache.edit(cacheKey);
+    final DiskLruCache.Editor editor;
+
+    cacheLock.readLock().lock();
+    try {
+      editor = cache.edit(cacheKey);
+    } finally {
+      cacheLock.readLock().unlock();
+    }
+
     if (editor == null) {
       return null;
     }
@@ -78,10 +104,25 @@ public DiskLruHttpCacheStore(@NotNull FileSystem fileSystem, @NotNull File direc
   }
 
   @Override public void delete() throws IOException {
-    cache.delete();
+    cacheLock.writeLock().lock();
+    try {
+      cache.delete();
+      cache = createDiskLruCache();
+    } finally {
+      cacheLock.writeLock().unlock();
+    }
   }
 
   @Override public void remove(@NotNull String cacheKey) throws IOException {
-    cache.remove(cacheKey);
+    cacheLock.readLock().lock();
+    try {
+      cache.remove(cacheKey);
+    } finally {
+      cacheLock.readLock().unlock();
+    }
+  }
+
+  private DiskLruCache createDiskLruCache() {
+    return DiskLruCache.create(fileSystem, directory, VERSION, ENTRY_COUNT, maxSize);
   }
 }
diff --git a/apollo-integration/src/test/java/com/apollographql/apollo/HttpCacheTest.java b/apollo-integration/src/test/java/com/apollographql/apollo/HttpCacheTest.java
@@ -273,6 +273,25 @@ public class HttpCacheTest {
     assertThat(lastHttResponse.cacheResponse()).isNotNull();
   }
 
+  @Test @SuppressWarnings("CheckReturnValue") public void cacheAfterDelete() throws Exception {
+    enqueueResponse("/HttpCacheTestAllPlanets.json");
+    Rx2Apollo.from(apolloClient
+        .query(new AllPlanetsQuery()))
+        .test();
+    checkCachedResponse("/HttpCacheTestAllPlanets.json");
+
+    cacheStore.delegate.delete();
+
+    enqueueResponse("/HttpCacheTestAllPlanets.json");
+    Rx2Apollo.from(apolloClient
+        .query(new AllPlanetsQuery())
+        .httpCachePolicy(HttpCachePolicy.CACHE_FIRST))
+        .test();
+    checkCachedResponse("/HttpCacheTestAllPlanets.json");
+
+    assertThat(server.getRequestCount()).isEqualTo(2);
+  }
+
   @Test @SuppressWarnings("CheckReturnValue") public void cacheStale() throws Exception {
     enqueueResponse("/HttpCacheTestAllPlanets.json");
     Rx2Apollo.from(apolloClient