Fix issue with HttpCache causes HttpParseException

Closes apollographql#1786

apollo-http-cache-api/src/main/kotlin/com/apollographql/apollo/api/cache/http/HttpCache.kt

@@ -76,5 +76,10 @@ interface HttpCache {
      * Do not store the http response
      */
     const val CACHE_DO_NOT_STORE = "X-APOLLO-CACHE-DO-NOT-STORE"
+
+    /**
+     * Signals that HTTP response comes from the local cache
+     */
+    const val FROM_CACHE = "X-APOLLO-FROM-CACHE"
   }
 }

apollo-http-cache/src/main/java/com/apollographql/apollo/cache/http/ApolloHttpCache.java

@@ -83,6 +83,7 @@ public void close() throws IOException {
       String contentType = response.header("Content-Type");
       String contentLength = response.header("Content-Length");
       return response.newBuilder()
+          .addHeader(FROM_CACHE, "true")
           .body(new CacheResponseBody(cacheResponseSource, contentType, contentLength))
           .build();
     } catch (Exception e) {

apollo-http-cache/src/main/java/com/apollographql/apollo/cache/http/ResponseBodyProxy.java

@@ -22,7 +22,7 @@
 final class ResponseBodyProxy extends ResponseBody {
   private final String contentType;
   private final String contentLength;
-  private final Source responseBodySource;
+  private final BufferedSource responseBodySource;
 
   ResponseBodyProxy(@NotNull HttpCacheRecordEditor cacheRecordEditor, @NotNull Response sourceResponse,
       @NotNull ApolloLogger logger) {
@@ -31,7 +31,7 @@ final class ResponseBodyProxy extends ResponseBody {
     checkNotNull(logger, "logger == null");
     this.contentType = sourceResponse.header("Content-Type");
     this.contentLength = sourceResponse.header("Content-Length");
-    this.responseBodySource = new ProxySource(cacheRecordEditor, sourceResponse.body().source(), logger);
+    this.responseBodySource = Okio.buffer(new ProxySource(cacheRecordEditor, sourceResponse.body().source(), logger));
   }
 
   @Override public MediaType contentType() {
@@ -46,18 +46,18 @@ final class ResponseBodyProxy extends ResponseBody {
     }
   }
 
-  @Override public BufferedSource source() {
-    return Okio.buffer(responseBodySource);
+  @NotNull @Override public BufferedSource source() {
+    return responseBodySource;
   }
 
   private static class ProxySource implements Source {
-    final HttpCacheRecordEditor cacheRecordEditor;
-    final ResponseBodyCacheSink responseBodyCacheSink;
-    final Source responseBodySource;
-    final ApolloLogger logger;
-    boolean closed;
+    private final HttpCacheRecordEditor cacheRecordEditor;
+    private final ResponseBodyCacheSink responseBodyCacheSink;
+    private final BufferedSource responseBodySource;
+    private final ApolloLogger logger;
+    private boolean closed;
 
-    ProxySource(HttpCacheRecordEditor cacheRecordEditor, Source responseBodySource, final ApolloLogger logger) {
+    ProxySource(HttpCacheRecordEditor cacheRecordEditor, BufferedSource responseBodySource, final ApolloLogger logger) {
       this.cacheRecordEditor = cacheRecordEditor;
       this.responseBodySource = responseBodySource;
       this.logger = logger;
@@ -95,24 +95,23 @@ private static class ProxySource implements Source {
       return bytesRead;
     }
 
-    @Override public Timeout timeout() {
+    @NotNull @Override public Timeout timeout() {
       return responseBodySource.timeout();
     }
 
-    @Override public void close() throws IOException {
+    @Override public void close() {
       if (closed) return;
       closed = true;
 
       if (discard(this, 100, MILLISECONDS)) {
-        responseBodySource.close();
         commitCache();
       } else {
-        responseBodySource.close();
         abortCacheQuietly();
       }
     }
 
     private void commitCache() {
+      closeQuietly(responseBodySource);
       try {
         responseBodyCacheSink.close();
         cacheRecordEditor.commit();
@@ -124,11 +123,12 @@ private void commitCache() {
     }
 
     void abortCacheQuietly() {
+      closeQuietly(responseBodySource);
       closeQuietly(responseBodyCacheSink);
       try {
         cacheRecordEditor.abort();
-      } catch (Exception ignore) {
-        logger.w(ignore, "Failed to abort cache edit");
+      } catch (Exception e) {
+        logger.w(e, "Failed to abort cache edit");
       }
     }
   }

gradle/dependencies.gradle

@@ -71,6 +71,7 @@ ext.dep = [
     okHttp                : [
         mockWebServer: "com.squareup.okhttp3:mockwebserver:$versions.okHttp",
         okHttp       : "com.squareup.okhttp3:okhttp:$versions.okHttp",
+        logging      : "com.squareup.okhttp3:logging-interceptor:$versions.okHttp",
     ],
     okio                  : [
         okio             : "com.squareup.okio:okio:$versions.okio",

samples/kotlin-sample/build.gradle.kts

@@ -37,6 +37,8 @@ dependencies {
     add("implementation", "com.apollographql.apollo:apollo-rx2-support")
     add("implementation", "com.apollographql.apollo:apollo-coroutines-support")
     add("implementation", "com.apollographql.apollo:apollo-runtime")
+    add("implementation", "com.apollographql.apollo:apollo-http-cache")
+    add("implementation", groovy.util.Eval.x(project, "x.dep.okHttp.logging"))
     add("implementation", groovy.util.Eval.x(project, "x.dep.android.appcompat"))
     add("implementation", groovy.util.Eval.x(project, "x.dep.android.recyclerView"))
     add("implementation", groovy.util.Eval.x(project, "x.dep.kotlin.coroutines.android"))

samples/kotlin-sample/src/main/java/com/apollographql/apollo/kotlinsample/KotlinSampleApp.kt

@@ -1,9 +1,13 @@
 package com.apollographql.apollo.kotlinsample
 
 import android.app.Application
+import android.util.Log
 import com.apollographql.apollo.ApolloClient
 import com.apollographql.apollo.api.Operation
 import com.apollographql.apollo.api.ResponseField
+import com.apollographql.apollo.api.cache.http.HttpCachePolicy
+import com.apollographql.apollo.cache.http.ApolloHttpCache
+import com.apollographql.apollo.cache.http.DiskLruHttpCacheStore
 import com.apollographql.apollo.cache.normalized.CacheKey
 import com.apollographql.apollo.cache.normalized.CacheKeyResolver
 import com.apollographql.apollo.cache.normalized.sql.ApolloSqlHelper
@@ -13,11 +17,21 @@ import com.apollographql.apollo.kotlinsample.data.ApolloCoroutinesService
 import com.apollographql.apollo.kotlinsample.data.ApolloRxService
 import com.apollographql.apollo.kotlinsample.data.GitHubDataSource
 import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import java.io.File
 
 @Suppress("unused")
 class KotlinSampleApp : Application() {
   private val baseUrl = "https://api.github.com/graphql"
   private val apolloClient: ApolloClient by lazy {
+    val logInterceptor = HttpLoggingInterceptor(
+        object : HttpLoggingInterceptor.Logger {
+          override fun log(message: String) {
+            Log.d("OkHttp", message)
+          }
+        }
+    ).apply { level = HttpLoggingInterceptor.Level.BODY }
+
     val okHttpClient = OkHttpClient.Builder()
         .addNetworkInterceptor { chain ->
           val request = chain.request().newBuilder()
@@ -26,6 +40,7 @@ class KotlinSampleApp : Application() {
 
           chain.proceed(request)
         }
+        .addInterceptor(logInterceptor)
         .build()
 
     val apolloSqlHelper = ApolloSqlHelper.create(this, "github_cache")
@@ -44,9 +59,14 @@ class KotlinSampleApp : Application() {
       }
     }
 
+    // Create the http response cache store
+    val cacheStore = DiskLruHttpCacheStore(File(cacheDir, "apolloCache"), 1024 * 1024)
+
     ApolloClient.builder()
         .serverUrl(baseUrl)
         .normalizedCache(sqlNormalizedCacheFactory, cacheKeyResolver)
+        .httpCache(ApolloHttpCache(cacheStore))
+        .defaultHttpCachePolicy(HttpCachePolicy.CACHE_FIRST)
         .okHttpClient(okHttpClient)
         .build()
   }
@@ -71,4 +91,4 @@ class KotlinSampleApp : Application() {
     RX_JAVA,
     COROUTINES
   }
-}
+}