Log gzipped bodies when HttpLoggingInterceptor is used as a NetworkInterceptor (#3792)

* (in-progress) Support gzipped bodies as a networkInterceptor

* Fixed buffer cloning, added test for a still-unsupported encoding (Brotli)

* Avoid try-with-resources and too-long lines to appease build checks

* Fixed method name typo

* Added suggested comma between byte and gzipped-byte count

* Account for added comma in test

* Use buffer.writeAll to ensure all body content is read

* Indentation consistency

* Added test to confirm response body remains valid

okhttp-logging-interceptor/src/main/java/okhttp3/logging/HttpLoggingInterceptor.java

@@ -32,6 +32,7 @@ import okhttp3.internal.http.HttpHeaders;
 import okhttp3.internal.platform.Platform;
 import okio.Buffer;
 import okio.BufferedSource;
+import okio.GzipSource;
 
 import static okhttp3.internal.platform.Platform.INFO;
 
@@ -182,7 +183,7 @@ public final class HttpLoggingInterceptor implements Interceptor {
 
       if (!logBody || !hasRequestBody) {
         logger.log("--> END " + request.method());
-      } else if (bodyEncoded(request.headers())) {
+      } else if (bodyHasUnknownEncoding(request.headers())) {
         logger.log("--> END " + request.method() + " (encoded body omitted)");
       } else {
         Buffer buffer = new Buffer();
@@ -233,13 +234,28 @@ public final class HttpLoggingInterceptor implements Interceptor {
 
       if (!logBody || !HttpHeaders.hasBody(response)) {
         logger.log("<-- END HTTP");
-      } else if (bodyEncoded(response.headers())) {
+      } else if (bodyHasUnknownEncoding(response.headers())) {
         logger.log("<-- END HTTP (encoded body omitted)");
       } else {
         BufferedSource source = responseBody.source();
         source.request(Long.MAX_VALUE); // Buffer the entire body.
         Buffer buffer = source.buffer();
 
+        Long gzippedLength = null;
+        if ("gzip".equalsIgnoreCase(headers.get("Content-Encoding"))) {
+          gzippedLength = buffer.size();
+          GzipSource gzippedResponseBody = null;
+          try {
+            gzippedResponseBody = new GzipSource(buffer.clone());
+            buffer = new Buffer();
+            buffer.writeAll(gzippedResponseBody);
+          } finally {
+            if (gzippedResponseBody != null) {
+              gzippedResponseBody.close();
+            }
+          }
+        }
+
         Charset charset = UTF8;
         MediaType contentType = responseBody.contentType();
         if (contentType != null) {
@@ -257,7 +273,12 @@ public final class HttpLoggingInterceptor implements Interceptor {
           logger.log(buffer.clone().readString(charset));
         }
 
-        logger.log("<-- END HTTP (" + buffer.size() + "-byte body)");
+        if (gzippedLength != null) {
+            logger.log("<-- END HTTP (" + buffer.size() + "-byte, "
+                + gzippedLength + "-gzipped-byte body)");
+        } else {
+            logger.log("<-- END HTTP (" + buffer.size() + "-byte body)");
+        }
       }
     }
 
@@ -288,8 +309,10 @@ public final class HttpLoggingInterceptor implements Interceptor {
     }
   }
 
-  private boolean bodyEncoded(Headers headers) {
+  private boolean bodyHasUnknownEncoding(Headers headers) {
     String contentEncoding = headers.get("Content-Encoding");
-    return contentEncoding != null && !contentEncoding.equalsIgnoreCase("identity");
+    return contentEncoding != null
+        && !contentEncoding.equalsIgnoreCase("identity")
+        && !contentEncoding.equalsIgnoreCase("gzip");
   }
 }

okhttp-logging-interceptor/src/test/java/okhttp3/logging/HttpLoggingInterceptorTest.java

@@ -31,6 +31,7 @@ import okhttp3.RecordingHostnameVerifier;
 import okhttp3.Request;
 import okhttp3.RequestBody;
 import okhttp3.Response;
+import okhttp3.ResponseBody;
 import okhttp3.internal.tls.SslClient;
 import okhttp3.logging.HttpLoggingInterceptor.Level;
 import okhttp3.mockwebserver.MockResponse;
@@ -532,7 +533,7 @@ public final class HttpLoggingInterceptorTest {
         .assertNoMoreLogs();
   }
 
-  @Test public void bodyResponseNotIdentityEncoded() throws IOException {
+  @Test public void bodyResponseGzipEncoded() throws IOException {
     setLevel(Level.BODY);
 
     server.enqueue(new MockResponse()
@@ -541,7 +542,10 @@ public final class HttpLoggingInterceptorTest {
         .setBody(new Buffer().write(ByteString.decodeBase64(
             "H4sIAAAAAAAAAPNIzcnJ11HwQKIAdyO+9hMAAAA="))));
     Response response = client.newCall(request().build()).execute();
-    response.body().close();
+
+    ResponseBody responseBody = response.body();
+    assertEquals("Expected response body to be valid","Hello, Hello, Hello", responseBody.string());
+    responseBody.close();
 
     networkLogs
         .assertLogEqual("--> GET " + url + " http/1.1")
@@ -554,7 +558,9 @@ public final class HttpLoggingInterceptorTest {
         .assertLogEqual("Content-Encoding: gzip")
         .assertLogEqual("Content-Type: text/plain; charset=utf-8")
         .assertLogMatch("Content-Length: \\d+")
-        .assertLogEqual("<-- END HTTP (encoded body omitted)")
+        .assertLogEqual("")
+        .assertLogEqual("Hello, Hello, Hello")
+        .assertLogEqual("<-- END HTTP (19-byte, 29-gzipped-byte body)")
         .assertNoMoreLogs();
 
     applicationLogs
@@ -568,6 +574,43 @@ public final class HttpLoggingInterceptorTest {
         .assertNoMoreLogs();
   }
 
+  @Test public void bodyResponseUnknownEncoded() throws IOException {
+      setLevel(Level.BODY);
+
+      server.enqueue(new MockResponse()
+          // It's invalid to return this if not requested, but the server might anyway
+          .setHeader("Content-Encoding", "br")
+          .setHeader("Content-Type", PLAIN)
+          .setBody(new Buffer().write(ByteString.decodeBase64(
+              "iwmASGVsbG8sIEhlbGxvLCBIZWxsbwoD"))));
+      Response response = client.newCall(request().build()).execute();
+      response.body().close();
+
+      networkLogs
+          .assertLogEqual("--> GET " + url + " http/1.1")
+          .assertLogEqual("Host: " + host)
+          .assertLogEqual("Connection: Keep-Alive")
+          .assertLogEqual("Accept-Encoding: gzip")
+          .assertLogMatch("User-Agent: okhttp/.+")
+          .assertLogEqual("--> END GET")
+          .assertLogMatch("<-- 200 OK " + url + " \\(\\d+ms\\)")
+          .assertLogEqual("Content-Encoding: br")
+          .assertLogEqual("Content-Type: text/plain; charset=utf-8")
+          .assertLogMatch("Content-Length: \\d+")
+          .assertLogEqual("<-- END HTTP (encoded body omitted)")
+          .assertNoMoreLogs();
+
+      applicationLogs
+          .assertLogEqual("--> GET " + url)
+          .assertLogEqual("--> END GET")
+          .assertLogMatch("<-- 200 OK " + url + " \\(\\d+ms\\)")
+          .assertLogEqual("Content-Encoding: br")
+          .assertLogEqual("Content-Type: text/plain; charset=utf-8")
+          .assertLogMatch("Content-Length: \\d+")
+          .assertLogEqual("<-- END HTTP (encoded body omitted)")
+          .assertNoMoreLogs();
+    }
+
   @Test public void bodyGetMalformedCharset() throws IOException {
     setLevel(Level.BODY);