Merge "Use SkFILEStream directly when possible" into nyc-dev

3 files changed, 15 insertions, 1 deletions

diff --git a/core/jni/android/graphics/BitmapFactory.cpp b/core/jni/android/graphics/BitmapFactory.cpp
index 8b248b07a07d..29c1075a3420 100644
--- a/core/jni/android/graphics/BitmapFactory.cpp
+++ b/core/jni/android/graphics/BitmapFactory.cpp
@@ -555,6 +555,12 @@ static jobject nativeDecodeFileDescriptor(JNIEnv* env, jobject clazz, jobject fi
     std::unique_ptr<SkFILEStream> fileStream(new SkFILEStream(file,
             SkFILEStream::kCallerPasses_Ownership));
 
+    // If there is no offset for the file descriptor, we use SkFILEStream directly.
+    if (::lseek(descriptor, 0, SEEK_CUR) == 0) {
+        assert(isSeekable(dupDescriptor));
+        return doDecode(env, fileStream.release(), padding, bitmapFactoryOptions);
+    }
+
     // Use a buffered stream. Although an SkFILEStream can be rewound, this
     // ensures that SkImageDecoder::Factory never rewinds beyond the
     // current position of the file descriptor.
@@ -584,7 +590,7 @@ static jobject nativeDecodeByteArray(JNIEnv* env, jobject, jbyteArray byteArray,
 
 static jboolean nativeIsSeekable(JNIEnv* env, jobject, jobject fileDescriptor) {
     jint descriptor = jniGetFDFromFileDescriptor(env, fileDescriptor);
-    return ::lseek64(descriptor, 0, SEEK_CUR) != -1 ? JNI_TRUE : JNI_FALSE;
+    return isSeekable(descriptor) ? JNI_TRUE : JNI_FALSE;
 }
 
 jobject decodeBitmap(JNIEnv* env, void* data, size_t size) {
diff --git a/core/jni/android/graphics/Utils.cpp b/core/jni/android/graphics/Utils.cpp
index 4f9ce8bfcef7..5fa445e256fe 100644
--- a/core/jni/android/graphics/Utils.cpp
+++ b/core/jni/android/graphics/Utils.cpp
@@ -116,3 +116,7 @@ jobject android::nullObjectReturn(const char msg[]) {
     }
     return NULL;
 }
+
+bool android::isSeekable(int descriptor) {
+    return ::lseek64(descriptor, 0, SEEK_CUR) != -1;
+}
diff --git a/core/jni/android/graphics/Utils.h b/core/jni/android/graphics/Utils.h
index c0b941004758..d1a74a0adf6c 100644
--- a/core/jni/android/graphics/Utils.h
+++ b/core/jni/android/graphics/Utils.h
@@ -68,6 +68,10 @@ private:
 
 jobject nullObjectReturn(const char msg[]);
 
+/** Check if the file descriptor is seekable.
+ */
+bool isSeekable(int descriptor);
+
 }; // namespace android
 
 #endif  // _ANDROID_GRAPHICS_UTILS_H_