1 files changed, 73 insertions, 0 deletions
diff --git a/externals/oboe/src/common/FixedBlockReader.cpp b/externals/oboe/src/common/FixedBlockReader.cpp
new file mode 100644
index 0000000000..62e9664d9f
--- /dev/null
+++ b/externals/oboe/src/common/FixedBlockReader.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+#include <memory.h>
+
+#include "FixedBlockAdapter.h"
+
+#include "FixedBlockReader.h"
+
+
+FixedBlockReader::FixedBlockReader(FixedBlockProcessor &fixedBlockProcessor)
+        : FixedBlockAdapter(fixedBlockProcessor) {
+    mPosition = mSize;
+}
+
+int32_t FixedBlockReader::open(int32_t bytesPerFixedBlock) {
+    int32_t result = FixedBlockAdapter::open(bytesPerFixedBlock);
+    mPosition = 0;
+    mValid = 0;
+    return result;
+}
+
+int32_t FixedBlockReader::readFromStorage(uint8_t *buffer, int32_t numBytes) {
+    int32_t bytesToRead = numBytes;
+    int32_t dataAvailable = mValid - mPosition;
+    if (bytesToRead > dataAvailable) {
+        bytesToRead = dataAvailable;
+    }
+    memcpy(buffer, mStorage.get() + mPosition, bytesToRead);
+    mPosition += bytesToRead;
+    return bytesToRead;
+}
+
+int32_t FixedBlockReader::read(uint8_t *buffer, int32_t numBytes) {
+    int32_t bytesRead;
+    int32_t bytesLeft = numBytes;
+    while(bytesLeft > 0) {
+        if (mPosition < mValid) {
+            // Use up bytes currently in storage.
+            bytesRead = readFromStorage(buffer, bytesLeft);
+            buffer += bytesRead;
+            bytesLeft -= bytesRead;
+        } else if (bytesLeft >= mSize) {
+            // Nothing in storage. Read through if enough for a complete block.
+            bytesRead = mFixedBlockProcessor.onProcessFixedBlock(buffer, mSize);
+            if (bytesRead < 0) return bytesRead;
+            buffer += bytesRead;
+            bytesLeft -= bytesRead;
+        } else {
+            // Just need a partial block so we have to reload storage.
+            bytesRead = mFixedBlockProcessor.onProcessFixedBlock(mStorage.get(), mSize);
+            if (bytesRead < 0) return bytesRead;
+            mPosition = 0;
+            mValid = bytesRead;
+            if (bytesRead == 0) break;
+        }
+    }
+    return numBytes - bytesLeft;
+}