1 files changed, 97 insertions, 0 deletions
diff --git a/media/libstagefright/CallbackDataSource.cpp b/media/libstagefright/CallbackDataSource.cpp
new file mode 100644
index 0000000..e16cef7
--- /dev/null
+++ b/media/libstagefright/CallbackDataSource.cpp
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2015 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.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "CallbackDataSource"
+#include <utils/Log.h>
+
+#include "include/CallbackDataSource.h"
+
+#include <binder/IMemory.h>
+#include <media/IDataSource.h>
+#include <media/stagefright/foundation/ADebug.h>
+
+#include <algorithm>
+
+namespace android {
+
+CallbackDataSource::CallbackDataSource(
+    const sp<IDataSource>& binderDataSource)
+    : mIDataSource(binderDataSource) {
+    // Set up the buffer to read into.
+    mMemory = mIDataSource->getIMemory();
+}
+
+CallbackDataSource::~CallbackDataSource() {
+    ALOGV("~CallbackDataSource");
+    mIDataSource->close();
+}
+
+status_t CallbackDataSource::initCheck() const {
+    if (mMemory == NULL) {
+        return UNKNOWN_ERROR;
+    }
+    return OK;
+}
+
+ssize_t CallbackDataSource::readAt(off64_t offset, void* data, size_t size) {
+    if (mMemory == NULL) {
+        return -1;
+    }
+
+    // IDataSource can only read up to mMemory->size() bytes at a time, but this
+    // method should be able to read any number of bytes, so read in a loop.
+    size_t totalNumRead = 0;
+    size_t numLeft = size;
+    const size_t bufferSize = mMemory->size();
+
+    while (numLeft > 0) {
+        size_t numToRead = std::min(numLeft, bufferSize);
+        ssize_t numRead =
+            mIDataSource->readAt(offset + totalNumRead, numToRead);
+        // A negative return value represents an error. Pass it on.
+        if (numRead < 0) {
+            return numRead;
+        }
+        // A zero return value signals EOS. Return the bytes read so far.
+        if (numRead == 0) {
+            return totalNumRead;
+        }
+        // Sanity check.
+        CHECK((size_t)numRead <= numToRead && numRead >= 0 &&
+              numRead <= bufferSize);
+        memcpy(((uint8_t*)data) + totalNumRead, mMemory->pointer(), numRead);
+        numLeft -= numRead;
+        totalNumRead += numRead;
+    }
+
+    return totalNumRead;
+}
+
+status_t CallbackDataSource::getSize(off64_t *size) {
+    status_t err = mIDataSource->getSize(size);
+    if (err != OK) {
+        return err;
+    }
+    if (*size < 0) {
+        // IDataSource will set size to -1 to indicate unknown size, but
+        // DataSource returns ERROR_UNSUPPORTED for that.
+        return ERROR_UNSUPPORTED;
+    }
+    return OK;
+}
+
+} // namespace android