Use callbacks for Midi I/O

Instead of having the Sonivox engine directly open the file and
use stdio to read from it, use caller-provided callbacks.

Change-Id: Ie55129109060a4a7862fee3177f994401e00b6c1

1 files changed, 76 insertions, 0 deletions

diff --git a/media/libmedia/MidiIoWrapper.cpp b/media/libmedia/MidiIoWrapper.cpp
new file mode 100644
index 0000000..ef931d2
--- /dev/null
+++ b/media/libmedia/MidiIoWrapper.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2014 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 "MidiIoWrapper"
+#include <utils/Log.h>
+#include <utils/RefBase.h>
+
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "media/MidiIoWrapper.h"
+
+static int readAt(void *handle, void *buffer, int pos, int size) {
+    return ((android::MidiIoWrapper*)handle)->readAt(buffer, pos, size);
+}
+static int size(void *handle) {
+    return ((android::MidiIoWrapper*)handle)->size();
+}
+
+namespace android {
+
+MidiIoWrapper::MidiIoWrapper(const char *path) {
+    ALOGV("MidiIoWrapper(%s)", path);
+    mFd = open(path, O_RDONLY | O_LARGEFILE);
+    mBase = 0;
+    mLength = lseek(mFd, 0, SEEK_END);
+}
+
+MidiIoWrapper::MidiIoWrapper(int fd, off64_t offset, int64_t size) {
+    ALOGV("MidiIoWrapper(fd=%d)", fd);
+    mFd = dup(fd);
+    mBase = offset;
+    mLength = size;
+}
+
+MidiIoWrapper::~MidiIoWrapper() {
+    ALOGV("~MidiIoWrapper");
+    close(mFd);
+}
+
+int MidiIoWrapper::readAt(void *buffer, int offset, int size) {
+    ALOGV("readAt(%p, %d, %d)", buffer, offset, size);
+    lseek(mFd, mBase + offset, SEEK_SET);
+    if (offset + size > mLength) {
+        size = mLength - offset;
+    }
+    return read(mFd, buffer, size);
+}
+
+int MidiIoWrapper::size() {
+    ALOGV("size() = %d", mLength);
+    return mLength;
+}
+
+EAS_FILE_LOCATOR MidiIoWrapper::getLocator() {
+    mEasFile.handle = this;
+    mEasFile.readAt = ::readAt;
+    mEasFile.size = ::size;
+    return &mEasFile;
+}
+
+}  // namespace android