Add metadata store to surfaces

This adds a key/value metadata storage mechanism to
surfaces that allows the windowmanager to pass information
to the surfaceflinger frontend.

This then moves the existing metadata (window type and
ownerUID) into this metadata structure.

Bug: 122925737
Test: Phone boots and surfaces fling. Some unittests
Change-Id: I72c574737b7f75be2311a341812b15d385f507ed

1 files changed, 114 insertions, 0 deletions

diff --git a/libs/gui/LayerMetadata.cpp b/libs/gui/LayerMetadata.cpp
new file mode 100644
index 0000000000..c8a2b0754b
--- /dev/null
+++ b/libs/gui/LayerMetadata.cpp
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2019 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 <android-base/stringprintf.h>
+#include <binder/Parcel.h>
+#include <gui/LayerMetadata.h>
+
+using android::base::StringPrintf;
+
+namespace android {
+
+LayerMetadata::LayerMetadata() = default;
+
+LayerMetadata::LayerMetadata(std::unordered_map<uint32_t, std::vector<uint8_t>> map)
+      : mMap(std::move(map)) {}
+
+LayerMetadata::LayerMetadata(const LayerMetadata& other) = default;
+
+LayerMetadata::LayerMetadata(LayerMetadata&& other) = default;
+
+void LayerMetadata::merge(const LayerMetadata& other) {
+    for (const auto& entry : other.mMap) {
+        mMap[entry.first] = entry.second;
+    }
+}
+
+status_t LayerMetadata::writeToParcel(Parcel* parcel) const {
+    parcel->writeInt32(static_cast<int>(mMap.size()));
+    status_t status = OK;
+    for (const auto& entry : mMap) {
+        status = parcel->writeUint32(entry.first);
+        if (status != OK) {
+            break;
+        }
+        status = parcel->writeByteVector(entry.second);
+        if (status != OK) {
+            break;
+        }
+    }
+    return status;
+}
+
+status_t LayerMetadata::readFromParcel(const Parcel* parcel) {
+    int size = parcel->readInt32();
+    status_t status = OK;
+    mMap.clear();
+    for (int i = 0; i < size; ++i) {
+        uint32_t key = parcel->readUint32();
+        status = parcel->readByteVector(&mMap[key]);
+        if (status != OK) {
+            break;
+        }
+    }
+    return status;
+}
+
+LayerMetadata& LayerMetadata::operator=(const LayerMetadata& other) {
+    mMap = other.mMap;
+    return *this;
+}
+
+LayerMetadata& LayerMetadata::operator=(LayerMetadata&& other) {
+    mMap = std::move(other.mMap);
+    return *this;
+}
+
+bool LayerMetadata::has(uint32_t key) const {
+    return mMap.count(key);
+}
+
+int32_t LayerMetadata::getInt32(uint32_t key, int32_t fallback) const {
+    if (!has(key)) return fallback;
+    const std::vector<uint8_t>& data = mMap.at(key);
+    if (data.size() < sizeof(uint32_t)) return fallback;
+    Parcel p;
+    p.setData(data.data(), data.size());
+    return p.readInt32();
+}
+
+void LayerMetadata::setInt32(uint32_t key, int32_t value) {
+    std::vector<uint8_t>& data = mMap[key];
+    Parcel p;
+    p.writeInt32(value);
+    data.resize(p.dataSize());
+    memcpy(data.data(), p.data(), p.dataSize());
+}
+
+std::string LayerMetadata::itemToString(uint32_t key, const char* separator) const {
+    if (!has(key)) return std::string();
+    switch (key) {
+        case METADATA_OWNER_UID:
+            return StringPrintf("ownerUID%s%d", separator, getInt32(key, 0));
+        case METADATA_WINDOW_TYPE:
+            return StringPrintf("windowType%s%d", separator, getInt32(key, 0));
+        default:
+            return StringPrintf("%d%s%dbytes", key, separator,
+                                static_cast<int>(mMap.at(key).size()));
+    }
+}
+
+} // namespace android