1 files changed, 68 insertions, 0 deletions
diff --git a/logd/LogSize.cpp b/logd/LogSize.cpp
new file mode 100644
index 000000000..fe829baac
--- /dev/null
+++ b/logd/LogSize.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2020 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 <LogSize.h>
+
+#include <array>
+#include <optional>
+#include <string>
+
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+
+bool IsValidBufferSize(size_t value) {
+    return kLogBufferMinSize <= value && value <= kLogBufferMaxSize;
+}
+
+static std::optional<size_t> GetBufferSizeProperty(const std::string& key) {
+    std::string value = android::base::GetProperty(key, "");
+    if (value.empty()) {
+        return {};
+    }
+
+    uint32_t size;
+    if (!android::base::ParseByteCount(value, &size)) {
+        return {};
+    }
+
+    if (!IsValidBufferSize(size)) {
+        return {};
+    }
+
+    return size;
+}
+
+size_t GetBufferSizeFromProperties(log_id_t log_id) {
+    std::string buffer_name = android_log_id_to_name(log_id);
+    std::array<std::string, 4> properties = {
+            "persist.logd.size." + buffer_name,
+            "ro.logd.size." + buffer_name,
+            "persist.logd.size",
+            "ro.logd.size",
+    };
+
+    for (const auto& property : properties) {
+        if (auto size = GetBufferSizeProperty(property)) {
+            return *size;
+        }
+    }
+
+    if (android::base::GetBoolProperty("ro.config.low_ram", false)) {
+        return kLogBufferMinSize;
+    }
+
+    return kDefaultLogBufferSize;
+}