Introduce Java-like OutputStream

native/jni/utils/include/OutStream.h

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <unistd.h>
+#include <memory>
+
+class OutStream {
+public:
+	virtual bool write(const void *buf, size_t len) = 0;
+	virtual ~OutStream() = default;
+};
+
+typedef std::unique_ptr<OutStream> strm_ptr;
+
+class FilterOutStream : public OutStream {
+public:
+	FilterOutStream() = default;
+
+	FilterOutStream(strm_ptr &&ptr) : out(std::move(ptr)) {}
+
+	void set_out(strm_ptr &&ptr) { out = std::move(ptr); }
+
+	bool write(const void *buf, size_t len) override {
+		return out ? out->write(buf, len) : false;
+	}
+
+protected:
+	strm_ptr out;
+};
+
+class FDOutStream : public OutStream {
+public:
+	FDOutStream(int fd, bool close = false) : fd(fd), close(close) {}
+
+	bool write(const void *buf, size_t len) override {
+		return ::write(fd, buf, len) == len;
+	}
+
+	~FDOutStream() override {
+		if (close)
+			::close(fd);
+	}
+
+protected:
+	int fd;
+	bool close;
+};