Add NullTraceWriter
Add a null implementation of TraceWriter. This simplifies error handling
for clients of SharedMemoryArbiter since they always get a valid
TraceWriter. NullTraceWriter is backed by a ScatteredStreamWriter
which in turn is backed by a ScatteredStreamWriterNullDelegate.
ScatteredStreamWriterNullDelegate always returns the same chunk of
memory.
Change-Id: I7390c7698f414bffeb2ca1df900893af536a5f2c
diff --git a/Android.bp b/Android.bp
index de7759d..b9c1996 100644
--- a/Android.bp
+++ b/Android.bp
@@ -61,6 +61,7 @@
"src/protozero/message.cc",
"src/protozero/message_handle.cc",
"src/protozero/proto_utils.cc",
+ "src/protozero/scattered_stream_null_delegate.cc",
"src/protozero/scattered_stream_writer.cc",
"src/traced/probes/filesystem/fs_mount.cc",
"src/traced/probes/filesystem/inode_file_data_source.cc",
@@ -77,6 +78,7 @@
"src/tracing/core/data_source_descriptor.cc",
"src/tracing/core/ftrace_config.cc",
"src/tracing/core/id_allocator.cc",
+ "src/tracing/core/null_trace_writer.cc",
"src/tracing/core/packet_stream_validator.cc",
"src/tracing/core/service_impl.cc",
"src/tracing/core/shared_memory_abi.cc",
@@ -162,6 +164,7 @@
"src/protozero/message.cc",
"src/protozero/message_handle.cc",
"src/protozero/proto_utils.cc",
+ "src/protozero/scattered_stream_null_delegate.cc",
"src/protozero/scattered_stream_writer.cc",
"src/tracing/core/chrome_config.cc",
"src/tracing/core/commit_data_request.cc",
@@ -169,6 +172,7 @@
"src/tracing/core/data_source_descriptor.cc",
"src/tracing/core/ftrace_config.cc",
"src/tracing/core/id_allocator.cc",
+ "src/tracing/core/null_trace_writer.cc",
"src/tracing/core/packet_stream_validator.cc",
"src/tracing/core/service_impl.cc",
"src/tracing/core/shared_memory_abi.cc",
@@ -284,7 +288,6 @@
"src/ftrace_reader/proto_translation_table.cc",
"src/ftrace_reader/test/cpu_reader_support.cc",
"src/ftrace_reader/test/scattered_stream_delegate_for_testing.cc",
- "src/ftrace_reader/test/scattered_stream_null_delegate.cc",
"src/ipc/buffered_frame_deserializer.cc",
"src/ipc/client_impl.cc",
"src/ipc/deferred.cc",
@@ -296,6 +299,7 @@
"src/protozero/message.cc",
"src/protozero/message_handle.cc",
"src/protozero/proto_utils.cc",
+ "src/protozero/scattered_stream_null_delegate.cc",
"src/protozero/scattered_stream_writer.cc",
"src/traced/probes/filesystem/fs_mount.cc",
"src/traced/probes/filesystem/inode_file_data_source.cc",
@@ -310,6 +314,7 @@
"src/tracing/core/data_source_descriptor.cc",
"src/tracing/core/ftrace_config.cc",
"src/tracing/core/id_allocator.cc",
+ "src/tracing/core/null_trace_writer.cc",
"src/tracing/core/packet_stream_validator.cc",
"src/tracing/core/service_impl.cc",
"src/tracing/core/shared_memory_abi.cc",
@@ -3119,6 +3124,7 @@
"src/protozero/message.cc",
"src/protozero/message_handle.cc",
"src/protozero/proto_utils.cc",
+ "src/protozero/scattered_stream_null_delegate.cc",
"src/protozero/scattered_stream_writer.cc",
"src/tracing/core/chrome_config.cc",
"src/tracing/core/commit_data_request.cc",
@@ -3126,6 +3132,7 @@
"src/tracing/core/data_source_descriptor.cc",
"src/tracing/core/ftrace_config.cc",
"src/tracing/core/id_allocator.cc",
+ "src/tracing/core/null_trace_writer.cc",
"src/tracing/core/packet_stream_validator.cc",
"src/tracing/core/service_impl.cc",
"src/tracing/core/shared_memory_abi.cc",
@@ -3305,7 +3312,6 @@
"src/ftrace_reader/proto_translation_table_unittest.cc",
"src/ftrace_reader/test/cpu_reader_support.cc",
"src/ftrace_reader/test/scattered_stream_delegate_for_testing.cc",
- "src/ftrace_reader/test/scattered_stream_null_delegate.cc",
"src/ipc/buffered_frame_deserializer.cc",
"src/ipc/buffered_frame_deserializer_unittest.cc",
"src/ipc/client_impl.cc",
@@ -3329,6 +3335,7 @@
"src/protozero/message_unittest.cc",
"src/protozero/proto_utils.cc",
"src/protozero/proto_utils_unittest.cc",
+ "src/protozero/scattered_stream_null_delegate.cc",
"src/protozero/scattered_stream_writer.cc",
"src/protozero/scattered_stream_writer_unittest.cc",
"src/protozero/test/fake_scattered_buffer.cc",
@@ -3352,6 +3359,8 @@
"src/tracing/core/ftrace_config.cc",
"src/tracing/core/id_allocator.cc",
"src/tracing/core/id_allocator_unittest.cc",
+ "src/tracing/core/null_trace_writer.cc",
+ "src/tracing/core/null_trace_writer_unittest.cc",
"src/tracing/core/packet_stream_validator.cc",
"src/tracing/core/packet_stream_validator_unittest.cc",
"src/tracing/core/patch_list_unittest.cc",