Compress/decompress memory automatically in trace files

src/xenia/gpu/trace_writer.cc

@@ -9,8 +9,12 @@
 
 #include "xenia/gpu/trace_writer.h"
 
+#include "xenia/base/assert.h"
+#include "xenia/base/logging.h"
 #include "xenia/base/string.h"
 
+#include "third_party/zlib/zlib.h"
+
 namespace xe {
 namespace gpu {
 
@@ -22,6 +26,9 @@ TraceWriter::~TraceWriter() = default;
 bool TraceWriter::Open(const std::wstring& path) {
   Close();
 
+  // Reserve 2 MB of space.
+  tmp_buff_.reserve(1024 * 2048);
+
   auto canonical_path = xe::to_absolute_path(path);
   auto base_path = xe::find_base_path(canonical_path);
   xe::filesystem::CreateFolder(base_path);
@@ -109,22 +116,48 @@ void TraceWriter::WriteMemoryRead(uint32_t base_ptr, size_t length) {
   if (!file_) {
     return;
   }
+
+  bool compress = compress_output_ && length > compression_threshold_;
+
   auto cmd = MemoryReadCommand({
-      TraceCommandType::kMemoryRead, base_ptr, uint32_t(length),
+      TraceCommandType::kMemoryRead, base_ptr, uint32_t(length), 0,
   });
-  fwrite(&cmd, 1, sizeof(cmd), file_);
-  fwrite(membase_ + base_ptr, 1, length, file_);
+
+  if (compress) {
+    size_t written = WriteCompressed(membase_ + base_ptr, length);
+    cmd.length = uint32_t(written);
+    cmd.full_length = uint32_t(length);
+
+    fwrite(&cmd, 1, sizeof(cmd), file_);
+    fwrite(tmp_buff_.data(), 1, written, file_);
+  } else {
+    fwrite(&cmd, 1, sizeof(cmd), file_);
+    fwrite(membase_ + base_ptr, 1, length, file_);
+  }
 }
 
 void TraceWriter::WriteMemoryWrite(uint32_t base_ptr, size_t length) {
   if (!file_) {
     return;
   }
+
+  bool compress = compress_output_ && length > compression_threshold_;
+
   auto cmd = MemoryWriteCommand({
-      TraceCommandType::kMemoryWrite, base_ptr, uint32_t(length),
+      TraceCommandType::kMemoryWrite, base_ptr, uint32_t(length), 0,
   });
-  fwrite(&cmd, 1, sizeof(cmd), file_);
-  fwrite(membase_ + base_ptr, 1, length, file_);
+
+  if (compress) {
+    size_t written = WriteCompressed(membase_ + base_ptr, length);
+    cmd.length = uint32_t(written);
+    cmd.full_length = uint32_t(length);
+
+    fwrite(&cmd, 1, sizeof(cmd), file_);
+    fwrite(tmp_buff_.data(), 1, written, file_);
+  } else {
+    fwrite(&cmd, 1, sizeof(cmd), file_);
+    fwrite(membase_ + base_ptr, 1, length, file_);
+  }
 }
 
 void TraceWriter::WriteEvent(EventType event_type) {
@@ -137,5 +170,15 @@ void TraceWriter::WriteEvent(EventType event_type) {
   fwrite(&cmd, 1, sizeof(cmd), file_);
 }
 
+size_t TraceWriter::WriteCompressed(void* buf, size_t length) {
+  tmp_buff_.resize(compressBound(uint32_t(length)));
+
+  uLongf dest_len = (uint32_t)tmp_buff_.size();
+  int ret =
+      compress(tmp_buff_.data(), &dest_len, (uint8_t*)buf, uint32_t(length));
+  assert_true(ret >= 0);
+  return dest_len;
+}
+
 }  //  namespace gpu
 }  //  namespace xe