Send the fill policy parameter to tracing service

Change-Id: I488a82d11c1f142182355471eb00fcccb8938e53
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1713846Reviewed-by: oysteine <oysteine@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680443}

services/tracing/public/mojom/perfetto_service.mojom

@@ -143,10 +143,20 @@ interface PerfettoService {
                         ProducerHost& producer_host);
 };
 
-// The size of a buffer that the Consumer can request Perfetto to allocate
-// and then configure specific data sources to be written into.
+// The policy for filling the trace buffer.
+enum BufferFillPolicy {
+  kUnspecified,
+  // Overwrite old chunks for new ones.
+  kRingBuffer,
+  // Discard all chunks once the buffer is full.
+  kDiscard
+};
+
 struct BufferConfig {
+  // The size of a buffer that the Consumer can request Perfetto to allocate
+  // and then configure specific data sources to be written into.
   uint32 size_kb;
+  BufferFillPolicy fill_policy;
 };
 
 struct DataSource {

services/tracing/public/mojom/perfetto_service.typemap

@@ -29,6 +29,7 @@ public_deps = [
   "//third_party/perfetto:libperfetto",
 ]
 type_mappings = [
+  "tracing.mojom.BufferFillPolicy=perfetto::TraceConfig::BufferConfig::FillPolicy",
   "tracing.mojom.CommitDataRequest=perfetto::CommitDataRequest",
   "tracing.mojom.ChunksToMove=perfetto::CommitDataRequest::ChunksToMove",
   "tracing.mojom.ChunkPatch=perfetto::CommitDataRequest::ChunkToPatch::Patch",

services/tracing/public/mojom/trace_config_mojom_traits.cc

@@ -16,6 +16,10 @@ bool StructTraits<tracing::mojom::BufferConfigDataView,
     Read(tracing::mojom::BufferConfigDataView data,
          perfetto::TraceConfig::BufferConfig* out) {
   out->set_size_kb(data.size_kb());
+  perfetto::TraceConfig::BufferConfig::FillPolicy policy;
+  if (data.ReadFillPolicy(&policy)) {
+    out->set_fill_policy(policy);
+  }
 
   return true;
 }

services/tracing/public/mojom/trace_config_mojom_traits.h

@@ -11,12 +11,45 @@
 #include <string>
 #include <vector>
 
+#include "mojo/public/cpp/bindings/enum_traits.h"
 #include "mojo/public/cpp/bindings/struct_traits.h"
 #include "services/tracing/public/mojom/perfetto_service.mojom.h"
 #include "third_party/perfetto/include/perfetto/tracing/core/trace_config.h"
 
 namespace mojo {
 
+// perfetto::TraceConfig::BufferConfig::FillPolicy
+template <>
+struct EnumTraits<tracing::mojom::BufferFillPolicy,
+                  perfetto::TraceConfig::BufferConfig::FillPolicy> {
+  static tracing::mojom::BufferFillPolicy ToMojom(
+      perfetto::TraceConfig::BufferConfig::FillPolicy input) {
+    switch (input) {
+      case perfetto::TraceConfig::BufferConfig::UNSPECIFIED:
+        return tracing::mojom::BufferFillPolicy::kUnspecified;
+      case perfetto::TraceConfig::BufferConfig::RING_BUFFER:
+        return tracing::mojom::BufferFillPolicy::kRingBuffer;
+      case perfetto::TraceConfig::BufferConfig::DISCARD:
+        return tracing::mojom::BufferFillPolicy::kDiscard;
+    }
+  }
+
+  static bool FromMojom(tracing::mojom::BufferFillPolicy input,
+                        perfetto::TraceConfig::BufferConfig::FillPolicy* out) {
+    switch (input) {
+      case tracing::mojom::BufferFillPolicy::kUnspecified:
+        *out = perfetto::TraceConfig::BufferConfig::UNSPECIFIED;
+        return true;
+      case tracing::mojom::BufferFillPolicy::kRingBuffer:
+        *out = perfetto::TraceConfig::BufferConfig::RING_BUFFER;
+        return true;
+      case tracing::mojom::BufferFillPolicy::kDiscard:
+        *out = perfetto::TraceConfig::BufferConfig::DISCARD;
+        return true;
+    }
+  }
+};
+
 // perfetto::TraceConfig::BufferConfig
 template <>
 class StructTraits<tracing::mojom::BufferConfigDataView,
@@ -26,6 +59,11 @@ class StructTraits<tracing::mojom::BufferConfigDataView,
     return src.size_kb();
   }
 
+  static perfetto::TraceConfig::BufferConfig::FillPolicy fill_policy(
+      const perfetto::TraceConfig::BufferConfig& src) {
+    return src.fill_policy();
+  }
+
   static bool Read(tracing::mojom::BufferConfigDataView data,
                    perfetto::TraceConfig::BufferConfig* out);
 };