logging/WriterFrontend: Add LogWriteHeader as member

The header captures the enum values as well as the fields

src/logging/Manager.cc

@@ -536,11 +536,11 @@ Manager::WriterInfo* Manager::FindWriter(WriterFrontend* writer) {
 }
 
 bool Manager::CompareFields(const Filter* filter, const WriterFrontend* writer) {
-    if ( filter->num_fields != writer->NumFields() )
+    if ( filter->num_fields != static_cast<int>(writer->GetFields().size()) )
         return false;
 
     for ( int i = 0; i < filter->num_fields; ++i )
-        if ( filter->fields[i]->type != writer->Fields()[i]->type )
+        if ( filter->fields[i]->type != writer->GetFields()[i].type )
             return false;
 
     return true;
@@ -1779,8 +1779,13 @@ void Manager::SendAllWritersTo(const broker::endpoint_info& ei) {
         for ( Stream::WriterMap::iterator i = stream->writers.begin(); i != stream->writers.end(); i++ ) {
             WriterFrontend* writer = i->second->writer;
             const auto& writer_val = et->GetEnumVal(i->first.first);
-            broker_mgr->PublishLogCreate((*s)->id, writer_val.get(), *i->second->info, writer->NumFields(),
-                                         writer->Fields(), ei);
+
+            std::vector<const threading::Field*> fields(writer->GetFields().size());
+            for ( size_t i = 0; i < writer->GetFields().size(); i++ )
+                fields[i] = &writer->GetFields()[i];
+
+            broker_mgr->PublishLogCreate((*s)->id, writer_val.get(), *i->second->info, fields.size(), fields.data(),
+                                         ei);
         }
     }
 }

src/logging/WriterFrontend.cc

@@ -90,10 +90,11 @@ private:
 WriterFrontend::WriterFrontend(const WriterBackend::WriterInfo& arg_info, EnumVal* arg_stream, EnumVal* arg_writer,
                                bool arg_local, bool arg_remote)
     : write_buffer(detail::WriteBuffer(BifConst::Log::write_buffer_size)) {
-    stream = arg_stream;
-    writer = arg_writer;
-    Ref(stream);
-    Ref(writer);
+    // The header's fields are initialized in Init()
+    header = detail::LogWriteHeader{{zeek::NewRef{}, arg_stream},
+                                    {zeek::NewRef{}, arg_writer},
+                                    arg_info.filter_name,
+                                    arg_info.path};
 
     disabled = initialized = false;
     buf = true;
@@ -108,7 +109,7 @@ WriterFrontend::WriterFrontend(const WriterBackend::WriterInfo& arg_info, EnumVa
     name = util::copy_string(util::fmt("%s/%s", arg_info.path, w));
 
     if ( local ) {
-        backend = log_mgr->CreateBackend(this, writer);
+        backend = log_mgr->CreateBackend(this, header.writer_id.get());
 
         if ( backend )
             backend->Start();
@@ -124,8 +125,6 @@ WriterFrontend::~WriterFrontend() {
 
     delete[] fields;
 
-    Unref(stream);
-    Unref(writer);
     delete info;
     delete[] name;
 }
@@ -166,8 +165,12 @@ void WriterFrontend::Init(int arg_num_fields, const Field* const* arg_fields) {
     }
 
     if ( remote ) {
-        broker_mgr->PublishLogCreate(stream, writer, *info, arg_num_fields, arg_fields);
+        broker_mgr->PublishLogCreate(header.stream_id.get(), header.writer_id.get(), *info, arg_num_fields, arg_fields);
     }
+
+    header.fields.reserve(arg_num_fields);
+    for ( int i = 0; i < arg_num_fields; i++ )
+        header.fields.emplace_back(*arg_fields[i]);
 }
 
 void WriterFrontend::Write(detail::LogRecord&& arg_vals) {
@@ -183,7 +186,7 @@ void WriterFrontend::Write(detail::LogRecord&& arg_vals) {
     }
 
     if ( remote ) {
-        broker_mgr->PublishLogWrite(stream, writer, info->path, vals);
+        broker_mgr->PublishLogWrite(header.stream_id.get(), header.writer_id.get(), info->path, vals);
     }
 
     if ( ! backend )

src/logging/WriterFrontend.h

@@ -2,6 +2,7 @@
 
 #pragma once
 
+#include "zeek/logging/Types.h"
 #include "zeek/logging/WriterBackend.h"
 
 namespace zeek::logging {
@@ -228,7 +229,10 @@ public:
     /**
      * Returns the number of log fields as passed into the constructor.
      */
-    int NumFields() const { return num_fields; }
+    [[deprecated("Remove in v8.1: Use GetFields() instead")]]
+    int NumFields() const {
+        return num_fields;
+    }
 
     /**
      * Returns a descriptive name for the writer, including the type of
@@ -246,14 +250,19 @@ public:
     /**
      * Returns the log fields as passed into the constructor.
      */
-    const threading::Field* const* Fields() const { return fields; }
+    [[deprecated("Remove in v8.1: Use GetFields() instead")]]
+    const threading::Field* const* Fields() const {
+        return fields;
+    }
+
+    /**
+     * Returns the log fields once Init() was called on the frontend.
+     */
+    const std::vector<threading::Field>& GetFields() const { return header.fields; }
 
 protected:
     friend class Manager;
 
-    EnumVal* stream;
-    EnumVal* writer;
-
     WriterBackend* backend; // The backend we have instantiated.
     bool disabled;          // True if disabled.
     bool initialized;       // True if initialized.
@@ -263,9 +272,10 @@ protected:
 
     const char* name;                      // Descriptive name of the
     WriterBackend::WriterInfo* info;       // The writer information.
-    int num_fields;                        // The number of log fields.
-    const threading::Field* const* fields; // The log fields.
+    int num_fields;                        // Remove in v8.1.
+    const threading::Field* const* fields; // Remove in v8.1.
 
+    detail::LogWriteHeader header;    // Collected information about the WriterFrontend.
     detail::WriteBuffer write_buffer; // Buffer for bulk writes.
 };