Second stage of optimizer_trace optimizations

- Move testing of my_writer to inline functions to avoid calls
- Made more functions inline. Especially thd->thread_started()
  is now very optimized!
- Moved Opt_trace_stmt classe to opt_trace_context.h to get critical
  functions inline

sql/my_json_writer.cc

@@ -260,50 +260,6 @@ void Json_writer::add_str(const String &str)
   add_str(str.ptr(), str.length());
 }
 
-Json_writer_object::Json_writer_object(THD *thd) :
-  Json_writer_struct(thd)
-{
-  if (unlikely(my_writer))
-    my_writer->start_object();
-}
-
-Json_writer_object::Json_writer_object(THD* thd, const char *str) :
-  Json_writer_struct(thd)
-{
-  if (unlikely(my_writer))
-    my_writer->add_member(str).start_object();
-}
-
-Json_writer_object::~Json_writer_object()
-{
-  if (my_writer && !closed)
-    my_writer->end_object();
-  closed= TRUE;
-}
-
-Json_writer_array::Json_writer_array(THD *thd) :
-  Json_writer_struct(thd)
-{
-  if (unlikely(my_writer))
-    my_writer->start_array();
-}
-
-Json_writer_array::Json_writer_array(THD *thd, const char *str) :
-  Json_writer_struct(thd)
-{
-  if (unlikely(my_writer))
-    my_writer->add_member(str).start_array();
-
-}
-Json_writer_array::~Json_writer_array()
-{
-  if (unlikely(my_writer && !closed))
-  {
-    my_writer->end_array();
-    closed= TRUE;
-  }
-}
-
 Json_writer_temp_disable::Json_writer_temp_disable(THD *thd_arg)
 {
   thd= thd_arg;

sql/my_json_writer.h

@@ -256,63 +256,51 @@ class Json_value_helper
   void init(Json_writer *my_writer) { writer= my_writer; }
   void add_str(const char* val)
   {
-    if (unlikely(writer))
       writer->add_str(val);
   }
   void add_str(const char* val, size_t length)
   {
-    if (unlikely(writer))
       writer->add_str(val, length);
   }
   void add_str(const String &str)
   {
-    if (unlikely(writer))
       writer->add_str(str.ptr(), str.length());
   }
   void add_str(const LEX_CSTRING &str)
   {
-    if (unlikely(writer))
       writer->add_str(str.str, str.length);
   }
   void add_str(Item *item)
   {
-    if (unlikely(writer))
       writer->add_str(item);
   }
 
   void add_ll(longlong val)
   {
-    if (unlikely(writer))
       writer->add_ll(val);
   }
   void add_size(longlong val)
   {
-    if (unlikely(writer))
       writer->add_size(val);
   }
   void add_double(double val)
   {
-    if (unlikely(writer))
       writer->add_double(val);
   }
   void add_bool(bool val)
   {
-    if (unlikely(writer))
       writer->add_bool(val);
   }
   void add_null()
   {
-    if (unlikely(writer))
       writer->add_null();
   }
   void add_table_name(const JOIN_TAB *tab)
   {
-    if (unlikely(writer))
       writer->add_table_name(tab);
   }
   void add_table_name(const TABLE* table)
   {
-    if (unlikely(writer))
       writer->add_table_name(table);
   }
 };
@@ -355,55 +343,90 @@ class Json_writer_object : public Json_writer_struct
 private:
   void add_member(const char *name)
   {
-    if (unlikely(my_writer))
-      my_writer->add_member(name);
+    my_writer->add_member(name);
   }
 public:
-  explicit Json_writer_object(THD *thd);
-  explicit Json_writer_object(THD *thd, const char *str);
+  explicit Json_writer_object(THD *thd)
+  : Json_writer_struct(thd)
+  {
+    if (unlikely(my_writer))
+      my_writer->start_object();
+  }
+
+  explicit Json_writer_object(THD* thd, const char *str)
+    : Json_writer_struct(thd)
+  {
+    if (unlikely(my_writer))
+      my_writer->add_member(str).start_object();
+  }
+
+  ~Json_writer_object()
+  {
+    if (my_writer && !closed)
+      my_writer->end_object();
+    closed= TRUE;
+  }
 
   Json_writer_object& add(const char *name, bool value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_bool(value);
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_bool(value);
+    }
     return *this;
   }
   Json_writer_object& add(const char *name, ulonglong value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_ll(static_cast<longlong>(value));
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_ll(static_cast<longlong>(value));
+    }
     return *this;
   }
   Json_writer_object& add(const char *name, longlong value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_ll(value);
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_ll(value);
+    }
     return *this;
   }
   Json_writer_object& add(const char *name, double value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_double(value);
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_double(value);
+    }
     return *this;
   }
   #ifndef _WIN64
   Json_writer_object& add(const char *name, size_t value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_ll(static_cast<longlong>(value));
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_ll(static_cast<longlong>(value));
+    }
     return *this;
   }
   #endif
   Json_writer_object& add(const char *name, const char *value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_str(value);
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_str(value);
+    }
     return *this;
   }
   Json_writer_object& add(const char *name, const char *value, size_t num_bytes)
@@ -415,46 +438,64 @@ class Json_writer_object : public Json_writer_struct
   Json_writer_object& add(const char *name, const LEX_CSTRING &value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_str(value.str, value.length);
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_str(value.str, value.length);
+    }
     return *this;
   }
   Json_writer_object& add(const char *name, Item *value)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_str(value);
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_str(value);
+    }
     return *this;
   }
   Json_writer_object& add_null(const char*name)
   {
     DBUG_ASSERT(!closed);
-    add_member(name);
-    context.add_null();
+    if (my_writer)
+    {
+      add_member(name);
+      context.add_null();
+    }
     return *this;
   }
   Json_writer_object& add_table_name(const JOIN_TAB *tab)
   {
     DBUG_ASSERT(!closed);
-    add_member("table");
-    context.add_table_name(tab);
+    if (my_writer)
+    {
+      add_member("table");
+      context.add_table_name(tab);
+    }
     return *this;
   }
   Json_writer_object& add_table_name(const TABLE *table)
   {
     DBUG_ASSERT(!closed);
-    add_member("table");
-    context.add_table_name(table);
+    if (my_writer)
+    {
+      add_member("table");
+      context.add_table_name(table);
+    }
     return *this;
   }
   Json_writer_object& add_select_number(uint select_number)
   {
     DBUG_ASSERT(!closed);
-    add_member("select_id");
-    if (unlikely(select_number >= INT_MAX))
-      context.add_str("fake");
-    else
-      context.add_ll(static_cast<longlong>(select_number));
+    if (my_writer)
+    {
+      add_member("select_id");
+      if (unlikely(select_number >= INT_MAX))
+        context.add_str("fake");
+      else
+        context.add_ll(static_cast<longlong>(select_number));
+    }
     return *this;
   }
   void end()
@@ -464,7 +505,6 @@ class Json_writer_object : public Json_writer_struct
       my_writer->end_object();
     closed= TRUE;
   }
-  ~Json_writer_object();
 };
 
 
@@ -479,8 +519,25 @@ class Json_writer_object : public Json_writer_struct
 class Json_writer_array : public Json_writer_struct
 {
 public:
-  Json_writer_array(THD *thd);
-  Json_writer_array(THD *thd, const char *str);
+  Json_writer_array(THD *thd): Json_writer_struct(thd)
+  {
+    if (unlikely(my_writer))
+      my_writer->start_array();
+  }
+
+  Json_writer_array(THD *thd, const char *str) : Json_writer_struct(thd)
+  {
+    if (unlikely(my_writer))
+      my_writer->add_member(str).start_array();
+  }
+  ~Json_writer_array()
+  {
+    if (unlikely(my_writer && !closed))
+    {
+      my_writer->end_array();
+      closed= TRUE;
+    }
+  }
   void end()
   {
     DBUG_ASSERT(!closed);
@@ -492,78 +549,89 @@ class Json_writer_array : public Json_writer_struct
   Json_writer_array& add(bool value)
   {
     DBUG_ASSERT(!closed);
-    context.add_bool(value);
+    if (my_writer)
+      context.add_bool(value);
     return *this;
   }
   Json_writer_array& add(ulonglong value)
   {
     DBUG_ASSERT(!closed);
-    context.add_ll(static_cast<longlong>(value));
+    if (my_writer)
+      context.add_ll(static_cast<longlong>(value));
     return *this;
   }
   Json_writer_array& add(longlong value)
   {
     DBUG_ASSERT(!closed);
-    context.add_ll(value);
+    if (my_writer)
+      context.add_ll(value);
     return *this;
   }
   Json_writer_array& add(double value)
   {
     DBUG_ASSERT(!closed);
-    context.add_double(value);
+    if (my_writer)
+      context.add_double(value);
     return *this;
   }
   #ifndef _WIN64
   Json_writer_array& add(size_t value)
   {
     DBUG_ASSERT(!closed);
-    context.add_ll(static_cast<longlong>(value));
+    if (my_writer)
+      context.add_ll(static_cast<longlong>(value));
     return *this;
   }
   #endif
   Json_writer_array& add(const char *value)
   {
     DBUG_ASSERT(!closed);
-    context.add_str(value);
+    if (my_writer)
+      context.add_str(value);
     return *this;
   }
   Json_writer_array& add(const char *value, size_t num_bytes)
   {
     DBUG_ASSERT(!closed);
-    context.add_str(value, num_bytes);
+    if (my_writer)
+      context.add_str(value, num_bytes);
     return *this;
   }
   Json_writer_array& add(const LEX_CSTRING &value)
   {
     DBUG_ASSERT(!closed);
-    context.add_str(value.str, value.length);
+    if (my_writer)
+      context.add_str(value.str, value.length);
     return *this;
   }
   Json_writer_array& add(Item *value)
   {
     DBUG_ASSERT(!closed);
-    context.add_str(value);
+    if (my_writer)
+      context.add_str(value);
     return *this;
   }
   Json_writer_array& add_null()
   {
     DBUG_ASSERT(!closed);
-    context.add_null();
+    if (my_writer)
+      context.add_null();
     return *this;
   }
   Json_writer_array& add_table_name(const JOIN_TAB *tab)
   {
     DBUG_ASSERT(!closed);
-    context.add_table_name(tab);
+    if (my_writer)
+      context.add_table_name(tab);
     return *this;
   }
   Json_writer_array& add_table_name(const TABLE *table)
   {
     DBUG_ASSERT(!closed);
-    context.add_table_name(table);
+    if (my_writer)
+      context.add_table_name(table);
     return *this;
   }
-  ~Json_writer_array();
 };
 
 /*

sql/opt_trace.cc

@@ -328,64 +328,33 @@ void opt_trace_disable_if_no_view_access(THD *thd, TABLE_LIST *view,
   The trace of one statement.
 */
 
-class Opt_trace_stmt {
- public:
-  /**
-     Constructor, starts a trace for information_schema and dbug.
-     @param  ctx_arg          context
-  */
-  Opt_trace_stmt(Opt_trace_context *ctx_arg)
-  {
-    ctx= ctx_arg;
-    current_json= new Json_writer();
-    missing_priv= false;
-    I_S_disabled= 0;
-  }
-  ~Opt_trace_stmt()
-  {
-    delete current_json;
-  }
-  void set_query(const char *query_ptr, size_t length, const CHARSET_INFO *charset);
-  void open_struct(const char *key, char opening_bracket);
-  void close_struct(const char *saved_key, char closing_bracket);
-  void fill_info(Opt_trace_info* info);
-  void add(const char *key, char *opening_bracket, size_t val_length);
-  Json_writer* get_current_json() {return current_json;}
-  void missing_privilege();
-  void disable_tracing_for_children();
-  void enable_tracing_for_children();
-  bool is_enabled();
-
-  void set_allowed_mem_size(size_t mem_size);
-  size_t get_length() { return current_json->output.length(); }
-  size_t get_truncated_bytes() { return current_json->get_truncated_bytes(); }
-  bool get_missing_priv() { return missing_priv; }
-
-private:
-  Opt_trace_context *ctx;
-  String query;  // store the query sent by the user
-  Json_writer *current_json; // stores the trace
-  bool missing_priv;  ///< whether user lacks privilege to see this trace
-  /*
-    0 <=> this trace should be in information_schema.
-  !=0 tracing is disabled, this currently happens when we want to trace a
-      sub-statement. For now traces are only collect for the top statement
-      not for the sub-statments.
-  */
-  uint I_S_disabled;
-};
+Opt_trace_stmt::Opt_trace_stmt(Opt_trace_context *ctx_arg)
+{
+  ctx= ctx_arg;
+  current_json= new Json_writer();
+  missing_priv= false;
+  I_S_disabled= 0;
+}
 
-void Opt_trace_stmt::set_query(const char *query_ptr, size_t length,
-                               const CHARSET_INFO *charset)
+Opt_trace_stmt::~Opt_trace_stmt()
 {
-  query.append(query_ptr, length, charset);
+  delete current_json;
 }
 
-Json_writer* Opt_trace_context::get_current_json()
+size_t Opt_trace_stmt::get_length()
 {
-  if (!is_started())
-    return NULL;
-  return current_trace->get_current_json();
+  return current_json->output.length();
+}
+
+size_t Opt_trace_stmt::get_truncated_bytes()
+{
+  return current_json->get_truncated_bytes();
+}
+
+void Opt_trace_stmt::set_query(const char *query_ptr, size_t length,
+                               const CHARSET_INFO *charset)
+{
+  query.append(query_ptr, length, charset);
 }
 
 void Opt_trace_context::missing_privilege()
@@ -573,11 +542,6 @@ void Opt_trace_stmt::enable_tracing_for_children()
     --I_S_disabled;
 }
 
-bool Opt_trace_stmt::is_enabled()
-{
-  return I_S_disabled == 0;
-}
-
 void Opt_trace_stmt::set_allowed_mem_size(size_t mem_size)
 {
   current_json->set_size_limit(mem_size);

sql/opt_trace.h

@@ -21,8 +21,6 @@ class Item;
 class THD;
 struct TABLE_LIST;
 
-class Opt_trace_stmt;
-
 /*
    User-visible information about a trace.
 */

sql/opt_trace_context.h

@@ -3,7 +3,50 @@
 
 #include "sql_array.h"
 
-class Opt_trace_stmt;
+class Opt_trace_context;
+class Opt_trace_info;
+class Json_writer;
+
+class Opt_trace_stmt {
+ public:
+  /**
+     Constructor, starts a trace for information_schema and dbug.
+     @param  ctx_arg          context
+  */
+  Opt_trace_stmt(Opt_trace_context *ctx_arg);
+  ~Opt_trace_stmt();
+  void set_query(const char *query_ptr, size_t length, const CHARSET_INFO *charset);
+  void open_struct(const char *key, char opening_bracket);
+  void close_struct(const char *saved_key, char closing_bracket);
+  void fill_info(Opt_trace_info* info);
+  void add(const char *key, char *opening_bracket, size_t val_length);
+  Json_writer* get_current_json() {return current_json;}
+  void missing_privilege();
+  void disable_tracing_for_children();
+  void enable_tracing_for_children();
+  bool is_enabled()
+  {
+   return I_S_disabled == 0;
+  }
+  void set_allowed_mem_size(size_t mem_size);
+  size_t get_length();
+  size_t get_truncated_bytes();
+  bool get_missing_priv() { return missing_priv; }
+
+private:
+  Opt_trace_context *ctx;
+  String query;  // store the query sent by the user
+  Json_writer *current_json; // stores the trace
+  bool missing_priv;  ///< whether user lacks privilege to see this trace
+  /*
+    0 <=> this trace should be in information_schema.
+  !=0 tracing is disabled, this currently happens when we want to trace a
+      sub-statement. For now traces are only collect for the top statement
+      not for the sub-statments.
+  */
+  uint I_S_disabled;
+};
+
 
 class Opt_trace_context
 {
@@ -48,7 +91,12 @@ class Opt_trace_context
     This returns the current trace, to which we are still writing and has not been finished
   */
 
-  Json_writer* get_current_json();
+  Json_writer* get_current_json()
+  {
+    if (!is_started())
+      return NULL;
+    return current_trace->get_current_json();
+  }
 
   bool empty()
   {
@@ -57,7 +105,7 @@ class Opt_trace_context
 
   bool is_started()
   {
-    return current_trace && is_enabled();
+    return current_trace && current_trace->is_enabled();
   }
 
   bool disable_tracing_if_required();