sysio::chain::ostream_snapshot_writer Class Reference

#include <snapshot.hpp>

Inheritance diagram for sysio::chain::ostream_snapshot_writer:

Collaboration diagram for sysio::chain::ostream_snapshot_writer:

Public Member Functions
	ostream_snapshot_writer (std::ostream &snapshot)
void	write_start_section (const std::string &section_name) override
void	write_row (const detail::abstract_snapshot_row_writer &row_writer) override
void	write_end_section () override
void	finalize ()
Public Member Functions inherited from sysio::chain::snapshot_writer
template<typename F >
void	write_section (const std::string section_name, F f)
template<typename T , typename F >
void	write_section (F f)
virtual	~snapshot_writer ()

Static Public Attributes
static const uint32_t	magic_number = 0x30510550

Additional Inherited Members

Protected Member Functions inherited from sysio::chain::snapshot_writer

Detailed Description

Definition at line 329 of file snapshot.hpp.

Constructor & Destructor Documentation

ostream_snapshot_writer()

sysio::chain::ostream_snapshot_writer::ostream_snapshot_writer ( std::ostream & snapshot )

explicit

Definition at line 122 of file snapshot.cpp.

:snapshot(snapshot)
,header_pos(snapshot.tellp())
,section_pos(-1)
,row_count(0)
{
   // write magic number
   auto totem = magic_number;
   snapshot.write((char*)&totem, sizeof(totem));
 
   // write version
   auto version = current_snapshot_version;
   snapshot.write((char*)&version, sizeof(version));
}

Member Function Documentation

finalize()

void sysio::chain::ostream_snapshot_writer::finalize

(

)

Definition at line 186 of file snapshot.cpp.

                                       {
   uint64_t end_marker = std::numeric_limits<uint64_t>::max();
 
   // write a placeholder for the section size
   snapshot.write((char*)&end_marker, sizeof(end_marker));
}

write_end_section()

void sysio::chain::ostream_snapshot_writer::write_end_section ( )

overridevirtual

Implements sysio::chain::snapshot_writer.

Definition at line 167 of file snapshot.cpp.

                                                 {
   auto restore = snapshot.tellp();
 
   uint64_t section_size = restore - section_pos - sizeof(uint64_t);
 
   snapshot.seekp(section_pos);
 
   // write a the section size
   snapshot.write((char*)&section_size, sizeof(section_size));
 
   // write the row count
   snapshot.write((char*)&row_count, sizeof(row_count));
 
   snapshot.seekp(restore);
 
   section_pos = std::streampos(-1);
   row_count = 0;
}

write_row()

void sysio::chain::ostream_snapshot_writer::write_row ( const detail::abstract_snapshot_row_writer & row_writer )

overridevirtual

Implements sysio::chain::snapshot_writer.

Definition at line 156 of file snapshot.cpp.

                                                                                              {
   auto restore = snapshot.tellp();
   try {
      row_writer.write(snapshot);
   } catch (...) {
      snapshot.seekp(restore);
      throw;
   }
   row_count++;
}

Here is the call graph for this function:

write_start_section()

void sysio::chain::ostream_snapshot_writer::write_start_section ( const std::string & section_name )

overridevirtual

Implements sysio::chain::snapshot_writer.

Definition at line 137 of file snapshot.cpp.

{
   SYS_ASSERT(section_pos == std::streampos(-1), snapshot_exception, "Attempting to write a new section without closing the previous section");
   section_pos = snapshot.tellp();
   row_count = 0;
 
   uint64_t placeholder = std::numeric_limits<uint64_t>::max();
 
   // write a placeholder for the section size
   snapshot.write((char*)&placeholder, sizeof(placeholder));
 
   // write placeholder for row count
   snapshot.write((char*)&placeholder, sizeof(placeholder));
 
   // write the section name (null terminated)
   snapshot.write(section_name.data(), section_name.size());
   snapshot.put(0);
}

Member Data Documentation

magic_number

const uint32_t sysio::chain::ostream_snapshot_writer::magic_number = 0x30510550

static

Definition at line 338 of file snapshot.hpp.

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The documentation for this class was generated from the following files:

• libraries/chain/include/sysio/chain/snapshot.hpp
• libraries/chain/snapshot.cpp