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#include "../base/SRC_FIRST.hpp"
#include "file_container.hpp"
#include "varint.hpp"
#include "write_to_sink.hpp"
/////////////////////////////////////////////////////////////////////////////
// FilesContainerBase
/////////////////////////////////////////////////////////////////////////////
void FilesContainerBase::ReadInfo(FileReader & reader)
{
uint64_t offset = ReadPrimitiveFromPos<uint64_t>(reader, 0);
ReaderSource<FileReader> src(reader);
src.Skip(offset);
uint32_t const count = ReadVarUint<uint32_t>(src);
m_info.resize(count);
for (uint32_t i = 0; i < count; ++i)
{
uint32_t const tagSize = ReadVarUint<uint32_t>(src);
m_info[i].m_tag.resize(tagSize);
src.Read(&m_info[i].m_tag[0], tagSize);
m_info[i].m_offset = ReadVarUint<uint64_t>(src);
m_info[i].m_size = ReadVarUint<uint64_t>(src);
}
}
/////////////////////////////////////////////////////////////////////////////
// FilesContainerR
/////////////////////////////////////////////////////////////////////////////
FilesContainerR::FilesContainerR(string const & fName,
uint32_t logPageSize,
uint32_t logPageCount)
: m_source(fName, logPageSize, logPageCount)
{
ReadInfo(m_source);
}
FileReader FilesContainerR::GetReader(Tag const & tag) const
{
InfoContainer::const_iterator i =
lower_bound(m_info.begin(), m_info.end(), tag, LessInfo());
if (i != m_info.end() && i->m_tag == tag)
return m_source.SubReader(i->m_offset, i->m_size);
else
MYTHROW(Reader::OpenException, (tag));
}
/////////////////////////////////////////////////////////////////////////////
// FilesContainerW
/////////////////////////////////////////////////////////////////////////////
FilesContainerW::FilesContainerW(string const & fName, FileWriter::Op op)
: m_name(fName), m_bFinished(false)
{
switch (op)
{
case FileWriter::OP_WRITE_TRUNCATE: // default usage
break;
case FileWriter::OP_APPEND:
m_bNeedRewrite = true; // need to override service info after appending
// 'break' doesn't present!
case FileWriter::OP_WRITE_EXISTING:
{
// read an existing service info
FileReader reader(fName);
ReadInfo(reader);
}
}
if (m_info.empty())
{
// leave space for offset to service info
FileWriter writer(fName);
uint64_t skip = 0;
writer.Write(&skip, sizeof(skip));
m_bNeedRewrite = false;
}
}
FilesContainerW::~FilesContainerW()
{
if (!m_bFinished)
Finish();
}
uint64_t FilesContainerW::SaveCurrentSize()
{
ASSERT(!m_bFinished, ());
uint64_t const curr = FileReader(m_name).Size();
if (!m_info.empty())
m_info.back().m_size = curr - m_info.back().m_offset;
return curr;
}
FileWriter FilesContainerW::GetWriter(Tag const & tag)
{
ASSERT(!m_bFinished, ());
if (m_bNeedRewrite)
{
m_bNeedRewrite = false;
ASSERT ( !m_info.empty(), () );
uint64_t const curr = m_info.back().m_offset + m_info.back().m_size;
m_info.push_back(Info(tag, curr));
FileWriter writer(m_name, FileWriter::OP_WRITE_EXISTING);
writer.Seek(curr);
return writer;
}
else
{
uint64_t const curr = SaveCurrentSize();
m_info.push_back(Info(tag, curr));
return FileWriter(m_name, FileWriter::OP_APPEND);
}
}
FileWriter FilesContainerW::GetExistingWriter(Tag const & tag)
{
InfoContainer::const_iterator i =
lower_bound(m_info.begin(), m_info.end(), tag, LessInfo());
if (i != m_info.end() && i->m_tag == tag)
{
FileWriter writer(m_name, FileWriter::OP_WRITE_EXISTING);
writer.Seek(i->m_offset);
return writer;
}
else
MYTHROW(Writer::OpenException, (tag));
}
void FilesContainerW::Append(string const & fName, Tag const & tag)
{
ASSERT(!m_bFinished, ());
uint64_t const bufferSize = 4*1024;
char buffer[bufferSize];
FileReader reader(fName);
ReaderSource<FileReader> src(reader);
FileWriter writer = GetWriter(tag);
uint64_t size = reader.Size();
while (size > 0)
{
size_t const curr = static_cast<size_t>(min(bufferSize, size));
src.Read(&buffer[0], curr);
writer.Write(&buffer[0], curr);
size -= curr;
}
}
void FilesContainerW::Append(vector<char> const & buffer, Tag const & tag)
{
ASSERT(!m_bFinished, ());
if (!buffer.empty())
GetWriter(tag).Write(&buffer[0], buffer.size());
}
void FilesContainerW::Finish()
{
ASSERT(!m_bFinished, ());
{
uint64_t const curr = SaveCurrentSize();
FileWriter writer(m_name, FileWriter::OP_WRITE_EXISTING);
writer.Seek(0);
WriteToSink(writer, curr);
}
sort(m_info.begin(), m_info.end(), LessInfo());
FileWriter writer(m_name, FileWriter::OP_APPEND);
uint32_t const count = m_info.size();
WriteVarUint(writer, count);
for (uint32_t i = 0; i < count; ++i)
{
size_t const tagSize = m_info[i].m_tag.size();
WriteVarUint(writer, tagSize);
writer.Write(&m_info[i].m_tag[0], tagSize);
WriteVarUint(writer, m_info[i].m_offset);
WriteVarUint(writer, m_info[i].m_size);
}
m_bFinished = true;
}
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