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#include "slof_indexer.hpp"
#include "../words/slof.hpp"
#include "../coding/byte_stream.hpp"
#include "../coding/endianness.hpp"
#include "../coding/varint.hpp"
#include "../coding/writer.hpp"
#include "../coding/write_to_sink.hpp"
#include "../base/assert.hpp"
#include "../base/base.hpp"
#include "../base/logging.hpp"
#include "../std/algorithm.hpp"
#include "../std/set.hpp"
#include "../std/string.hpp"
namespace
{
template <typename T> uint8_t VarUintSize(T x)
{
uint8_t res = 0;
while (x > 127)
{
++res;
x >>= 7;
}
return res + 1;
}
}
sl::SlofIndexer::SlofIndexer(Writer & writer,
size_t maxUncompressedArticleChunkSize,
function<void (char const *, size_t, string &)> const & compressor) :
m_Writer(writer),
m_MaxUncompressedArticleChunkSize(maxUncompressedArticleChunkSize),
m_Compressor(compressor),
m_ArticleOffset(m_Writer.Pos() + sizeof(sl::SlofHeader)),
m_ArticleCount(0),
m_ArticleChunkCount(0),
m_MaxArticleSize(0)
{
CHECK_LESS(maxUncompressedArticleChunkSize, 1 << 24, ());
m_Writer.Seek(sizeof(sl::SlofHeader));
CHECK_EQUAL(m_ArticleOffset, m_Writer.Pos(), ());
}
void sl::SlofIndexer::AddKey(string const & word, uint64_t articleId)
{
CHECK(!word.empty(), ());
WordsContainerType::const_iterator it = m_Words.lower_bound(make_pair(word, 0ULL));
if (it != m_Words.end() && it->first == word)
{
LOG(LINFO, ("Duplicate key:", word, it->second, articleId));
}
CHECK(m_Words.insert(make_pair(word, articleId)).second, (word, articleId));
}
uint64_t sl::SlofIndexer::AddArticle(string const & article, bool forceChunkFlush)
{
// if (article.size() > m_MaxUncompressedArticleChunkSize)
// LOG(LWARNING, ("Article bigger than chunk:", article.size(), article.substr(0, 64)));
if (m_CurrentArticleChunk.size() + article.size() > m_MaxUncompressedArticleChunkSize ||
forceChunkFlush)
FlushArticleChunk();
uint64_t const articleId =
((m_Writer.Pos() - m_ArticleOffset) << 24) + m_ArticleSizesInChunk.size();
m_CurrentArticleChunk += article;
m_ArticleSizesInChunk.push_back(article.size());
++m_ArticleCount;
m_TotalArticleSizeUncompressed += article.size();
m_MaxArticleSize = max(m_MaxArticleSize, static_cast<uint32_t>(article.size()));
return articleId;
}
void sl::SlofIndexer::FlushArticleChunk()
{
if (m_ArticleSizesInChunk.empty())
return;
vector<char> chunkHeader;
{ // Write chunk header.
{
PushBackByteSink<vector<char> > sink(chunkHeader);
// Write decompressed size of all articles.
WriteVarUint(sink, m_CurrentArticleChunk.size());
// Write individual article sizes.
for (size_t i = 0; i < m_ArticleSizesInChunk.size(); ++i)
WriteVarUint(sink, m_ArticleSizesInChunk[i]);
}
{ // Write size of the header at the beginning of the header.
vector<char> chunkHeaderSize;
PushBackByteSink<vector<char> > sink(chunkHeaderSize);
WriteVarUint(sink, chunkHeader.size());
chunkHeader.insert(chunkHeader.begin(), chunkHeaderSize.begin(), chunkHeaderSize.end());
}
}
// Compress the article chunk.
string compressedArticleChunk;
m_Compressor(&m_CurrentArticleChunk[0], m_CurrentArticleChunk.size(), compressedArticleChunk);
// Write everything.
WriteToSink(m_Writer, static_cast<uint32_t>(chunkHeader.size() + compressedArticleChunk.size()));
m_Writer.Write(&chunkHeader[0], chunkHeader.size());
m_Writer.Write(&compressedArticleChunk[0], compressedArticleChunk.size());
// Reset everything.
m_CurrentArticleChunk.clear();
m_ArticleSizesInChunk.clear();
++m_ArticleChunkCount;
}
void sl::SlofIndexer::LogStats() const
{
LOG(LINFO, ("Dictionary stats"));
set<uint64_t> articleIds;
uint32_t maxKeyLength = 0, totalWordLength = 0, dupKeysCount = 0;
for (WordsContainerType::const_iterator it = m_Words.begin(); it != m_Words.end(); ++it)
{
WordsContainerType::const_iterator next = it;
++next;
if (next != m_Words.end() && next->first == it->first)
++dupKeysCount;
maxKeyLength = max(maxKeyLength, static_cast<uint32_t>(it->first.size()));
totalWordLength += it->first.size();
articleIds.insert(it->second);
}
CHECK_EQUAL(m_ArticleCount, articleIds.size(), ());
LOG(LINFO, ("Keys:", m_Words.size()));
LOG(LINFO, ("Unique keys:", m_Words.size() - dupKeysCount));
LOG(LINFO, ("Duplicate keys:", dupKeysCount));
LOG(LINFO, ("Duplicate keys %:", 100.0 * dupKeysCount / m_Words.size()));
LOG(LINFO, ("Max key length:", maxKeyLength));
LOG(LINFO, ("Average key length:", totalWordLength * 1.0 / m_Words.size()));
LOG(LINFO, ("Articles:", m_ArticleCount));
LOG(LINFO, ("Keys per article:", m_Words.size() * 1.0 / m_ArticleCount));
LOG(LINFO, ("Article chunks:", m_ArticleChunkCount));
LOG(LINFO, ("Articles per chunk:", m_ArticleCount * 1.0 / m_ArticleChunkCount));
LOG(LINFO, ("Average article size:", m_TotalArticleSizeUncompressed * 1.0 / m_ArticleCount));
LOG(LINFO, ("Max article size:", m_MaxArticleSize));
}
sl::SlofIndexer::~SlofIndexer()
{
FlushArticleChunk();
// Filling in header information.
sl::SlofHeader header;
memcpy(&header.m_Signature, "slof", 4);
header.m_MajorVersion = SwapIfBigEndian(uint16_t(1));
header.m_MinorVersion = SwapIfBigEndian(uint16_t(1));
header.m_KeyCount = SwapIfBigEndian(static_cast<uint32_t>(m_Words.size()));
header.m_ArticleCount = SwapIfBigEndian(m_ArticleCount);
header.m_ArticleOffset = SwapIfBigEndian(static_cast<uint64_t>(sizeof(header)));
// Writing key index.
header.m_KeyIndexOffset = SwapIfBigEndian(m_Writer.Pos());
{
WriteToSink(m_Writer, static_cast<uint32_t>(0));
uint32_t cumSize = 0;
for (WordsContainerType::const_iterator it = m_Words.begin(); it != m_Words.end(); ++it)
{
cumSize += it->first.size();
cumSize += VarUintSize(it->second >> 24);
cumSize += VarUintSize(it->second & 0xFFFFF);
WriteToSink(m_Writer, cumSize);
}
}
// Writing key data.
header.m_KeyDataOffset = SwapIfBigEndian(m_Writer.Pos());
for (WordsContainerType::const_iterator it = m_Words.begin(); it != m_Words.end(); ++it)
{
WriteVarUint(m_Writer, it->second >> 24);
WriteVarUint(m_Writer, it->second & 0xFFFFFF);
m_Writer.Write(&it->first[0], it->first.size());
}
// Writing header.
uint64_t const lastPos = m_Writer.Pos();
m_Writer.Seek(0);
m_Writer.Write(&header, sizeof(header));
m_Writer.Seek(lastPos);
}
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