winamp/Src/external_dependencies/openmpt-trunk/common/serialization_utils.cpp
2024-09-24 14:54:57 +02:00

722 lines
19 KiB
C++

/*
* serialization_utils.cpp
* -----------------------
* Purpose: Serializing data to and from MPTM files.
* Notes : (currently none)
* Authors: OpenMPT Devs
* The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
*/
#include "stdafx.h"
#include "serialization_utils.h"
#include "mpt/io/io.hpp"
#include "mpt/io/io_stdstream.hpp"
#include <array>
#include <istream>
#include <ostream>
#include <sstream>
#include "misc_util.h"
OPENMPT_NAMESPACE_BEGIN
namespace srlztn
{
#ifdef MPT_ALL_LOGGING
#define SSB_LOGGING
#endif
#ifdef SSB_LOGGING
#define SSB_LOG(x) MPT_LOG_GLOBAL(LogDebug, "serialization", x)
#else
#define SSB_LOG(x) do { } while(0)
#endif
static const uint8 HeaderId_FlagByte = 0;
// Indexing starts from 0.
static inline bool Testbit(uint8 val, uint8 bitindex) {return ((val & (1 << bitindex)) != 0);}
static inline void Setbit(uint8& val, uint8 bitindex, bool newval)
{
if(newval) val |= (1 << bitindex);
else val &= ~(1 << bitindex);
}
bool ID::IsPrintable() const
{
for(std::size_t i = 0; i < m_ID.length(); ++i)
{
if(m_ID[i] <= 0 || isprint(static_cast<unsigned char>(m_ID[i])) == 0)
{
return false;
}
}
return true;
}
//Format: First bit tells whether the size indicator is 1 or 2 bytes.
static void WriteAdaptive12String(std::ostream& oStrm, const std::string& str)
{
uint16 s = static_cast<uint16>(str.size());
LimitMax(s, uint16(std::numeric_limits<uint16>::max() / 2));
mpt::IO::WriteAdaptiveInt16LE(oStrm, s);
oStrm.write(str.c_str(), s);
}
void WriteItemString(std::ostream& oStrm, const std::string &str)
{
uint32 id = static_cast<uint32>(std::min(str.size(), static_cast<std::size_t>((std::numeric_limits<uint32>::max() >> 4)))) << 4;
id |= 12; // 12 == 1100b
Binarywrite<uint32>(oStrm, id);
id >>= 4;
if(id > 0)
oStrm.write(str.data(), id);
}
void ReadItemString(std::istream& iStrm, std::string& str, const DataSize)
{
// bits 0,1: Bytes per char type: 1,2,3,4.
// bits 2,3: Bytes in size indicator, 1,2,3,4
uint32 id = 0;
Binaryread(iStrm, id, 1);
const uint8 nSizeBytes = (id & 12) >> 2; // 12 == 1100b
if (nSizeBytes > 0)
{
uint8 bytes = std::min(uint8(3), nSizeBytes);
uint8 v2 = 0;
uint8 v3 = 0;
uint8 v4 = 0;
if(bytes >= 1) Binaryread(iStrm, v2);
if(bytes >= 2) Binaryread(iStrm, v3);
if(bytes >= 3) Binaryread(iStrm, v4);
id &= 0xff;
id |= (v2 << 8) | (v3 << 16) | (v4 << 24);
}
// Limit to 1 MB.
str.resize(std::min(id >> 4, uint32(1000000)));
for(size_t i = 0; i < str.size(); i++)
iStrm.read(&str[i], 1);
id = (id >> 4) - static_cast<uint32>(str.size());
if(id > 0)
iStrm.ignore(id);
}
mpt::ustring ID::AsString() const
{
if(IsPrintable())
{
return mpt::ToUnicode(mpt::Charset::ISO8859_1, m_ID);
}
if(m_ID.length() > 8)
{
return mpt::ustring();
}
uint64le val;
val.set(0);
std::memcpy(&val, m_ID.data(), m_ID.length());
return mpt::ufmt::val(val);
}
const char Ssb::s_EntryID[3] = {'2','2','8'};
Ssb::Ssb()
: m_Status(SNT_NONE)
, m_nFixedEntrySize(0)
, m_posStart(0)
, m_nIdbytes(IdSizeVariable)
, m_nCounter(0)
, m_Flags((1 << RwfWMapStartPosEntry) + (1 << RwfWMapSizeEntry) + (1 << RwfWVersionNum))
{
return;
}
SsbWrite::SsbWrite(std::ostream& os)
: oStrm(os)
, m_posEntrycount(0)
, m_posMapPosField(0)
{
return;
}
SsbRead::SsbRead(std::istream& is)
: iStrm(is)
, m_nReadVersion(0)
, m_rposMapBegin(0)
, m_posMapEnd(0)
, m_posDataBegin(0)
, m_rposEndofHdrData(0)
, m_nReadEntrycount(0)
, m_nNextReadHint(0)
{
return;
}
void SsbWrite::AddWriteNote(const SsbStatus s)
{
m_Status |= s;
SSB_LOG(MPT_UFORMAT("{}: 0x{}")(U_("Write note: "), mpt::ufmt::hex(s)));
}
void SsbRead::AddReadNote(const SsbStatus s)
{
m_Status |= s;
SSB_LOG(MPT_UFORMAT("{}: 0x{}")(U_("Read note: "), mpt::ufmt::hex(s)));
}
void SsbRead::AddReadNote(const ReadEntry* const pRe, const NumType nNum)
{
m_Status |= SNT_PROGRESS;
SSB_LOG(MPT_UFORMAT("Read entry: {{num, id, rpos, size, desc}} = {{{}, {}, {}, {}, {}}}")(
nNum,
(pRe && pRe->nIdLength < 30 && m_Idarray.size() > 0) ? ID(&m_Idarray[pRe->nIdpos], pRe->nIdLength).AsString() : U_(""),
(pRe) ? pRe->rposStart : 0,
(pRe && pRe->nSize != invalidDatasize) ? mpt::ufmt::val(pRe->nSize) : U_(""),
U_("")));
#ifndef SSB_LOGGING
MPT_UNREFERENCED_PARAMETER(pRe);
MPT_UNREFERENCED_PARAMETER(nNum);
#endif
}
// Called after writing an entry.
void SsbWrite::AddWriteNote(const ID &id, const NumType nEntryNum, const DataSize nBytecount, const RposType rposStart)
{
m_Status |= SNT_PROGRESS;
SSB_LOG(MPT_UFORMAT("Wrote entry: {{num, id, rpos, size}} = {{{}, {}, {}, {}}}")(nEntryNum, id.AsString(), rposStart, nBytecount));
#ifndef SSB_LOGGING
MPT_UNREFERENCED_PARAMETER(id);
MPT_UNREFERENCED_PARAMETER(nEntryNum);
MPT_UNREFERENCED_PARAMETER(nBytecount);
MPT_UNREFERENCED_PARAMETER(rposStart);
#endif
}
void SsbRead::ResetReadstatus()
{
m_Status = SNT_NONE;
m_Idarray.reserve(32);
m_Idarray.push_back(0);
}
void SsbWrite::WriteMapItem(const ID &id,
const RposType& rposDataStart,
const DataSize& nDatasize,
const char* pszDesc)
{
SSB_LOG(MPT_UFORMAT("Writing map entry: id={}, rpos={}, size={}")(
(id.GetSize() > 0) ? id.AsString() : U_(""),
rposDataStart,
nDatasize));
std::ostringstream mapStream;
if(m_nIdbytes > 0)
{
if (m_nIdbytes != IdSizeVariable && id.GetSize() != m_nIdbytes)
{ AddWriteNote(SNW_CHANGING_IDSIZE_WITH_FIXED_IDSIZESETTING); return; }
if (m_nIdbytes == IdSizeVariable) //Variablesize ID?
mpt::IO::WriteAdaptiveInt16LE(mapStream, static_cast<uint16>(id.GetSize()));
if(id.GetSize() > 0)
mapStream.write(id.GetBytes(), id.GetSize());
}
if (GetFlag(RwfWMapStartPosEntry)) //Startpos
mpt::IO::WriteAdaptiveInt64LE(mapStream, rposDataStart);
if (GetFlag(RwfWMapSizeEntry)) //Entrysize
mpt::IO::WriteAdaptiveInt64LE(mapStream, nDatasize);
if (GetFlag(RwfWMapDescEntry)) //Entry descriptions
WriteAdaptive12String(mapStream, std::string(pszDesc));
m_MapStreamString.append(mapStream.str());
}
void SsbWrite::IncrementWriteCounter()
{
m_nCounter++;
if(m_nCounter >= static_cast<uint16>(std::numeric_limits<uint16>::max() >> 2))
{
FinishWrite();
AddWriteNote(SNW_MAX_WRITE_COUNT_REACHED);
}
}
void SsbWrite::BeginWrite(const ID &id, const uint64& nVersion)
{
SSB_LOG(MPT_UFORMAT("Write header with ID = {}")(id.AsString()));
ResetWritestatus();
if(!oStrm.good())
{ AddWriteNote(SNRW_BADGIVEN_STREAM); return; }
// Start bytes.
oStrm.write(s_EntryID, sizeof(s_EntryID));
m_posStart = oStrm.tellp() - Offtype(sizeof(s_EntryID));
// Object ID.
{
uint8 idsize = static_cast<uint8>(id.GetSize());
Binarywrite<uint8>(oStrm, idsize);
if(idsize > 0) oStrm.write(id.GetBytes(), id.GetSize());
}
// Form header.
uint8 header = 0;
SetFlag(RwfWMapStartPosEntry, GetFlag(RwfWMapStartPosEntry) && m_nFixedEntrySize == 0);
SetFlag(RwfWMapSizeEntry, GetFlag(RwfWMapSizeEntry) && m_nFixedEntrySize == 0);
header = (m_nIdbytes != 4) ? (m_nIdbytes & 3) : 3; //0,1 : Bytes per IDtype, 0,1,2,4
Setbit(header, 2, GetFlag(RwfWMapStartPosEntry)); //2 : Startpos in map?
Setbit(header, 3, GetFlag(RwfWMapSizeEntry)); //3 : Datasize in map?
Setbit(header, 4, GetFlag(RwfWVersionNum)); //4 : Version numeric field?
Setbit(header, 7, GetFlag(RwfWMapDescEntry)); //7 : Entrydescriptions in map?
// Write header
Binarywrite<uint8>(oStrm, header);
// Additional options.
uint8 tempU8 = 0;
Setbit(tempU8, 0, (m_nIdbytes == IdSizeVariable) || (m_nIdbytes == 3) || (m_nIdbytes > 4));
Setbit(tempU8, 1, m_nFixedEntrySize != 0);
const uint8 flags = tempU8;
if(flags != s_DefaultFlagbyte)
{
mpt::IO::WriteAdaptiveInt32LE(oStrm, 2); //Headersize - now it is 2.
Binarywrite<uint8>(oStrm, HeaderId_FlagByte);
Binarywrite<uint8>(oStrm, flags);
}
else
mpt::IO::WriteAdaptiveInt32LE(oStrm, 0);
if(Testbit(header, 4)) // Version(numeric)?
mpt::IO::WriteAdaptiveInt64LE(oStrm, nVersion);
if(Testbit(flags, 0)) // Custom IDbytecount?
{
uint8 n = (m_nIdbytes == IdSizeVariable) ? 1 : static_cast<uint8>((m_nIdbytes << 1));
Binarywrite<uint8>(oStrm, n);
}
if(Testbit(flags, 1)) // Fixedsize entries?
mpt::IO::WriteAdaptiveInt32LE(oStrm, m_nFixedEntrySize);
//Entrycount. Reserve two bytes(max uint16_max / 4 entries), actual value is written after writing data.
m_posEntrycount = oStrm.tellp();
Binarywrite<uint16>(oStrm, 0);
SetFlag(RwfRwHasMap, (m_nIdbytes != 0 || GetFlag(RwfWMapStartPosEntry) || GetFlag(RwfWMapSizeEntry) || GetFlag(RwfWMapDescEntry)));
m_posMapPosField = oStrm.tellp();
if (GetFlag(RwfRwHasMap)) //Mapping begin pos(reserve space - actual value is written after writing data)
Binarywrite<uint64>(oStrm, 0);
}
SsbRead::ReadRv SsbRead::OnReadEntry(const ReadEntry* pE, const ID &id, const Postype& posReadBegin)
{
if (pE != nullptr)
AddReadNote(pE, m_nCounter);
else if (GetFlag(RwfRMapHasId) == false) // Not ID's in map.
{
ReadEntry e;
e.rposStart = static_cast<RposType>(posReadBegin - m_posStart);
e.nSize = static_cast<DataSize>(iStrm.tellg() - posReadBegin);
AddReadNote(&e, m_nCounter);
}
else // Entry not found.
{
SSB_LOG(MPT_UFORMAT("No entry with id {} found.")(id.AsString()));
#ifndef SSB_LOGGING
MPT_UNREFERENCED_PARAMETER(id);
#endif
return EntryNotFound;
}
m_nCounter++;
return EntryRead;
}
void SsbWrite::OnWroteItem(const ID &id, const Postype& posBeforeWrite)
{
const Offtype nRawEntrySize = oStrm.tellp() - posBeforeWrite;
MPT_MAYBE_CONSTANT_IF(nRawEntrySize < 0 || static_cast<uint64>(nRawEntrySize) > std::numeric_limits<DataSize>::max())
{
AddWriteNote(SNW_INSUFFICIENT_DATASIZETYPE);
return;
}
if(GetFlag(RwfRMapHasSize) && (nRawEntrySize < 0 || static_cast<uint64>(nRawEntrySize) > (std::numeric_limits<DataSize>::max() >> 2)))
{ AddWriteNote(SNW_DATASIZETYPE_OVERFLOW); return; }
DataSize nEntrySize = static_cast<DataSize>(nRawEntrySize);
// Handle fixed size entries:
if (m_nFixedEntrySize > 0)
{
if(nEntrySize <= m_nFixedEntrySize)
{
for(uint32 i = 0; i<m_nFixedEntrySize-nEntrySize; i++)
oStrm.put(0);
nEntrySize = m_nFixedEntrySize;
}
else
{ AddWriteNote(SNW_INSUFFICIENT_FIXEDSIZE); return; }
}
if (GetFlag(RwfRwHasMap))
WriteMapItem(id, static_cast<RposType>(posBeforeWrite - m_posStart), nEntrySize, "");
AddWriteNote(id, m_nCounter, nEntrySize, static_cast<RposType>(posBeforeWrite - m_posStart));
IncrementWriteCounter();
}
void SsbRead::BeginRead(const ID &id, const uint64& nVersion)
{
SSB_LOG(MPT_UFORMAT("Read header with expected ID = {}")(id.AsString()));
ResetReadstatus();
if (!iStrm.good())
{ AddReadNote(SNRW_BADGIVEN_STREAM); return; }
m_posStart = iStrm.tellg();
// Start bytes.
{
char temp[sizeof(s_EntryID)];
ArrayReader<char>(sizeof(s_EntryID))(iStrm, temp, sizeof(s_EntryID));
if(std::memcmp(temp, s_EntryID, sizeof(s_EntryID)))
{
AddReadNote(SNR_STARTBYTE_MISMATCH);
return;
}
}
// Compare IDs.
uint8 storedIdLen = 0;
Binaryread<uint8>(iStrm, storedIdLen);
std::array<char, 256> storedIdBuf;
storedIdBuf = {};
if(storedIdLen > 0)
{
iStrm.read(storedIdBuf.data(), storedIdLen);
}
if(!(id == ID(storedIdBuf.data(), storedIdLen)))
{
AddReadNote(SNR_OBJECTCLASS_IDMISMATCH);
}
if ((m_Status & SNT_FAILURE) != 0)
{
SSB_LOG(U_("ID mismatch, terminating read."));
return;
}
SSB_LOG(U_("ID match, continuing reading."));
// Header
uint8 tempU8;
Binaryread<uint8>(iStrm, tempU8);
const uint8 header = tempU8;
m_nIdbytes = ((header & 3) == 3) ? 4 : (header & 3);
if (Testbit(header, 6))
SetFlag(RwfRTwoBytesDescChar, true);
// Read headerdata size
uint32 tempU32 = 0;
mpt::IO::ReadAdaptiveInt32LE(iStrm, tempU32);
const uint32 headerdatasize = tempU32;
// If headerdatasize != 0, read known headerdata and ignore rest.
uint8 flagbyte = s_DefaultFlagbyte;
if(headerdatasize >= 2)
{
Binaryread<uint8>(iStrm, tempU8);
if(tempU8 == HeaderId_FlagByte)
Binaryread<uint8>(iStrm, flagbyte);
iStrm.ignore( (tempU8 == HeaderId_FlagByte) ? headerdatasize - 2 : headerdatasize - 1);
}
uint64 tempU64 = 0;
// Read version numeric if available.
if (Testbit(header, 4))
{
mpt::IO::ReadAdaptiveInt64LE(iStrm, tempU64);
m_nReadVersion = tempU64;
if(tempU64 > nVersion)
AddReadNote(SNR_LOADING_OBJECT_WITH_LARGER_VERSION);
}
if (Testbit(header, 5))
{
Binaryread<uint8>(iStrm, tempU8);
iStrm.ignore(tempU8);
}
if(Testbit(flagbyte, 0)) // Custom ID?
{
Binaryread<uint8>(iStrm, tempU8);
if ((tempU8 & 1) != 0)
m_nIdbytes = IdSizeVariable;
else
m_nIdbytes = (tempU8 >> 1);
if(m_nIdbytes == 0)
AddReadNote(SNR_NO_ENTRYIDS_WITH_CUSTOMID_DEFINED);
}
m_nFixedEntrySize = 0;
if(Testbit(flagbyte, 1)) // Fixedsize entries?
mpt::IO::ReadAdaptiveInt32LE(iStrm, m_nFixedEntrySize);
SetFlag(RwfRMapHasStartpos, Testbit(header, 2));
SetFlag(RwfRMapHasSize, Testbit(header, 3));
SetFlag(RwfRMapHasId, (m_nIdbytes > 0));
SetFlag(RwfRMapHasDesc, Testbit(header, 7));
SetFlag(RwfRwHasMap, GetFlag(RwfRMapHasId) || GetFlag(RwfRMapHasStartpos) || GetFlag(RwfRMapHasSize) || GetFlag(RwfRMapHasDesc));
if (GetFlag(RwfRwHasMap) == false)
{
SSB_LOG(U_("No map in the file."));
}
if (Testbit(flagbyte, 2)) // Object description?
{
uint16 size = 0;
mpt::IO::ReadAdaptiveInt16LE(iStrm, size);
iStrm.ignore(size * (GetFlag(RwfRTwoBytesDescChar) ? 2 : 1));
}
if(Testbit(flagbyte, 3))
iStrm.ignore(5);
// Read entrycount
mpt::IO::ReadAdaptiveInt64LE(iStrm, tempU64);
if(tempU64 > 16000)
// The current code can only write 16383 entries because it uses a Adaptive64LE with a fixed size=2
// Additionally, 16000 is an arbitrary limit to avoid an out-of-memory DoS when caching the map.
{ AddReadNote(SNR_TOO_MANY_ENTRIES_TO_READ); return; }
m_nReadEntrycount = static_cast<NumType>(tempU64);
if(m_nReadEntrycount == 0)
AddReadNote(SNR_ZEROENTRYCOUNT);
// Read map rpos if map exists.
if (GetFlag(RwfRwHasMap))
{
mpt::IO::ReadAdaptiveInt64LE(iStrm, tempU64);
if(tempU64 > static_cast<uint64>(std::numeric_limits<Offtype>::max()))
{ AddReadNote(SNR_INSUFFICIENT_STREAM_OFFTYPE); return; }
}
const Offtype rawEndOfHdrData = iStrm.tellg() - m_posStart;
MPT_MAYBE_CONSTANT_IF(rawEndOfHdrData < 0 || static_cast<uint64>(rawEndOfHdrData) > std::numeric_limits<RposType>::max())
{
AddReadNote(SNR_INSUFFICIENT_RPOSTYPE);
return;
}
m_rposEndofHdrData = static_cast<RposType>(rawEndOfHdrData);
m_rposMapBegin = (GetFlag(RwfRwHasMap)) ? static_cast<RposType>(tempU64) : m_rposEndofHdrData;
if (GetFlag(RwfRwHasMap) == false)
m_posMapEnd = m_posStart + m_rposEndofHdrData;
SetFlag(RwfRHeaderIsRead, true);
}
void SsbRead::CacheMap()
{
if(GetFlag(RwfRwHasMap) || m_nFixedEntrySize > 0)
{
iStrm.seekg(m_posStart + m_rposMapBegin);
if(iStrm.fail())
{ AddReadNote(SNR_BADSTREAM_AFTER_MAPHEADERSEEK); return; }
SSB_LOG(MPT_UFORMAT("Reading map from rpos: {}")(m_rposMapBegin));
mapData.resize(m_nReadEntrycount);
m_Idarray.reserve(m_nReadEntrycount * 4);
//Read map
for(NumType i = 0; i<m_nReadEntrycount; i++)
{
if(iStrm.fail())
{ AddReadNote(SNR_BADSTREAM_AT_MAP_READ); return; }
// Read ID.
uint16 nIdsize = m_nIdbytes;
if(nIdsize == IdSizeVariable) //Variablesize ID
mpt::IO::ReadAdaptiveInt16LE(iStrm, nIdsize);
const size_t nOldEnd = m_Idarray.size();
if (nIdsize > 0 && (Util::MaxValueOfType(nOldEnd) - nOldEnd >= nIdsize))
{
m_Idarray.resize(nOldEnd + nIdsize);
iStrm.read(&m_Idarray[nOldEnd], nIdsize);
}
mapData[i].nIdLength = nIdsize;
mapData[i].nIdpos = nOldEnd;
// Read position.
if(GetFlag(RwfRMapHasStartpos))
{
uint64 tempU64;
mpt::IO::ReadAdaptiveInt64LE(iStrm, tempU64);
if(tempU64 > static_cast<uint64>(std::numeric_limits<Offtype>::max()))
{ AddReadNote(SNR_INSUFFICIENT_STREAM_OFFTYPE); return; }
mapData[i].rposStart = static_cast<RposType>(tempU64);
}
// Read entry size.
if (m_nFixedEntrySize > 0)
mapData[i].nSize = m_nFixedEntrySize;
else if(GetFlag(RwfRMapHasSize)) // Map has datasize field.
{
uint64 tempU64;
mpt::IO::ReadAdaptiveInt64LE(iStrm, tempU64);
if(tempU64 > static_cast<uint64>(std::numeric_limits<Offtype>::max()))
{ AddReadNote(SNR_INSUFFICIENT_STREAM_OFFTYPE); return; }
mapData[i].nSize = static_cast<DataSize>(tempU64);
}
// If there's no entry startpos in map, count start pos from datasizes.
// Here readentry.rposStart is set to relative position from databegin.
if (mapData[i].nSize != invalidDatasize && GetFlag(RwfRMapHasStartpos) == false)
mapData[i].rposStart = (i > 0) ? mapData[i-1].rposStart + mapData[i-1].nSize : 0;
if(GetFlag(RwfRMapHasDesc)) //Map has entrydescriptions?
{
uint16 size = 0;
mpt::IO::ReadAdaptiveInt16LE(iStrm, size);
if(GetFlag(RwfRTwoBytesDescChar))
iStrm.ignore(size * 2);
else
iStrm.ignore(size);
}
}
m_posMapEnd = iStrm.tellg();
SSB_LOG(MPT_UFORMAT("End of map(rpos): {}")(m_posMapEnd - m_posStart));
}
SetFlag(RwfRMapCached, true);
m_posDataBegin = (m_rposMapBegin == m_rposEndofHdrData) ? m_posMapEnd : m_posStart + Postype(m_rposEndofHdrData);
iStrm.seekg(m_posDataBegin);
// If there are no positions in the map but there are entry sizes, rposStart will
// be relative to data start. Now that posDataBegin is known, make them relative to
// startpos.
if (GetFlag(RwfRMapHasStartpos) == false && (GetFlag(RwfRMapHasSize) || m_nFixedEntrySize > 0))
{
const RposType offset = static_cast<RposType>(m_posDataBegin - m_posStart);
for(size_t i = 0; i < m_nReadEntrycount; i++)
mapData[i].rposStart += offset;
}
}
const ReadEntry* SsbRead::Find(const ID &id)
{
iStrm.clear();
if (GetFlag(RwfRMapCached) == false)
CacheMap();
if (m_nFixedEntrySize > 0 && GetFlag(RwfRMapHasStartpos) == false && GetFlag(RwfRMapHasSize) == false)
iStrm.seekg(m_posDataBegin + Postype(m_nFixedEntrySize * m_nCounter));
if (GetFlag(RwfRMapHasId) == true)
{
const size_t nEntries = mapData.size();
for(size_t i0 = 0; i0 < nEntries; i0++)
{
const size_t i = (i0 + m_nNextReadHint) % nEntries;
if(mapData[i].nIdpos < m_Idarray.size() && id == ID(&m_Idarray[mapData[i].nIdpos], mapData[i].nIdLength))
{
m_nNextReadHint = (i + 1) % nEntries;
if (mapData[i].rposStart != 0)
iStrm.seekg(m_posStart + Postype(mapData[i].rposStart));
return &mapData[i];
}
}
}
return nullptr;
}
void SsbWrite::FinishWrite()
{
const Postype posDataEnd = oStrm.tellp();
Postype posMapStart = oStrm.tellp();
SSB_LOG(MPT_UFORMAT("Writing map to rpos: {}")(posMapStart - m_posStart));
if (GetFlag(RwfRwHasMap)) //Write map
{
oStrm.write(m_MapStreamString.c_str(), m_MapStreamString.length());
}
const Postype posMapEnd = oStrm.tellp();
// Write entry count.
oStrm.seekp(m_posEntrycount);
// Write a fixed size=2 Adaptive64LE because space for this value has already been reserved berforehand.
mpt::IO::WriteAdaptiveInt64LE(oStrm, m_nCounter, 2);
if (GetFlag(RwfRwHasMap))
{ // Write map start position.
oStrm.seekp(m_posMapPosField);
const uint64 rposMap = posMapStart - m_posStart;
// Write a fixed size=8 Adaptive64LE because space for this value has already been reserved berforehand.
mpt::IO::WriteAdaptiveInt64LE(oStrm, rposMap, 8);
}
// Seek to end.
oStrm.seekp(std::max(posMapEnd, posDataEnd));
SSB_LOG(MPT_UFORMAT("End of stream(rpos): {}")(oStrm.tellp() - m_posStart));
}
} // namespace srlztn
OPENMPT_NAMESPACE_END