Archive.h

#pragma once
 
#include <Foundation/Containers/DynamicArray.h>
#include <Foundation/Containers/HashTable.h>
#include <Foundation/Strings/HashedString.h>
 
class plRawMemoryStreamReader;
 
enum class plArchiveCompressionMode : plUInt8
{
  Uncompressed,
  Compressed_zstd,
  Compressed_zip,
};
 
class PL_FOUNDATION_DLL plArchiveEntry
{
public:
  plUInt64 m_uiDataStartOffset = 0;      
  plUInt64 m_uiUncompressedDataSize = 0; 
  plUInt64 m_uiStoredDataSize = 0;       
  plUInt32 m_uiPathStringOffset = 0;     
  plArchiveCompressionMode m_CompressionMode = plArchiveCompressionMode::Uncompressed;
 
  plResult Serialize(plStreamWriter& inout_stream) const;
  plResult Deserialize(plStreamReader& inout_stream);
};
 
class PL_FOUNDATION_DLL plArchiveStoredString
{
public:
  PL_DECLARE_POD_TYPE();
 
  plArchiveStoredString() = default;
 
  plArchiveStoredString(plUInt64 uiLowerCaseHash, plUInt32 uiSrcStringOffset)
    : m_uiLowerCaseHash(plHashingUtils::StringHashTo32(uiLowerCaseHash))
    , m_uiSrcStringOffset(uiSrcStringOffset)
  {
  }
 
  plUInt32 m_uiLowerCaseHash;
  plUInt32 m_uiSrcStringOffset;
};
 
void operator<<(plStreamWriter& inout_stream, const plArchiveStoredString& value);
void operator>>(plStreamReader& inout_stream, plArchiveStoredString& value);
 
class plArchiveLookupString
{
  PL_DISALLOW_COPY_AND_ASSIGN(plArchiveLookupString);
 
public:
  PL_DECLARE_POD_TYPE();
 
  plArchiveLookupString(plUInt64 uiLowerCaseHash, plStringView sString, const plDynamicArray<plUInt8>& archiveAllPathStrings)
    : m_uiLowerCaseHash(plHashingUtils::StringHashTo32(uiLowerCaseHash))
    , m_sString(sString)
    , m_ArchiveAllPathStrings(archiveAllPathStrings)
  {
  }
 
  plUInt32 m_uiLowerCaseHash;
  plStringView m_sString;
  const plDynamicArray<plUInt8>& m_ArchiveAllPathStrings;
};
 
template <>
struct plHashHelper<plArchiveStoredString>
{
  PL_ALWAYS_INLINE static plUInt32 Hash(const plArchiveStoredString& hs) { return hs.m_uiLowerCaseHash; }
  PL_ALWAYS_INLINE static plUInt32 Hash(const plArchiveLookupString& hs) { return hs.m_uiLowerCaseHash; }
 
  PL_ALWAYS_INLINE static bool Equal(const plArchiveStoredString& a, const plArchiveStoredString& b) { return a.m_uiSrcStringOffset == b.m_uiSrcStringOffset; }
 
  PL_ALWAYS_INLINE static bool Equal(const plArchiveStoredString& a, const plArchiveLookupString& b)
  {
    // in case that we want to lookup a string using a plArchiveLookupString, we validate
    // that the stored string is actually equal to the lookup string, to enable handling of hash collisions
    return b.m_sString.IsEqual_NoCase(reinterpret_cast<const char*>(&b.m_ArchiveAllPathStrings[a.m_uiSrcStringOffset]));
  }
};
 
class PL_FOUNDATION_DLL plArchiveTOC
{
public:
  plDynamicArray<plArchiveEntry> m_Entries;
  plHashTable<plArchiveStoredString, plUInt32> m_PathToEntryIndex;
  plDynamicArray<plUInt8> m_AllPathStrings;
 
  plUInt32 FindEntry(plStringView sFile) const;
 
  plUInt32 AddPathString(plStringView sPathString);
 
  void RebuildPathToEntryHashes();
 
  plStringView GetEntryPathString(plUInt32 uiEntryIdx) const;
 
  plResult Serialize(plStreamWriter& inout_stream) const;
  plResult Deserialize(plStreamReader& inout_stream, plUInt8 uiArchiveVersion);
};