PAK.cpp

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#include <vpkpp/format/PAK.h>
 
#include <filesystem>
 
#include <FileStream.h>
 
using namespace sourcepp;
using namespace vpkpp;
 
std::unique_ptr<PackFile> PAK::create(const std::string& path, bool hrot) {
    {
        FileStream stream{path, FileStream::OPT_TRUNCATE | FileStream::OPT_CREATE_IF_NONEXISTENT};
        stream
            .write(hrot ? PAK_HROT_SIGNATURE : PAK_SIGNATURE)
            .write<uint32_t>(0)
            .write<uint32_t>(0);
    }
    return PAK::open(path);
}
 
std::unique_ptr<PackFile> PAK::open(const std::string& path, const EntryCallback& callback) {
    if (!std::filesystem::exists(path)) {
        // File does not exist
        return nullptr;
    }
 
    auto* pak = new PAK{path};
    auto packFile = std::unique_ptr<PackFile>(pak);
 
    FileStream reader{pak->fullFilePath};
    reader.seek_in(0);
 
    if (auto signature = reader.read<uint32_t>(); signature == PAK_SIGNATURE) {
        pak->isHROT_ = false;
    } else if (signature == PAK_HROT_SIGNATURE) {
        pak->isHROT_ = true;
    } else {
        // File is not a PAK
        return nullptr;
    }
 
    auto directoryOffset = reader.read<uint32_t>();
    // Directory size / file entry size
    auto fileCount = reader.read<uint32_t>() / (pak->isHROT() ? 128 : 64);
 
    reader.seek_in(directoryOffset);
    for (uint32_t i = 0; i < fileCount; i++) {
        Entry entry = createNewEntry();
 
        auto entryPath = pak->cleanEntryPath(reader.read_string(pak->isHROT() ? PAK_HROT_FILENAME_MAX_SIZE : PAK_FILENAME_MAX_SIZE));
 
        entry.offset = reader.read<uint32_t>();
        entry.length = reader.read<uint32_t>();
 
        pak->entries.emplace(entryPath, entry);
 
        if (callback) {
            callback(entryPath, entry);
        }
    }
 
    return packFile;
}
 
std::optional<std::vector<std::byte>> PAK::readEntry(const std::string& path_) const {
    auto path = this->cleanEntryPath(path_);
    auto entry = this->findEntry(path);
    if (!entry) {
        return std::nullopt;
    }
    if (entry->unbaked) {
        return readUnbakedEntry(*entry);
    }
 
    // It's baked into the file on disk
    FileStream stream{this->fullFilePath};
    if (!stream) {
        return std::nullopt;
    }
    stream.seek_in_u(entry->offset);
    return stream.read_bytes(entry->length);
}
 
void PAK::addEntryInternal(Entry& entry, const std::string& path, std::vector<std::byte>& buffer, EntryOptions options) {
    entry.length = buffer.size();
 
    // Offset will be reset when it's baked
    entry.offset = 0;
}
 
bool PAK::bake(const std::string& outputDir_, BakeOptions options, const EntryCallback& callback) {
    // Get the proper file output folder
    std::string outputDir = this->getBakeOutputDir(outputDir_);
    std::string outputPath = outputDir + '/' + this->getFilename();
 
    // Reconstruct data for ease of access
    std::vector<std::pair<std::string, Entry*>> entriesToBake;
    this->runForAllEntriesInternal([&entriesToBake](const std::string& path, Entry& entry) {
        entriesToBake.emplace_back(path, &entry);
    });
 
    // Read data before overwriting, we don't know if we're writing to ourself
    std::vector<std::byte> fileData;
    for (auto& [path, entry] : entriesToBake) {
        if (auto binData = this->readEntry(path)) {
            entry->offset = fileData.size();
 
            fileData.insert(fileData.end(), binData->begin(), binData->end());
        } else {
            entry->offset = 0;
            entry->length = 0;
        }
    }
 
    {
        FileStream stream{outputPath, FileStream::OPT_TRUNCATE | FileStream::OPT_CREATE_IF_NONEXISTENT};
        stream.seek_out(0);
 
        // Signature
        stream.write(this->isHROT() ? PAK_HROT_SIGNATURE : PAK_SIGNATURE);
 
        // Index and size of directory
        static constexpr uint32_t DIRECTORY_INDEX = sizeof(PAK_SIGNATURE) + sizeof(uint32_t) * 2;
        stream.write(DIRECTORY_INDEX);
        const uint32_t directorySize = entriesToBake.size() * (this->isHROT() ? 128 : 64);
        stream.write(directorySize);
 
        // Directory
        for (const auto& [path, entry] : entriesToBake) {
            stream.write(path, false, this->isHROT() ? PAK_HROT_FILENAME_MAX_SIZE : PAK_FILENAME_MAX_SIZE);
            stream.write(static_cast<uint32_t>(entry->offset + DIRECTORY_INDEX + directorySize));
            stream.write(static_cast<uint32_t>(entry->length));
 
            if (callback) {
                callback(path, *entry);
            }
        }
 
        // File data
        stream.write(fileData);
    }
 
    // Clean up
    this->mergeUnbakedEntries();
    PackFile::setFullFilePath(outputDir);
    return true;
}
 
Attribute PAK::getSupportedEntryAttributes() const {
    using enum Attribute;
    return LENGTH;
}
 
bool PAK::isHROT() const {
    return this->isHROT_;
}
 
void PAK::setHROT(bool hrot) {
    this->isHROT_ = hrot;
}