xcdat/include/xcdat.hpp

#pragma once

#include <fstream>
#include <string>

#include "xcdat/bc_vector_15.hpp"
#include "xcdat/bc_vector_16.hpp"
#include "xcdat/bc_vector_7.hpp"
#include "xcdat/bc_vector_8.hpp"
#include "xcdat/load_visitor.hpp"
#include "xcdat/mmap_visitor.hpp"
#include "xcdat/save_visitor.hpp"
#include "xcdat/size_visitor.hpp"
#include "xcdat/trie.hpp"

namespace xcdat {

//! The trie type with standard DACs using 8-bit integers
using trie_8_type = trie<bc_vector_8>;

//! The trie type with standard DACs using 16-bit integers
using trie_16_type = trie<bc_vector_16>;

//! The trie type with pointer-based DACs using 7-bit integers (for the 1st layer)
using trie_7_type = trie<bc_vector_7>;

//! The trie type with pointer-based DACs using 15-bit integers (for the 1st layer)
using trie_15_type = trie<bc_vector_15>;

//! Set the continuous memory block to a new trie instance (for a memory-mapped file).
template <class Trie>
[[maybe_unused]] Trie mmap(const char* address) {
    mmap_visitor visitor(address);

    std::uint32_t flag;
    visitor.visit(flag);
    XCDAT_THROW_IF(flag != Trie::l1_bits, "The input dictionary type is different.");

    Trie idx;
    visitor.visit(idx);
    return idx;
}

//! Load the trie dictionary from the file.
template <class Trie>
[[maybe_unused]] Trie load(const std::string& filepath) {
    load_visitor visitor(filepath);

    std::uint32_t flag;
    visitor.visit(flag);
    XCDAT_THROW_IF(flag != Trie::l1_bits, "The input dictionary type is different.");

    Trie idx;
    visitor.visit(idx);
    return idx;
}

//! Save the trie dictionary to the file and returns the file size in bytes.
template <class Trie>
[[maybe_unused]] std::uint64_t save(const Trie& idx, const std::string& filepath) {
    save_visitor visitor(filepath);
    visitor.visit(static_cast<std::uint32_t>(Trie::l1_bits));  // flag
    visitor.visit(const_cast<Trie&>(idx));
    return visitor.bytes();
}

//! Get the dictionary size in bytes.
template <class Trie>
[[maybe_unused]] std::uint64_t memory_in_bytes(const Trie& idx) {
    size_visitor visitor;
    visitor.visit(static_cast<std::uint32_t>(Trie::l1_bits));  // flag
    visitor.visit(const_cast<Trie&>(idx));
    return visitor.bytes();
}

//! Get the flag indicating the trie dictionary type, embedded by the function 'save'.
//! The flag corresponds to trie::l1_bits and will be used to detect the trie type from the file.
[[maybe_unused]] std::uint32_t get_flag(const std::string& filepath) {
    std::ifstream ifs(filepath);
    XCDAT_THROW_IF(!ifs.good(), "Cannot open the input file");

    std::uint32_t flag;
    ifs.read(reinterpret_cast<char*>(&flag), sizeof(flag));
    return flag;
}

//! Load the keywords from the file.
[[maybe_unused]] std::vector<std::string> load_strings(const std::string& filepath, char delim = '\n') {
    std::ifstream ifs(filepath);
    XCDAT_THROW_IF(!ifs.good(), "Cannot open the input file");

    std::vector<std::string> strs;
    for (std::string str; std::getline(ifs, str, delim);) {
        strs.push_back(str);
    }
    return strs;
}

}  // namespace xcdat