//===-- FileSystem.cpp ------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Host/FileSystem.h"

#include "llvm/Support/MD5.h"

#include <fstream>
#include <vector>

using namespace lldb;
using namespace lldb_private;

namespace {

bool
CalcMD5(const FileSpec &file_spec, llvm::MD5::MD5Result &md5_result)
{
    llvm::MD5 md5_hash;
    std::ifstream file(file_spec.GetPath(), std::ios::binary);
    if (!file.is_open())
        return false;

    std::vector<char> read_buf(4096);
    while (!file.eof())
    {
        file.read(&read_buf[0], read_buf.size());
        const auto read_bytes = file.gcount();
        if (read_bytes == 0)
            break;

        md5_hash.update(llvm::StringRef(&read_buf[0], read_bytes));
    }

    md5_hash.final(md5_result);
    return true;
}

}  // namespace

bool
FileSystem::CalculateMD5(const FileSpec &file_spec, uint64_t &low, uint64_t &high)
{
    llvm::MD5::MD5Result md5_result;
    if (!CalcMD5(file_spec, md5_result))
        return false;

    const auto uint64_res = reinterpret_cast<const uint64_t*>(md5_result);
    high = uint64_res[0];
    low = uint64_res[1];

    return true;
}

bool
FileSystem::CalculateMD5AsString(const FileSpec &file_spec, std::string& digest_str)
{
    llvm::MD5::MD5Result md5_result;
    if (!CalcMD5(file_spec, md5_result))
        return false;

    llvm::SmallString<32> result_str;
    llvm::MD5::stringifyResult(md5_result, result_str);
    digest_str = result_str.c_str();
    return true;
}