assimp/code/Common/DefaultIOSystem.cpp

/*
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Open Asset Import Library (assimp)
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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  derived from this software without specific prior
  written permission of the assimp team.

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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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*/
/** @file Default implementation of IOSystem using the standard C file functions */

#include <assimp/StringComparison.h>

#include <assimp/DefaultIOStream.h>
#include <assimp/DefaultIOSystem.h>
#include <assimp/ai_assert.h>
#include <stdlib.h>
#include <assimp/DefaultLogger.hpp>

#ifdef __unix__
#    include <stdlib.h>
#    include <sys/param.h>
#endif

#ifdef _WIN32
#    include <windows.h>
#endif

using namespace Assimp;

#ifdef _WIN32

const std::wstring wdummy;

static std::wstring Utf8ToWide(const char *in) {
    if (nullptr == in) {
        return wdummy;
    }
    int size = MultiByteToWideChar(CP_UTF8, 0, in, -1, nullptr, 0);
    // size includes terminating null; std::wstring adds null automatically
    std::wstring out(static_cast<size_t>(size) - 1, L'\0');
    MultiByteToWideChar(CP_UTF8, 0, in, -1, &out[0], size);
    
    return out;
}

const std::string dummy;

static std::string WideToUtf8(const wchar_t *in) {
    if (nullptr == in) {
        return dummy;
    }
    int size = WideCharToMultiByte(CP_UTF8, 0, in, -1, nullptr, 0, nullptr, nullptr);
    // size includes terminating null; std::string adds null automatically
    std::string out(static_cast<size_t>(size) - 1, '\0');
    WideCharToMultiByte(CP_UTF8, 0, in, -1, &out[0], size, nullptr, nullptr);
    
    return out;
}
#endif

// ------------------------------------------------------------------------------------------------
// Tests for the existence of a file at the given path.
bool DefaultIOSystem::Exists(const char *pFile) const {
#ifdef _WIN32
    struct __stat64 filestat;
    if (_wstat64(Utf8ToWide(pFile).c_str(), &filestat) != 0) {
        return false;
    }
#else
    FILE *file = ::fopen(pFile, "rb");
    if (!file) {
        return false;
    }

    ::fclose(file);
#endif

    return true;
}

// ------------------------------------------------------------------------------------------------
// Open a new file with a given path.
IOStream *DefaultIOSystem::Open(const char *strFile, const char *strMode) {
    ai_assert(strFile != nullptr);
    ai_assert(strMode != nullptr);
    FILE *file;
#ifdef _WIN32
    std::wstring name = Utf8ToWide(strFile);
    if (name.empty()) {
        return nullptr;
    }
    
    file = ::_wfopen(name.c_str(), Utf8ToWide(strMode).c_str());
#else
    file = ::fopen(strFile, strMode);
#endif
    if (!file) {
        return nullptr;
    }

    return new DefaultIOStream(file, strFile);
}

// ------------------------------------------------------------------------------------------------
// Closes the given file and releases all resources associated with it.
void DefaultIOSystem::Close(IOStream *pFile) {
    delete pFile;
}

// ------------------------------------------------------------------------------------------------
// Returns the operation specific directory separator
char DefaultIOSystem::getOsSeparator() const {
#ifndef _WIN32
    return '/';
#else
    return '\\';
#endif
}

// ------------------------------------------------------------------------------------------------
// IOSystem default implementation (ComparePaths isn't a pure virtual function)
bool IOSystem::ComparePaths(const char *one, const char *second) const {
    return !ASSIMP_stricmp(one, second);
}

// ------------------------------------------------------------------------------------------------
// Convert a relative path into an absolute path
inline static std::string MakeAbsolutePath(const char *in) {
    ai_assert(in);
    std::string out;
#ifdef _WIN32
    wchar_t *ret = ::_wfullpath(nullptr, Utf8ToWide(in).c_str(), 0);
    if (ret) {
        out = WideToUtf8(ret);
        free(ret);
    }
#else
    char *ret = realpath(in, nullptr);
    if (ret) {
        out = ret;
        free(ret);
    }
#endif
    if (!ret) {
        // preserve the input path, maybe someone else is able to fix
        // the path before it is accessed (e.g. our file system filter)
        ASSIMP_LOG_WARN_F("Invalid path: ", std::string(in));
        out = in;
    }
    return out;
}

// ------------------------------------------------------------------------------------------------
// DefaultIOSystem's more specialized implementation
bool DefaultIOSystem::ComparePaths(const char *one, const char *second) const {
    // chances are quite good both paths are formatted identically,
    // so we can hopefully return here already
    if (!ASSIMP_stricmp(one, second))
        return true;

    std::string temp1 = MakeAbsolutePath(one);
    std::string temp2 = MakeAbsolutePath(second);

    return !ASSIMP_stricmp(temp1, temp2);
}

// ------------------------------------------------------------------------------------------------
std::string DefaultIOSystem::fileName(const std::string &path) {
    std::string ret = path;
    std::size_t last = ret.find_last_of("\\/");
    if (last != std::string::npos) ret = ret.substr(last + 1);
    return ret;
}

// ------------------------------------------------------------------------------------------------
std::string DefaultIOSystem::completeBaseName(const std::string &path) {
    std::string ret = fileName(path);
    std::size_t pos = ret.find_last_of('.');
    if (pos != std::string::npos) ret = ret.substr(0, pos);
    return ret;
}

// ------------------------------------------------------------------------------------------------
std::string DefaultIOSystem::absolutePath(const std::string &path) {
    std::string ret = path;
    std::size_t last = ret.find_last_of("\\/");
    if (last != std::string::npos) ret = ret.substr(0, last);
    return ret;
}

// ------------------------------------------------------------------------------------------------