add assimp library code

libs/assimp/code/Common/DefaultIOStream.cpp

@@ -0,0 +1,179 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2021, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+/** @file  DefaultIOStream.cpp
+ *  @brief Default File I/O implementation for #Importer
+ */
+
+#include <assimp/DefaultIOStream.h>
+#include <assimp/ai_assert.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+using namespace Assimp;
+
+namespace {
+
+template <size_t sizeOfPointer>
+inline size_t select_ftell(FILE *file) {
+    return ::ftell(file);
+}
+
+template <size_t sizeOfPointer>
+inline int select_fseek(FILE *file, int64_t offset, int origin) {
+    return ::fseek(file, static_cast<long>(offset), origin);
+}
+
+
+    
+#if defined _WIN32 && (!defined __GNUC__ || __MSVCRT_VERSION__ >= 0x0601)
+template <>
+inline size_t select_ftell<8>(FILE *file) {
+    return (size_t)::_ftelli64(file);
+}
+
+template <>
+inline int select_fseek<8>(FILE *file, int64_t offset, int origin) {
+    return ::_fseeki64(file, offset, origin);
+}
+
+#endif // #if defined _WIN32 && (!defined __GNUC__ || __MSVCRT_VERSION__ >= 0x0601)
+    
+} // namespace
+
+// ----------------------------------------------------------------------------------
+DefaultIOStream::~DefaultIOStream() {
+    if (mFile) {
+        ::fclose(mFile);
+        mFile = nullptr;
+    }
+}
+
+// ----------------------------------------------------------------------------------
+size_t DefaultIOStream::Read(void *pvBuffer,
+        size_t pSize,
+        size_t pCount) {
+    ai_assert(nullptr != pvBuffer);
+    ai_assert(0 != pSize);
+    ai_assert(0 != pCount);
+
+    return (mFile ? ::fread(pvBuffer, pSize, pCount, mFile) : 0);
+}
+
+// ----------------------------------------------------------------------------------
+size_t DefaultIOStream::Write(const void *pvBuffer,
+        size_t pSize,
+        size_t pCount) {
+    ai_assert(nullptr != pvBuffer);
+    ai_assert(0 != pSize);
+
+    return (mFile ? ::fwrite(pvBuffer, pSize, pCount, mFile) : 0);
+}
+
+// ----------------------------------------------------------------------------------
+aiReturn DefaultIOStream::Seek(size_t pOffset,
+        aiOrigin pOrigin) {
+    if (!mFile) {
+        return AI_FAILURE;
+    }
+
+    // Just to check whether our enum maps one to one with the CRT constants
+    static_assert(aiOrigin_CUR == SEEK_CUR &&
+                          aiOrigin_END == SEEK_END && aiOrigin_SET == SEEK_SET,
+            "aiOrigin_CUR == SEEK_CUR && \
+        aiOrigin_END == SEEK_END && aiOrigin_SET == SEEK_SET");
+
+    // do the seek
+    return (0 == select_fseek<sizeof(void *)>(mFile, (int64_t)pOffset, (int)pOrigin) ? AI_SUCCESS : AI_FAILURE);
+}
+
+// ----------------------------------------------------------------------------------
+size_t DefaultIOStream::Tell() const {
+    if (!mFile) {
+        return 0;
+    }
+    return select_ftell<sizeof(void *)>(mFile);
+}
+
+// ----------------------------------------------------------------------------------
+size_t DefaultIOStream::FileSize() const {
+    if (!mFile || mFilename.empty()) {
+        return 0;
+    }
+
+    if (SIZE_MAX == mCachedSize) {
+
+        // Although fseek/ftell would allow us to reuse the existing file handle here,
+        // it is generally unsafe because:
+        //  - For binary streams, it is not technically well-defined
+        //  - For text files the results are meaningless
+        // That's why we use the safer variant fstat here.
+        //
+        // See here for details:
+        // https://www.securecoding.cert.org/confluence/display/seccode/FIO19-C.+Do+not+use+fseek()+and+ftell()+to+compute+the+size+of+a+regular+file
+#if defined _WIN32 && (!defined __GNUC__ || __MSVCRT_VERSION__ >= 0x0601)
+        struct __stat64 fileStat;
+        //using fileno + fstat avoids having to handle the filename
+        int err = _fstat64(_fileno(mFile), &fileStat);
+        if (0 != err)
+            return 0;
+        mCachedSize = (size_t)(fileStat.st_size);
+#elif defined __GNUC__ || defined __APPLE__ || defined __MACH__ || defined __FreeBSD__
+        struct stat fileStat;
+        int err = stat(mFilename.c_str(), &fileStat);
+        if (0 != err)
+            return 0;
+        const unsigned long long cachedSize = fileStat.st_size;
+        mCachedSize = static_cast<size_t>(cachedSize);
+#else
+#error "Unknown platform"
+#endif
+    }
+    return mCachedSize;
+}
+
+// ----------------------------------------------------------------------------------
+void DefaultIOStream::Flush() {
+    if (mFile) {
+        ::fflush(mFile);
+    }
+}
+
+// ----------------------------------------------------------------------------------