1 files changed, 147 insertions, 0 deletions
diff --git a/common/alfstream.cpp b/common/alfstream.cpp
new file mode 100644
index 00000000..7378c678
--- /dev/null
+++ b/common/alfstream.cpp
@@ -0,0 +1,147 @@
+
+#include "config.h"
+
+#include "alfstream.h"
+
+#include "strutils.h"
+
+#ifdef _WIN32
+
+namespace al {
+
+auto filebuf::underflow() -> int_type
+{
+    if(mFile != INVALID_HANDLE_VALUE && gptr() == egptr())
+    {
+        // Read in the next chunk of data, and set the pointers on success
+        DWORD got{};
+        if(ReadFile(mFile, mBuffer.data(), static_cast<DWORD>(mBuffer.size()), &got, nullptr))
+            setg(mBuffer.data(), mBuffer.data(), mBuffer.data()+got);
+    }
+    if(gptr() == egptr())
+        return traits_type::eof();
+    return traits_type::to_int_type(*gptr());
+}
+
+auto filebuf::seekoff(off_type offset, std::ios_base::seekdir whence, std::ios_base::openmode mode) -> pos_type
+{
+    if(mFile == INVALID_HANDLE_VALUE || (mode&std::ios_base::out) || !(mode&std::ios_base::in))
+        return traits_type::eof();
+
+    LARGE_INTEGER fpos{};
+    switch(whence)
+    {
+        case std::ios_base::beg:
+            fpos.QuadPart = offset;
+            if(!SetFilePointerEx(mFile, fpos, &fpos, FILE_BEGIN))
+                return traits_type::eof();
+            break;
+
+        case std::ios_base::cur:
+            // If the offset remains in the current buffer range, just
+            // update the pointer.
+            if((offset >= 0 && offset < off_type(egptr()-gptr())) ||
+                (offset < 0 && -offset <= off_type(gptr()-eback())))
+            {
+                // Get the current file offset to report the correct read
+                // offset.
+                fpos.QuadPart = 0;
+                if(!SetFilePointerEx(mFile, fpos, &fpos, FILE_CURRENT))
+                    return traits_type::eof();
+                setg(eback(), gptr()+offset, egptr());
+                return fpos.QuadPart - off_type(egptr()-gptr());
+            }
+            // Need to offset for the file offset being at egptr() while
+            // the requested offset is relative to gptr().
+            offset -= off_type(egptr()-gptr());
+            fpos.QuadPart = offset;
+            if(!SetFilePointerEx(mFile, fpos, &fpos, FILE_CURRENT))
+                return traits_type::eof();
+            break;
+
+        case std::ios_base::end:
+            fpos.QuadPart = offset;
+            if(!SetFilePointerEx(mFile, fpos, &fpos, FILE_END))
+                return traits_type::eof();
+            break;
+
+        default:
+            return traits_type::eof();
+    }
+    setg(nullptr, nullptr, nullptr);
+    return fpos.QuadPart;
+}
+
+auto filebuf::seekpos(pos_type pos, std::ios_base::openmode mode) -> pos_type
+{
+    // Simplified version of seekoff
+    if(mFile == INVALID_HANDLE_VALUE || (mode&std::ios_base::out) || !(mode&std::ios_base::in))
+        return traits_type::eof();
+
+    LARGE_INTEGER fpos{};
+    fpos.QuadPart = pos;
+    if(!SetFilePointerEx(mFile, fpos, &fpos, FILE_BEGIN))
+        return traits_type::eof();
+
+    setg(nullptr, nullptr, nullptr);
+    return fpos.QuadPart;
+}
+
+filebuf::~filebuf()
+{
+    if(mFile != INVALID_HANDLE_VALUE)
+        CloseHandle(mFile);
+    mFile = INVALID_HANDLE_VALUE;
+}
+
+bool filebuf::open(const wchar_t *filename, std::ios_base::openmode mode)
+{
+    if((mode&std::ios_base::out) || !(mode&std::ios_base::in))
+        return false;
+    HANDLE f{CreateFileW(filename, GENERIC_READ, FILE_SHARE_READ, nullptr, OPEN_EXISTING,
+        FILE_ATTRIBUTE_NORMAL, nullptr)};
+    if(f == INVALID_HANDLE_VALUE) return false;
+
+    if(mFile != INVALID_HANDLE_VALUE)
+        CloseHandle(mFile);
+    mFile = f;
+
+    setg(nullptr, nullptr, nullptr);
+    return true;
+}
+bool filebuf::open(const char *filename, std::ios_base::openmode mode)
+{
+    std::wstring wname{utf8_to_wstr(filename)};
+    return open(wname.c_str(), mode);
+}
+
+
+ifstream::ifstream(const wchar_t *filename, std::ios_base::openmode mode)
+  : std::istream{nullptr}
+{
+    init(&mStreamBuf);
+
+    // Set the failbit if the file failed to open.
+    if((mode&std::ios_base::out) || !mStreamBuf.open(filename, mode|std::ios_base::in))
+        clear(failbit);
+}
+
+ifstream::ifstream(const char *filename, std::ios_base::openmode mode)
+  : std::istream{nullptr}
+{
+    init(&mStreamBuf);
+
+    // Set the failbit if the file failed to open.
+    if((mode&std::ios_base::out) || !mStreamBuf.open(filename, mode|std::ios_base::in))
+        clear(failbit);
+}
+
+/* This is only here to ensure the compiler doesn't define an implicit
+ * destructor, which it tries to automatically inline and subsequently complain
+ * it can't inline without excessive code growth.
+ */
+ifstream::~ifstream() { }
+
+} // namespace al
+
+#endif