lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 275 insertions, 0 deletions

diff --git a/lib/mlibc/options/posix/generic/posix-file-io.cpp b/lib/mlibc/options/posix/generic/posix-file-io.cpp
new file mode 100644
index 0000000..1a4f38b
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix-file-io.cpp
@@ -0,0 +1,275 @@
+#include <mlibc/posix-file-io.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+#include <errno.h>
+
+namespace mlibc {
+
+int mem_file::reopen(const char *, const char *) {
+	mlibc::panicLogger() << "mlibc: freopen() on a mem_file stream is unimplemented!" << frg::endlog;
+	return -1;
+}
+
+int mem_file::determine_type(stream_type *type) {
+	*type = stream_type::file_like;
+	return 0;
+}
+
+int mem_file::determine_bufmode(buffer_mode *mode) {
+	*mode = buffer_mode::no_buffer;
+	return 0;
+}
+
+memstream_mem_file::memstream_mem_file(char **ptr, size_t *sizeloc, int flags, void (*do_dispose)(abstract_file *))
+: mem_file{flags, do_dispose}, _bufloc{ptr}, _sizeloc{sizeloc} { }
+
+
+int memstream_mem_file::close() {
+	_update_ptrs();
+	_buf.detach();
+
+	return 0;
+}
+
+int memstream_mem_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if ((_pos >= 0 && _pos >= _max_size) || !max_size) {
+		*actual_size = 0;
+		return 0;
+	}
+
+	size_t bytes_read = std::min(size_t(_max_size - _pos), max_size);
+	memcpy(buffer, _buffer().data() + _pos, bytes_read);
+	_pos += bytes_read;
+	*actual_size = bytes_read;
+	return 0;
+}
+
+int memstream_mem_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	if (_pos + max_size >= _buffer_size()) {
+		_buf.resize(_pos + max_size + 1, '\0');
+		_update_ptrs();
+	}
+
+	size_t bytes_write = std::min(static_cast<size_t>(_buffer_size() - _pos), max_size);
+	memcpy(_buffer().data() + _pos, buffer, bytes_write);
+	_pos += max_size;
+	*actual_size = max_size;
+
+	return 0;
+}
+
+int memstream_mem_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	switch (whence) {
+		case SEEK_SET:
+			_pos = offset;
+			if (_pos >= 0 && size_t(_pos) >= _buffer_size()) {
+				_buf.resize(_pos + 1, '\0');
+				_update_ptrs();
+			}
+			*new_offset = _pos;
+			break;
+		case SEEK_CUR:
+			_pos += offset;
+			if (_pos >= 0 && size_t(_pos) >= _buffer_size()) {
+				_buf.resize(_pos + 1, '\0');
+				_update_ptrs();
+			}
+			*new_offset = _pos;
+			break;
+		case SEEK_END:
+			_pos = _buffer_size() ? _buffer_size() - 1 + offset : _buffer_size() + offset;
+			_buf.resize(_pos + 1, '\0');
+			_update_ptrs();
+			*new_offset = _pos;
+			break;
+		default:
+			return EINVAL;
+	}
+	return 0;
+}
+
+void memstream_mem_file::_update_ptrs() {
+	*_bufloc = _buf.data();
+	*_sizeloc = _buf.size() - 1;
+}
+
+fmemopen_mem_file::fmemopen_mem_file(void *in_buf, size_t size, int flags, void (*do_dispose)(abstract_file *))
+: mem_file{flags, do_dispose}, _inBuffer{in_buf}, _inBufferSize{size} {
+	if(!_inBuffer) {
+		_inBuffer = getAllocator().allocate(size);
+		_needsDeallocation = true;
+	}
+
+	if(_flags & O_APPEND) {
+		// the initial seek-size for append is zero if buf was NULL, or the first '\0' found, or the size
+		_max_size = (_needsDeallocation) ? 0 : strnlen(reinterpret_cast<char *>(_inBuffer), _inBufferSize);
+		_pos = _max_size;
+	} else if((_flags & O_WRONLY || _flags & O_RDWR) && _flags & O_CREAT && _flags & O_TRUNC) {
+		// modes: "w", "w+"
+		_max_size = 0;
+	} else {
+		_max_size = size;
+	}
+}
+
+int fmemopen_mem_file::close() {
+	if(_needsDeallocation) {
+		getAllocator().free(_inBuffer);
+	}
+
+	return 0;
+}
+
+int fmemopen_mem_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if ((_pos >= 0 && _pos >= _max_size) || !max_size) {
+		*actual_size = 0;
+		return 0;
+	}
+
+	size_t bytes_read = std::min(size_t(_max_size - _pos), max_size);
+	memcpy(buffer, _buffer().data() + _pos, bytes_read);
+	_pos += bytes_read;
+	*actual_size = bytes_read;
+	return 0;
+}
+
+int fmemopen_mem_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	off_t bytes_write = std::min(static_cast<size_t>(_buffer_size() - _pos), max_size);
+	memcpy(_buffer().data() + _pos, buffer, bytes_write);
+	_pos += bytes_write;
+	*actual_size = bytes_write;
+
+	if(_pos > _max_size) {
+		_max_size = _pos;
+	}
+
+	// upon flushing, we need to put a null byte at the current position or at the end of the buffer
+	size_t null = _pos;
+	// a special case is if the mode is set to updating ('+'), then it always goes at the end
+	if(null >= _buffer_size() || _flags & O_RDWR) {
+		null = _buffer_size() - 1;
+	}
+
+	if(_buffer_size()) {
+		_buffer()[null] = '\0';
+	}
+
+	return 0;
+}
+
+int fmemopen_mem_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	switch (whence) {
+		case SEEK_SET:
+			if(offset < 0 || size_t(offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos = offset;
+			*new_offset = _pos;
+			break;
+		case SEEK_CUR:
+			// seeking to negative positions or positions larger than the buffer is disallowed in fmemopen(3)
+			if((_pos + offset) < 0 || size_t(_pos + offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos += offset;
+			*new_offset = _pos;
+			break;
+		case SEEK_END:
+			if((_max_size + offset) < 0 || size_t(_max_size + offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos = _max_size + offset;
+			*new_offset = _pos;
+			break;
+		default:
+			return EINVAL;
+	}
+	return 0;
+}
+
+int cookie_file::close() {
+	if(!_funcs.close) {
+		return 0;
+	}
+
+	return _funcs.close(_cookie);
+}
+
+int cookie_file::reopen(const char *, const char *) {
+	mlibc::panicLogger() << "mlibc: freopen() on a cookie_file stream is unimplemented!" << frg::endlog;
+	return -1;
+}
+
+int cookie_file::determine_type(stream_type *type) {
+	*type = stream_type::file_like;
+	return 0;
+}
+
+int cookie_file::determine_bufmode(buffer_mode *mode) {
+	*mode = buffer_mode::no_buffer;
+	return 0;
+}
+
+int cookie_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if(!_funcs.read) {
+		return EOF;
+	}
+
+	*actual_size = _funcs.read(_cookie, buffer, max_size);
+
+	return 0;
+}
+
+int cookie_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	if(!_funcs.write) {
+		return 0;
+	}
+
+	*actual_size = _funcs.write(_cookie, buffer, max_size);
+
+	return 0;
+}
+
+int cookie_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	if(!_funcs.seek) {
+		return ENOTSUP;
+	}
+
+	*new_offset = offset;
+
+	return _funcs.seek(_cookie, new_offset, whence);
+}
+
+} // namespace mlibc
+
+FILE *fdopen(int fd, const char *mode) {
+	int flags = mlibc::fd_file::parse_modestring(mode);
+
+	flags &= ~O_TRUNC; // 'w' should not truncate the file
+
+	if (flags & O_APPEND) {
+		int cur_flags = fcntl(fd, F_GETFL, 0);
+		if (cur_flags < 0) {
+			errno = EINVAL;
+			return nullptr;
+		} else if (!(cur_flags & O_APPEND)) {
+			if (fcntl(fd, F_SETFL, cur_flags | O_APPEND)) {
+				errno = EINVAL;
+				return nullptr;
+			}
+		}
+	}
+
+	if (flags & O_CLOEXEC) {
+		if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
+			errno = EINVAL;
+			return nullptr;
+		}
+	}
+
+	// TODO: We may need to activate line buffered mode for terminals.
+
+	return frg::construct<mlibc::fd_file>(getAllocator(), fd,
+			mlibc::file_dispose_cb<mlibc::fd_file>);
+}