diff options
Diffstat (limited to 'lib/mlibc/options/ansi/generic/file-io.cpp')
| -rw-r--r-- | lib/mlibc/options/ansi/generic/file-io.cpp | 745 |
1 files changed, 0 insertions, 745 deletions
diff --git a/lib/mlibc/options/ansi/generic/file-io.cpp b/lib/mlibc/options/ansi/generic/file-io.cpp deleted file mode 100644 index e59b109..0000000 --- a/lib/mlibc/options/ansi/generic/file-io.cpp +++ /dev/null @@ -1,745 +0,0 @@ - -#include <errno.h> -#include <stdlib.h> -#include <stdint.h> -#include <string.h> -#include <stdio.h> -#if __MLIBC_GLIBC_OPTION -#include <stdio_ext.h> -#endif - -#include <bits/ensure.h> - -#include <mlibc/debug.hpp> - -#include <abi-bits/fcntl.h> -#include <frg/allocation.hpp> -#include <frg/mutex.hpp> -#include <mlibc/allocator.hpp> -#include <mlibc/file-io.hpp> -#include <mlibc/ansi-sysdeps.hpp> -#include <mlibc/lock.hpp> - -namespace mlibc { - -// -------------------------------------------------------------------------------------- -// abstract_file implementation. -// -------------------------------------------------------------------------------------- - -namespace { - using file_list = frg::intrusive_list< - abstract_file, - frg::locate_member< - abstract_file, - frg::default_list_hook<abstract_file>, - &abstract_file::_list_hook - > - >; - - // Useful when debugging the FILE implementation. - constexpr bool globallyDisableBuffering = false; - - // The maximum number of characters we permit the user to ungetc. - constexpr size_t ungetBufferSize = 8; - - // List of files that will be flushed before exit(). - file_list &global_file_list() { - static frg::eternal<file_list> list; - return list.get(); - }; -} - -// For pipe-like streams (seek returns ESPIPE), we need to make sure -// that the buffer only ever contains all-dirty or all-clean data. -// Regarding _type and _bufmode: -// As we might construct FILE objects for FDs that are not actually -// open (e.g. for std{in,out,err}), we defer the type determination and cache the result. - -abstract_file::abstract_file(void (*do_dispose)(abstract_file *)) -: _type{stream_type::unknown}, _bufmode{buffer_mode::unknown}, _do_dispose{do_dispose} { - // TODO: For __fwriting to work correctly, set the __io_mode to 1 if the write is write-only. - __buffer_ptr = nullptr; - __unget_ptr = nullptr; - __buffer_size = 4096; - __offset = 0; - __io_offset = 0; - __valid_limit = 0; - __dirty_begin = 0; - __dirty_end = 0; - __io_mode = 0; - __status_bits = 0; - - global_file_list().push_back(this); -} - -abstract_file::~abstract_file() { - if(__dirty_begin != __dirty_end) - mlibc::infoLogger() << "mlibc warning: File is not flushed before destruction" - << frg::endlog; - - if(__buffer_ptr) - getAllocator().free(__buffer_ptr - ungetBufferSize); - - auto it = global_file_list().iterator_to(this); - global_file_list().erase(it); -} - -void abstract_file::dispose() { - if(!_do_dispose) - return; - _do_dispose(this); -} - -// Note that read() and write() are asymmetric: -// While read() can trigger a write-back, write() can never trigger a read-ahead(). -// This peculiarity is reflected in their code. - -int abstract_file::read(char *buffer, size_t max_size, size_t *actual_size) { - __ensure(max_size); - - if(_init_bufmode()) - return -1; - - size_t unget_length = 0; - if (__unget_ptr != __buffer_ptr) { - unget_length = frg::min(max_size, (size_t)(__buffer_ptr - __unget_ptr)); - memcpy(buffer, __unget_ptr, unget_length); - - __unget_ptr += unget_length; - buffer += unget_length; - max_size -= unget_length; - - if (max_size == 0) { - *actual_size = unget_length; - return 0; - } - } - - if(globallyDisableBuffering || _bufmode == buffer_mode::no_buffer) { - size_t io_size; - if(int e = io_read(buffer, max_size, &io_size); e) { - __status_bits |= __MLIBC_ERROR_BIT; - return e; - } - if(!io_size) - __status_bits |= __MLIBC_EOF_BIT; - *actual_size = io_size + unget_length; - return 0; - } - - // Ensure correct buffer type for pipe-like streams. - // TODO: In order to support pipe-like streams we need to write-back the buffer. - if(__io_mode && __valid_limit) - mlibc::panicLogger() << "mlibc: Cannot read-write to same pipe-like stream" - << frg::endlog; - __io_mode = 0; - - // Clear the buffer, then buffer new data. - if(__offset == __valid_limit) { - // TODO: We only have to write-back/reset if __valid_limit reaches the buffer end. - if(int e = _write_back(); e) - return e; - if(int e = _reset(); e) - return e; - - // Perform a read-ahead. - _ensure_allocation(); - size_t io_size; - if(int e = io_read(__buffer_ptr, __buffer_size, &io_size); e) { - __status_bits |= __MLIBC_ERROR_BIT; - return e; - } - if(!io_size) { - __status_bits |= __MLIBC_EOF_BIT; - *actual_size = 0; - return 0; - } - - __io_offset = io_size; - __valid_limit = io_size; - } - - // Return data from the buffer. - __ensure(__offset < __valid_limit); - - auto chunk = frg::min(size_t(__valid_limit - __offset), max_size); - memcpy(buffer, __buffer_ptr + __offset, chunk); - __offset += chunk; - - *actual_size = chunk + unget_length; - return 0; -} - -int abstract_file::write(const char *buffer, size_t max_size, size_t *actual_size) { - __ensure(max_size); - - if(_init_bufmode()) - return -1; - if(globallyDisableBuffering || _bufmode == buffer_mode::no_buffer) { - // As we do not buffer, nothing can be dirty. - __ensure(__dirty_begin == __dirty_end); - size_t io_size; - if(int e = io_write(buffer, max_size, &io_size); e) { - __status_bits |= __MLIBC_ERROR_BIT; - return e; - } - *actual_size = io_size; - return 0; - } - - // Flush the buffer if necessary. - if(__offset == __buffer_size) { - if(int e = _write_back(); e) - return e; - if(int e = _reset(); e) - return e; - } - - // Ensure correct buffer type for pipe-like streams. - // TODO: We could full support pipe-like files - // by ungetc()ing all data before a write happens, - // however, for now we just report an error. - if(!__io_mode && __valid_limit) // TODO: Only check this for pipe-like streams. - mlibc::panicLogger() << "mlibc: Cannot read-write to same pipe-like stream" - << frg::endlog; - __io_mode = 1; - - __ensure(__offset < __buffer_size); - auto chunk = frg::min(__buffer_size - __offset, max_size); - - // Line-buffered streams perform I/O on full lines. - bool flush_line = false; - if(_bufmode == buffer_mode::line_buffer) { - auto nl = reinterpret_cast<char *>(memchr(buffer, '\n', chunk)); - if(nl) { - chunk = nl + 1 - buffer; - flush_line = true; - } - } - __ensure(chunk); - - // Buffer data (without necessarily performing I/O). - _ensure_allocation(); - memcpy(__buffer_ptr + __offset, buffer, chunk); - - if(__dirty_begin != __dirty_end) { - __dirty_begin = frg::min(__dirty_begin, __offset); - __dirty_end = frg::max(__dirty_end, __offset + chunk); - }else{ - __dirty_begin = __offset; - __dirty_end = __offset + chunk; - } - __valid_limit = frg::max(__offset + chunk, __valid_limit); - __offset += chunk; - - // Flush line-buffered streams. - if(flush_line) { - if(_write_back()) - return -1; - } - - *actual_size = chunk; - return 0; -} - -int abstract_file::unget(char c) { - if (!__unget_ptr) { - // This can happen if the file is unbuffered, but we still need - // a space to store ungetc'd data. - __ensure(!__buffer_ptr); - _ensure_allocation(); - __ensure(__unget_ptr); - } - - if ((size_t)(__buffer_ptr - __unget_ptr) + 1 > ungetBufferSize) - return EOF; - else { - *(--__unget_ptr) = c; - return c; - } -} - -int abstract_file::update_bufmode(buffer_mode mode) { - // setvbuf() has undefined behavior if I/O has been performed. - __ensure(__dirty_begin == __dirty_end - && "update_bufmode() must only be called before performing I/O"); - _bufmode = mode; - return 0; -} - -void abstract_file::purge() { - __offset = 0; - __io_offset = 0; - __valid_limit = 0; - __dirty_end = __dirty_begin; - __unget_ptr = __buffer_ptr; -} - -int abstract_file::flush() { - if (__dirty_end != __dirty_begin) { - if (int e = _write_back(); e) - return e; - } - - if (int e = _save_pos(); e) - return e; - purge(); - return 0; -} - -int abstract_file::tell(off_t *current_offset) { - off_t seek_offset; - if(int e = io_seek(0, SEEK_CUR, &seek_offset); e) - return e; - - *current_offset = seek_offset + (off_t(__offset) - off_t(__io_offset)); - return 0; -} - -int abstract_file::seek(off_t offset, int whence) { - if(int e = _write_back(); e) - return e; - - off_t new_offset; - if(whence == SEEK_CUR) { - auto seek_offset = offset + (off_t(__offset) - off_t(__io_offset)); - if(int e = io_seek(seek_offset, whence, &new_offset); e) { - __status_bits |= __MLIBC_ERROR_BIT; - return e; - } - }else{ - __ensure(whence == SEEK_SET || whence == SEEK_END); - if(int e = io_seek(offset, whence, &new_offset); e) { - __status_bits |= __MLIBC_ERROR_BIT; - return e; - } - } - - // We just forget the current buffer. - // TODO: If the seek is "small", we can just modify our internal offset. - purge(); - - return 0; -} - -int abstract_file::_init_type() { - if(_type != stream_type::unknown) - return 0; - - if(int e = determine_type(&_type); e) - return e; - __ensure(_type != stream_type::unknown); - return 0; -} - -int abstract_file::_init_bufmode() { - if(_bufmode != buffer_mode::unknown) - return 0; - - if(determine_bufmode(&_bufmode)) - return -1; - __ensure(_bufmode != buffer_mode::unknown); - return 0; -} - -int abstract_file::_write_back() { - if(int e = _init_type(); e) - return e; - - if(__dirty_begin == __dirty_end) - return 0; - - // For non-pipe streams, first do a seek to reset the - // I/O position to zero, then do a write(). - if(_type == stream_type::file_like) { - if(__io_offset != __dirty_begin) { - __ensure(__dirty_begin - __io_offset > 0); - off_t new_offset; - if(int e = io_seek(off_t(__dirty_begin) - off_t(__io_offset), SEEK_CUR, &new_offset); e) - return e; - __io_offset = __dirty_begin; - } - }else{ - __ensure(_type == stream_type::pipe_like); - __ensure(__io_offset == __dirty_begin); - } - - // Now, we are in the correct position to write-back everything. - while(__io_offset < __dirty_end) { - size_t io_size; - if(int e = io_write(__buffer_ptr + __io_offset, __dirty_end - __io_offset, &io_size); e) { - __status_bits |= __MLIBC_ERROR_BIT; - return e; - } - __ensure(io_size > 0 && "io_write() is expected to always write at least one byte"); - __io_offset += io_size; - __dirty_begin += io_size; - } - - return 0; -} - -int abstract_file::_save_pos() { - if (int e = _init_type(); e) - return e; - if (int e = _init_bufmode(); e) - return e; - - if (_type == stream_type::file_like && _bufmode != buffer_mode::no_buffer) { - off_t new_offset; - auto seek_offset = (off_t(__offset) - off_t(__io_offset)); - if (int e = io_seek(seek_offset, SEEK_CUR, &new_offset); e) { - __status_bits |= __MLIBC_ERROR_BIT; - mlibc::infoLogger() << "hit io_seek() error " << e << frg::endlog; - return e; - } - return 0; - } - return 0; // nothing to do for the rest -} - -int abstract_file::_reset() { - if(int e = _init_type(); e) - return e; - - // For pipe-like files, we must not forget already read data. - // TODO: Report this error to the user. - if(_type == stream_type::pipe_like) - __ensure(__offset == __valid_limit); - - __ensure(__dirty_begin == __dirty_end); - __offset = 0; - __io_offset = 0; - __valid_limit = 0; - - return 0; -} - -// This may still be called when buffering is disabled, for ungetc. -void abstract_file::_ensure_allocation() { - if(__buffer_ptr) - return; - - auto ptr = getAllocator().allocate(__buffer_size + ungetBufferSize); - __buffer_ptr = reinterpret_cast<char *>(ptr) + ungetBufferSize; - __unget_ptr = __buffer_ptr; -} - -// -------------------------------------------------------------------------------------- -// fd_file implementation. -// -------------------------------------------------------------------------------------- - -fd_file::fd_file(int fd, void (*do_dispose)(abstract_file *), bool force_unbuffered) -: abstract_file{do_dispose}, _fd{fd}, _force_unbuffered{force_unbuffered} { } - -int fd_file::fd() { - return _fd; -} - -int fd_file::close() { - if(__dirty_begin != __dirty_end) - mlibc::infoLogger() << "mlibc warning: File is not flushed before closing" - << frg::endlog; - if(int e = mlibc::sys_close(_fd); e) - return e; - return 0; -} - -int fd_file::reopen(const char *path, const char *mode) { - int mode_flags = parse_modestring(mode); - - int fd; - if(int e = sys_open(path, mode_flags, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH, &fd); e) { - return e; - } - - flush(); - close(); - getAllocator().deallocate(__buffer_ptr, __buffer_size + ungetBufferSize); - - __buffer_ptr = nullptr; - __unget_ptr = nullptr; - __buffer_size = 4096; - _reset(); - _fd = fd; - - if(mode_flags & O_APPEND) { - seek(0, SEEK_END); - } - - return 0; -} - -int fd_file::determine_type(stream_type *type) { - off_t offset; - int e = mlibc::sys_seek(_fd, 0, SEEK_CUR, &offset); - if(!e) { - *type = stream_type::file_like; - return 0; - }else if(e == ESPIPE) { - *type = stream_type::pipe_like; - return 0; - }else{ - return e; - } -} - -int fd_file::determine_bufmode(buffer_mode *mode) { - // When isatty() is not implemented, we fall back to the safest default (no buffering). - if(!mlibc::sys_isatty) { - MLIBC_MISSING_SYSDEP(); - *mode = buffer_mode::no_buffer; - return 0; - } - if(_force_unbuffered) { - *mode = buffer_mode::no_buffer; - return 0; - } - - if(int e = mlibc::sys_isatty(_fd); !e) { - *mode = buffer_mode::line_buffer; - return 0; - }else if(e == ENOTTY) { - *mode = buffer_mode::full_buffer; - return 0; - }else{ - mlibc::infoLogger() << "mlibc: sys_isatty() failed while determining whether" - " stream is interactive" << frg::endlog; - return -1; - } -} - -int fd_file::io_read(char *buffer, size_t max_size, size_t *actual_size) { - ssize_t s; - if(int e = mlibc::sys_read(_fd, buffer, max_size, &s); e) - return e; - *actual_size = s; - return 0; -} - -int fd_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) { - ssize_t s; - if(int e = mlibc::sys_write(_fd, buffer, max_size, &s); e) - return e; - *actual_size = s; - return 0; -} - -int fd_file::io_seek(off_t offset, int whence, off_t *new_offset) { - if(int e = mlibc::sys_seek(_fd, offset, whence, new_offset); e) - return e; - return 0; -} - -int fd_file::parse_modestring(const char *mode) { - // Consume the first char; this must be 'r', 'w' or 'a'. - int flags = 0; - bool has_plus = strchr(mode, '+'); - if(*mode == 'r') { - if(has_plus) { - flags = O_RDWR; - }else{ - flags = O_RDONLY; - } - }else if(*mode == 'w') { - if(has_plus) { - flags = O_RDWR; - }else{ - flags = O_WRONLY; - } - flags |= O_CREAT | O_TRUNC; - }else if(*mode == 'a') { - if(has_plus) { - flags = O_APPEND | O_RDWR; - }else{ - flags = O_APPEND | O_WRONLY; - } - flags |= O_CREAT; - }else{ - mlibc::infoLogger() << "Illegal fopen() mode '" << *mode << "'" << frg::endlog; - } - mode += 1; - - // Consume additional flags. - while(*mode) { - if(*mode == '+') { - mode++; // This is already handled above. - }else if(*mode == 'b') { - mode++; // mlibc assumes that there is no distinction between text and binary. - }else if(*mode == 'e') { - flags |= O_CLOEXEC; - mode++; - }else{ - mlibc::infoLogger() << "Illegal fopen() flag '" << mode << "'" << frg::endlog; - mode++; - } - } - - return flags; -} - -} // namespace mlibc - -namespace { - mlibc::fd_file stdin_file{0}; - mlibc::fd_file stdout_file{1}; - mlibc::fd_file stderr_file{2, nullptr, true}; - - struct stdio_guard { - stdio_guard() { } - - ~stdio_guard() { - // Only flush the files but do not close them. - for(auto it : mlibc::global_file_list()) { - if(int e = it->flush(); e) - mlibc::infoLogger() << "mlibc warning: Failed to flush file before exit()" - << frg::endlog; - } - } - } global_stdio_guard; -} - -FILE *stderr = &stderr_file; -FILE *stdin = &stdin_file; -FILE *stdout = &stdout_file; - -int fileno_unlocked(FILE *file_base) { - auto file = static_cast<mlibc::fd_file *>(file_base); - return file->fd(); -} - -int fileno(FILE *file_base) { - auto file = static_cast<mlibc::fd_file *>(file_base); - frg::unique_lock lock(file->_lock); - return fileno_unlocked(file_base); -} - -FILE *fopen(const char *path, const char *mode) { - int flags = mlibc::fd_file::parse_modestring(mode); - - int fd; - if(int e = mlibc::sys_open(path, flags, 0666, &fd); e) { - errno = e; - return nullptr; - } - - return frg::construct<mlibc::fd_file>(getAllocator(), fd, - mlibc::file_dispose_cb<mlibc::fd_file>); -} - -int fclose(FILE *file_base) { - auto file = static_cast<mlibc::abstract_file *>(file_base); - int e = 0; - if(file->flush()) - e = EOF; - if(file->close()) - e = EOF; - file->dispose(); - return e; -} - -int fseek(FILE *file_base, long offset, int whence) { - auto file = static_cast<mlibc::abstract_file *>(file_base); - frg::unique_lock lock(file->_lock); - if(int e = file->seek(offset, whence); e) { - errno = e; - return -1; - } - return 0; -} - -long ftell(FILE *file_base) { - auto file = static_cast<mlibc::abstract_file *>(file_base); - frg::unique_lock lock(file->_lock); - off_t current_offset; - if(int e = file->tell(¤t_offset); e) { - errno = e; - return -1; - } - return current_offset; -} - -int fflush_unlocked(FILE *file_base) { - if(file_base == NULL) { - // Only flush the files but do not close them. - for(auto it : mlibc::global_file_list()) { - if(int e = it->flush(); e) - mlibc::infoLogger() << "mlibc warning: Failed to flush file" - << frg::endlog; - } - return 0; - } - auto file = static_cast<mlibc::abstract_file *>(file_base); - if(file->flush()) - return EOF; - return 0; -} -int fflush(FILE *file_base) { - if(file_base == NULL) { - // Only flush the files but do not close them. - for(auto it : mlibc::global_file_list()) { - frg::unique_lock lock(it->_lock); - if(int e = it->flush(); e) - mlibc::infoLogger() << "mlibc warning: Failed to flush file" - << frg::endlog; - } - return 0; - } - - auto file = static_cast<mlibc::abstract_file *>(file_base); - frg::unique_lock lock(file->_lock); - if (file->flush()) - return EOF; - return 0; -} - -int setvbuf(FILE *file_base, char *, int mode, size_t) { - // TODO: We could also honor the buffer, but for now use just set the mode. - auto file = static_cast<mlibc::abstract_file *>(file_base); - if(mode == _IONBF) { - if(int e = file->update_bufmode(mlibc::buffer_mode::no_buffer); e) { - errno = e; - return -1; - } - }else if(mode == _IOLBF) { - if(int e = file->update_bufmode(mlibc::buffer_mode::line_buffer); e) { - errno = e; - return -1; - } - }else if(mode == _IOFBF) { - if(int e = file->update_bufmode(mlibc::buffer_mode::full_buffer); e) { - errno = e; - return -1; - } - }else{ - errno = EINVAL; - return -1; - } - - return 0; -} - -void rewind(FILE *file_base) { - auto file = static_cast<mlibc::abstract_file *>(file_base); - frg::unique_lock lock(file->_lock); - file->seek(0, SEEK_SET); - file_base->__status_bits &= ~(__MLIBC_EOF_BIT | __MLIBC_ERROR_BIT); -} - -int ungetc(int c, FILE *file_base) { - if (c == EOF) - return EOF; - - auto file = static_cast<mlibc::abstract_file *>(file_base); - frg::unique_lock lock(file->_lock); - return file->unget(c); -} - -#if __MLIBC_GLIBC_OPTION -void __fpurge(FILE *file_base) { - auto file = static_cast<mlibc::abstract_file *>(file_base); - frg::unique_lock lock(file->_lock); - file->purge(); -} -#endif - |