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LibC: Fix `FILE` buffering once again :D

This commit is contained in:
Bananymous 2025-05-20 20:28:49 +03:00
parent b907263f35
commit 5d80c880c8
1 changed files with 11 additions and 23 deletions
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34
userspace/libraries/LibC/stdio.cpp
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@ -82,13 +82,10 @@ static void init_closed_file(FILE* file)
static int drop_read_buffer(FILE* file) static int drop_read_buffer(FILE* file)
{ {
if (file->buffer_rd_size == 0) const off_t bytes_remaining = file->buffer_rd_size - file->buffer_idx;
return 0; if (bytes_remaining > 0)
ASSERT(file->buffer_idx != 0); if (syscall(SYS_SEEK, file->fd, -bytes_remaining, SEEK_CUR) == -1)
if (file->buffer_idx == 1) return EOF;
return 0;
if (syscall(SYS_SEEK, file->fd, file->buffer_idx - 1, SEEK_CUR) == -1)
return EOF;
file->buffer_rd_size = 0; file->buffer_rd_size = 0;
file->buffer_idx = 0; file->buffer_idx = 0;
return 0; return 0;
@ -452,8 +449,7 @@ int fseeko(FILE* file, off_t offset, int whence)
ScopeLock _(file); ScopeLock _(file);
if (fflush(file) == EOF) if (fflush(file) == EOF)
return -1; return -1;
long ret = syscall(SYS_SEEK, file->fd, offset, whence); if (syscall(SYS_SEEK, file->fd, offset, whence) == -1)
if (ret < 0)
return -1; return -1;
file->eof = false; file->eof = false;
return 0; return 0;
@ -472,12 +468,12 @@ long ftell(FILE* file)
off_t ftello(FILE* file) off_t ftello(FILE* file)
{ {
ScopeLock _(file); ScopeLock _(file);
if (fflush(file) == EOF) auto offset = syscall(SYS_TELL, file->fd);
if (offset == -1)
return -1; return -1;
long ret = syscall(SYS_TELL, file->fd); if (file->buffer_rd_size)
if (ret < 0) offset -= file->buffer_rd_size - file->buffer_idx;
return -1; return offset - file->unget_buf_idx;
return ret;
} }
int ftrylockfile(FILE* fp) int ftrylockfile(FILE* fp)
@ -541,10 +537,7 @@ int getc_unlocked(FILE* file)
if (file->unget_buf_idx) if (file->unget_buf_idx)
{ {
file->unget_buf_idx--; file->unget_buf_idx--;
unsigned char ch = file->unget_buffer[file->unget_buf_idx]; return file->unget_buffer[file->unget_buf_idx];
if (fseeko(file, 1, SEEK_CUR) == -1)
return EOF;
return ch;
} }
// read from unbuffered file // read from unbuffered file
@ -582,8 +575,6 @@ int getc_unlocked(FILE* file)
((nread == 0) ? file->eof : file->error) = true; ((nread == 0) ? file->eof : file->error) = true;
return EOF; return EOF;
} }
if (fseeko(file, 1 - nread, SEEK_CUR) == -1)
return EOF;
file->buffer_rd_size = nread; file->buffer_rd_size = nread;
file->buffer_idx = 1; file->buffer_idx = 1;
return file->buffer[0]; return file->buffer[0];
@ -1020,9 +1011,6 @@ int ungetc_unlocked(int c, FILE* stream)
return EOF; return EOF;
} }
if (fseeko(stream, -1, SEEK_CUR) == -1)
return EOF;
stream->unget_buffer[stream->unget_buf_idx] = c; stream->unget_buffer[stream->unget_buf_idx] = c;
stream->unget_buf_idx++; stream->unget_buf_idx++;
stream->eof = false; stream->eof = false;