diff options
Diffstat (limited to 'stdio/internals.c')
| -rw-r--r-- | stdio/internals.c | 688 |
1 files changed, 0 insertions, 688 deletions
diff --git a/stdio/internals.c b/stdio/internals.c deleted file mode 100644 index 81f15deb18..0000000000 --- a/stdio/internals.c +++ /dev/null @@ -1,688 +0,0 @@ -/* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - -#include <errno.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - - -/* Make sure that FP has its functions set. */ -void -__stdio_check_funcs (register FILE *fp) -{ - if (!fp->__seen) - { - /* Initialize the stream's info, including buffering info. - This may give a buffer, change I/O functions, etc. - If no buffer is set (and the stream is not made explicitly - unbuffered), we allocate a buffer below, using the bufsize - set by this function. */ - extern void __stdio_init_stream __P ((FILE *)); - fp->__room_funcs = __default_room_functions; - fp->__io_funcs = __default_io_functions; - __stdio_init_stream (fp); - fp->__seen = 1; - } -} - - -/* Minimum size of a buffer we will allocate by default. - If this much memory is not available, - the stream in question will be made unbuffered instead. */ -#define MIN_BUFSIZE 128 - -/* Figure out what kind of buffering (none, line, or full) - and what buffer size to give FP. */ -static void -init_stream (register FILE *fp) -{ - __stdio_check_funcs (fp); - - if (fp->__buffer == NULL && !fp->__userbuf) - { - int save; - - if (fp->__bufsize == 0) - fp->__bufsize = BUFSIZ; - - /* Try to get however many bytes of buffering __stdio_pickbuf - specified, but if that much memory isn't available, - try half as much each time until it succeeds or the buffer - size becomes too small to be useful. */ - save = errno; - while (fp->__bufsize >= MIN_BUFSIZE) - { - fp->__buffer = (char *) malloc (fp->__bufsize); - if (fp->__buffer == NULL) - fp->__bufsize /= 2; - else - break; - } - __set_errno (save); - - if (fp->__buffer == NULL) - { - /* We can't get space for the buffer, so make it unbuffered. */ - fp->__userbuf = 1; - fp->__bufsize = 0; - } - } - - if (fp->__bufp == NULL) - { - /* Set the buffer pointer to the beginning of the buffer. */ - fp->__bufp = fp->__buffer; - fp->__put_limit = fp->__get_limit = fp->__buffer; - } -} - - -/* Determine the current file position of STREAM if it is unknown. */ -int -__stdio_check_offset (stream) - FILE *stream; -{ - init_stream (stream); - - if (stream->__offset == (fpos_t) -1) - { - /* This stream's offset is unknown or unknowable. */ - if (stream->__io_funcs.__seek == NULL) - { - /* Unknowable. */ - __set_errno (ESPIPE); - return EOF; - } - else - { - /* Unknown. Find it out. */ - fpos_t pos = (fpos_t) 0; - if ((*stream->__io_funcs.__seek) (stream->__cookie, - &pos, SEEK_CUR) < 0) - { - if (errno == ESPIPE) - /* Object is incapable of seeking. */ - stream->__io_funcs.__seek = NULL; - return EOF; - } - stream->__offset = pos; - } - } - - if (stream->__target == (fpos_t) -1) - /* This stream was opened on an existing object with - an unknown file position. The position is now known. - Make this the target position. */ - stream->__target = stream->__offset; - - return 0; -} - - -/* Move FP's file position to its target file position, - seeking as necessary and updating its `offset' field. - Sets ferror(FP) (and possibly errno) for errors. */ -static void -seek_to_target (FILE *fp) -{ - int save = errno; - if (__stdio_check_offset (fp) == EOF) - { - if (errno == ESPIPE) - __set_errno (save); - else - fp->__error = 1; - } - else if (fp->__target != fp->__offset) - { - /* We are not at the target file position. - Seek to that position. */ - if (fp->__io_funcs.__seek == NULL) - { - /* We can't seek! */ - __set_errno (ESPIPE); - fp->__error = 1; - } - else - { - fpos_t pos = fp->__target; - if ((*fp->__io_funcs.__seek) (fp->__cookie, &pos, SEEK_SET) < 0) - /* Seek failed! */ - fp->__error = 1; - else - { - fp->__offset = pos; - if (pos != fp->__target) - { - /* Seek didn't go to the right place! - This should never happen. */ -#ifdef EGRATUITOUS - /* It happens in the Hurd when the io server doesn't - obey the protocol for io_seek. */ - __set_errno (EGRATUITOUS); -#else - /* I don't think this can happen in Unix. */ - __set_errno (ESPIPE); /* ??? */ -#endif - fp->__error = 1; - } - } - } - } -} - -/* Flush the buffer for FP. - If C is not EOF, it is also to be written. - If the stream is line buffered and C is a newline, it is written - to the output, otherwise it is put in the buffer after it has been - flushed to avoid a system call for a single character. - This is the default `output room' function. */ -static void -flushbuf (register FILE *fp, int c) -{ - int flush_only = c == EOF; - size_t buffer_written; - size_t to_write; - - /* Set if target and get_limit have already been twiddled appropriately. */ - int twiddled = 0; - - if (fp->__put_limit == fp->__buffer) - { - /* The stream needs to be primed for writing. */ - - size_t buffer_offset = 0; - - if (fp->__target == -1) - /* For an unseekable object, data recently read bears no relation - to data we will write later. Discard the buffer. */ - fp->__get_limit = fp->__buffer; - else - /* If the user has read some of the buffer, the target position - is incremented for each character he has read. */ - fp->__target += fp->__bufp - fp->__buffer; - - if (fp->__mode.__read && fp->__room_funcs.__input != NULL && - !fp->__mode.__append) - { - int save = errno; - const int aligned = (fp->__buffer == NULL || - __stdio_check_offset (fp) == EOF || - fp->__target % fp->__bufsize == 0); - __set_errno (save); - - if (!aligned) - { - /* Move to a block (buffer size) boundary and read in a block. - Then the output will be written as a whole block, too. */ - const size_t o = fp->__target % fp->__bufsize; - fp->__target -= o; - if ((*fp->__room_funcs.__input) (fp) == EOF && ferror (fp)) - return; - else - __clearerr (fp); - - if ((size_t) (fp->__get_limit - fp->__buffer) < o) - /* Oops. We didn't read enough (probably because we got EOF). - Forget we even mentioned it. */ - fp->__target += o; - else - /* Start bufp as far into the buffer as we were into - this block before we read it. */ - buffer_offset = o; - - /* The target position is now set to where the beginning of the - buffer maps to; and the get_limit was set by the input-room - function. */ - twiddled = 1; - } - } - - if (fp->__buffer != NULL) - { - /* Set up to write output into the buffer. */ - fp->__put_limit = fp->__buffer + fp->__bufsize; - fp->__bufp = fp->__buffer + buffer_offset; - - if (!flush_only) - { - /* Put C in the buffer to be written out. - We only need to actually write it out now if - it is a newline on a line-buffered stream. */ - *fp->__bufp++ = (unsigned char) c; - if (!fp->__linebuf || (unsigned char) c != '\n') - { - /* There is no need to flush C from the buffer right now. - Record that nothing was written from the buffer, - and go do clean-up at end. */ - buffer_written = 0; - goto end; - } - else - /* We put C in the buffer, so don't write it again later. */ - flush_only = 1; - } - } - - if ((size_t) (fp->__bufp - fp->__buffer) <= buffer_offset && flush_only) - { - /* There is nothing new in the buffer, only data that - was read back aligned from the file. */ - buffer_written = 0; - goto end; - } - } - - /* If there is read data in the buffer past what was written, - write all of that as well. Otherwise, just write what has been - written into the buffer. */ - buffer_written = fp->__bufp - fp->__buffer; - to_write = (buffer_written == 0 ? 0 : - fp->__get_limit > fp->__bufp ? - fp->__get_limit - fp->__buffer : - buffer_written); - - if (fp->__io_funcs.__write == NULL || (to_write == 0 && flush_only)) - { - /* There is no writing function or we're coming from an fflush - call with nothing in the buffer, so just say the buffer's - been flushed, increment the file offset, and return. */ - fp->__bufp = fp->__buffer; - if (fp->__offset != -1) - fp->__offset += to_write; - goto end; - } - - if (to_write > 0) - { - int wrote; - - /* Go to the target file position. Don't bother if appending; - the write will just ignore the file position anyway. */ - if (!fp->__mode.__append) - seek_to_target (fp); - - if (!ferror(fp)) - { - /* Write out the buffered data. */ - wrote = (*fp->__io_funcs.__write) (fp->__cookie, fp->__buffer, - to_write); - if (wrote > 0) - { - if (fp->__mode.__append) - /* The write has written the data to the end of the file - and updated the file position to after the data. Don't - bother to find the current position; we can get it - later if we need it. */ - fp->__offset = fp->__target = -1; - else if (fp->__offset != -1) - /* Record that we've moved forward in the file. */ - fp->__offset += wrote; - } - if (wrote < (int) to_write) - /* The writing function should always write - the whole buffer unless there is an error. */ - fp->__error = 1; - } - } - - /* Reset the buffer pointer to the beginning of the buffer. */ - fp->__bufp = fp->__buffer; - - /* If we're not just flushing, write the last character, C. */ - if (!flush_only && !ferror (fp)) - { - if (fp->__buffer == NULL || (fp->__linebuf && (unsigned char) c == '\n')) - { - /* Either we're unbuffered, or we're line-buffered and - C is a newline, so really write it out immediately. */ - char cc = (unsigned char) c; - if ((*fp->__io_funcs.__write)(fp->__cookie, &cc, 1) < 1) - fp->__error = 1; - else if (fp->__offset != -1) - { - /* Record that we've moved forward in the file. */ - ++fp->__offset; - ++fp->__target; - } - } - else - /* Just put C in the buffer. */ - *fp->__bufp++ = (unsigned char) c; - } - - end: - - if (!twiddled) - { - if (fp->__target != -1) - /* The new target position moves up as - much as the user wrote into the buffer. */ - fp->__target += buffer_written; - - /* Set the reading limit to the beginning of the buffer, - so the next `getc' will call __fillbf. */ - fp->__get_limit = fp->__buffer; - } - - if (feof (fp) || ferror (fp)) - fp->__bufp = fp->__put_limit; -} - - -/* Fill the buffer for FP and return the first character read (or EOF). - This is the default `input_room' function. */ -static int -fillbuf (register FILE *fp) -{ - /* How far into the buffer we read we want to start bufp. */ - size_t buffer_offset = 0; - register char *buffer; - register size_t to_read, nread = 0; - /* This must be unsigned to avoid sign extension in return. */ - unsigned char c; - - if (fp->__io_funcs.__read == NULL) - { - /* There is no read function, so always return EOF. */ - fp->__eof = 1; - goto end; - } - - if (fp->__buffer == NULL) - { - /* We're unbuffered, so we want to read only one character. */ - buffer = (char *) &c; - to_read = 1; - } - else - { - /* We're buffered, so try to fill the buffer. */ - buffer = fp->__buffer; - to_read = fp->__bufsize; - } - - /* We're reading, so we're not at the end-of-file. */ - fp->__eof = 0; - - /* Go to the target file position. */ - { - int save = errno; - if (__stdio_check_offset (fp) == 0 && fp->__target != fp->__offset) - { - /* Move to a block (buffer size) boundary. */ - if (fp->__bufsize != 0) - { - buffer_offset = fp->__target % fp->__bufsize; - fp->__target -= buffer_offset; - } - seek_to_target (fp); - } - __set_errno (save); - } - - while (!ferror (fp) && !feof (fp) && nread <= buffer_offset) - { - /* Try to fill the buffer. */ - int count = (*fp->__io_funcs.__read) (fp->__cookie, buffer, to_read); - if (count == 0) - fp->__eof = 1; - else if (count < 0) - fp->__error = 1; - else - { - buffer += count; - nread += count; - to_read -= count; - if (fp->__offset != -1) - /* Record that we've moved forward in the file. */ - fp->__offset += count; - } - } - - if (fp->__buffer == NULL) - /* There is no buffer, so return the character we read - without all the buffer pointer diddling. */ - return (feof (fp) || ferror (fp)) ? EOF : c; - - /* Reset the buffer pointer to the beginning of the buffer - (plus whatever offset we may have set above). */ - fp->__bufp = fp->__buffer + buffer_offset; - - end:; - - if (feof (fp) || ferror (fp)) - { - /* Set both end pointers to the beginning of the buffer so - the next i/o call will force a call to __fillbf/__flshfp. */ - fp->__put_limit = fp->__get_limit = fp->__buffer; - return EOF; - } - - /* Set the end pointer to one past the last character we read. */ - fp->__get_limit = fp->__buffer + nread; - - /* Make it so the next `putc' will call __flshfp. */ - fp->__put_limit = fp->__buffer; - - /* Return the first character in the buffer. */ - return *((unsigned char *) (fp->__bufp++)); -} - - -/* Default I/O and room functions. */ - -extern __io_read_fn __stdio_read; -extern __io_write_fn __stdio_write; -extern __io_seek_fn __stdio_seek; -extern __io_close_fn __stdio_close; -extern __io_fileno_fn __stdio_fileno; -const __io_functions __default_io_functions = - { - __stdio_read, __stdio_write, __stdio_seek, __stdio_close, __stdio_fileno - }; - -const __room_functions __default_room_functions = - { - fillbuf, flushbuf - }; - - -/* Flush the buffer for FP and also write C if FLUSH_ONLY is nonzero. - This is the function used by putc and fflush. */ -int -__flshfp (fp, c) - register FILE *fp; - int c; -{ - int flush_only = c == EOF; - - if (!__validfp (fp) || !fp->__mode.__write) - { - __set_errno (EINVAL); - return EOF; - } - - if (ferror (fp)) - return EOF; - - if (fp->__pushed_back) - { - /* Discard the char pushed back by ungetc. */ - fp->__bufp = fp->__pushback_bufp; - fp->__pushed_back = 0; - } - - /* Make sure the stream is initialized (has functions and buffering). */ - init_stream (fp); - - /* Do this early, so a `putc' on such a stream will never return success. */ - if (fp->__room_funcs.__output == NULL) - { - /* A NULL `output room' function means - to always return an output error. */ - fp->__error = 1; - return EOF; - } - - if (!flush_only && - /* Will C fit into the buffer? - See below about linebuf_active. */ - fp->__bufp < (fp->__linebuf_active ? fp->__buffer + fp->__bufsize : - fp->__put_limit)) - { - /* The character will fit in the buffer, so put it there. */ - *fp->__bufp++ = (unsigned char) c; - if (fp->__linebuf && (unsigned char) c == '\n') - flush_only = 1; - else - return (unsigned char) c; - } - - if (fp->__linebuf_active) - /* This is an active line-buffered stream, so its put-limit is set - to the beginning of the buffer in order to force a __flshfp call - on each putc (see below). We undo this hack here (by setting - the limit to the end of the buffer) to simplify the interface - with the output-room function. */ - fp->__put_limit = fp->__buffer + fp->__bufsize; - - /* Make room in the buffer. */ - (*fp->__room_funcs.__output) (fp, flush_only ? EOF : (unsigned char) c); - - if (fp->__linebuf) - { - /* This is a line-buffered stream, and it is now ready to do - some output. We call this an "active line-buffered stream". - We set the put_limit to the beginning of the buffer, - so the next `putc' call will force a call to this function. - Setting the linebuf_active flag tells the code above - (on the next call) to undo this hackery. */ - fp->__put_limit = fp->__buffer; - fp->__linebuf_active = 1; - } - - if (ferror (fp)) - return EOF; - if (flush_only) - return 0; - return (unsigned char) c; -} - - -/* Fill the buffer for FP and return the first character read. - This is the function used by getc. */ -int -__fillbf (fp) - register FILE *fp; -{ - register int c; - fpos_t new_target; - - if (!__validfp (fp) || !fp->__mode.__read) - { - __set_errno (EINVAL); - return EOF; - } - - if (fp->__pushed_back) - { - /* Return the char pushed back by ungetc. */ - fp->__bufp = fp->__pushback_bufp; - fp->__pushed_back = 0; - return fp->__pushback; - } - - /* Make sure the stream is initialized (has functions and buffering). */ - init_stream (fp); - - /* If we're trying to read the first character of a new - line of input from an unbuffered or line buffered stream, - we must flush all line-buffered output streams. */ - if (fp->__buffer == NULL || fp->__linebuf) - { - register FILE *f; - for (f = __stdio_head; f != NULL; f = f->__next) - if (__validfp (f) && f->__linebuf && f->__mode.__write) - (void) __flshfp (f, EOF); - } - - /* Note we must do this after flushing all line-buffered - streams, or else __flshfp would undo it! */ - if (fp->__linebuf_active) - { - /* This is an active line-buffered stream, meaning it is in the midst - of writing, but has a bogus put_limit. Restore it to normality. */ - fp->__put_limit = fp->__buffer + fp->__bufsize; - fp->__linebuf_active = 0; - } - - /* We want the beginning of the buffer to now - map to just past the last data we read. */ - new_target = fp->__target + (fp->__get_limit - fp->__buffer); - - if (fp->__put_limit > fp->__buffer) - { - /* There is written data in the buffer. - Flush it out. */ - if (fp->__room_funcs.__output == NULL) - fp->__error = 1; - else - (*fp->__room_funcs.__output) (fp, EOF); - } - - fp->__target = new_target; - - if (ferror (fp)) - c = EOF; - else if (fp->__room_funcs.__input != NULL) - { - c = (*fp->__room_funcs.__input) (fp); - if (fp->__buffer == NULL) - /* This is an unbuffered stream, so the target sync above - won't do anything the next time around. Instead, note that - we have read one character. The (nonexistent) buffer now - maps to the position just past that character. */ - ++fp->__target; - } - else - { - /* A NULL `input_room' function means always return EOF. */ - fp->__eof = 1; - c = EOF; - } - - return c; -} - - -/* Nuke a stream, but don't kill its link in the chain. */ -void -__invalidate (stream) - register FILE *stream; -{ - /* Save its link. */ - register FILE *next = stream->__next; - - /* Pulverize the deceased. */ - memset((void *) stream, 0, sizeof(FILE)); - - /* Restore the deceased's link. */ - stream->__next = next; -} |