freebsd-nq/contrib/apr/file_io/unix/readwrite.c
2014-05-27 07:15:14 +00:00

527 lines
15 KiB
C

/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr_arch_file_io.h"
#include "apr_strings.h"
#include "apr_thread_mutex.h"
#include "apr_support.h"
/* The only case where we don't use wait_for_io_or_timeout is on
* pre-BONE BeOS, so this check should be sufficient and simpler */
#if !defined(BEOS_R5)
#define USE_WAIT_FOR_IO
#endif
static apr_status_t file_read_buffered(apr_file_t *thefile, void *buf,
apr_size_t *nbytes)
{
apr_ssize_t rv;
char *pos = (char *)buf;
apr_uint64_t blocksize;
apr_uint64_t size = *nbytes;
if (thefile->direction == 1) {
rv = apr_file_flush_locked(thefile);
if (rv) {
return rv;
}
thefile->bufpos = 0;
thefile->direction = 0;
thefile->dataRead = 0;
}
rv = 0;
if (thefile->ungetchar != -1) {
*pos = (char)thefile->ungetchar;
++pos;
--size;
thefile->ungetchar = -1;
}
while (rv == 0 && size > 0) {
if (thefile->bufpos >= thefile->dataRead) {
int bytesread = read(thefile->filedes, thefile->buffer,
thefile->bufsize);
if (bytesread == 0) {
thefile->eof_hit = TRUE;
rv = APR_EOF;
break;
}
else if (bytesread == -1) {
rv = errno;
break;
}
thefile->dataRead = bytesread;
thefile->filePtr += thefile->dataRead;
thefile->bufpos = 0;
}
blocksize = size > thefile->dataRead - thefile->bufpos ? thefile->dataRead - thefile->bufpos : size;
memcpy(pos, thefile->buffer + thefile->bufpos, blocksize);
thefile->bufpos += blocksize;
pos += blocksize;
size -= blocksize;
}
*nbytes = pos - (char *)buf;
if (*nbytes) {
rv = 0;
}
return rv;
}
APR_DECLARE(apr_status_t) apr_file_read(apr_file_t *thefile, void *buf, apr_size_t *nbytes)
{
apr_ssize_t rv;
apr_size_t bytes_read;
if (*nbytes <= 0) {
*nbytes = 0;
return APR_SUCCESS;
}
if (thefile->buffered) {
file_lock(thefile);
rv = file_read_buffered(thefile, buf, nbytes);
file_unlock(thefile);
return rv;
}
else {
bytes_read = 0;
if (thefile->ungetchar != -1) {
bytes_read = 1;
*(char *)buf = (char)thefile->ungetchar;
buf = (char *)buf + 1;
(*nbytes)--;
thefile->ungetchar = -1;
if (*nbytes == 0) {
*nbytes = bytes_read;
return APR_SUCCESS;
}
}
do {
rv = read(thefile->filedes, buf, *nbytes);
} while (rv == -1 && errno == EINTR);
#ifdef USE_WAIT_FOR_IO
if (rv == -1 &&
(errno == EAGAIN || errno == EWOULDBLOCK) &&
thefile->timeout != 0) {
apr_status_t arv = apr_wait_for_io_or_timeout(thefile, NULL, 1);
if (arv != APR_SUCCESS) {
*nbytes = bytes_read;
return arv;
}
else {
do {
rv = read(thefile->filedes, buf, *nbytes);
} while (rv == -1 && errno == EINTR);
}
}
#endif
*nbytes = bytes_read;
if (rv == 0) {
thefile->eof_hit = TRUE;
return APR_EOF;
}
if (rv > 0) {
*nbytes += rv;
return APR_SUCCESS;
}
return errno;
}
}
APR_DECLARE(apr_status_t) apr_file_write(apr_file_t *thefile, const void *buf, apr_size_t *nbytes)
{
apr_size_t rv;
if (thefile->buffered) {
char *pos = (char *)buf;
int blocksize;
int size = *nbytes;
file_lock(thefile);
if ( thefile->direction == 0 ) {
/* Position file pointer for writing at the offset we are
* logically reading from
*/
apr_int64_t offset = thefile->filePtr - thefile->dataRead + thefile->bufpos;
if (offset != thefile->filePtr)
lseek(thefile->filedes, offset, SEEK_SET);
thefile->bufpos = thefile->dataRead = 0;
thefile->direction = 1;
}
rv = 0;
while (rv == 0 && size > 0) {
if (thefile->bufpos == thefile->bufsize) /* write buffer is full*/
rv = apr_file_flush_locked(thefile);
blocksize = size > thefile->bufsize - thefile->bufpos ?
thefile->bufsize - thefile->bufpos : size;
memcpy(thefile->buffer + thefile->bufpos, pos, blocksize);
thefile->bufpos += blocksize;
pos += blocksize;
size -= blocksize;
}
file_unlock(thefile);
return rv;
}
else {
do {
rv = write(thefile->filedes, buf, *nbytes);
} while (rv == (apr_size_t)-1 && errno == EINTR);
#ifdef USE_WAIT_FOR_IO
if (rv == (apr_size_t)-1 &&
(errno == EAGAIN || errno == EWOULDBLOCK) &&
thefile->timeout != 0) {
apr_status_t arv = apr_wait_for_io_or_timeout(thefile, NULL, 0);
if (arv != APR_SUCCESS) {
*nbytes = 0;
return arv;
}
else {
do {
do {
rv = write(thefile->filedes, buf, *nbytes);
} while (rv == (apr_size_t)-1 && errno == EINTR);
if (rv == (apr_size_t)-1 &&
(errno == EAGAIN || errno == EWOULDBLOCK)) {
*nbytes /= 2; /* yes, we'll loop if kernel lied
* and we can't even write 1 byte
*/
}
else {
break;
}
} while (1);
}
}
#endif
if (rv == (apr_size_t)-1) {
(*nbytes) = 0;
return errno;
}
*nbytes = rv;
return APR_SUCCESS;
}
}
APR_DECLARE(apr_status_t) apr_file_writev(apr_file_t *thefile, const struct iovec *vec,
apr_size_t nvec, apr_size_t *nbytes)
{
#ifdef HAVE_WRITEV
apr_status_t rv;
apr_ssize_t bytes;
if (thefile->buffered) {
file_lock(thefile);
rv = apr_file_flush_locked(thefile);
if (rv != APR_SUCCESS) {
file_unlock(thefile);
return rv;
}
if (thefile->direction == 0) {
/* Position file pointer for writing at the offset we are
* logically reading from
*/
apr_int64_t offset = thefile->filePtr - thefile->dataRead +
thefile->bufpos;
if (offset != thefile->filePtr)
lseek(thefile->filedes, offset, SEEK_SET);
thefile->bufpos = thefile->dataRead = 0;
}
file_unlock(thefile);
}
if ((bytes = writev(thefile->filedes, vec, nvec)) < 0) {
*nbytes = 0;
rv = errno;
}
else {
*nbytes = bytes;
rv = APR_SUCCESS;
}
return rv;
#else
/**
* The problem with trying to output the entire iovec is that we cannot
* maintain the behaviour that a real writev would have. If we iterate
* over the iovec one at a time, we lose the atomic properties of
* writev(). The other option is to combine the entire iovec into one
* buffer that we could then send in one call to write(). This is not
* reasonable since we do not know how much data an iovec could contain.
*
* The only reasonable option, that maintains the semantics of a real
* writev(), is to only write the first iovec. Callers of file_writev()
* must deal with partial writes as they normally would. If you want to
* ensure an entire iovec is written, use apr_file_writev_full().
*/
*nbytes = vec[0].iov_len;
return apr_file_write(thefile, vec[0].iov_base, nbytes);
#endif
}
APR_DECLARE(apr_status_t) apr_file_putc(char ch, apr_file_t *thefile)
{
apr_size_t nbytes = 1;
return apr_file_write(thefile, &ch, &nbytes);
}
APR_DECLARE(apr_status_t) apr_file_ungetc(char ch, apr_file_t *thefile)
{
thefile->ungetchar = (unsigned char)ch;
return APR_SUCCESS;
}
APR_DECLARE(apr_status_t) apr_file_getc(char *ch, apr_file_t *thefile)
{
apr_size_t nbytes = 1;
return apr_file_read(thefile, ch, &nbytes);
}
APR_DECLARE(apr_status_t) apr_file_puts(const char *str, apr_file_t *thefile)
{
return apr_file_write_full(thefile, str, strlen(str), NULL);
}
apr_status_t apr_file_flush_locked(apr_file_t *thefile)
{
apr_status_t rv = APR_SUCCESS;
if (thefile->direction == 1 && thefile->bufpos) {
apr_ssize_t written = 0, ret;
do {
ret = write(thefile->filedes, thefile->buffer + written,
thefile->bufpos - written);
if (ret > 0)
written += ret;
} while (written < thefile->bufpos &&
(ret > 0 || (ret == -1 && errno == EINTR)));
if (ret == -1) {
rv = errno;
} else {
thefile->filePtr += written;
thefile->bufpos = 0;
}
}
return rv;
}
APR_DECLARE(apr_status_t) apr_file_flush(apr_file_t *thefile)
{
apr_status_t rv = APR_SUCCESS;
if (thefile->buffered) {
file_lock(thefile);
rv = apr_file_flush_locked(thefile);
file_unlock(thefile);
}
/* There isn't anything to do if we aren't buffering the output
* so just return success.
*/
return rv;
}
APR_DECLARE(apr_status_t) apr_file_sync(apr_file_t *thefile)
{
apr_status_t rv = APR_SUCCESS;
file_lock(thefile);
if (thefile->buffered) {
rv = apr_file_flush_locked(thefile);
if (rv != APR_SUCCESS) {
file_unlock(thefile);
return rv;
}
}
if (fsync(thefile->filedes)) {
rv = apr_get_os_error();
}
file_unlock(thefile);
return rv;
}
APR_DECLARE(apr_status_t) apr_file_datasync(apr_file_t *thefile)
{
apr_status_t rv = APR_SUCCESS;
file_lock(thefile);
if (thefile->buffered) {
rv = apr_file_flush_locked(thefile);
if (rv != APR_SUCCESS) {
file_unlock(thefile);
return rv;
}
}
#ifdef HAVE_FDATASYNC
if (fdatasync(thefile->filedes)) {
#else
if (fsync(thefile->filedes)) {
#endif
rv = apr_get_os_error();
}
file_unlock(thefile);
return rv;
}
APR_DECLARE(apr_status_t) apr_file_gets(char *str, int len, apr_file_t *thefile)
{
apr_status_t rv = APR_SUCCESS; /* get rid of gcc warning */
apr_size_t nbytes;
const char *str_start = str;
char *final = str + len - 1;
if (len <= 1) {
/* sort of like fgets(), which returns NULL and stores no bytes
*/
return APR_SUCCESS;
}
/* If we have an underlying buffer, we can be *much* more efficient
* and skip over the apr_file_read calls.
*/
if (thefile->buffered) {
file_lock(thefile);
if (thefile->direction == 1) {
rv = apr_file_flush_locked(thefile);
if (rv) {
file_unlock(thefile);
return rv;
}
thefile->direction = 0;
thefile->bufpos = 0;
thefile->dataRead = 0;
}
while (str < final) { /* leave room for trailing '\0' */
/* Force ungetc leftover to call apr_file_read. */
if (thefile->bufpos < thefile->dataRead &&
thefile->ungetchar == -1) {
*str = thefile->buffer[thefile->bufpos++];
}
else {
nbytes = 1;
rv = file_read_buffered(thefile, str, &nbytes);
if (rv != APR_SUCCESS) {
break;
}
}
if (*str == '\n') {
++str;
break;
}
++str;
}
file_unlock(thefile);
}
else {
while (str < final) { /* leave room for trailing '\0' */
nbytes = 1;
rv = apr_file_read(thefile, str, &nbytes);
if (rv != APR_SUCCESS) {
break;
}
if (*str == '\n') {
++str;
break;
}
++str;
}
}
/* We must store a terminating '\0' if we've stored any chars. We can
* get away with storing it if we hit an error first.
*/
*str = '\0';
if (str > str_start) {
/* we stored chars; don't report EOF or any other errors;
* the app will find out about that on the next call
*/
return APR_SUCCESS;
}
return rv;
}
struct apr_file_printf_data {
apr_vformatter_buff_t vbuff;
apr_file_t *fptr;
char *buf;
};
static int file_printf_flush(apr_vformatter_buff_t *buff)
{
struct apr_file_printf_data *data = (struct apr_file_printf_data *)buff;
if (apr_file_write_full(data->fptr, data->buf,
data->vbuff.curpos - data->buf, NULL)) {
return -1;
}
data->vbuff.curpos = data->buf;
return 0;
}
APR_DECLARE_NONSTD(int) apr_file_printf(apr_file_t *fptr,
const char *format, ...)
{
struct apr_file_printf_data data;
va_list ap;
int count;
/* don't really need a HUGE_STRING_LEN anymore */
data.buf = malloc(HUGE_STRING_LEN);
if (data.buf == NULL) {
return -1;
}
data.vbuff.curpos = data.buf;
data.vbuff.endpos = data.buf + HUGE_STRING_LEN;
data.fptr = fptr;
va_start(ap, format);
count = apr_vformatter(file_printf_flush,
(apr_vformatter_buff_t *)&data, format, ap);
/* apr_vformatter does not call flush for the last bits */
if (count >= 0) file_printf_flush((apr_vformatter_buff_t *)&data);
va_end(ap);
free(data.buf);
return count;
}