istream-file.c revision cd1eef2109b4476842b7757f1d69b104196d5941
/* Copyright (c) 2002-2003 Timo Sirainen */
/* @UNSAFE: whole file */
#include "lib.h"
#include "ioloop.h"
#include "istream-internal.h"
#include "network.h"
#include <time.h>
#include <unistd.h>
#include <sys/stat.h>
#define I_STREAM_MIN_SIZE 4096
struct file_istream {
struct _istream istream;
size_t max_buffer_size;
uoff_t skip_left;
unsigned int file:1;
unsigned int autoclose_fd:1;
};
static void _close(struct _iostream *stream)
{
struct file_istream *fstream = (struct file_istream *) stream;
struct _istream *_stream = (struct _istream *) stream;
if (fstream->autoclose_fd && _stream->fd != -1) {
if (close(_stream->fd) < 0)
i_error("file_istream.close() failed: %m");
}
_stream->fd = -1;
}
static void _destroy(struct _iostream *stream)
{
struct _istream *_stream = (struct _istream *) stream;
p_free(_stream->iostream.pool, _stream->w_buffer);
}
static void _set_max_buffer_size(struct _iostream *stream, size_t max_size)
{
struct file_istream *fstream = (struct file_istream *) stream;
fstream->max_buffer_size = max_size;
}
static void i_stream_grow_buffer(struct _istream *stream, size_t bytes)
{
struct file_istream *fstream = (struct file_istream *) stream;
size_t old_size;
old_size = stream->buffer_size;
stream->buffer_size = stream->pos + bytes;
if (stream->buffer_size <= I_STREAM_MIN_SIZE)
stream->buffer_size = I_STREAM_MIN_SIZE;
else {
stream->buffer_size =
pool_get_exp_grown_size(stream->iostream.pool,
old_size, stream->buffer_size);
}
if (fstream->max_buffer_size > 0 &&
stream->buffer_size > fstream->max_buffer_size)
stream->buffer_size = fstream->max_buffer_size;
stream->buffer = stream->w_buffer =
p_realloc(stream->iostream.pool, stream->w_buffer,
old_size, stream->buffer_size);
}
static void i_stream_compress(struct _istream *stream)
{
memmove(stream->w_buffer, stream->w_buffer + stream->skip,
stream->pos - stream->skip);
stream->pos -= stream->skip;
stream->skip = 0;
}
static ssize_t _read(struct _istream *stream)
{
struct file_istream *fstream = (struct file_istream *) stream;
size_t size;
ssize_t ret;
if (stream->istream.closed)
return -1;
stream->istream.stream_errno = 0;
if (stream->pos == stream->buffer_size) {
if (stream->skip > 0) {
/* remove the unused bytes from beginning of buffer */
i_stream_compress(stream);
} else if (fstream->max_buffer_size == 0 ||
stream->buffer_size < fstream->max_buffer_size) {
/* buffer is full - grow it */
i_stream_grow_buffer(stream, I_STREAM_MIN_SIZE);
}
if (stream->pos == stream->buffer_size)
return -2; /* buffer full */
}
size = stream->buffer_size - stream->pos;
ret = -1;
do {
if (fstream->file) {
ret = pread(stream->fd, stream->w_buffer + stream->pos,
size, stream->istream.v_offset +
(stream->pos - stream->skip));
} else {
ret = read(stream->fd, stream->w_buffer + stream->pos,
size);
}
} while (ret < 0 && errno == EINTR && stream->istream.blocking);
if (ret == 0) {
/* EOF */
stream->istream.eof = TRUE;
return -1;
}
if (ret < 0) {
if (errno == EINTR || errno == EAGAIN) {
i_assert(!stream->istream.blocking);
ret = 0;
} else {
stream->istream.eof = TRUE;
stream->istream.stream_errno = errno;
return -1;
}
}
if (ret > 0 && fstream->skip_left > 0) {
i_assert(!fstream->file);
i_assert(stream->skip == stream->pos);
if (fstream->skip_left >= (size_t)ret) {
fstream->skip_left -= ret;
ret = 0;
} else {
ret -= fstream->skip_left;
stream->pos += fstream->skip_left;
stream->skip += fstream->skip_left;
fstream->skip_left = 0;
}
}
stream->pos += ret;
i_assert(ret != 0 || !fstream->file);
return ret;
}
static void _seek(struct _istream *stream, uoff_t v_offset,
bool mark __attr_unused__)
{
struct file_istream *fstream = (struct file_istream *) stream;
if (!stream->istream.seekable) {
if (v_offset < stream->istream.v_offset) {
stream->istream.stream_errno = ESPIPE;
return;
}
fstream->skip_left += v_offset - stream->istream.v_offset;
}
stream->istream.stream_errno = 0;
stream->istream.v_offset = v_offset;
stream->skip = stream->pos = 0;
}
static void _sync(struct _istream *stream)
{
if (!stream->istream.seekable) {
/* can't do anything or data would be lost */
return;
}
stream->skip = stream->pos = 0;
}
static const struct stat *
_stat(struct _istream *stream, bool exact __attr_unused__)
{
struct file_istream *fstream = (struct file_istream *) stream;
if (fstream->file) {
if (fstat(fstream->istream.fd, &fstream->istream.statbuf) < 0) {
i_error("file_istream.fstat() failed: %m");
return NULL;
}
}
return &stream->statbuf;
}
struct istream *i_stream_create_file(int fd, pool_t pool,
size_t max_buffer_size, bool autoclose_fd)
{
struct file_istream *fstream;
struct stat st;
fstream = p_new(pool, struct file_istream, 1);
fstream->max_buffer_size = max_buffer_size;
fstream->autoclose_fd = autoclose_fd;
fstream->istream.iostream.close = _close;
fstream->istream.iostream.destroy = _destroy;
fstream->istream.iostream.set_max_buffer_size = _set_max_buffer_size;
fstream->istream.read = _read;
fstream->istream.seek = _seek;
fstream->istream.sync = _sync;
fstream->istream.stat = _stat;
/* if it's a file, set the flags properly */
if (fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) {
fstream->file = TRUE;
fstream->istream.istream.blocking = TRUE;
fstream->istream.istream.seekable = TRUE;
}
return _i_stream_create(&fstream->istream, pool, fd, 0);
}