src/lib/istream-file.c

	istream-file.c revision 7ef5ca6fb59a318c821a852ae48a2edbb671d7dd
a81d5c3f5a4ad5d100b258d10d4c75f4a02ab1f6Stephan Bosch/* Copyright (c) 2002-2003 Timo Sirainen */
a81d5c3f5a4ad5d100b258d10d4c75f4a02ab1f6Stephan Bosch
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi/* @UNSAFE: whole file */
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#include "lib.h"
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#include "ioloop.h"
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#include "istream-internal.h"
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#include "network.h"
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#include <time.h>
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#include <unistd.h>
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#include <sys/stat.h>
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi#define I_STREAM_MIN_SIZE 4096
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomistruct file_istream {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    struct _istream istream;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    uoff_t skip_left;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    unsigned int file:1;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    unsigned int autoclose_fd:1;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi};
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomistatic void _close(struct _iostream *stream)
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi{
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    struct file_istream *fstream = (struct file_istream *) stream;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    struct _istream *_stream = (struct _istream *) stream;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    if (fstream->autoclose_fd && _stream->fd != -1) {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        if (close(_stream->fd) < 0)
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi            i_error("file_istream.close() failed: %m");
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    }
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    _stream->fd = -1;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi}
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomistatic void _destroy(struct _iostream *stream)
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi{
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    struct _istream *_stream = (struct _istream *) stream;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    p_free(_stream->iostream.pool, _stream->w_buffer);
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi}
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomistatic void i_stream_compress(struct _istream *stream)
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi{
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    memmove(stream->w_buffer, stream->w_buffer + stream->skip,
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        stream->pos - stream->skip);
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    stream->pos -= stream->skip;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    stream->skip = 0;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi}
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomistatic ssize_t _read(struct _istream *stream)
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi{
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    struct file_istream *fstream = (struct file_istream *) stream;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    size_t size;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    ssize_t ret;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    if (stream->istream.closed)
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        return -1;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    stream->istream.stream_errno = 0;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    if (stream->pos == stream->buffer_size) {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        if (stream->skip > 0) {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi            /* remove the unused bytes from beginning of buffer */
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi                        i_stream_compress(stream);
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        } else if (stream->max_buffer_size == 0 ||
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi               stream->buffer_size < stream->max_buffer_size) {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi            /* buffer is full - grow it */
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi            _i_stream_grow_buffer(stream, I_STREAM_MIN_SIZE);
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        }
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        if (stream->pos == stream->buffer_size)
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi            return -2; /* buffer full */
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    }
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    size = stream->buffer_size - stream->pos;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    ret = -1;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    do {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        if (fstream->file) {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi            ret = pread(stream->fd, stream->w_buffer + stream->pos,
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi                    size, stream->istream.v_offset +
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi                    (stream->pos - stream->skip));
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        } else {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi            ret = read(stream->fd, stream->w_buffer + stream->pos,
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi                   size);
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        }
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    } while (ret < 0 && errno == EINTR && stream->istream.blocking);
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    if (ret == 0) {
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        /* EOF */
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        stream->istream.eof = TRUE;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi        return -1;
df74b8f6ff432d9a26727669dfed9a15d77efb55Aki Tuomi    }

    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->autoclose_fd = autoclose_fd;

    fstream->istream.iostream.close = _close;
    fstream->istream.iostream.destroy = _destroy;

    fstream->istream.max_buffer_size = 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);
}