src/lib/ostream.c

	ostream.c revision 9a48c2243fe98ca8393be7908f84d20c634bcdf9
/* Copyright (c) 2002-2013 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "istream.h"
#include "ostream-private.h"

void o_stream_set_name(struct ostream *stream, const char *name)
{
    i_free(stream->real_stream->iostream.name);
    stream->real_stream->iostream.name = i_strdup(name);
}

const char *o_stream_get_name(struct ostream *stream)
{
    while (stream->real_stream->iostream.name == NULL) {
        stream = stream->real_stream->parent;
        if (stream == NULL)
            return "";
    }
    return stream->real_stream->iostream.name;
}

int o_stream_get_fd(struct ostream *stream)
{
    return stream->real_stream->fd;
}

const char *o_stream_get_error(struct ostream *stream)
{
    struct ostream *s;

    /* we'll only return errors for streams that have stream_errno set.
       we might be returning unintended error otherwise. */
    if (stream->stream_errno == 0)
        return "<no error>";

    for (s = stream; s != NULL; s = s->real_stream->parent) {
        if (s->stream_errno == 0)
            break;
        if (s->real_stream->iostream.error != NULL)
            return s->real_stream->iostream.error;
    }
    return strerror(stream->stream_errno);
}

static void o_stream_close_full(struct ostream *stream, bool close_parents)
{
    if (!stream->closed && !stream->real_stream->closing) {
        /* first mark the stream as being closed so the
           o_stream_copy_error_from_parent() won't recurse us back
           here. but don't immediately mark the stream closed, because
           we may still want to write something to it. */
        stream->real_stream->closing = TRUE;
        io_stream_close(&stream->real_stream->iostream, close_parents);
        stream->closed = TRUE;
    }

    if (stream->stream_errno == 0)
        stream->stream_errno = EPIPE;
}

void o_stream_destroy(struct ostream **stream)
{
    o_stream_close_full(*stream, FALSE);
    o_stream_unref(stream);
}

void o_stream_ref(struct ostream *stream)
{
    io_stream_ref(&stream->real_stream->iostream);
}

void o_stream_unref(struct ostream **_stream)
{
    struct ostream *stream = *_stream;

    if (stream->real_stream->last_errors_not_checked &&
        !stream->real_stream->error_handling_disabled &&
        stream->real_stream->iostream.refcount == 1) {
        i_panic("output stream %s is missing error handling",
            o_stream_get_name(stream));
    }

    io_stream_unref(&stream->real_stream->iostream);
    *_stream = NULL;
}

void o_stream_close(struct ostream *stream)
{
    o_stream_close_full(stream, TRUE);
}

#undef o_stream_set_flush_callback
void o_stream_set_flush_callback(struct ostream *stream,
                 stream_flush_callback_t *callback,
                 void *context)
{
    struct ostream_private *_stream = stream->real_stream;

    _stream->set_flush_callback(_stream, callback, context);
}

void o_stream_unset_flush_callback(struct ostream *stream)
{
    struct ostream_private *_stream = stream->real_stream;

    _stream->set_flush_callback(_stream, NULL, NULL);
}

void o_stream_set_max_buffer_size(struct ostream *stream, size_t max_size)
{
    io_stream_set_max_buffer_size(&stream->real_stream->iostream, max_size);
}

void o_stream_cork(struct ostream *stream)
{
    struct ostream_private *_stream = stream->real_stream;

    if (unlikely(stream->closed))
        return;

    _stream->cork(_stream, TRUE);
}

void o_stream_uncork(struct ostream *stream)
{
    struct ostream_private *_stream = stream->real_stream;

    if (unlikely(stream->closed))
        return;

    _stream->cork(_stream, FALSE);
}

static void o_stream_clear_error(struct ostream *stream)
{
    stream->stream_errno = 0;
    i_free_and_null(stream->real_stream->iostream.error);
}

int o_stream_flush(struct ostream *stream)
{
    struct ostream_private *_stream = stream->real_stream;
    int ret = 1;

    if (unlikely(stream->closed)) {
        errno = stream->stream_errno;
        return -1;
    }

    o_stream_clear_error(stream);
    if (unlikely((ret = _stream->flush(_stream)) < 0)) {
        i_assert(stream->stream_errno != 0);
        stream->last_failed_errno = stream->stream_errno;
        errno = stream->stream_errno;
    }
    return ret;
}

void o_stream_set_flush_pending(struct ostream *stream, bool set)
{
    struct ostream_private *_stream = stream->real_stream;

    if (unlikely(stream->closed))
        return;

    _stream->flush_pending(_stream, set);
}

size_t o_stream_get_buffer_used_size(const struct ostream *stream)
{
    const struct ostream_private *_stream = stream->real_stream;

    return _stream->get_used_size(_stream);
}

size_t o_stream_get_buffer_avail_size(const struct ostream *stream)
{
    size_t used = o_stream_get_buffer_used_size(stream);

    return stream->real_stream->max_buffer_size <= used ? 0 :
        stream->real_stream->max_buffer_size - used;
}

int o_stream_seek(struct ostream *stream, uoff_t offset)
{
    struct ostream_private *_stream = stream->real_stream;

    if (unlikely(stream->closed)) {
        errno = stream->stream_errno;
        return -1;
    }

    o_stream_clear_error(stream);
    if (unlikely(_stream->seek(_stream, offset) < 0)) {
        i_assert(stream->stream_errno != 0);
        stream->last_failed_errno = stream->stream_errno;
        errno = stream->stream_errno;
        return -1;
    }
    return 1;
}

ssize_t o_stream_send(struct ostream *stream, const void *data, size_t size)
{
    struct const_iovec iov;

    memset(&iov, 0, sizeof(iov));
    iov.iov_base = data;
    iov.iov_len = size;

    return o_stream_sendv(stream, &iov, 1);
}

ssize_t o_stream_sendv(struct ostream *stream, const struct const_iovec *iov,
               unsigned int iov_count)
{
    struct ostream_private *_stream = stream->real_stream;
    unsigned int i;
    size_t total_size;
    ssize_t ret;

    if (unlikely(stream->closed)) {
        errno = stream->stream_errno;
        return -1;
    }

    o_stream_clear_error(stream);
    for (i = 0, total_size = 0; i < iov_count; i++)
        total_size += iov[i].iov_len;
    if (total_size == 0)
        return 0;

    ret = _stream->sendv(_stream, iov, iov_count);
    if (unlikely(ret != (ssize_t)total_size)) {
        if (ret < 0) {
            i_assert(stream->stream_errno != 0);
            stream->last_failed_errno = stream->stream_errno;
            errno = stream->stream_errno;
        } else {
            stream->overflow = TRUE;
        }
    }
    return ret;
}

ssize_t o_stream_send_str(struct ostream *stream, const char *str)
{
    return o_stream_send(stream, str, strlen(str));
}

void o_stream_nsend(struct ostream *stream, const void *data, size_t size)
{
    struct const_iovec iov;

    memset(&iov, 0, sizeof(iov));
    iov.iov_base = data;
    iov.iov_len = size;

    o_stream_nsendv(stream, &iov, 1);
}

void o_stream_nsendv(struct ostream *stream, const struct const_iovec *iov,
             unsigned int iov_count)
{
    if (unlikely(stream->closed))
        return;
    (void)o_stream_sendv(stream, iov, iov_count);
    stream->real_stream->last_errors_not_checked = TRUE;
}

void o_stream_nsend_str(struct ostream *stream, const char *str)
{
    o_stream_nsend(stream, str, strlen(str));
}

void o_stream_nflush(struct ostream *stream)
{
    if (unlikely(stream->closed))
        return;
    (void)o_stream_flush(stream);
    stream->real_stream->last_errors_not_checked = TRUE;
}

int o_stream_nfinish(struct ostream *stream)
{
    o_stream_nflush(stream);
    o_stream_ignore_last_errors(stream);
    errno = stream->last_failed_errno;
    return stream->last_failed_errno != 0 ? -1 : 0;
}

void o_stream_ignore_last_errors(struct ostream *stream)
{
    while (stream != NULL) {
        stream->real_stream->last_errors_not_checked = FALSE;
        stream = stream->real_stream->parent;
    }
}

void o_stream_set_no_error_handling(struct ostream *stream, bool set)
{
    stream->real_stream->error_handling_disabled = set;
}

off_t o_stream_send_istream(struct ostream *outstream,
                struct istream *instream)
{
    struct ostream_private *_outstream = outstream->real_stream;
    off_t ret;

    if (unlikely(outstream->closed || instream->closed)) {
        errno = outstream->stream_errno;
        return -1;
    }

    o_stream_clear_error(outstream);
    ret = _outstream->send_istream(_outstream, instream);
    if (unlikely(ret < 0)) {
        i_assert(outstream->stream_errno != 0);
        outstream->last_failed_errno = outstream->stream_errno;
        errno = outstream->stream_errno;
    }
    return ret;
}

int o_stream_pwrite(struct ostream *stream, const void *data, size_t size,
            uoff_t offset)
{
    int ret;

    if (unlikely(stream->closed)) {
        errno = stream->stream_errno;
        return -1;
    }

    o_stream_clear_error(stream);
    ret = stream->real_stream->write_at(stream->real_stream,
                        data, size, offset);
    if (unlikely(ret < 0)) {
        i_assert(stream->stream_errno != 0);
        stream->last_failed_errno = stream->stream_errno;
        errno = stream->stream_errno;
    }
    return ret;
}

off_t io_stream_copy(struct ostream *outstream, struct istream *instream,
             size_t block_size)
{
    uoff_t start_offset;
    struct const_iovec iov;
    const unsigned char *data;
    ssize_t ret;

    start_offset = instream->v_offset;
    for (;;) {
        (void)i_stream_read_data(instream, &data, &iov.iov_len,
                     block_size-1);
        if (iov.iov_len == 0) {
            /* all sent */
            break;
        }

        iov.iov_base = data;
        ret = o_stream_sendv(outstream, &iov, 1);
        if (ret <= 0) {
            if (ret == 0)
                break;
            return -1;
        }
        i_stream_skip(instream, ret);

        if ((size_t)ret != iov.iov_len)
            break;
    }

    return (off_t)(instream->v_offset - start_offset);
}

void o_stream_switch_ioloop(struct ostream *stream)
{
    struct ostream_private *_stream = stream->real_stream;

    _stream->switch_ioloop(_stream);
}

static void o_stream_default_close(struct iostream_private *stream,
                   bool close_parent)
{
    struct ostream_private *_stream = (struct ostream_private *)stream;

    (void)o_stream_flush(&_stream->ostream);
    if (close_parent && _stream->parent != NULL)
        o_stream_close(_stream->parent);
}

static void o_stream_default_destroy(struct iostream_private *stream)
{
    struct ostream_private *_stream = (struct ostream_private *)stream;

    if (_stream->parent != NULL)
        o_stream_unref(&_stream->parent);
}

static void
o_stream_default_set_max_buffer_size(struct iostream_private *stream,
                     size_t max_size)
{
    struct ostream_private *_stream = (struct ostream_private *)stream;

    if (_stream->parent != NULL)
        o_stream_set_max_buffer_size(_stream->parent, max_size);
    _stream->max_buffer_size = max_size;
}

static void o_stream_default_cork(struct ostream_private *_stream, bool set)
{
    _stream->corked = set;
    if (set) {
        if (_stream->parent != NULL)
            o_stream_cork(_stream->parent);
    } else {
        (void)o_stream_flush(&_stream->ostream);
        if (_stream->parent != NULL)
            o_stream_uncork(_stream->parent);
    }
}

void o_stream_copy_error_from_parent(struct ostream_private *_stream)
{
    struct ostream *src = _stream->parent;
    struct ostream *dest = &_stream->ostream;

    dest->stream_errno = src->stream_errno;
    dest->last_failed_errno = src->last_failed_errno;
    dest->overflow = src->overflow;
    if (src->closed)
        o_stream_close(dest);
}

static int o_stream_default_flush(struct ostream_private *_stream)
{
    int ret;

    if (_stream->parent == NULL)
        return 1;

    if ((ret = o_stream_flush(_stream->parent)) < 0)
        o_stream_copy_error_from_parent(_stream);
    return ret;
}

static void
o_stream_default_set_flush_callback(struct ostream_private *_stream,
                    stream_flush_callback_t *callback,
                    void *context)
{
    if (_stream->parent != NULL)
        o_stream_set_flush_callback(_stream->parent, callback, context);

    _stream->callback = callback;
    _stream->context = context;
}

static void
o_stream_default_set_flush_pending(struct ostream_private *_stream, bool set)
{
    if (_stream->parent != NULL)
        o_stream_set_flush_pending(_stream->parent, set);
}

static size_t
o_stream_default_get_used_size(const struct ostream_private *_stream)
{
    if (_stream->parent == NULL)
        return 0;
    else
        return o_stream_get_buffer_used_size(_stream->parent);
}

static int
o_stream_default_seek(struct ostream_private *_stream,
              uoff_t offset ATTR_UNUSED)
{
    _stream->ostream.stream_errno = ESPIPE;
    return -1;
}

static int
o_stream_default_write_at(struct ostream_private *_stream,
              const void *data ATTR_UNUSED,
              size_t size ATTR_UNUSED, uoff_t offset ATTR_UNUSED)
{
    _stream->ostream.stream_errno = ESPIPE;
    return -1;
}

static off_t o_stream_default_send_istream(struct ostream_private *outstream,
                       struct istream *instream)
{
    return io_stream_copy(&outstream->ostream, instream, IO_BLOCK_SIZE);
}

static void o_stream_default_switch_ioloop(struct ostream_private *_stream)
{
    if (_stream->parent != NULL)
        o_stream_switch_ioloop(_stream->parent);
}

struct ostream *
o_stream_create(struct ostream_private *_stream, struct ostream *parent, int fd)
{
    _stream->fd = fd;
    _stream->ostream.real_stream = _stream;
    if (parent != NULL) {
        _stream->parent = parent;
        o_stream_ref(parent);

        _stream->callback = parent->real_stream->callback;
        _stream->context = parent->real_stream->context;
        _stream->max_buffer_size = parent->real_stream->max_buffer_size;
        _stream->error_handling_disabled =
            parent->real_stream->error_handling_disabled;
    }

    if (_stream->iostream.close == NULL)
        _stream->iostream.close = o_stream_default_close;
    if (_stream->iostream.destroy == NULL)
        _stream->iostream.destroy = o_stream_default_destroy;
    if (_stream->iostream.set_max_buffer_size == NULL) {
        _stream->iostream.set_max_buffer_size =
            o_stream_default_set_max_buffer_size;
    }

    if (_stream->cork == NULL)
        _stream->cork = o_stream_default_cork;
    if (_stream->flush == NULL)
        _stream->flush = o_stream_default_flush;
    if (_stream->set_flush_callback == NULL) {
        _stream->set_flush_callback =
            o_stream_default_set_flush_callback;
    }
    if (_stream->flush_pending == NULL)
        _stream->flush_pending = o_stream_default_set_flush_pending;
    if (_stream->get_used_size == NULL)
        _stream->get_used_size = o_stream_default_get_used_size;
    if (_stream->seek == NULL)
        _stream->seek = o_stream_default_seek;
    if (_stream->write_at == NULL)
        _stream->write_at = o_stream_default_write_at;
    if (_stream->send_istream == NULL)
        _stream->send_istream = o_stream_default_send_istream;
    if (_stream->switch_ioloop == NULL)
        _stream->switch_ioloop = o_stream_default_switch_ioloop;

    io_stream_init(&_stream->iostream);
    return &_stream->ostream;
}

struct ostream *o_stream_create_error(int stream_errno)
{
    struct ostream_private *stream;
    struct ostream *output;

    stream = i_new(struct ostream_private, 1);
    stream->ostream.closed = TRUE;
    stream->ostream.stream_errno = stream_errno;
    stream->ostream.last_failed_errno = stream_errno;

    output = o_stream_create(stream, NULL, -1);
    o_stream_set_no_error_handling(output, TRUE);
    o_stream_set_name(output, "(error)");
    return output;
}

struct ostream *
o_stream_create_error_str(int stream_errno, const char *fmt, ...)
{
    struct ostream *output;
    va_list args;

    va_start(args, fmt);
    output = o_stream_create_error(stream_errno);
    io_stream_set_verror(&output->real_stream->iostream, fmt, args);
    va_end(args);
    return output;
}