src/lib/istream.c

	istream.c revision 7e1f68ad71d3485f1882142837b01f7a98ca8467
/* Copyright (c) 2002-2003 Timo Sirainen */

#include "lib.h"
#include "istream-internal.h"

void i_stream_ref(struct istream *stream)
{
    _io_stream_ref(&stream->real_stream->iostream);
}

void i_stream_unref(struct istream *stream)
{
    _io_stream_unref(&stream->real_stream->iostream);
}

int i_stream_get_fd(struct istream *stream)
{
    struct _istream *_stream = stream->real_stream;

    return _stream->fd;
}

void i_stream_close(struct istream *stream)
{
    _io_stream_close(&stream->real_stream->iostream);
    stream->closed = TRUE;
}

void i_stream_set_max_buffer_size(struct istream *stream, size_t max_size)
{
    _io_stream_set_max_buffer_size(&stream->real_stream->iostream,
                       max_size);
}

ssize_t i_stream_read(struct istream *stream)
{
    struct _istream *_stream = stream->real_stream;

    if (stream->closed)
        return -1;

    stream->eof = FALSE;
    return _stream->read(_stream);
}

void i_stream_skip(struct istream *stream, uoff_t count)
{
    struct _istream *_stream = stream->real_stream;
    size_t data_size;

    data_size = _stream->pos - _stream->skip;
    if (count <= data_size) {
        /* within buffer */
        stream->v_offset += count;
        _stream->skip += count;
        return;
    }

    /* have to seek forward */
    count -= data_size;
    _stream->skip = _stream->pos;
    stream->v_offset += data_size;

    if (stream->closed)
        return;

    _stream->seek(_stream, stream->v_offset + count);
}

void i_stream_seek(struct istream *stream, uoff_t v_offset)
{
    struct _istream *_stream = stream->real_stream;

    if (v_offset >= stream->v_offset) {
        i_stream_skip(stream, v_offset - stream->v_offset);
        return;
    }

    if (stream->closed)
        return;

    stream->eof = FALSE;
    _stream->seek(_stream, v_offset);
}

uoff_t i_stream_get_size(struct istream *stream)
{
    struct _istream *_stream = stream->real_stream;

    return _stream->get_size(_stream);
}

int i_stream_have_bytes_left(struct istream *stream)
{
    struct _istream *_stream = stream->real_stream;

    return !stream->eof || _stream->skip != _stream->pos;
}

char *i_stream_next_line(struct istream *stream)
{
    struct _istream *_stream = stream->real_stream;
    char *ret_buf;
        size_t i;

        i_assert(stream != NULL);

    if (_stream->skip >= _stream->pos) {
        stream->stream_errno = 0;
        return NULL;
    }

    if (_stream->w_buffer == NULL) {
        i_error("i_stream_next_line() called for unmodifyable stream");
        return NULL;
    }

    /* @UNSAFE */
    ret_buf = NULL;
    for (i = _stream->skip; i < _stream->pos; i++) {
        if (_stream->buffer[i] == 10) {
            /* got it */
            if (i > 0 && _stream->buffer[i-1] == '\r')
                _stream->w_buffer[i-1] = '\0';
            else
                _stream->w_buffer[i] = '\0';
            ret_buf = (char *) _stream->w_buffer + _stream->skip;

            i++;
            stream->v_offset += i - _stream->skip;
            _stream->skip = i;
                        break;
        }
    }

        return ret_buf;
}

char *i_stream_read_next_line(struct istream *stream)
{
    char *line;

    line = i_stream_next_line(stream);
    if (line != NULL)
        return line;

    if (i_stream_read(stream) > 0)
        line = i_stream_next_line(stream);
    return line;
}

const unsigned char *i_stream_get_data(struct istream *stream, size_t *size)
{
    struct _istream *_stream = stream->real_stream;

    if (_stream->skip >= _stream->pos) {
        *size = 0;
        return NULL;
    }

        *size = _stream->pos - _stream->skip;
        return _stream->buffer + _stream->skip;
}

unsigned char *i_stream_get_modifyable_data(struct istream *stream,
                        size_t *size)
{
    struct _istream *_stream = stream->real_stream;

    if (_stream->skip >= _stream->pos || _stream->w_buffer == NULL) {
        *size = 0;
        return NULL;
    }

        *size = _stream->pos - _stream->skip;
        return _stream->w_buffer + _stream->skip;
}

int i_stream_read_data(struct istream *stream, const unsigned char **data,
               size_t *size, size_t threshold)
{
    ssize_t ret = 0;
    int read_more = FALSE;

    do {
        *data = i_stream_get_data(stream, size);
        if (*size > threshold)
            return 1;

        /* we need more data */
        ret = i_stream_read(stream);
        if (ret > 0)
            read_more = TRUE;
    } while (ret > 0);

    *data = i_stream_get_data(stream, size);
    return ret == -2 ? -2 :
        (read_more || ret == 0 ? 0 : -1);
}

struct istream *_i_stream_create(struct _istream *_stream, pool_t pool, int fd,
                 uoff_t abs_start_offset)
{
    _stream->fd = fd;
    _stream->abs_start_offset = abs_start_offset;
    _stream->istream.real_stream = _stream;

    _io_stream_init(pool, &_stream->iostream);
    return &_stream->istream;
}

#ifdef STREAM_TEST
/* gcc istream.c -o teststream liblib.a -Wall -DHAVE_CONFIG_H -DSTREAM_TEST -g */

#include <fcntl.h>
#include <unistd.h>
#include "ostream.h"

#define BUF_VALUE(offset) \
        (((offset) % 256) ^ ((offset) / 256))

static void check_buffer(const unsigned char *data, size_t size, size_t offset)
{
    size_t i;

    for (i = 0; i < size; i++)
        i_assert(data[i] == BUF_VALUE(i+offset));
}

int main(void)
{
    struct istream *input, *l_input;
    struct ostream *output1, *output2;
    int i, fd1, fd2;
    unsigned char buf[1024];
    const unsigned char *data;
    size_t size;

    lib_init();

    fd1 = open("teststream.1", O_RDWR | O_CREAT | O_TRUNC, 0600);
    if (fd1 < 0)
        i_fatal("open() failed: %m");
    fd2 = open("teststream.2", O_RDWR | O_CREAT | O_TRUNC, 0600);
    if (fd2 < 0)
        i_fatal("open() failed: %m");

    /* write initial data */
    for (i = 0; i < sizeof(buf); i++)
        buf[i] = BUF_VALUE(i);
    write(fd1, buf, sizeof(buf));

    /* test reading */
    input = i_stream_create_file(fd1, default_pool, 512, FALSE);
    i_assert(i_stream_get_size(input) == sizeof(buf));

    i_assert(i_stream_read_data(input, &data, &size, 0) > 0);
    i_assert(size == 512);
    check_buffer(data, size, 0);

    i_stream_seek(input, 256);
    i_assert(i_stream_read_data(input, &data, &size, 0) > 0);
    i_assert(size == 512);
    check_buffer(data, size, 256);

    i_stream_seek(input, 0);
    i_assert(i_stream_read_data(input, &data, &size, 512) == -2);
    i_assert(size == 512);
    check_buffer(data, size, 0);

    i_stream_skip(input, 900);
    i_assert(i_stream_read_data(input, &data, &size, 0) > 0);
    i_assert(size == sizeof(buf) - 900);
    check_buffer(data, size, 900);

    /* test moving data */
    output1 = o_stream_create_file(fd1, default_pool, 512, FALSE);
    output2 = o_stream_create_file(fd2, default_pool, 512, FALSE);

    i_stream_seek(input, 1); size = sizeof(buf)-1;
    i_assert(o_stream_send_istream(output2, input) == size);
    o_stream_flush(output2);

    lseek(fd2, 0, SEEK_SET);
    i_assert(read(fd2, buf, sizeof(buf)) == size);
    check_buffer(buf, size, 1);

    i_stream_seek(input, 0);
    o_stream_seek(output1, sizeof(buf));
    i_assert(o_stream_send_istream(output1, input) == sizeof(buf));

    /* test moving with limits */
    l_input = i_stream_create_limit(default_pool, input,
                    sizeof(buf)/2, 512);
    i_stream_seek(l_input, 0);
    o_stream_seek(output1, 10);
    i_assert(o_stream_send_istream(output1, l_input) == 512);

    i_stream_set_max_buffer_size(input, sizeof(buf));

    i_stream_seek(input, 0);
    i_assert(i_stream_read_data(input, &data, &size, sizeof(buf)-1) > 0);
    i_assert(size == sizeof(buf));
    check_buffer(data, 10, 0);
    check_buffer(data + 10, 512, sizeof(buf)/2);
    check_buffer(data + 10 + 512,
             size - (10 + 512), 10 + 512);

    /* reading within limits */
    i_stream_seek(l_input, 0);
    i_assert(i_stream_read_data(l_input, &data, &size, 511) > 0);
    i_assert(size == 512);
    i_assert(i_stream_read_data(l_input, &data, &size, 512) == -2);
    i_assert(size == 512);
    i_stream_skip(l_input, 511);
    i_assert(i_stream_read_data(l_input, &data, &size, 0) > 0);
    i_assert(size == 1);
    i_stream_skip(l_input, 1);
    i_assert(i_stream_read_data(l_input, &data, &size, 0) == -1);
    i_assert(size == 0);

    unlink("teststream.1");
    unlink("teststream.2");
    return 0;
}
#endif