src/lib/istream-limit.c

	istream-limit.c revision 61e6367a259e2473f33df42fda8ceeb3b8b48416
bcb4e51a409d94ae670de96afb8483a4f7855294Stephan Bosch/* Copyright (c) 2003-2009 Dovecot authors, see the included COPYING file */
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen#include "lib.h"
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen#include "istream-internal.h"
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen
57591c5ea045b6829ebcfed9b145d719d63f935aTimo Sirainenstruct limit_istream {
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    struct istream_private istream;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    uoff_t v_size;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen};
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainenstatic void i_stream_limit_destroy(struct iostream_private *stream)
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen{
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    struct limit_istream *lstream = (struct limit_istream *) stream;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    uoff_t v_offset;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
4ee00532a265bdfb38539d811fcd12d51210ac35Timo Sirainen    v_offset = lstream->istream.parent_start_offset +
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        lstream->istream.istream.v_offset;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    if (lstream->istream.parent->seekable ||
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        v_offset > lstream->istream.parent->v_offset) {
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen        /* get to same position in parent stream */
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        i_stream_seek(lstream->istream.parent, v_offset);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    }
ce9619645e0ec302c208690e9f9bc65037c05196Timo Sirainen    i_stream_unref(&lstream->istream.parent);
57591c5ea045b6829ebcfed9b145d719d63f935aTimo Sirainen}
ce9619645e0ec302c208690e9f9bc65037c05196Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainenstatic void
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Siraineni_stream_limit_set_max_buffer_size(struct iostream_private *stream,
4f79049854ca6a69453deb5487f2b722fdae3e35Timo Sirainen                   size_t max_size)
4f79049854ca6a69453deb5487f2b722fdae3e35Timo Sirainen{
4f79049854ca6a69453deb5487f2b722fdae3e35Timo Sirainen    struct limit_istream *lstream = (struct limit_istream *) stream;
4f79049854ca6a69453deb5487f2b722fdae3e35Timo Sirainen
4f79049854ca6a69453deb5487f2b722fdae3e35Timo Sirainen    lstream->istream.max_buffer_size = max_size;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    i_stream_set_max_buffer_size(lstream->istream.parent, max_size);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen}
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainenstatic ssize_t i_stream_limit_read(struct istream_private *stream)
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen{
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    struct limit_istream *lstream = (struct limit_istream *) stream;
5525765548dda226c3b4432228d2fb1a9c7549d9Timo Sirainen    uoff_t left;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    ssize_t ret;
efe78d3ba24fc866af1c79b9223dc0809ba26cadStephan Bosch    size_t pos;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    if (stream->istream.v_offset +
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        (stream->pos - stream->skip) >= lstream->v_size) {
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        stream->istream.eof = TRUE;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        return -1;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    }
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    if (stream->parent->v_offset !=
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        lstream->istream.parent_start_offset + stream->istream.v_offset) {
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        i_stream_seek(stream->parent,
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen                  lstream->istream.parent_start_offset +
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen                  stream->istream.v_offset);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    }
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    stream->pos -= stream->skip;
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen    stream->skip = 0;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    stream->buffer = i_stream_get_data(stream->parent, &pos);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    if (pos > stream->pos)
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        ret = 0;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    else do {
9269bbf0d2ad5491b09145458b56a3da92b67246Timo Sirainen        if ((ret = i_stream_read(stream->parent)) == -2)
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen            return -2;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        stream->istream.stream_errno = stream->parent->stream_errno;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        stream->istream.eof = stream->parent->eof;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        stream->buffer = i_stream_get_data(stream->parent, &pos);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    } while (pos <= stream->pos && ret > 0);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    if (lstream->v_size != (uoff_t)-1) {
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        left = lstream->v_size - stream->istream.v_offset;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        if (pos >= left) {
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen            pos = left;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen            stream->istream.eof = TRUE;
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen        }
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen    }
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen    ret = pos > stream->pos ? (ssize_t)(pos - stream->pos) :
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen        (ret == 0 ? 0 : -1);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    stream->pos = pos;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    i_assert(ret != -1 || stream->istream.eof ||
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen         stream->istream.stream_errno != 0);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    return ret;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen}
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainenstatic void i_stream_limit_seek(struct istream_private *stream, uoff_t v_offset,
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen                bool mark ATTR_UNUSED)
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen{
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    struct limit_istream *lstream = (struct limit_istream *) stream;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
528bfe84f996046645103de898564ef5bcb5edadTimo Sirainen    i_assert(v_offset <= lstream->v_size);
528bfe84f996046645103de898564ef5bcb5edadTimo Sirainen
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen    stream->istream.v_offset = v_offset;
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen    stream->skip = stream->pos = 0;
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen}
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen
528bfe84f996046645103de898564ef5bcb5edadTimo Sirainenstatic const struct stat *
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Siraineni_stream_limit_stat(struct istream_private *stream, bool exact)
0b9801048312b6c0d14c801545afebb02bbb74f3Timo Sirainen{
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen    struct limit_istream *lstream = (struct limit_istream *) stream;
ad456029ce2e1841f2f4ad81dbd7a6c69ebd014fTimo Sirainen    const struct stat *st;
528bfe84f996046645103de898564ef5bcb5edadTimo Sirainen
528bfe84f996046645103de898564ef5bcb5edadTimo Sirainen    st = i_stream_stat(stream->parent, exact);
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen    if (st == NULL)
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen        return NULL;
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen    stream->statbuf = *st;
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen    if (lstream->v_size != (uoff_t)-1)
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen        stream->statbuf.st_size = lstream->v_size;
3858a7a5da361c35f1e6e50c8e3214dc0cf379d6Phil Carmody    return &stream->statbuf;
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen}
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainenstatic int i_stream_limit_get_size(struct istream_private *stream,
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen                   bool exact, uoff_t *size_r)
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen{
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen    struct limit_istream *lstream = (struct limit_istream *) stream;
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen    const struct stat *st;
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen    if (lstream->v_size != (uoff_t)-1) {
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen        *size_r = lstream->v_size;
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen        return 1;
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen    }
80bc6f4feafd94bfaf3bf77e7b4038c03b81de3aTimo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    st = i_stream_stat(&stream->istream, exact);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    if (st == NULL)
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen        return -1;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    if (st->st_size == -1)
f418346521fbd7d7fc5398fcb8ddeee77aac3cd8Timo Sirainen        return 0;
f418346521fbd7d7fc5398fcb8ddeee77aac3cd8Timo Sirainen
f418346521fbd7d7fc5398fcb8ddeee77aac3cd8Timo Sirainen    *size_r = st->st_size;
f418346521fbd7d7fc5398fcb8ddeee77aac3cd8Timo Sirainen    return 1;
f418346521fbd7d7fc5398fcb8ddeee77aac3cd8Timo Sirainen}
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainenstruct istream *i_stream_create_limit(struct istream *input, uoff_t v_size)
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen{
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    struct limit_istream *lstream;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    i_stream_ref(input);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    lstream = i_new(struct limit_istream, 1);
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    lstream->v_size = v_size;
7ed711d973b319320da100d3e905ef7b99ed69d6Timo Sirainen    lstream->istream.max_buffer_size = input->real_stream->max_buffer_size;
09304bdc1e5e416aa343802732a15064f49495ccTimo Sirainen
09304bdc1e5e416aa343802732a15064f49495ccTimo Sirainen    lstream->istream.iostream.destroy = i_stream_limit_destroy;
09304bdc1e5e416aa343802732a15064f49495ccTimo Sirainen    lstream->istream.iostream.set_max_buffer_size =
09304bdc1e5e416aa343802732a15064f49495ccTimo Sirainen        i_stream_limit_set_max_buffer_size;
57591c5ea045b6829ebcfed9b145d719d63f935aTimo Sirainen
57591c5ea045b6829ebcfed9b145d719d63f935aTimo Sirainen    lstream->istream.parent = input;
09304bdc1e5e416aa343802732a15064f49495ccTimo Sirainen    lstream->istream.read = i_stream_limit_read;
09304bdc1e5e416aa343802732a15064f49495ccTimo Sirainen    lstream->istream.seek = i_stream_limit_seek;
71df09024cea5f2faa93da3bb9513ee96ba6bf22Timo Sirainen    lstream->istream.stat = i_stream_limit_stat;
71df09024cea5f2faa93da3bb9513ee96ba6bf22Timo Sirainen    lstream->istream.get_size = i_stream_limit_get_size;
71df09024cea5f2faa93da3bb9513ee96ba6bf22Timo Sirainen
71df09024cea5f2faa93da3bb9513ee96ba6bf22Timo Sirainen    lstream->istream.istream.blocking = input->blocking;
66fff40a31842c0d9cdbf0a6037655f089735f8fTimo Sirainen    lstream->istream.istream.seekable = input->seekable;
66fff40a31842c0d9cdbf0a6037655f089735f8fTimo Sirainen    return i_stream_create(&lstream->istream, input,
66fff40a31842c0d9cdbf0a6037655f089735f8fTimo Sirainen                   i_stream_get_fd(input));
66fff40a31842c0d9cdbf0a6037655f089735f8fTimo Sirainen}
71df09024cea5f2faa93da3bb9513ee96ba6bf22Timo Sirainen