istream-limit.c revision 07e4875d250e7a7157cd99132aafc773cf3cdf83
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen/* Copyright (C) 2003 Timo Sirainen */
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen#include "lib.h"
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen#include "istream-internal.h"
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainenstruct limit_istream {
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen struct _istream istream;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen struct istream *input;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen uoff_t v_start_offset, v_size;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen};
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainenstatic void _close(struct _iostream *stream __attr_unused__)
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen{
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen}
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainenstatic void _destroy(struct _iostream *stream)
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen{
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen struct limit_istream *lstream = (struct limit_istream *) stream;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen /* get to same position in parent stream */
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen i_stream_seek(lstream->input, lstream->v_start_offset +
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->istream.istream.v_offset);
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen i_stream_unref(lstream->input);
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen}
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainenstatic void _set_max_buffer_size(struct _iostream *stream, size_t max_size)
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen{
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen struct limit_istream *lstream = (struct limit_istream *) stream;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen i_stream_set_max_buffer_size(lstream->input, max_size);
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen}
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainenstatic ssize_t _read(struct _istream *stream)
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen{
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen struct limit_istream *lstream = (struct limit_istream *) stream;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen uoff_t left;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen ssize_t ret;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen size_t pos;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
601f5f14c6cde28f0e0c6ca7c5d735315d3d48dfTimo Sirainen if (stream->istream.v_offset +
859cc94211b759825db5e15b0c88754da902ca14Timo Sirainen (stream->pos - stream->skip) >= lstream->v_size) {
859cc94211b759825db5e15b0c88754da902ca14Timo Sirainen stream->istream.eof = TRUE;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen return -1;
859cc94211b759825db5e15b0c88754da902ca14Timo Sirainen }
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen if (lstream->input->v_offset !=
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->v_start_offset + stream->istream.v_offset) {
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen i_stream_seek(lstream->input,
601f5f14c6cde28f0e0c6ca7c5d735315d3d48dfTimo Sirainen lstream->v_start_offset +
601f5f14c6cde28f0e0c6ca7c5d735315d3d48dfTimo Sirainen stream->istream.v_offset);
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen }
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
42aaebd4b237403aff6bbfafdcdf52cf5f8c1c06Timo Sirainen stream->buffer = i_stream_get_data(lstream->input, &pos);
42aaebd4b237403aff6bbfafdcdf52cf5f8c1c06Timo Sirainen if (pos <= stream->pos) {
9b1d6da0f2b42b8b6f612a570a83355c2a5088eeTimo Sirainen if ((ret = i_stream_read(lstream->input)) == -2) {
42aaebd4b237403aff6bbfafdcdf52cf5f8c1c06Timo Sirainen if (stream->skip == 0)
42aaebd4b237403aff6bbfafdcdf52cf5f8c1c06Timo Sirainen return -2;
42aaebd4b237403aff6bbfafdcdf52cf5f8c1c06Timo Sirainen }
9e095dd6a77097356aca8216356d4d71ef1bea45Timo Sirainen stream->istream.eof = lstream->input->eof;
42aaebd4b237403aff6bbfafdcdf52cf5f8c1c06Timo Sirainen stream->buffer = i_stream_get_data(lstream->input, &pos);
9b1d6da0f2b42b8b6f612a570a83355c2a5088eeTimo Sirainen } else {
9b1d6da0f2b42b8b6f612a570a83355c2a5088eeTimo Sirainen ret = 0;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen }
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen stream->pos -= stream->skip;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen stream->skip = 0;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
1117aa7adc2909c750031fd7551a58a486d100d8Timo Sirainen if (lstream->v_size != (uoff_t)-1) {
1117aa7adc2909c750031fd7551a58a486d100d8Timo Sirainen left = lstream->v_size - stream->istream.v_offset;
1117aa7adc2909c750031fd7551a58a486d100d8Timo Sirainen if (pos > left)
1117aa7adc2909c750031fd7551a58a486d100d8Timo Sirainen pos = left;
1117aa7adc2909c750031fd7551a58a486d100d8Timo Sirainen }
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
9b1d6da0f2b42b8b6f612a570a83355c2a5088eeTimo Sirainen ret = pos > stream->pos ? (ssize_t)(pos - stream->pos) :
9b1d6da0f2b42b8b6f612a570a83355c2a5088eeTimo Sirainen (ret == 0 ? 0 : -1);
601f5f14c6cde28f0e0c6ca7c5d735315d3d48dfTimo Sirainen stream->pos = pos;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen return ret;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen}
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainenstatic void _seek(struct _istream *stream, uoff_t v_offset)
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen{
34ce7c45264902e217bfb5fa7f7a0aace9302074Timo Sirainen struct limit_istream *lstream = (struct limit_istream *) stream;
34ce7c45264902e217bfb5fa7f7a0aace9302074Timo Sirainen
34ce7c45264902e217bfb5fa7f7a0aace9302074Timo Sirainen i_assert(v_offset <= lstream->v_size);
34ce7c45264902e217bfb5fa7f7a0aace9302074Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen stream->istream.stream_errno = 0;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen stream->istream.v_offset = v_offset;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen stream->skip = stream->pos = 0;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen}
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainenstatic const struct stat *_stat(struct _istream *stream)
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen{
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen struct limit_istream *lstream = (struct limit_istream *) stream;
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen const struct stat *st;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen st = i_stream_stat(lstream->input);
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen if (st == NULL)
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen return NULL;
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen stream->statbuf = *st;
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen if (lstream->v_size != (uoff_t)-1)
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen stream->statbuf.st_size = lstream->v_size;
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen return &stream->statbuf;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen}
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainenstruct istream *i_stream_create_limit(pool_t pool, struct istream *input,
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen uoff_t v_start_offset, uoff_t v_size)
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen{
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen struct limit_istream *lstream;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen i_stream_ref(input);
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream = p_new(pool, struct limit_istream, 1);
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->input = input;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->v_start_offset = v_start_offset;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->v_size = v_size;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->istream.istream.v_offset =
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen input->v_offset < v_start_offset ? 0 :
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen input->v_offset - v_start_offset > v_size ? v_size :
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen input->v_offset - v_start_offset;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->istream.iostream.close = _close;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->istream.iostream.destroy = _destroy;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->istream.iostream.set_max_buffer_size = _set_max_buffer_size;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->istream.read = _read;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen lstream->istream.seek = _seek;
07e4875d250e7a7157cd99132aafc773cf3cdf83Timo Sirainen lstream->istream.stat = _stat;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen
411d6baa37f31d90730e90c4a28c43e1974bbe58Timo Sirainen lstream->istream.istream.seekable = input->seekable;
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen return _i_stream_create(&lstream->istream, pool, i_stream_get_fd(input),
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen input->real_stream->abs_start_offset +
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen v_start_offset);
dd62b77c932d1b518f2a3e4bf80e36542becc256Timo Sirainen}