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/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "hash-method.h"
#include "istream-private.h"
#include "istream-hash.h"
struct hash_istream {
struct istream_private istream;
const struct hash_method *method;
void *hash_context;
uoff_t high_offset;
};
static ssize_t
i_stream_hash_read(struct istream_private *stream)
{
struct hash_istream *hstream =
container_of(stream, struct hash_istream, istream);
const unsigned char *data;
size_t size;
uoff_t skip;
ssize_t ret;
i_stream_seek(stream->parent, stream->parent_start_offset +
stream->istream.v_offset);
ret = i_stream_read_copy_from_parent(&stream->istream);
if (ret > 0 && hstream->hash_context != NULL) {
data = i_stream_get_data(&stream->istream, &size);
i_assert((size_t)ret <= size);
i_assert(stream->istream.v_offset <= hstream->high_offset);
skip = hstream->high_offset - stream->istream.v_offset;
if (skip < (size_t)size) {
hstream->high_offset += (size-skip);
hstream->method->loop(hstream->hash_context,
data+skip, size-skip);
}
} else if (ret < 0) {
/* we finished hashing it. don't access it anymore, because
the memory pointed by the hash may be freed before the
istream itself */
hstream->hash_context = NULL;
}
return ret;
}
static void
i_stream_hash_seek(struct istream_private *stream,
uoff_t v_offset, bool mark ATTR_UNUSED)
{
struct hash_istream *hstream =
container_of(stream, struct hash_istream, istream);
if (hstream->hash_context != NULL) {
io_stream_set_error(&stream->iostream,
"Seeking not supported before hashing is finished");
stream->istream.stream_errno = ESPIPE;
}
stream->istream.v_offset = v_offset;
stream->skip = stream->pos = 0;
}
struct istream *
i_stream_create_hash(struct istream *input, const struct hash_method *method,
void *hash_context)
{
struct hash_istream *hstream;
hstream = i_new(struct hash_istream, 1);
hstream->istream.max_buffer_size = input->real_stream->max_buffer_size;
hstream->istream.stream_size_passthrough = TRUE;
hstream->istream.read = i_stream_hash_read;
hstream->istream.seek = i_stream_hash_seek;
hstream->istream.istream.readable_fd = input->readable_fd;
hstream->istream.istream.blocking = input->blocking;
hstream->istream.istream.seekable = input->seekable;
hstream->method = method;
hstream->hash_context = hash_context;
return i_stream_create(&hstream->istream, input,
i_stream_get_fd(input), 0);
}
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