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Updated auto decoder to handle LZMA_CONCATENATED when decoding

LZMA_Alone files. Decoding of concatenated LZMA_Alone files is
intentionally not supported, so it is better to put this in
auto decoder than LZMA_Alone decoder.
This commit is contained in:
Lasse Collin 2008-09-02 19:12:12 +03:00
parent 80c4158f19
commit 689602336d

View file

@ -22,10 +22,17 @@
struct lzma_coder_s {
/// Stream decoder or LZMA_Alone decoder
lzma_next_coder next;
uint64_t memlimit;
uint32_t flags;
bool initialized;
enum {
SEQ_INIT,
SEQ_CODE,
SEQ_FINISH,
} sequence;
};
@ -35,28 +42,67 @@ auto_decode(lzma_coder *coder, lzma_allocator *allocator,
size_t in_size, uint8_t *restrict out,
size_t *restrict out_pos, size_t out_size, lzma_action action)
{
if (!coder->initialized) {
switch (coder->sequence) {
case SEQ_INIT:
if (*in_pos >= in_size)
return LZMA_OK;
lzma_ret ret;
// Update the sequence now, because we want to continue from
// SEQ_CODE even if we return some LZMA_*_CHECK.
coder->sequence = SEQ_CODE;
if (in[*in_pos] == 0xFF)
ret = lzma_stream_decoder_init(
// Detect the file format. For now this is simple, since if
// it doesn't start with 0xFF (the first magic byte of the
// new format), it has to be LZMA_Alone, or something that
// we don't support at all.
if (in[*in_pos] == 0xFF) {
return_if_error(lzma_stream_decoder_init(
&coder->next, allocator,
coder->memlimit, coder->flags);
else
ret = lzma_alone_decoder_init(&coder->next,
allocator, coder->memlimit);
coder->memlimit, coder->flags));
} else {
return_if_error(lzma_alone_decoder_init(&coder->next,
allocator, coder->memlimit));
if (ret != LZMA_OK)
// If the application wants a warning about missing
// integrity check or about the check in general, we
// need to handle it here, because LZMA_Alone decoder
// doesn't accept any flags.
if (coder->flags & LZMA_WARN_NO_CHECK)
return LZMA_NO_CHECK;
if (coder->flags & LZMA_TELL_CHECK)
return LZMA_SEE_CHECK;
}
// Fall through
case SEQ_CODE: {
const lzma_ret ret = coder->next.code(
coder->next.coder, allocator,
in, in_pos, in_size,
out, out_pos, out_size, action);
if (ret != LZMA_STREAM_END
|| (coder->flags & LZMA_CONCATENATED) == 0)
return ret;
coder->initialized = true;
coder->sequence = SEQ_FINISH;
// Fall through
case SEQ_FINISH:
// When LZMA_DECODE_CONCATENATED was used and we were decoding
// LZMA_Alone file, we need to check check that there is no
// trailing garbage and wait for LZMA_FINISH.
if (*in_pos < in_size)
return LZMA_DATA_ERROR;
return action == LZMA_FINISH ? LZMA_STREAM_END : LZMA_OK;
}
return coder->next.code(coder->next.coder, allocator,
in, in_pos, in_size, out, out_pos, out_size, action);
default:
assert(0);
return LZMA_PROG_ERROR;
}
}
@ -69,6 +115,15 @@ auto_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
}
static lzma_check
auto_decoder_see_check(const lzma_coder *coder)
{
// It is LZMA_Alone if see_check is NULL.
return coder->next.see_check == NULL ? LZMA_CHECK_NONE
: coder->next.see_check(coder->next.coder);
}
static lzma_ret
auto_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
uint64_t memlimit, uint32_t flags)
@ -85,12 +140,13 @@ auto_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
next->code = &auto_decode;
next->end = &auto_decoder_end;
next->see_check = &auto_decoder_see_check;
next->coder->next = LZMA_NEXT_CODER_INIT;
}
next->coder->memlimit = memlimit;
next->coder->flags = flags;
next->coder->initialized = false;
next->coder->sequence = SEQ_INIT;
return LZMA_OK;
}
@ -102,7 +158,6 @@ lzma_auto_decoder(lzma_stream *strm, uint64_t memlimit, uint32_t flags)
lzma_next_strm_init(auto_decoder_init, strm, memlimit, flags);
strm->internal->supported_actions[LZMA_RUN] = true;
// strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true; FIXME
strm->internal->supported_actions[LZMA_FINISH] = true;
return LZMA_OK;