void XzCompress::Encode(void)
{
direct = 0; // set direction needed by parent [Get|Send]Chars()
// get buffer
char chunk[1024];
char *buf = (char *)calloc(1, 1024);
char *chunkbuf = buf;
unsigned long chunklen;
unsigned long len = 0;
while((chunklen = GetChars(chunk, 1023))) {
memcpy(chunkbuf, chunk, chunklen);
len += chunklen;
if (chunklen < 1023)
break;
else buf = (char *)realloc(buf, len + 1024);
chunkbuf = buf+len;
}
zlen = (long) (len*1.001)+15; // TODO: check that this is sufficient
char *zbuf = new char[zlen+1];
size_t zpos = 0;
if (len)
{
//printf("Doing compress\n");
if (lzma_block_buffer_encode(&block, NULL, (const uint8_t*)buf, (size_t)len, (uint8_t*)zbuf, &zpos, (size_t)zlen) != LZMA_OK)
{
printf("ERROR in compression\n");
}
else {
SendChars(zbuf, zlen);
}
}
else
{
fprintf(stderr, "ERROR: no buffer to compress\n");
}
delete [] zbuf;
free (buf);
}
lzma_stream_buffer_encode(lzma_filter *filters, lzma_check check,
lzma_allocator *allocator, const uint8_t *in, size_t in_size,
uint8_t *out, size_t *out_pos_ptr, size_t out_size)
{
// Sanity checks
if (filters == NULL || (unsigned int)(check) > LZMA_CHECK_ID_MAX
|| (in == NULL && in_size != 0) || out == NULL
|| out_pos_ptr == NULL || *out_pos_ptr > out_size)
return LZMA_PROG_ERROR;
if (!lzma_check_is_supported(check))
return LZMA_UNSUPPORTED_CHECK;
// Note for the paranoids: Index encoder prevents the Stream from
// getting too big and still being accepted with LZMA_OK, and Block
// encoder catches if the input is too big. So we don't need to
// separately check if the buffers are too big.
// Use a local copy. We update *out_pos_ptr only if everything
// succeeds.
size_t out_pos = *out_pos_ptr;
// Check that there's enough space for both Stream Header and
// Stream Footer.
if (out_size - out_pos <= 2 * LZMA_STREAM_HEADER_SIZE)
return LZMA_BUF_ERROR;
// Reserve space for Stream Footer so we don't need to check for
// available space again before encoding Stream Footer.
out_size -= LZMA_STREAM_HEADER_SIZE;
// Encode the Stream Header.
lzma_stream_flags stream_flags = {
.version = 0,
.check = check,
};
if (lzma_stream_header_encode(&stream_flags, out + out_pos)
!= LZMA_OK)
return LZMA_PROG_ERROR;
out_pos += LZMA_STREAM_HEADER_SIZE;
// Encode a Block but only if there is at least one byte of input.
lzma_block block = {
.version = 0,
.check = check,
.filters = filters,
};
if (in_size > 0)
return_if_error(lzma_block_buffer_encode(&block, allocator,
in, in_size, out, &out_pos, out_size));
// Index
{
// Create an Index. It will have one Record if there was
// at least one byte of input to encode. Otherwise the
// Index will be empty.
lzma_index *i = lzma_index_init(allocator);
if (i == NULL)
return LZMA_MEM_ERROR;
lzma_ret ret = LZMA_OK;
if (in_size > 0)
ret = lzma_index_append(i, allocator,
lzma_block_unpadded_size(&block),
block.uncompressed_size);
// If adding the Record was successful, encode the Index
// and get its size which will be stored into Stream Footer.
if (ret == LZMA_OK) {
ret = lzma_index_buffer_encode(
i, out, &out_pos, out_size);
stream_flags.backward_size = lzma_index_size(i);
}
lzma_index_end(i, allocator);
if (ret != LZMA_OK)
return ret;
}
// Stream Footer. We have already reserved space for this.
if (lzma_stream_footer_encode(&stream_flags, out + out_pos)
!= LZMA_OK)
return LZMA_PROG_ERROR;
out_pos += LZMA_STREAM_HEADER_SIZE;
// Everything went fine, make the new output position available
// to the application.
*out_pos_ptr = out_pos;
return LZMA_OK;
}
