extern lzma_ret
lzma_delta_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
const lzma_filter_info *filters)
{
// Allocate memory for the decoder if needed.
if (next->coder == NULL) {
next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
if (next->coder == NULL)
return LZMA_MEM_ERROR;
// End function is the same for encoder and decoder.
next->end = &delta_coder_end;
next->coder->next = LZMA_NEXT_CODER_INIT;
}
// Validate the options.
if (lzma_delta_coder_memusage(filters[0].options) == UINT64_MAX)
return LZMA_OPTIONS_ERROR;
// Set the delta distance.
const lzma_options_delta *opt = filters[0].options;
next->coder->distance = opt->dist;
// Initialize the rest of the variables.
next->coder->pos = 0;
memzero(next->coder->history, LZMA_DELTA_DIST_MAX);
// Initialize the next decoder in the chain, if any.
return lzma_next_filter_init(&next->coder->next,
allocator, filters + 1);
}
extern lzma_ret
lzma_raw_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
const lzma_filter *options,
lzma_filter_find coder_find, bool is_encoder)
{
// Do some basic validation and get the number of filters.
size_t count;
return_if_error(validate_chain(options, &count));
// Set the filter functions and copy the options pointer.
lzma_filter_info filters[LZMA_FILTERS_MAX + 1];
if (is_encoder) {
for (size_t i = 0; i < count; ++i) {
// The order of the filters is reversed in the
// encoder. It allows more efficient handling
// of the uncompressed data.
const size_t j = count - i - 1;
const lzma_filter_coder *const fc
= coder_find(options[i].id);
if (fc == NULL || fc->init == NULL)
return LZMA_OPTIONS_ERROR;
filters[j].id = options[i].id;
filters[j].init = fc->init;
filters[j].options = options[i].options;
}
} else {
for (size_t i = 0; i < count; ++i) {
const lzma_filter_coder *const fc
= coder_find(options[i].id);
if (fc == NULL || fc->init == NULL)
return LZMA_OPTIONS_ERROR;
filters[i].id = options[i].id;
filters[i].init = fc->init;
filters[i].options = options[i].options;
}
}
// Terminate the array.
filters[count].id = LZMA_VLI_UNKNOWN;
filters[count].init = NULL;
// Initialize the filters.
const lzma_ret ret = lzma_next_filter_init(next, allocator, filters);
if (ret != LZMA_OK)
lzma_next_end(next, allocator);
return ret;
}
