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; }