void huffman_node_write_decode()

in source/huffman_generator/generator.c [176:215]

• 25 lines of code
• 6 McCabe index (conditional complexity)

void huffman_node_write_decode(struct huffman_node *node, FILE *file, uint8_t current_bit) {

    /* Value nodes should have been inlined into parent branch checks */
    assert(!node->value);
    assert(node->children[0] || node->children[1]);

    static int write_label = 0;

    if (write_label) {
        /* Write this node's label after the first run */
        fprintf(file, "node_");
        code_write(&node->code, file);
        fprintf(file, ":\n");
    }

    write_label = 1;

    /* Check 1 bit pattern */
    uint32_t single_bit_mask = (uint32_t)(1ull << (31 - current_bit));
    uint32_t left_aligned_pattern = ((node->code.bits << 1) + 1) << (31 - node->code.num_bits);
    uint32_t check_pattern = left_aligned_pattern & single_bit_mask;
    fprintf(file, "    if (bits & 0x%x) {\n", check_pattern);

    huffman_node_write_decode_handle_value(node->children[1], file);

    fprintf(file, "    } else {\n");

    /* Child 0 is valid, go there */
    huffman_node_write_decode_handle_value(node->children[0], file);

    fprintf(file, "    }\n\n");

    /* Recursively write child nodes */
    for (uint8_t i = 0; i < 2; ++i) {
        struct huffman_node *child = node->children[i];
        if (child && !child->value) {
            huffman_node_write_decode(child, file, current_bit + 1);
        }
    }
}