void construct_lcp_kasai(cache_config& config)
{
int_vector<> lcp;
typedef int_vector<>::size_type size_type;
construct_isa(config);
{
int_vector<t_width> text;
if (!load_from_cache(text, key_text_trait<t_width>::KEY_TEXT, config)) {
return;
}
int_vector_file_buffer<> isa_buf(config.file_map[constants::KEY_ISA], 1000000); // init isa file_buffer
int_vector<> sa;
if (!load_from_cache(sa, constants::KEY_SA, config)) {
return;
}
// use Kasai algorithm to compute the lcp values
for (size_type i=0,j=0,sa_1=0,l=0, r_sum=0, r=isa_buf.load_next_block(), n=isa_buf.int_vector_size; r_sum < n;) {
for (; i < r_sum+r; ++i) {
sa_1 = isa_buf[i-r_sum]; // = isa[i]
if (sa_1) {
j = sa[sa_1-1];
if (l) --l;
assert(i!=j);
while (text[i+l]==text[j+l]) { // i+l < n and j+l < n are not necessary, since text[n]=0 and text[i]!=0 (i<n) and i!=j
++l;
}
sa[ sa_1-1 ] = l; //overwrite sa array with lcp values
} else {
l = 0;
sa[ n-1 ] = 0;
}
}
r_sum += r;
r = isa_buf.load_next_block();
}
for (size_type i=sa.size(); i>1; --i) {
sa[i-1] = sa[i-2];
}
sa[0] = 0;
lcp.swap(sa);
}
store_to_cache(lcp, constants::KEY_LCP, config);
}
void construct_lcp_kasai(cache_config& config)
{
static_assert(t_width == 0 or t_width == 8 , "construct_lcp_kasai: width must be `0` for integer alphabet and `8` for byte alphabet");
int_vector<> lcp;
typedef int_vector<>::size_type size_type;
construct_isa(config);
{
int_vector<t_width> text;
if (!load_from_cache(text, key_text_trait<t_width>::KEY_TEXT, config)) {
return;
}
int_vector_buffer<> isa_buf(config.file_map[conf::KEY_ISA], std::ios::in, 1000000); // init isa file_buffer
int_vector<> sa;
if (!load_from_cache(sa, conf::KEY_SA, config)) {
return;
}
// use Kasai algorithm to compute the lcp values
for (size_type i=0,j=0,sa_1=0,l=0, n=isa_buf.size(); i < n; ++i) {
sa_1 = isa_buf[i]; // = isa[i]
if (sa_1) {
j = sa[sa_1-1];
if (l) --l;
assert(i!=j);
while (text[i+l]==text[j+l]) { // i+l < n and j+l < n are not necessary, since text[n]=0 and text[i]!=0 (i<n) and i!=j
++l;
}
sa[ sa_1-1 ] = l; //overwrite sa array with lcp values
} else {
l = 0;
sa[ n-1 ] = 0;
}
}
for (size_type i=sa.size(); i>1; --i) {
sa[i-1] = sa[i-2];
}
sa[0] = 0;
lcp.swap(sa);
}
store_to_cache(lcp, conf::KEY_LCP, config);
}
