ikarus/bin/ikarus-symbol-table.c

98 lines
2.5 KiB
C

#include "ikarus.h"
#include <strings.h>
#include <string.h>
#include <stdlib.h>
static ikp
initialize_symbol_table(ikpcb* pcb){
#define NUM_OF_BUCKETS 4096 /* power of 2 */
int size = align_to_next_page(disp_vector_data + NUM_OF_BUCKETS * wordsize);
ikp st = ik_mmap_ptr(size, 0, pcb) + vector_tag;
bzero(st-vector_tag, size);
ref(st, off_vector_length) = fix(NUM_OF_BUCKETS);
pcb->oblist = st;
return st;
}
static int
compute_hash(ikp str){
int len = unfix(ref(str, off_string_length));
char* data = (char*) str + off_string_data;
int h = len;
char* last = data + len;
while(data < last){
char c = *data;
h = h + c;
h = h + (h << 10);
h = h ^ (h >> 6);
data++;
}
h = h + (h << 3);
h = h ^ (h >> 11);
h = h + (h << 15);
return h;
}
static int strings_eqp(ikp str1, ikp str2){
ikp len = ref(str1, off_string_length);
if(len == ref(str2, off_string_length)){
return
(memcmp(str1+off_string_data, str2+off_string_data, unfix(len)) == 0);
}
return 0;
}
static ikp ik_make_symbol(ikp str, ikpcb* pcb){
ikp sym = ik_alloc(pcb, symbol_size) + symbol_tag;
ref(sym, off_symbol_string) = str;
ref(sym, off_symbol_ustring) = false_object;
ref(sym, off_symbol_value) = str; //unbound_object;
ref(sym, off_symbol_plist) = null_object;
ref(sym, off_symbol_system_value) = str;
ref(sym, off_symbol_system_plist) = null_object;
return sym;
}
ikp ik_oblist(ikpcb* pcb){
fprintf(stderr, "oblist dead!\n");
exit(-1);
}
ikp ik_intern_string(ikp str, ikpcb* pcb){
ikp st = pcb->oblist;
if(st == 0){
st = initialize_symbol_table(pcb);
}
int h = compute_hash(str);
int idx = h & (unfix(ref(st, off_vector_length)) - 1);
ikp bckt = ref(st, off_vector_data + idx*wordsize);
ikp b = bckt;
while(b){
ikp sym = ref(b, off_car);
ikp sym_str = ref(sym, off_symbol_string);
if(strings_eqp(sym_str, str)){
return sym;
}
b = ref(b, off_cdr);
}
ikp sym = ik_make_symbol(str, pcb);
b = ik_alloc(pcb, pair_size) + pair_tag;
ref(b, off_car) = sym;
ref(b, off_cdr) = bckt;
ref(st, off_vector_data + idx*wordsize) = b;
pcb->dirty_vector[page_index(st+off_vector_data+idx*wordsize)] = -1;
return sym;
}
ikp
ik_cstring_to_symbol(char* str, ikpcb* pcb){
int n = strlen(str);
int size = n + disp_string_data + 1;
ikp s = ik_alloc(pcb, align(size)) + string_tag;
ref(s, off_string_length) = fix(n);
memcpy(s+off_string_data, str, n+1);
ikp sym = ik_intern_string(s, pcb);
return sym;
}