ikarus/src/ikarus-symbol-table.c

233 lines
6.3 KiB
C

/*
* Ikarus Scheme -- A compiler for R6RS Scheme.
* Copyright (C) 2006,2007,2008 Abdulaziz Ghuloum
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "ikarus-data.h"
#include <strings.h>
#include <string.h>
#include <stdlib.h>
static ikptr
make_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);
ikptr st = ik_mmap_ptr(size, 0, pcb) + vector_tag;
bzero((char*)(long)st-vector_tag, size);
ref(st, off_vector_length) = fix(NUM_OF_BUCKETS);
return st;
}
/* one-at-a-time from http://burtleburtle.net/bob/hash/doobs.html */
static long int
compute_hash(ikptr str){
long int len = unfix(ref(str, off_string_length));
int* data = (int*)(str + off_string_data);
int h = len;
int* last = data + len;
/* one-at-a-time */
while(data < last){
int c = (*data >> 8);
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 >= 0) ? h : (1 - h);
}
ikptr
ikrt_string_hash(ikptr str){
return (ikptr)(compute_hash(str) & (~ fx_mask));
}
static int strings_eqp(ikptr str1, ikptr str2){
ikptr len = ref(str1, off_string_length);
if(len == ref(str2, off_string_length)){
return
(memcmp((char*)(long)str1+off_string_data,
(char*)(long)str2+off_string_data,
unfix(len) * string_char_size)
== 0);
}
return 0;
}
static ikptr
ik_make_symbol(ikptr str, ikptr ustr, ikpcb* pcb){
ikptr sym = ik_unsafe_alloc(pcb, symbol_record_size) + record_tag;
ref(sym, -record_tag) = symbol_record_tag;
ref(sym, off_symbol_record_string) = str;
ref(sym, off_symbol_record_ustring) = ustr;
ref(sym, off_symbol_record_value) = unbound_object;
ref(sym, off_symbol_record_proc) = str;
ref(sym, off_symbol_record_plist) = null_object;
return sym;
}
static ikptr
intern_string(ikptr str, ikptr st, ikpcb* pcb){
int h = compute_hash(str);
int idx = h & (unfix(ref(st, off_vector_length)) - 1);
ikptr bckt = ref(st, off_vector_data + idx*wordsize);
ikptr b = bckt;
while(b){
ikptr sym = ref(b, off_car);
ikptr sym_str = ref(sym, off_symbol_record_string);
if(strings_eqp(sym_str, str)){
return sym;
}
b = ref(b, off_cdr);
}
ikptr sym = ik_make_symbol(str, false_object, pcb);
b = ik_unsafe_alloc(pcb, pair_size) + pair_tag;
ref(b, off_car) = sym;
ref(b, off_cdr) = bckt;
ref(st, off_vector_data + idx*wordsize) = b;
((int*)(long)pcb->dirty_vector)[page_index(st+off_vector_data+idx*wordsize)] = -1;
return sym;
}
static ikptr
intern_unique_string(ikptr str, ikptr ustr, ikptr st, ikpcb* pcb){
int h = compute_hash(ustr);
int idx = h & (unfix(ref(st, off_vector_length)) - 1);
ikptr bckt = ref(st, off_vector_data + idx*wordsize);
ikptr b = bckt;
while(b){
ikptr sym = ref(b, off_car);
ikptr sym_ustr = ref(sym, off_symbol_record_ustring);
if(strings_eqp(sym_ustr, ustr)){
return sym;
}
b = ref(b, off_cdr);
}
ikptr sym = ik_make_symbol(str, ustr, pcb);
b = ik_unsafe_alloc(pcb, pair_size) + pair_tag;
ref(b, off_car) = sym;
ref(b, off_cdr) = bckt;
ref(st, off_vector_data + idx*wordsize) = b;
((int*)(long)pcb->dirty_vector)[page_index(st+off_vector_data+idx*wordsize)] = -1;
return sym;
}
ikptr
ikrt_intern_gensym(ikptr sym, ikpcb* pcb){
ikptr st = pcb->gensym_table;
if(st == 0){
st = make_symbol_table(pcb);
pcb->gensym_table = st;
}
ikptr ustr = ref(sym, off_symbol_record_ustring);
int h = compute_hash(ustr);
int idx = h & (unfix(ref(st, off_vector_length)) - 1);
ikptr bckt = ref(st, off_vector_data + idx*wordsize);
ikptr b = bckt;
while(b){
ikptr sym = ref(b, off_car);
ikptr sym_ustr = ref(sym, off_symbol_record_ustring);
if(strings_eqp(sym_ustr, ustr)){
return false_object;
}
b = ref(b, off_cdr);
}
b = ik_unsafe_alloc(pcb, pair_size) + pair_tag;
ref(b, off_car) = sym;
ref(b, off_cdr) = bckt;
ref(st, off_vector_data + idx*wordsize) = b;
((int*)(long)pcb->dirty_vector)[page_index(st+off_vector_data+idx*wordsize)] = -1;
return true_object;
}
ikptr
ikrt_unintern_gensym(ikptr sym, ikpcb* pcb){
ikptr st = pcb->gensym_table;
if(st == 0){
/* no symbol table */
return false_object;
}
ikptr ustr = ref(sym, off_symbol_record_ustring);
if (tagof(ustr) != string_tag) {
return false_object;
}
int h = compute_hash(ustr);
int idx = h & (unfix(ref(st, off_vector_length)) - 1);
ikptr loc = (ikptr)(st+off_vector_data+idx*wordsize);
ikptr bckt = ref(loc, 0);
while(bckt){
if (ref(bckt, off_car) == sym) {
/* found it */
ref(sym, off_symbol_record_ustring) = true_object;
ref(loc, 0) = ref(bckt, off_cdr);
return true_object;
} else {
loc = (ikptr)(bckt + off_cdr);
bckt = ref(loc, 0);
}
}
return false_object;
}
ikptr
ikrt_get_symbol_table(ikpcb* pcb){
ikptr st = pcb->symbol_table;
pcb->symbol_table = false_object;
if(st == false_object) {
fprintf(stderr, "bug in ikarus, attempt to access dead symbol table\n");
exit(-1);
}
return st;
}
ikptr
ikrt_string_to_symbol(ikptr str, ikpcb* pcb){
ikptr st = pcb->symbol_table;
if(st == false_object) {
fprintf(stderr, "bug in ikarus, attempt to access dead symbol table\n");
exit(-1);
}
if(st == 0){
st = make_symbol_table(pcb);
pcb->symbol_table = st;
}
return intern_string(str, st, pcb);
}
ikptr
ik_intern_string(ikptr str, ikpcb* pcb){
return ikrt_string_to_symbol(str, pcb);
}
ikptr
ikrt_strings_to_gensym(ikptr str, ikptr ustr, ikpcb* pcb){
ikptr st = pcb->gensym_table;
if(st == 0){
st = make_symbol_table(pcb);
pcb->gensym_table = st;
}
return intern_unique_string(str, ustr, st, pcb);
}