vm/strings.cpp

   1 #include "master.hpp"
   2
   3 namespace factor
   4 {
   5
   6 /* Allocates memory */
   7 string *factor_vm::allot_string_internal(cell capacity)
   8 {
   9         string *str = allot<string>(string_size(capacity));
  10
  11         str->length = tag_fixnum(capacity);
  12         str->hashcode = false_object;
  13         str->aux = false_object;
  14
  15         return str;
  16 }
  17
  18 /* Allocates memory */
  19 void factor_vm::fill_string(string *str_, cell start, cell capacity, cell fill)
  20 {
  21         data_root<string> str(str_,this);
  22
  23         if(fill <= 0x7f)
  24                 memset(&str->data()[start],(u8)fill,capacity - start);
  25         else
  26         {
  27                 byte_array *aux;
  28                 if(to_boolean(str->aux))
  29                         aux = untag<byte_array>(str->aux);
  30                 else
  31                 {
  32                         aux = allot_uninitialized_array<byte_array>(untag_fixnum(str->length) * 2);
  33                         str->aux = tag<byte_array>(aux);
  34                         write_barrier(&str->aux);
  35                 }
  36
  37                 u8 lo_fill = (u8)((fill & 0x7f) | 0x80);
  38                 u16 hi_fill = (u16)((fill >> 7) ^ 0x1);
  39                 memset(&str->data()[start],lo_fill,capacity - start);
  40                 memset_2(&aux->data<u16>()[start],hi_fill,(capacity - start) * sizeof(u16));
  41         }
  42 }
  43
  44 /* Allocates memory */
  45 string *factor_vm::allot_string(cell capacity, cell fill)
  46 {
  47         data_root<string> str(allot_string_internal(capacity),this);
  48         fill_string(str.untagged(),0,capacity,fill);
  49         return str.untagged();
  50 }
  51
  52 void factor_vm::primitive_string()
  53 {
  54         cell initial = to_cell(ctx->pop());
  55         cell length = unbox_array_size();
  56         ctx->push(tag<string>(allot_string(length,initial)));
  57 }
  58
  59 bool factor_vm::reallot_string_in_place_p(string *str, cell capacity)
  60 {
  61         return nursery.contains_p(str)
  62                 && (!to_boolean(str->aux) || nursery.contains_p(untag<byte_array>(str->aux)))
  63                 && capacity <= string_capacity(str);
  64 }
  65
  66 string* factor_vm::reallot_string(string *str_, cell capacity)
  67 {
  68         data_root<string> str(str_,this);
  69
  70         if(reallot_string_in_place_p(str.untagged(),capacity))
  71         {
  72                 str->length = tag_fixnum(capacity);
  73
  74                 if(to_boolean(str->aux))
  75                 {
  76                         byte_array *aux = untag<byte_array>(str->aux);
  77                         aux->capacity = tag_fixnum(capacity * 2);
  78                 }
  79
  80                 return str.untagged();
  81         }
  82         else
  83         {
  84                 cell to_copy = string_capacity(str.untagged());
  85                 if(capacity < to_copy)
  86                         to_copy = capacity;
  87
  88                 data_root<string> new_str(allot_string_internal(capacity),this);
  89
  90                 memcpy(new_str->data(),str->data(),to_copy);
  91
  92                 if(to_boolean(str->aux))
  93                 {
  94                         byte_array *new_aux = allot_uninitialized_array<byte_array>(capacity * 2);
  95                         new_str->aux = tag<byte_array>(new_aux);
  96                         write_barrier(&new_str->aux);
  97
  98                         byte_array *aux = untag<byte_array>(str->aux);
  99                         memcpy(new_aux->data<u16>(),aux->data<u16>(),to_copy * sizeof(u16));
 100                 }
 101
 102                 fill_string(new_str.untagged(),to_copy,capacity,'\0');
 103                 return new_str.untagged();
 104         }
 105 }
 106
 107 void factor_vm::primitive_resize_string()
 108 {
 109         data_root<string> str(ctx->pop(),this);
 110         str.untag_check(this);
 111         cell capacity = unbox_array_size();
 112         ctx->push(tag<string>(reallot_string(str.untagged(),capacity)));
 113 }
 114
 115 void factor_vm::primitive_set_string_nth_fast()
 116 {
 117         string *str = untag<string>(ctx->pop());
 118         cell index = untag_fixnum(ctx->pop());
 119         cell value = untag_fixnum(ctx->pop());
 120         str->data()[index] = (u8)value;
 121 }
 122
 123 }