summaryrefslogtreecommitdiffstats
path: root/kjs/create_hash_table
blob: e8103fb99b3c57da2564af801509e8a9416cee2e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
#! /usr/bin/perl -w
#
# Static Hashtable Generator
#
# (c) 2000-2002 by Harri Porten <[email protected]> and
#                  David Faure <[email protected]>

$file = $ARGV[0];
shift;
my $findSize = 0;
my $includelookup = 0;
# Use -s as second argument to make it try many hash sizes
$findSize = 1 if (defined($ARGV[0]) && $ARGV[0] eq "-s");
# Use -i as second argument to make it include "lookup.h"
$includelookup = 1 if (defined($ARGV[0]) && $ARGV[0] eq "-i");
print STDERR "Creating hashtable for $file\n";
open(IN, $file) or die "No such file $file";

@keys = ();
@values = ();
@attrs = ();
@params = ();

my $inside = 0;
my $name;
my $size;
my $hashsize;
my $banner = 0;
my $namespace = "KJS";

sub calcTable();
sub output();
sub hashValue($);

while (<IN>) {
  chop;
  s/^\s*//g;
  if (/^\#|^$/) {
      # comment. do nothing
    } elsif (/^\@namespace\s+(\w+)/ && !$inside) {
        $namespace = $1;
    } elsif (/^\@begin/ && !$inside) {
      if (/^\@begin\s*([:_\w]+)\s*(\d+)\s*$/) {
        $inside = 1;
        $name = $1;
        $hashsize = $2;
      } else {
         printf STDERR "WARNING: \@begin without table name and hashsize, skipping $_\n";
      }
    } elsif (/^\@end\s*$/ && $inside) {

      if($findSize) {
	my $entriesnum=@keys;
        print STDERR "Table: $name   $entriesnum entries\n";
	for( $i=3 ; $i<79 ; ++$i) { $hashsize=$i ; calcTable(); }
      } else {
        calcTable();
      }

      output();
      @keys = ();
      @values = ();
      @attrs = ();
      @params = ();
      $inside = 0;
	} elsif (/^([-:\@\w\[\=\]]+)\s*([\w\:-]+)\s*([\w\|]*)\s*(\w*)\s*$/ && $inside) {
      my $key = $1;
      my $val = $2;
      my $att = $3;
      my $param = $4;
      push(@keys, $key);
      # values in HashEntry are short but can be unsigned in C++ code
      # therefore it is necessary to force the cast in the generated files
      push(@values, "(short)".$val);
      printf STDERR "WARNING: Number of arguments missing for $key/$val\n"
        if ( $att =~ m/Function/ && length($param) == 0);
      push(@attrs, length($att) > 0 ? $att : "0");
      push(@params, length($param) > 0 ? $param : "0");
    } elsif ($inside) {
      die "invalid data";
    }
}

die "missing closing \@end" if ($inside);

sub calcTable() {
  @table = ();
  @links = ();
  $size = $hashsize;
  my $collisions = 0;
  my $maxdepth = 0;
  my $i = 0;
  foreach $key (@keys) {
    my $depth = 0;
    my $h = hashValue($key) % $hashsize;
    while (defined($table[$h])) {
      if (defined($links[$h])) {
	$h = $links[$h];
	$depth++;
      } else {
	$collisions++;
	$links[$h] = $size;
	$h = $size;
	$size++;
      }
    }
    #print STDERR "table[$h] = $i\n";
    $table[$h] = $i;
    $i++;
    $maxdepth = $depth if ( $depth > $maxdepth);
  }

  # Ensure table is big enough (in case of undef entries at the end)
  if ( $#table+1 < $size ) {
    $#table = $size-1;
  }
  #print STDERR "After loop: size=$size table=".($#table+1)."\n";

  if ($findSize) {
    my $emptycount = 0;
    foreach $entry (@table) {
      $emptycount++ if (!defined($entry));
    }
    print STDERR "Hashsize: $hashsize  Total Size: $size Empty: $emptycount MaxDepth: $maxdepth Collisions: $collisions\n";
  }
#  my $debugtable = 0;
#  foreach $entry (@table) {
#    print STDERR "$debugtable " . (defined $entry ? $entry : '<undefined>');
#    print STDERR " -> " . $links[$debugtable] if (defined($links[$debugtable]));
#    print STDERR "\n";
#    $debugtable++;
#  }
}

sub hashValue($) {
  @chars = split(/ */, $_[0]);
  my $val = 0;
  foreach $c (@chars) {
    $val += ord($c);
  }
  return $val;
}

sub output() {
  if (!$banner) {
    $banner = 1;
    print "/* Automatically generated from $file using $0. DO NOT EDIT ! */\n";
  }

  my $nameEntries = "${name}Entries";
  $nameEntries =~ s/:/_/g;
  my $nameStringTable = "${name}Strings";
  $nameStringTable =~ y/:/_/;

  print "\n#include \"lookup.h\"\n" if ($includelookup);
  print "\nusing namespace KJS;\n"; # because of DontDelete etc.
  print "\nnamespace $namespace {\n";

  # first, build the string table
  my %soffset = ();
  print "\nstatic const char $nameStringTable\[\] = {\n";
  my $s = "\0";
  print "    \"\\0\"\n";
  for my $k (sort { length $b <=> length $a || $a cmp $b } @keys) {
    if ($s =~ /^(.*)\Q$k\E\0/) {
      $soffset{$k} = length $1;
     } else {
       $soffset{$k} = length $s;
       print "    \"$k\\0\"\n";
       $s .= $k;
       $s .= "\0";
     }
  }
  print "};\n\n";

  # now, dump the hash table

  print "\nstatic const struct HashEntry ".$nameEntries."[] = {\n";
  my $i = 0;
  #print STDERR "writing out table with ".($#table+1)." entries\n";
  foreach $entry (@table) {
    if (defined($entry)) {
      my $key = $keys[$entry];
      print "   \{ " . $soffset{$key};
      print ", " . $values[$entry];
      print ", " . $attrs[$entry];
      print ", " . $params[$entry];
      print ", ";
      if (defined($links[$i])) {
	print $links[$i] . " \}";
      } else {
	print "-1 \}"
      }
    } else {
      print "   \{ 0, 0, 0, 0, -1 \}";
    }
    print "," unless ($i == $size - 1);
    print "\n";
    $i++;
  }
  print "};\n\n";
  print "const struct HashTable $name = ";
  print "\{ 2, $size, ".$nameEntries.", $hashsize, ".$nameStringTable."\};\n\n";
  print "} // namespace\n";
}