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diff --git a/triehash/triehash.pl b/triehash/triehash.pl
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+#!/usr/bin/perl -w
+#
+# Copyright (C) 2016 Julian Andres Klode <jak@jak-linux.org>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+
+=head1 NAME
+
+triehash - Generate a perfect hash function derived from a trie.
+
+=cut
+
+use strict;
+use warnings;
+use Getopt::Long;
+
+=head1 SYNOPSIS
+
+B<triehash> [S<I<option>>] [S<I<input file>>]
+
+=head1 DESCRIPTION
+
+triehash takes a list of words in input file and generates a function and
+an enumeration to describe the word
+
+=head1 INPUT FILE FORMAT
+
+The file consists of multiple lines of the form:
+
+ [label ~ ] word [= value]
+
+This maps word to value, and generates an enumeration with entries of the form:
+
+ label = value
+
+If I<label> is undefined, the word will be used, the minus character will be
+replaced by an underscore. If value is undefined it is counted upwards from
+the last value.
+
+There may also be one line of the format
+
+ [ label ~] = value
+
+Which defines the value to be used for non-existing keys. Note that this also
+changes default value for other keys, as for normal entries. So if you place
+
+ = 0
+
+at the beginning of the file, unknown strings map to 0, and the other strings
+map to values starting with 1. If label is not specified, the default is
+I<Unknown>.
+
+=head1 OPTIONS
+
+=over 4
+
+=item B<-C>I<.c file> B<--code>=I<.c file>
+
+Generate code in the given file.
+
+=item B<-H>I<header file> B<--header>=I<header file>
+
+Generate a header in the given file, containing a declaration of the hash
+function and an enumeration.
+
+=item B<--enum-name=>I<word>
+
+The name of the enumeration.
+
+=item B<--function-name=>I<word>
+
+The name of the function.
+
+=item B<--namespace=>I<name>
+
+Put the function and enum into a namespace (C++)
+
+=item B<--class=>I<name>
+
+Put the function and enum into a class (C++)
+
+=item B<--enum-class>
+
+Generate an enum class instead of an enum (C++)
+
+=item B<--counter-name=>I<name>
+
+Use I<name> for a counter that is set to the latest entry in the enumeration
++ 1. This can be useful for defining array sizes.
+
+=item B<--extern-c>
+
+Wrap everything into an extern "C" block. Not compatible with the C++
+options, as a header with namespaces, classes, or enum classes is not
+valid C.
+
+=item B<--multi-byte>=I<value>
+
+Generate code reading multiple bytes at once. The value is a string of power
+of twos to enable. The default value is 320 meaning that 8, 4, and single byte
+reads are enabled. Specify 0 to disable multi-byte completely, or add 2 if you
+also want to allow 2-byte reads. 2-byte reads are disabled by default because
+they negatively affect performance on older Intel architectures.
+
+This generates code for both multiple bytes and single byte reads, but only
+enables the multiple byte reads of GNU C compatible compilers, as the following
+extensions are used:
+
+=over 8
+
+=item Byte-aligned integers
+
+We must be able to generate integers that are aligned to a single byte using:
+
+ typedef uint64_t __attribute__((aligned (1))) triehash_uu64;
+
+=item Byte-order
+
+The macros __BYTE_ORDER__ and __ORDER_LITTLE_ENDIAN__ must be defined.
+
+=back
+
+We forcefully disable multi-byte reads on platforms where the variable
+I<__ARM_ARCH> is defined and I<__ARM_FEATURE_UNALIGNED> is not defined,
+as there is a measurable overhead from emulating the unaligned reads on
+ARM.
+
+=item B<--language=>I<language>
+
+Generate a file in the specified language. Currently known are 'C' and 'tree',
+the latter generating a tree.
+
+=item B<--include=>I<header>
+
+Add the header to the include statements of the header file. The value must
+be surrounded by quotes or angle brackets for C code. May be specified multiple
+times.
+
+=back
+
+=cut
+
+my $unknown = -1;
+my $unknown_label = "Unknown";
+my $counter_start = 0;
+my $enum_name = "PerfectKey";
+my $function_name = "PerfectHash";
+my $enum_class = 0;
+
+my $code_name = "-";
+my $header_name = "-";
+my $code;
+my $header;
+my $ignore_case = 0;
+my $multi_byte = "320";
+my $language = 'C';
+my $counter_name = undef;
+my @includes = ();
+
+
+Getopt::Long::config('default',
+ 'bundling',
+ 'no_getopt_compat',
+ 'no_auto_abbrev',
+ 'permute',
+ 'auto_help');
+
+GetOptions ("code|C=s" => \$code_name,
+ "header|H=s" => \$header_name,
+ "function-name=s" => \$function_name,
+ "ignore-case" => \$ignore_case,
+ "enum-name=s" => \$enum_name,
+ "language|l=s" => \$language,
+ "multi-byte=s" => \$multi_byte,
+ "enum-class" => \$enum_class,
+ "include=s" => \@includes,
+ "counter-name=s" => \$counter_name)
+ or die("Could not parse options!");
+
+
+package Trie {
+
+ sub new {
+ my $class = shift;
+ my $self = {};
+ bless $self, $class;
+
+ $self->{children} = {};
+ $self->{value} = undef;
+ $self->{label} = undef;
+
+ return $self;
+ }
+
+ # Return the largest power of 2 smaller or equal to the argument
+ sub alignpower2 {
+ my ($self, $length) = @_;
+
+ return 8 if ($length >= 8 && $multi_byte =~ /3/);
+ return 4 if ($length >= 4 && $multi_byte =~ /2/);
+ return 2 if ($length >= 2 && $multi_byte =~ /1/);
+
+ return 1;
+ }
+
+ # Split the key into a head block and a tail
+ sub split_key {
+ my ($self, $key) = @_;
+ my $length = length $key;
+ my $split = $self->alignpower2($length);
+
+ return (substr($key, 0, $split), substr($key, $split));
+ }
+
+ sub insert {
+ my ($self, $key, $label, $value) = @_;
+
+ if (length($key) == 0) {
+ $self->{label} = $label;
+ $self->{value} = $value;
+ return;
+ }
+
+ my ($child, $tail) = $self->split_key($key);
+
+ $self->{children}{$child} = Trie->new if (!defined($self->{children}{$child}));
+
+ $self->{children}{$child}->insert($tail, $label, $value);
+ }
+
+ sub filter_depth {
+ my ($self, $togo) = @_;
+
+ my $new = Trie->new;
+
+ if ($togo != 0) {
+ my $found = 0;
+ foreach my $key (sort keys %{$self->{children}}) {
+ if ($togo > length($key) || defined $self->{children}{$key}->{value}) {
+ my $child = $self->{children}{$key}->filter_depth($togo - length($key));
+
+ $new->{children}{$key}= $child if defined $child;
+ $found = 1 if defined $child;
+ }
+ }
+ return undef if (!$found);
+ } else {
+ $new->{value} = $self->{value};
+ $new->{label} = $self->{label};
+ }
+
+ return $new;
+ }
+
+ # Reinsert all value nodes into the specified $trie, prepending $prefix
+ # to their $paths.
+ sub reinsert_value_nodes_into {
+ my ($self, $trie, $prefix) = @_;
+
+ $trie->insert($prefix, $self->{label}, $self->{value}) if (defined $self->{value});
+
+ foreach my $key (sort keys %{$self->{children}}) {
+ $self->{children}{$key}->reinsert_value_nodes_into($trie, $prefix . $key);
+ }
+ }
+
+ # Find an earlier split due a an ambiguous character
+ sub find_ealier_split {
+ my ($self, $key) = @_;
+
+ if ($ignore_case) {
+ for my $i (0..length($key)-1) {
+ # If the key starts with an ambiguous character, we need to
+ # take only it. Otherwise, we need to take everything
+ # before the character.
+ return $self->alignpower2($i || 1) if (main::ambiguous(substr($key, $i, 1)));
+ }
+ }
+ return $self->alignpower2(length $key);
+ }
+
+ # Rebuild the trie, splitting at ambigous chars, and unifying key lengths
+ sub rebuild_tree {
+ my $self = shift;
+ # Determine if/where we need to split before an ambiguous character
+ my $new_split = 99999999999999999;
+ foreach my $key (sort keys %{$self->{children}}) {
+ my $special_length = $self->find_ealier_split($key);
+ $new_split = $special_length if ($special_length < $new_split);
+ }
+
+ # Start building a new uniform trie
+ my $newself = Trie->new;
+ $newself->{label} = $self->{label};
+ $newself->{value} = $self->{value};
+ $newself->{children} = {};
+
+ foreach my $key (sort keys %{$self->{children}}) {
+ my $head = substr($key, 0, $new_split);
+ my $tail = substr($key, $new_split);
+ # Rebuild the child node at $head, pushing $tail downwards
+ $newself->{children}{$head} //= Trie->new;
+ $self->{children}{$key}->reinsert_value_nodes_into($newself->{children}{$head}, $tail);
+ # We took up to one special character of each key label. There might
+ # be more, so we need to rebuild recursively.
+ $newself->{children}{$head} = $newself->{children}{$head}->rebuild_tree();
+ }
+
+ return $newself;
+ }
+}
+
+# Code generator for C and C++
+package CCodeGen {
+ my $static = ($code_name eq $header_name) ? "static" : "";
+ my $enum_specifier = $enum_class ? "enum class" : "enum";
+
+ sub new {
+ my $class = shift;
+ my $self = {};
+ bless $self, $class;
+
+ return $self;
+ }
+
+ sub open_output {
+ my $self = shift;
+ if ($code_name ne "-") {
+ open($code, '>', $code_name) or die "Cannot open $code_name: $!" ;
+ } else {
+ $code = *STDOUT;
+ }
+ if($code_name eq $header_name) {
+ $header = $code;
+ } elsif ($header_name ne "-") {
+ open($header, '>', $header_name) or die "Cannot open $header_name: $!" ;
+ } else {
+ $header = *STDOUT;
+ }
+ }
+
+ sub word_to_label {
+ my ($class, $word) = @_;
+
+ $word =~ s/_/__/g;
+ $word =~ s/-/_/g;
+ return $word;
+ }
+
+ # Return a case label, by shifting and or-ing bytes in the word
+ sub case_label {
+ my ($self, $key) = @_;
+
+ return sprintf("'%s'", substr($key, 0, 1)) if not $multi_byte;
+
+ my $output = '0';
+
+ for my $i (0..length($key)-1) {
+ $output .= sprintf("| onechar('%s', %d, %d)", substr($key, $i, 1), 8 * $i, 8*length($key));
+ }
+
+ return $output;
+ }
+
+ # Return an appropriate read instruction for $length bytes from $offset
+ sub switch_key {
+ my ($self, $offset, $length) = @_;
+
+ return "string[$offset]" if $length == 1;
+ return sprintf("*((triehash_uu%s*) &string[$offset])", $length * 8);
+ }
+
+ sub print_table {
+ my ($self, $trie, $fh, $indent, $index) = @_;
+ $indent //= 0;
+ $index //= 0;
+
+ if (defined $trie->{value}) {
+ printf $fh (" " x $indent . "return %s;\n", ($enum_class ? "${enum_name}::" : "").$trie->{label});
+ return;
+ }
+
+ # The difference between lowercase and uppercase alphabetical characters
+ # is that they have one bit flipped. If we have alphabetical characters
+ # in the search space, and the entire search space works fine if we
+ # always turn on the flip, just OR the character we are switching over
+ # with the bit.
+ my $want_use_bit = 0;
+ my $can_use_bit = 1;
+ my $key_length = 0;
+ foreach my $key (sort keys %{$trie->{children}}) {
+ $can_use_bit &= not main::ambiguous($key);
+ $want_use_bit |= ($key =~ /^[a-zA-Z]+$/);
+ $key_length = length($key);
+ }
+
+ if ($ignore_case && $can_use_bit && $want_use_bit) {
+ printf $fh ((" " x $indent) . "switch(%s | 0x%s) {\n", $self->switch_key($index, $key_length), "20" x $key_length);
+ } else {
+ printf $fh ((" " x $indent) . "switch(%s) {\n", $self->switch_key($index, $key_length));
+ }
+
+ my $notfirst = 0;
+ foreach my $key (sort keys %{$trie->{children}}) {
+ if ($notfirst) {
+ printf $fh (" " x $indent . " break;\n");
+ }
+ if ($ignore_case) {
+ printf $fh (" " x $indent . "case %s:\n", $self->case_label(lc($key)));
+ printf $fh (" " x $indent . "case %s:\n", $self->case_label(uc($key))) if lc($key) ne uc($key) && !($can_use_bit && $want_use_bit);
+ } else {
+ printf $fh (" " x $indent . "case %s:\n", $self->case_label($key));
+ }
+
+ $self->print_table($trie->{children}{$key}, $fh, $indent + 1, $index + length($key));
+
+ $notfirst=1;
+ }
+
+ printf $fh (" " x $indent . "}\n");
+ }
+
+ sub print_words {
+ my ($self, $trie, $fh, $indent, $sofar) = @_;
+
+ $indent //= 0;
+ $sofar //= "";
+
+
+ printf $fh (" " x $indent."%s = %s,\n", $trie->{label}, $trie->{value}) if defined $trie->{value};
+
+ foreach my $key (sort keys %{$trie->{children}}) {
+ $self->print_words($trie->{children}{$key}, $fh, $indent, $sofar . $key);
+ }
+ }
+
+ sub print_functions {
+ my ($self, $trie, %lengths) = @_;
+ foreach my $local_length (sort { $a <=> $b } (keys %lengths)) {
+ print $code ("static enum ${enum_name} ${function_name}${local_length}(const char *string)\n");
+ print $code ("{\n");
+ $self->print_table($trie->filter_depth($local_length)->rebuild_tree(), $code, 1);
+ printf $code (" return %s$unknown_label;\n", ($enum_class ? "${enum_name}::" : ""));
+ print $code ("}\n");
+ }
+ }
+
+ sub main {
+ my ($self, $trie, $num_values, %lengths) = @_;
+ print $header ("#ifndef TRIE_HASH_${function_name}\n");
+ print $header ("#define TRIE_HASH_${function_name}\n");
+ print $header ("#include <stddef.h>\n");
+ print $header ("#include <stdint.h>\n");
+ foreach my $include (@includes) {
+ print $header ("#include $include\n");
+ }
+ printf $header ("enum { $counter_name = $num_values };\n") if (defined($counter_name));
+ print $header ("${enum_specifier} ${enum_name} {\n");
+ $self->print_words($trie, $header, 1);
+ printf $header (" $unknown_label = $unknown,\n");
+ print $header ("};\n");
+ print $header ("$static enum ${enum_name} ${function_name}(const char *string, size_t length);\n");
+
+ print $code ("#include \"$header_name\"\n") if ($header_name ne $code_name);
+
+ if ($multi_byte) {
+ print $code ("#ifdef __GNUC__\n");
+ for (my $i=16; $i <= 64; $i *= 2) {
+ print $code ("typedef uint${i}_t __attribute__((aligned (1))) triehash_uu${i};\n");
+ print $code ("typedef char static_assert${i}[__alignof__(triehash_uu${i}) == 1 ? 1 : -1];\n");
+ }
+
+ print $code ("#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__\n");
+ print $code ("#define onechar(c, s, l) (((uint64_t)(c)) << (s))\n");
+ print $code ("#else\n");
+ print $code ("#define onechar(c, s, l) (((uint64_t)(c)) << (l-8-s))\n");
+ print $code ("#endif\n");
+ print $code ("#if (!defined(__ARM_ARCH) || defined(__ARM_FEATURE_UNALIGNED)) && !defined(TRIE_HASH_NO_MULTI_BYTE)\n");
+ print $code ("#define TRIE_HASH_MULTI_BYTE\n");
+ print $code ("#endif\n");
+ print $code ("#endif /*GNUC */\n");
+
+ print $code ("#ifdef TRIE_HASH_MULTI_BYTE\n");
+ $self->print_functions($trie, %lengths);
+ $multi_byte = 0;
+ print $code ("#else\n");
+ $self->print_functions($trie, %lengths);
+ print $code ("#endif /* TRIE_HASH_MULTI_BYTE */\n");
+ } else {
+ $self->print_functions($trie, %lengths);
+ }
+
+ print $code ("$static enum ${enum_name} ${function_name}(const char *string, size_t length)\n");
+ print $code ("{\n");
+ print $code (" switch (length) {\n");
+ foreach my $local_length (sort { $a <=> $b } (keys %lengths)) {
+ print $code (" case $local_length:\n");
+ print $code (" return ${function_name}${local_length}(string);\n");
+ }
+ print $code (" default:\n");
+ printf $code (" return %s$unknown_label;\n", ($enum_class ? "${enum_name}::" : ""));
+ print $code (" }\n");
+ print $code ("}\n");
+
+ # Print end of header here, in case header and code point to the same file
+ print $header ("#endif /* TRIE_HASH_${function_name} */\n");
+ }
+}
+
+# Check if the word can be reached by exactly one word in (alphabet OR 0x20).
+sub ambiguous {
+ my $word = shift;
+
+ foreach my $char (split //, $word) {
+ # Setting the lowercase flag in the character produces a different
+ # character, the character would thus not be matched.
+ return 1 if ((ord($char) | 0x20) != ord(lc($char)));
+
+ # A word is also ambiguous if any character in lowercase can be reached
+ # by ORing 0x20 from another character in the charset that is not a
+ # lowercase character of the current character.
+ # Assume that we have UTF-8 and the most significant bit can be set
+ for my $i (0..255) {
+ return 1 if (($i | 0x20) == ord(lc($char)) && lc(chr($i)) ne lc($char));
+ }
+ }
+
+ return 0;
+}
+
+sub build_trie {
+ my $codegen = shift;
+ my $trie = Trie->new;
+
+ my $counter = $counter_start;
+ my %lengths;
+
+ open(my $input, '<', $ARGV[0]) or die "Cannot open ".$ARGV[0].": $!";
+ while (my $line = <$input>) {
+ my ($label, $word, $value) = $line =~/\s*(?:([^~\s]+)\s*~)?(?:\s*([^~=\s]+)\s*)?(?:=\s*([^\s]+)\s+)?\s*/;
+
+ if (defined $word) {
+ $counter = $value if defined($value);
+ $label //= $codegen->word_to_label($word);
+
+ $trie->insert($word, $label, $counter);
+ $lengths{length($word)} = 1;
+ $counter++;
+ } elsif (defined $value) {
+ $unknown = $value;
+ $unknown_label = $label if defined($label);
+ $counter = $value + 1;
+ } else {
+ die "Invalid line: $line";
+ }
+ }
+
+ return ($trie, $counter, %lengths);
+}
+
+# Generates an ASCII art tree
+package TreeCodeGen {
+
+ sub new {
+ my $class = shift;
+ my $self = {};
+ bless $self, $class;
+
+ return $self;
+ }
+
+ sub word_to_label {
+ my ($self, $word) = @_;
+ return $word;
+ }
+
+ sub main {
+ my ($self, $trie, $counter, %lengths) = @_;
+ printf $code ("┌────────────────────────────────────────────────────┐\n");
+ printf $code ("│ Initial trie │\n");
+ printf $code ("└────────────────────────────────────────────────────┘\n");
+ $self->print($trie);
+ printf $code ("┌────────────────────────────────────────────────────┐\n");
+ printf $code ("│ Rebuilt trie │\n");
+ printf $code ("└────────────────────────────────────────────────────┘\n");
+ $self->print($trie->rebuild_tree());
+
+ foreach my $local_length (sort { $a <=> $b } (keys %lengths)) {
+ printf $code ("┌────────────────────────────────────────────────────┐\n");
+ printf $code ("│ Trie for words of length %-4d │\n", $local_length);
+ printf $code ("└────────────────────────────────────────────────────┘\n");
+ $self->print($trie->filter_depth($local_length)->rebuild_tree());
+ }
+ }
+
+ sub open_output {
+ my $self = shift;
+ if ($code_name ne "-") {
+ open($code, '>', $code_name) or die "Cannot open ".$ARGV[0].": $!" ;
+ } else {
+ $code = *STDOUT;
+ }
+ }
+
+ # Print a trie
+ sub print {
+ my ($self, $trie, $depth) = @_;
+ $depth //= 0;
+
+ print $code (" → ") if defined($trie->{label});
+ print $code ($trie->{label} // "", "\n");
+ foreach my $key (sort keys %{$trie->{children}}) {
+ print $code ("│ " x ($depth), "├── $key");
+ $self->print($trie->{children}{$key}, $depth + 1);
+ }
+ }
+}
+
+my %codegens = (
+ C => "CCodeGen",
+ tree => "TreeCodeGen",
+);
+
+
+defined($codegens{$language}) or die "Unknown language $language. Valid choices: ", join(", ", keys %codegens);
+my $codegen = $codegens{$language}->new();
+my ($trie, $counter, %lengths) = build_trie($codegen);
+
+$codegen->open_output();
+$codegen->main($trie, $counter, %lengths);
+
+
+=head1 LICENSE
+
+triehash is available under the MIT/Expat license, see the source code
+for more information.
+
+=head1 AUTHOR
+
+Julian Andres Klode <jak@jak-linux.org>
+
+=cut
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-14 11:33:36 +0000