1/************************************************ 2 3 bubblebabble.c - BubbleBabble encoding support 4 5 $Author: nobu $ 6 created at: Fri Oct 13 18:31:42 JST 2006 7 8 Copyright (C) 2006 Akinori MUSHA 9 10 $Id: bubblebabble.c 27437 2010-04-22 08:04:13Z nobu $ 11 12************************************************/ 13 14#include "ruby.h" 15#include "digest.h" 16 17static ID id_digest; 18 19static VALUE 20bubblebabble_str_new(VALUE str_digest) 21{ 22 char *digest; 23 size_t digest_len; 24 VALUE str; 25 char *p; 26 size_t i, j, seed = 1; 27 static const char vowels[] = { 28 'a', 'e', 'i', 'o', 'u', 'y' 29 }; 30 static const char consonants[] = { 31 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm', 'n', 32 'p', 'r', 's', 't', 'v', 'z', 'x' 33 }; 34 35 StringValue(str_digest); 36 digest = RSTRING_PTR(str_digest); 37 digest_len = RSTRING_LEN(str_digest); 38 39 if ((LONG_MAX - 2) / 3 < (digest_len | 1)) { 40 rb_raise(rb_eRuntimeError, "digest string too long"); 41 } 42 43 str = rb_str_new(0, (digest_len | 1) * 3 + 2); 44 p = RSTRING_PTR(str); 45 46 i = j = 0; 47 p[j++] = 'x'; 48 49 for (;;) { 50 unsigned char byte1, byte2; 51 52 if (i >= digest_len) { 53 p[j++] = vowels[seed % 6]; 54 p[j++] = consonants[16]; 55 p[j++] = vowels[seed / 6]; 56 break; 57 } 58 59 byte1 = digest[i++]; 60 p[j++] = vowels[(((byte1 >> 6) & 3) + seed) % 6]; 61 p[j++] = consonants[(byte1 >> 2) & 15]; 62 p[j++] = vowels[((byte1 & 3) + (seed / 6)) % 6]; 63 64 if (i >= digest_len) { 65 break; 66 } 67 68 byte2 = digest[i++]; 69 p[j++] = consonants[(byte2 >> 4) & 15]; 70 p[j++] = '-'; 71 p[j++] = consonants[byte2 & 15]; 72 73 seed = (seed * 5 + byte1 * 7 + byte2) % 36; 74 } 75 76 p[j] = 'x'; 77 78 return str; 79} 80 81/* 82 * call-seq: 83 * Digest.bubblebabble(string) -> bubblebabble_string 84 * 85 * Returns a BubbleBabble encoded version of a given _string_. 86 */ 87static VALUE 88rb_digest_s_bubblebabble(VALUE klass, VALUE str) 89{ 90 return bubblebabble_str_new(str); 91} 92 93/* 94 * call-seq: 95 * Digest::Class.bubblebabble(string, ...) -> hash_string 96 * 97 * Returns the BubbleBabble encoded hash value of a given _string_. 98 */ 99static VALUE 100rb_digest_class_s_bubblebabble(int argc, VALUE *argv, VALUE klass) 101{ 102 return bubblebabble_str_new(rb_funcall2(klass, id_digest, argc, argv)); 103} 104 105/* 106 * call-seq: 107 * digest_obj.bubblebabble -> hash_string 108 * 109 * Returns the resulting hash value in a Bubblebabble encoded form. 110 */ 111static VALUE 112rb_digest_instance_bubblebabble(VALUE self) 113{ 114 return bubblebabble_str_new(rb_funcall(self, id_digest, 0)); 115} 116 117/* 118 * This module adds some methods to Digest classes to perform 119 * BubbleBabble encoding. 120 */ 121void 122Init_bubblebabble(void) 123{ 124 VALUE mDigest, mDigest_Instance, cDigest_Class; 125 126 rb_require("digest"); 127 128 mDigest = rb_path2class("Digest"); 129 mDigest_Instance = rb_path2class("Digest::Instance"); 130 cDigest_Class = rb_path2class("Digest::Class"); 131 132 /* Digest::bubblebabble() */ 133 rb_define_module_function(mDigest, "bubblebabble", rb_digest_s_bubblebabble, 1); 134 135 /* Digest::Class::bubblebabble() */ 136 rb_define_singleton_method(cDigest_Class, "bubblebabble", rb_digest_class_s_bubblebabble, -1); 137 138 /* Digest::Instance#bubblebabble() */ 139 rb_define_method(mDigest_Instance, "bubblebabble", rb_digest_instance_bubblebabble, 0); 140 141 id_digest = rb_intern("digest"); 142} 143