diff options
Diffstat (limited to 'src/library_uuid.js')
-rw-r--r-- | src/library_uuid.js | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/library_uuid.js b/src/library_uuid.js new file mode 100644 index 00000000..adfd1882 --- /dev/null +++ b/src/library_uuid.js @@ -0,0 +1,140 @@ +// Implementation of libuuid creating RFC4122 version 4 random UUIDs. + +mergeInto(LibraryManager.library, { + // Clear a 'compact' UUID. + uuid_clear: function(uu) { + // void uuid_clear(uuid_t uu); + _memset(uu, 0, 16); + }, + + // Compare whether or not two 'compact' UUIDs are the same. + // Returns an integer less than, equal to, or greater than zero if uu1 is found, respectively, to be + // lexigraphically less than, equal, or greater than uu2. + uuid_compare__deps: ['memcmp'], + uuid_compare: function(uu1, uu2) { + // int uuid_compare(const uuid_t uu1, const uuid_t uu2); + return _memcmp(uu1, uu2, 16); + }, + + // Copies the 'compact' UUID variable from src to dst. + uuid_copy: function(dst, src) { + // void uuid_copy(uuid_t dst, const uuid_t src); + _memcpy(dst, src, 16); + }, + + // Write a RFC4122 version 4 compliant UUID largely based on the method found in + // http://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript + // tweaked slightly in order to use the 'compact' UUID form used by libuuid. + uuid_generate: function(out) { + // void uuid_generate(uuid_t out); + var uuid = null; + + if (ENVIRONMENT_IS_NODE) { + // If Node.js try to use crypto.randomBytes + try { + var rb = require('crypto').randomBytes; + uuid = rb(16); + } catch(e) {} + } else if (ENVIRONMENT_IS_WEB && + typeof(window.crypto) !== 'undefined' && + typeof(window.crypto.getRandomValues) !== 'undefined') { + // If crypto.getRandomValues is available try to use it. + uuid = new Uint8Array(16); + window.crypto.getRandomValues(uuid); + } + + // Fall back to Math.random if a higher quality random number generator is not available. + if (!uuid) { + uuid = new Array(16); + var d = new Date().getTime(); + for (var i = 0; i < 16; i++) { + var r = (d + Math.random()*256)%256 | 0; + d = Math.floor(d/256); + uuid[i] = r; + } + } + + uuid[6] = (uuid[6] & 0x0F) | 0x40; + uuid[8] = (uuid[8] & 0x7F) | 0x80; + writeArrayToMemory(uuid, out); + }, + + // Compares the value of the supplied 'compact' UUID variable uu to the NULL value. + // If the value is equal to the NULL UUID, 1 is returned, otherwise 0 is returned. + uuid_is_null: function(uu) { + // int uuid_is_null(const uuid_t uu); + for (var i = 0; i < 4; i++, uu = (uu+4)|0) { + var val = {{{ makeGetValue('uu', 0, 'i32') }}}; + if (val) { + return 0; + } + } + return 1; + }, + + // converts the UUID string given by inp into the binary representation. The input UUID is a string of + // the form "%08x-%04x-%04x-%04x-%012x" 36 bytes plus the trailing '\0'. + // Upon successfully parsing the input string, 0 is returned, and the UUID is stored in the location + // pointed to by uu, otherwise -1 is returned. + uuid_parse: function(inp, uu) { + // int uuid_parse(const char *in, uuid_t uu); + var inp = Pointer_stringify(inp); + if (inp.length === 36) { + var i = 0; + var uuid = new Array(16); + inp.toLowerCase().replace(/[0-9a-f]{2}/g, function(byte) { + if (i < 16) { + uuid[i++] = parseInt(byte, 16); + } + }); + + if (i < 16) { + return -1; + } else { + writeArrayToMemory(uuid, uu); + return 0; + } + } else { + return -1; + } + }, + + // Convert a 'compact' form UUID to a string, if the upper parameter is supplied make the string upper case. + uuid_unparse: function(uu, out, upper) { + // void uuid_unparse(const uuid_t uu, char *out); + var i = 0; + var uuid = 'xxxx-xx-xx-xx-xxxxxx'.replace(/[x]/g, function(c) { + var r = upper ? ({{{ makeGetValue('uu', 'i', 'i8', 0, 1) }}}).toString(16).toUpperCase() : + ({{{ makeGetValue('uu', 'i', 'i8', 0, 1) }}}).toString(16); + r = (r.length === 1) ? '0' + r : r; // Zero pad single digit hex values + i++; + return r; + }); + writeStringToMemory(uuid, out); + }, + + // Convert a 'compact' form UUID to a lower case string. + uuid_unparse_lower__deps: ['uuid_unparse'], + uuid_unparse_lower: function(uu, out) { + // void uuid_unparse_lower(const uuid_t uu, char *out); + _uuid_unparse(uu, out); + }, + + // Convert a 'compact' form UUID to an upper case string. + uuid_unparse_upper__deps: ['uuid_unparse'], + uuid_unparse_upper: function(uu, out) { + // void uuid_unparse_upper(const uuid_t uu, char *out); + _uuid_unparse(uu, out, true); + }, + + uuid_type: function(uu) { + // int uuid_type(const uuid_t uu); + return {{{ cDefine('UUID_TYPE_DCE_RANDOM') }}}; + }, + + uuid_variant: function(uu) { + // int uuid_variant(const uuid_t uu); + return {{{ cDefine('UUID_VARIANT_DCE') }}}; + } +}); + |