+++ /dev/null
-var util = require('util'),
- Match = require ('../match');
-
-/**
- * Binary search implementation (recursive)
- */
-function binarySearch(arr, searchValue) {
- function find(arr, searchValue, left, right) {
- if (right < left)
- return -1;
-
- /*
- int mid = mid = (left + right) / 2;
- There is a bug in the above line;
- Joshua Bloch suggests the following replacement:
- */
- var mid = Math.floor((left + right) >>> 1);
- if (searchValue > arr[mid])
- return find(arr, searchValue, mid + 1, right);
-
- if (searchValue < arr[mid])
- return find(arr, searchValue, left, mid - 1);
-
- return mid;
- };
-
- return find(arr, searchValue, 0, arr.length - 1);
-};
-
-// 'Character' iterated character class.
-// Recognizers for specific mbcs encodings make their 'characters' available
-// by providing a nextChar() function that fills in an instance of iteratedChar
-// with the next char from the input.
-// The returned characters are not converted to Unicode, but remain as the raw
-// bytes (concatenated into an int) from the codepage data.
-//
-// For Asian charsets, use the raw input rather than the input that has been
-// stripped of markup. Detection only considers multi-byte chars, effectively
-// stripping markup anyway, and double byte chars do occur in markup too.
-//
-function IteratedChar() {
-
- this.charValue = 0; // 1-4 bytes from the raw input data
- this.index = 0;
- this.nextIndex = 0;
- this.error = false;
- this.done = false;
-
- this.reset = function() {
- this.charValue = 0;
- this.index = -1;
- this.nextIndex = 0;
- this.error = false;
- this.done = false;
- };
-
- this.nextByte = function(det) {
- if (this.nextIndex >= det.fRawLength) {
- this.done = true;
- return -1;
- }
- var byteValue = det.fRawInput[this.nextIndex++] & 0x00ff;
- return byteValue;
- };
-};
-
-
-
-/**
- * Asian double or multi-byte - charsets.
- * Match is determined mostly by the input data adhering to the
- * encoding scheme for the charset, and, optionally,
- * frequency-of-occurence of characters.
- */
-
-function mbcs() {};
-
-/**
- * Test the match of this charset with the input text data
- * which is obtained via the CharsetDetector object.
- *
- * @param det The CharsetDetector, which contains the input text
- * to be checked for being in this charset.
- * @return Two values packed into one int (Damn java, anyhow)
- * bits 0-7: the match confidence, ranging from 0-100
- * bits 8-15: The match reason, an enum-like value.
- */
-mbcs.prototype.match = function(det) {
-
- var singleByteCharCount = 0, //TODO Do we really need this?
- doubleByteCharCount = 0,
- commonCharCount = 0,
- badCharCount = 0,
- totalCharCount = 0,
- confidence = 0;
-
- var iter = new IteratedChar();
-
- detectBlock: {
- for (iter.reset(); this.nextChar(iter, det);) {
- totalCharCount++;
- if (iter.error) {
- badCharCount++;
- } else {
- var cv = iter.charValue & 0xFFFFFFFF;
-
- if (cv <= 0xff) {
- singleByteCharCount++;
- } else {
- doubleByteCharCount++;
- if (this.commonChars != null) {
- // NOTE: This assumes that there are no 4-byte common chars.
- if (binarySearch(this.commonChars, cv) >= 0) {
- commonCharCount++;
- }
- }
- }
- }
- if (badCharCount >= 2 && badCharCount * 5 >= doubleByteCharCount) {
- // console.log('its here!')
- // Bail out early if the byte data is not matching the encoding scheme.
- break detectBlock;
- }
- }
-
- if (doubleByteCharCount <= 10 && badCharCount== 0) {
- // Not many multi-byte chars.
- if (doubleByteCharCount == 0 && totalCharCount < 10) {
- // There weren't any multibyte sequences, and there was a low density of non-ASCII single bytes.
- // We don't have enough data to have any confidence.
- // Statistical analysis of single byte non-ASCII charcters would probably help here.
- confidence = 0;
- }
- else {
- // ASCII or ISO file? It's probably not our encoding,
- // but is not incompatible with our encoding, so don't give it a zero.
- confidence = 10;
- }
- break detectBlock;
- }
-
- //
- // No match if there are too many characters that don't fit the encoding scheme.
- // (should we have zero tolerance for these?)
- //
- if (doubleByteCharCount < 20 * badCharCount) {
- confidence = 0;
- break detectBlock;
- }
-
- if (this.commonChars == null) {
- // We have no statistics on frequently occuring characters.
- // Assess confidence purely on having a reasonable number of
- // multi-byte characters (the more the better
- confidence = 30 + doubleByteCharCount - 20 * badCharCount;
- if (confidence > 100) {
- confidence = 100;
- }
- } else {
- //
- // Frequency of occurence statistics exist.
- //
- var maxVal = Math.log(parseFloat(doubleByteCharCount) / 4);
- var scaleFactor = 90.0 / maxVal;
- confidence = Math.floor(Math.log(commonCharCount + 1) * scaleFactor + 10);
- confidence = Math.min(confidence, 100);
- }
- } // end of detectBlock:
-
- return confidence == 0 ? null : new Match(det, this, confidence);
-};
-
-/**
- * Get the next character (however many bytes it is) from the input data
- * Subclasses for specific charset encodings must implement this function
- * to get characters according to the rules of their encoding scheme.
- *
- * This function is not a method of class iteratedChar only because
- * that would require a lot of extra derived classes, which is awkward.
- * @param it The iteratedChar 'struct' into which the returned char is placed.
- * @param det The charset detector, which is needed to get at the input byte data
- * being iterated over.
- * @return True if a character was returned, false at end of input.
- */
-
-mbcs.prototype.nextChar = function(iter, det) {};
-
-
-
-/**
- * Shift-JIS charset recognizer.
- */
-module.exports.sjis = function() {
- this.name = function() {
- return 'Shift-JIS';
- };
- this.language = function() {
- return 'ja';
- };
-
- // TODO: This set of data comes from the character frequency-
- // of-occurence analysis tool. The data needs to be moved
- // into a resource and loaded from there.
- this.commonChars = [
- 0x8140, 0x8141, 0x8142, 0x8145, 0x815b, 0x8169, 0x816a, 0x8175, 0x8176, 0x82a0,
- 0x82a2, 0x82a4, 0x82a9, 0x82aa, 0x82ab, 0x82ad, 0x82af, 0x82b1, 0x82b3, 0x82b5,
- 0x82b7, 0x82bd, 0x82be, 0x82c1, 0x82c4, 0x82c5, 0x82c6, 0x82c8, 0x82c9, 0x82cc,
- 0x82cd, 0x82dc, 0x82e0, 0x82e7, 0x82e8, 0x82e9, 0x82ea, 0x82f0, 0x82f1, 0x8341,
- 0x8343, 0x834e, 0x834f, 0x8358, 0x835e, 0x8362, 0x8367, 0x8375, 0x8376, 0x8389,
- 0x838a, 0x838b, 0x838d, 0x8393, 0x8e96, 0x93fa, 0x95aa
- ];
-
- this.nextChar = function(iter, det) {
- iter.index = iter.nextIndex;
- iter.error = false;
-
- var firstByte;
- firstByte = iter.charValue = iter.nextByte(det);
- if (firstByte < 0)
- return false;
-
- if (firstByte <= 0x7f || (firstByte > 0xa0 && firstByte <= 0xdf))
- return true;
-
- var secondByte = iter.nextByte(det);
- if (secondByte < 0)
- return false;
-
- iter.charValue = (firstByte << 8) | secondByte;
- if (! ((secondByte >= 0x40 && secondByte <= 0x7f) || (secondByte >= 0x80 && secondByte <= 0xff))) {
- // Illegal second byte value.
- iter.error = true;
- }
- return true;
- };
-};
-util.inherits(module.exports.sjis, mbcs);
-
-
-
-/**
- * Big5 charset recognizer.
- */
-module.exports.big5 = function() {
- this.name = function() {
- return 'Big5';
- };
- this.language = function() {
- return 'zh';
- };
- // TODO: This set of data comes from the character frequency-
- // of-occurence analysis tool. The data needs to be moved
- // into a resource and loaded from there.
- this.commonChars = [
- 0xa140, 0xa141, 0xa142, 0xa143, 0xa147, 0xa149, 0xa175, 0xa176, 0xa440, 0xa446,
- 0xa447, 0xa448, 0xa451, 0xa454, 0xa457, 0xa464, 0xa46a, 0xa46c, 0xa477, 0xa4a3,
- 0xa4a4, 0xa4a7, 0xa4c1, 0xa4ce, 0xa4d1, 0xa4df, 0xa4e8, 0xa4fd, 0xa540, 0xa548,
- 0xa558, 0xa569, 0xa5cd, 0xa5e7, 0xa657, 0xa661, 0xa662, 0xa668, 0xa670, 0xa6a8,
- 0xa6b3, 0xa6b9, 0xa6d3, 0xa6db, 0xa6e6, 0xa6f2, 0xa740, 0xa751, 0xa759, 0xa7da,
- 0xa8a3, 0xa8a5, 0xa8ad, 0xa8d1, 0xa8d3, 0xa8e4, 0xa8fc, 0xa9c0, 0xa9d2, 0xa9f3,
- 0xaa6b, 0xaaba, 0xaabe, 0xaacc, 0xaafc, 0xac47, 0xac4f, 0xacb0, 0xacd2, 0xad59,
- 0xaec9, 0xafe0, 0xb0ea, 0xb16f, 0xb2b3, 0xb2c4, 0xb36f, 0xb44c, 0xb44e, 0xb54c,
- 0xb5a5, 0xb5bd, 0xb5d0, 0xb5d8, 0xb671, 0xb7ed, 0xb867, 0xb944, 0xbad8, 0xbb44,
- 0xbba1, 0xbdd1, 0xc2c4, 0xc3b9, 0xc440, 0xc45f
- ];
- this.nextChar = function(iter, det) {
- iter.index = iter.nextIndex;
- iter.error = false;
-
- var firstByte = iter.charValue = iter.nextByte(det);
-
- if (firstByte < 0)
- return false;
-
- // single byte character.
- if (firstByte <= 0x7f || firstByte == 0xff)
- return true;
-
- var secondByte = iter.nextByte(det);
-
- if (secondByte < 0)
- return false;
-
- iter.charValue = (iter.charValue << 8) | secondByte;
-
- if (secondByte < 0x40 || secondByte == 0x7f || secondByte == 0xff)
- iter.error = true;
-
- return true;
- };
-};
-util.inherits(module.exports.big5, mbcs);
-
-
-
-/**
- * EUC charset recognizers. One abstract class that provides the common function
- * for getting the next character according to the EUC encoding scheme,
- * and nested derived classes for EUC_KR, EUC_JP, EUC_CN.
- *
- * Get the next character value for EUC based encodings.
- * Character 'value' is simply the raw bytes that make up the character
- * packed into an int.
- */
-function eucNextChar(iter, det) {
- iter.index = iter.nextIndex;
- iter.error = false;
- var firstByte = 0;
- var secondByte = 0;
- var thirdByte = 0;
- //int fourthByte = 0;
- buildChar: {
- firstByte = iter.charValue = iter.nextByte(det);
- if (firstByte < 0) {
- // Ran off the end of the input data
- iter.done = true;
- break buildChar;
- }
- if (firstByte <= 0x8d) {
- // single byte char
- break buildChar;
- }
- secondByte = iter.nextByte(det);
- iter.charValue = (iter.charValue << 8) | secondByte;
- if (firstByte >= 0xA1 && firstByte <= 0xfe) {
- // Two byte Char
- if (secondByte < 0xa1) {
- iter.error = true;
- }
- break buildChar;
- }
- if (firstByte == 0x8e) {
- // Code Set 2.
- // In EUC-JP, total char size is 2 bytes, only one byte of actual char value.
- // In EUC-TW, total char size is 4 bytes, three bytes contribute to char value.
- // We don't know which we've got.
- // Treat it like EUC-JP. If the data really was EUC-TW, the following two
- // bytes will look like a well formed 2 byte char.
- if (secondByte < 0xa1) {
- iter.error = true;
- }
- break buildChar;
- }
- if (firstByte == 0x8f) {
- // Code set 3.
- // Three byte total char size, two bytes of actual char value.
- thirdByte = iter.nextByte(det);
- iter.charValue = (iter.charValue << 8) | thirdByte;
- if (thirdByte < 0xa1) {
- iter.error = true;
- }
- }
- }
- return iter.done == false;
-};
-
-
-
-/**
- * The charset recognize for EUC-JP. A singleton instance of this class
- * is created and kept by the public CharsetDetector class
- */
-module.exports.euc_jp = function() {
- this.name = function() {
- return 'EUC-JP';
- };
- this.language = function() {
- return 'ja';
- };
-
- // TODO: This set of data comes from the character frequency-
- // of-occurence analysis tool. The data needs to be moved
- // into a resource and loaded from there.
- this.commonChars = [
- 0xa1a1, 0xa1a2, 0xa1a3, 0xa1a6, 0xa1bc, 0xa1ca, 0xa1cb, 0xa1d6, 0xa1d7, 0xa4a2,
- 0xa4a4, 0xa4a6, 0xa4a8, 0xa4aa, 0xa4ab, 0xa4ac, 0xa4ad, 0xa4af, 0xa4b1, 0xa4b3,
- 0xa4b5, 0xa4b7, 0xa4b9, 0xa4bb, 0xa4bd, 0xa4bf, 0xa4c0, 0xa4c1, 0xa4c3, 0xa4c4,
- 0xa4c6, 0xa4c7, 0xa4c8, 0xa4c9, 0xa4ca, 0xa4cb, 0xa4ce, 0xa4cf, 0xa4d0, 0xa4de,
- 0xa4df, 0xa4e1, 0xa4e2, 0xa4e4, 0xa4e8, 0xa4e9, 0xa4ea, 0xa4eb, 0xa4ec, 0xa4ef,
- 0xa4f2, 0xa4f3, 0xa5a2, 0xa5a3, 0xa5a4, 0xa5a6, 0xa5a7, 0xa5aa, 0xa5ad, 0xa5af,
- 0xa5b0, 0xa5b3, 0xa5b5, 0xa5b7, 0xa5b8, 0xa5b9, 0xa5bf, 0xa5c3, 0xa5c6, 0xa5c7,
- 0xa5c8, 0xa5c9, 0xa5cb, 0xa5d0, 0xa5d5, 0xa5d6, 0xa5d7, 0xa5de, 0xa5e0, 0xa5e1,
- 0xa5e5, 0xa5e9, 0xa5ea, 0xa5eb, 0xa5ec, 0xa5ed, 0xa5f3, 0xb8a9, 0xb9d4, 0xbaee,
- 0xbbc8, 0xbef0, 0xbfb7, 0xc4ea, 0xc6fc, 0xc7bd, 0xcab8, 0xcaf3, 0xcbdc, 0xcdd1
- ];
-
- this.nextChar = eucNextChar;
-};
-util.inherits(module.exports.euc_jp, mbcs);
-
-
-
-/**
- * The charset recognize for EUC-KR. A singleton instance of this class
- * is created and kept by the public CharsetDetector class
- */
-module.exports.euc_kr = function() {
- this.name = function() {
- return 'EUC-KR';
- };
- this.language = function() {
- return 'ko';
- };
-
- // TODO: This set of data comes from the character frequency-
- // of-occurence analysis tool. The data needs to be moved
- // into a resource and loaded from there.
- this.commonChars = [
- 0xb0a1, 0xb0b3, 0xb0c5, 0xb0cd, 0xb0d4, 0xb0e6, 0xb0ed, 0xb0f8, 0xb0fa, 0xb0fc,
- 0xb1b8, 0xb1b9, 0xb1c7, 0xb1d7, 0xb1e2, 0xb3aa, 0xb3bb, 0xb4c2, 0xb4cf, 0xb4d9,
- 0xb4eb, 0xb5a5, 0xb5b5, 0xb5bf, 0xb5c7, 0xb5e9, 0xb6f3, 0xb7af, 0xb7c2, 0xb7ce,
- 0xb8a6, 0xb8ae, 0xb8b6, 0xb8b8, 0xb8bb, 0xb8e9, 0xb9ab, 0xb9ae, 0xb9cc, 0xb9ce,
- 0xb9fd, 0xbab8, 0xbace, 0xbad0, 0xbaf1, 0xbbe7, 0xbbf3, 0xbbfd, 0xbcad, 0xbcba,
- 0xbcd2, 0xbcf6, 0xbdba, 0xbdc0, 0xbdc3, 0xbdc5, 0xbec6, 0xbec8, 0xbedf, 0xbeee,
- 0xbef8, 0xbefa, 0xbfa1, 0xbfa9, 0xbfc0, 0xbfe4, 0xbfeb, 0xbfec, 0xbff8, 0xc0a7,
- 0xc0af, 0xc0b8, 0xc0ba, 0xc0bb, 0xc0bd, 0xc0c7, 0xc0cc, 0xc0ce, 0xc0cf, 0xc0d6,
- 0xc0da, 0xc0e5, 0xc0fb, 0xc0fc, 0xc1a4, 0xc1a6, 0xc1b6, 0xc1d6, 0xc1df, 0xc1f6,
- 0xc1f8, 0xc4a1, 0xc5cd, 0xc6ae, 0xc7cf, 0xc7d1, 0xc7d2, 0xc7d8, 0xc7e5, 0xc8ad
- ];
-
- this.nextChar = eucNextChar;
-};
-util.inherits(module.exports.euc_kr, mbcs);
-
-
-
-/**
- * GB-18030 recognizer. Uses simplified Chinese statistics.
- */
-module.exports.gb_18030 = function() {
- this.name = function() {
- return 'GB18030';
- };
- this.language = function() {
- return 'zh';
- };
-
- /*
- * Get the next character value for EUC based encodings.
- * Character 'value' is simply the raw bytes that make up the character
- * packed into an int.
- */
- this.nextChar = function(iter, det) {
- iter.index = iter.nextIndex;
- iter.error = false;
- var firstByte = 0;
- var secondByte = 0;
- var thirdByte = 0;
- var fourthByte = 0;
- buildChar: {
- firstByte = iter.charValue = iter.nextByte(det);
- if (firstByte < 0) {
- // Ran off the end of the input data
- iter.done = true;
- break buildChar;
- }
- if (firstByte <= 0x80) {
- // single byte char
- break buildChar;
- }
- secondByte = iter.nextByte(det);
- iter.charValue = (iter.charValue << 8) | secondByte;
- if (firstByte >= 0x81 && firstByte <= 0xFE) {
- // Two byte Char
- if ((secondByte >= 0x40 && secondByte <= 0x7E) || (secondByte >=80 && secondByte <= 0xFE)) {
- break buildChar;
- }
- // Four byte char
- if (secondByte >= 0x30 && secondByte <= 0x39) {
- thirdByte = iter.nextByte(det);
- if (thirdByte >= 0x81 && thirdByte <= 0xFE) {
- fourthByte = iter.nextByte(det);
- if (fourthByte >= 0x30 && fourthByte <= 0x39) {
- iter.charValue = (iter.charValue << 16) | (thirdByte << 8) | fourthByte;
- break buildChar;
- }
- }
- }
- iter.error = true;
- break buildChar;
- }
- }
- return iter.done == false;
- };
-
- // TODO: This set of data comes from the character frequency-
- // of-occurence analysis tool. The data needs to be moved
- // into a resource and loaded from there.
- this.commonChars = [
- 0xa1a1, 0xa1a2, 0xa1a3, 0xa1a4, 0xa1b0, 0xa1b1, 0xa1f1, 0xa1f3, 0xa3a1, 0xa3ac,
- 0xa3ba, 0xb1a8, 0xb1b8, 0xb1be, 0xb2bb, 0xb3c9, 0xb3f6, 0xb4f3, 0xb5bd, 0xb5c4,
- 0xb5e3, 0xb6af, 0xb6d4, 0xb6e0, 0xb7a2, 0xb7a8, 0xb7bd, 0xb7d6, 0xb7dd, 0xb8b4,
- 0xb8df, 0xb8f6, 0xb9ab, 0xb9c9, 0xb9d8, 0xb9fa, 0xb9fd, 0xbacd, 0xbba7, 0xbbd6,
- 0xbbe1, 0xbbfa, 0xbcbc, 0xbcdb, 0xbcfe, 0xbdcc, 0xbecd, 0xbedd, 0xbfb4, 0xbfc6,
- 0xbfc9, 0xc0b4, 0xc0ed, 0xc1cb, 0xc2db, 0xc3c7, 0xc4dc, 0xc4ea, 0xc5cc, 0xc6f7,
- 0xc7f8, 0xc8ab, 0xc8cb, 0xc8d5, 0xc8e7, 0xc9cf, 0xc9fa, 0xcab1, 0xcab5, 0xcac7,
- 0xcad0, 0xcad6, 0xcaf5, 0xcafd, 0xccec, 0xcdf8, 0xceaa, 0xcec4, 0xced2, 0xcee5,
- 0xcfb5, 0xcfc2, 0xcfd6, 0xd0c2, 0xd0c5, 0xd0d0, 0xd0d4, 0xd1a7, 0xd2aa, 0xd2b2,
- 0xd2b5, 0xd2bb, 0xd2d4, 0xd3c3, 0xd3d0, 0xd3fd, 0xd4c2, 0xd4da, 0xd5e2, 0xd6d0
- ];
-};
-util.inherits(module.exports.gb_18030, mbcs);
projects / dotfiles / .git / blobdiff