--- /dev/null
+"use strict";
+var Buffer = require("safer-buffer").Buffer;
+
+// Multibyte codec. In this scheme, a character is represented by 1 or more bytes.
+// Our codec supports UTF-16 surrogates, extensions for GB18030 and unicode sequences.
+// To save memory and loading time, we read table files only when requested.
+
+exports._dbcs = DBCSCodec;
+
+var UNASSIGNED = -1,
+ GB18030_CODE = -2,
+ SEQ_START = -10,
+ NODE_START = -1000,
+ UNASSIGNED_NODE = new Array(0x100),
+ DEF_CHAR = -1;
+
+for (var i = 0; i < 0x100; i++)
+ UNASSIGNED_NODE[i] = UNASSIGNED;
+
+
+// Class DBCSCodec reads and initializes mapping tables.
+function DBCSCodec(codecOptions, iconv) {
+ this.encodingName = codecOptions.encodingName;
+ if (!codecOptions)
+ throw new Error("DBCS codec is called without the data.")
+ if (!codecOptions.table)
+ throw new Error("Encoding '" + this.encodingName + "' has no data.");
+
+ // Load tables.
+ var mappingTable = codecOptions.table();
+
+
+ // Decode tables: MBCS -> Unicode.
+
+ // decodeTables is a trie, encoded as an array of arrays of integers. Internal arrays are trie nodes and all have len = 256.
+ // Trie root is decodeTables[0].
+ // Values: >= 0 -> unicode character code. can be > 0xFFFF
+ // == UNASSIGNED -> unknown/unassigned sequence.
+ // == GB18030_CODE -> this is the end of a GB18030 4-byte sequence.
+ // <= NODE_START -> index of the next node in our trie to process next byte.
+ // <= SEQ_START -> index of the start of a character code sequence, in decodeTableSeq.
+ this.decodeTables = [];
+ this.decodeTables[0] = UNASSIGNED_NODE.slice(0); // Create root node.
+
+ // Sometimes a MBCS char corresponds to a sequence of unicode chars. We store them as arrays of integers here.
+ this.decodeTableSeq = [];
+
+ // Actual mapping tables consist of chunks. Use them to fill up decode tables.
+ for (var i = 0; i < mappingTable.length; i++)
+ this._addDecodeChunk(mappingTable[i]);
+
+ this.defaultCharUnicode = iconv.defaultCharUnicode;
+
+
+ // Encode tables: Unicode -> DBCS.
+
+ // `encodeTable` is array mapping from unicode char to encoded char. All its values are integers for performance.
+ // Because it can be sparse, it is represented as array of buckets by 256 chars each. Bucket can be null.
+ // Values: >= 0 -> it is a normal char. Write the value (if <=256 then 1 byte, if <=65536 then 2 bytes, etc.).
+ // == UNASSIGNED -> no conversion found. Output a default char.
+ // <= SEQ_START -> it's an index in encodeTableSeq, see below. The character starts a sequence.
+ this.encodeTable = [];
+
+ // `encodeTableSeq` is used when a sequence of unicode characters is encoded as a single code. We use a tree of
+ // objects where keys correspond to characters in sequence and leafs are the encoded dbcs values. A special DEF_CHAR key
+ // means end of sequence (needed when one sequence is a strict subsequence of another).
+ // Objects are kept separately from encodeTable to increase performance.
+ this.encodeTableSeq = [];
+
+ // Some chars can be decoded, but need not be encoded.
+ var skipEncodeChars = {};
+ if (codecOptions.encodeSkipVals)
+ for (var i = 0; i < codecOptions.encodeSkipVals.length; i++) {
+ var val = codecOptions.encodeSkipVals[i];
+ if (typeof val === 'number')
+ skipEncodeChars[val] = true;
+ else
+ for (var j = val.from; j <= val.to; j++)
+ skipEncodeChars[j] = true;
+ }
+
+ // Use decode trie to recursively fill out encode tables.
+ this._fillEncodeTable(0, 0, skipEncodeChars);
+
+ // Add more encoding pairs when needed.
+ if (codecOptions.encodeAdd) {
+ for (var uChar in codecOptions.encodeAdd)
+ if (Object.prototype.hasOwnProperty.call(codecOptions.encodeAdd, uChar))
+ this._setEncodeChar(uChar.charCodeAt(0), codecOptions.encodeAdd[uChar]);
+ }
+
+ this.defCharSB = this.encodeTable[0][iconv.defaultCharSingleByte.charCodeAt(0)];
+ if (this.defCharSB === UNASSIGNED) this.defCharSB = this.encodeTable[0]['?'];
+ if (this.defCharSB === UNASSIGNED) this.defCharSB = "?".charCodeAt(0);
+
+
+ // Load & create GB18030 tables when needed.
+ if (typeof codecOptions.gb18030 === 'function') {
+ this.gb18030 = codecOptions.gb18030(); // Load GB18030 ranges.
+
+ // Add GB18030 decode tables.
+ var thirdByteNodeIdx = this.decodeTables.length;
+ var thirdByteNode = this.decodeTables[thirdByteNodeIdx] = UNASSIGNED_NODE.slice(0);
+
+ var fourthByteNodeIdx = this.decodeTables.length;
+ var fourthByteNode = this.decodeTables[fourthByteNodeIdx] = UNASSIGNED_NODE.slice(0);
+
+ for (var i = 0x81; i <= 0xFE; i++) {
+ var secondByteNodeIdx = NODE_START - this.decodeTables[0][i];
+ var secondByteNode = this.decodeTables[secondByteNodeIdx];
+ for (var j = 0x30; j <= 0x39; j++)
+ secondByteNode[j] = NODE_START - thirdByteNodeIdx;
+ }
+ for (var i = 0x81; i <= 0xFE; i++)
+ thirdByteNode[i] = NODE_START - fourthByteNodeIdx;
+ for (var i = 0x30; i <= 0x39; i++)
+ fourthByteNode[i] = GB18030_CODE
+ }
+}
+
+DBCSCodec.prototype.encoder = DBCSEncoder;
+DBCSCodec.prototype.decoder = DBCSDecoder;
+
+// Decoder helpers
+DBCSCodec.prototype._getDecodeTrieNode = function(addr) {
+ var bytes = [];
+ for (; addr > 0; addr >>= 8)
+ bytes.push(addr & 0xFF);
+ if (bytes.length == 0)
+ bytes.push(0);
+
+ var node = this.decodeTables[0];
+ for (var i = bytes.length-1; i > 0; i--) { // Traverse nodes deeper into the trie.
+ var val = node[bytes[i]];
+
+ if (val == UNASSIGNED) { // Create new node.
+ node[bytes[i]] = NODE_START - this.decodeTables.length;
+ this.decodeTables.push(node = UNASSIGNED_NODE.slice(0));
+ }
+ else if (val <= NODE_START) { // Existing node.
+ node = this.decodeTables[NODE_START - val];
+ }
+ else
+ throw new Error("Overwrite byte in " + this.encodingName + ", addr: " + addr.toString(16));
+ }
+ return node;
+}
+
+
+DBCSCodec.prototype._addDecodeChunk = function(chunk) {
+ // First element of chunk is the hex mbcs code where we start.
+ var curAddr = parseInt(chunk[0], 16);
+
+ // Choose the decoding node where we'll write our chars.
+ var writeTable = this._getDecodeTrieNode(curAddr);
+ curAddr = curAddr & 0xFF;
+
+ // Write all other elements of the chunk to the table.
+ for (var k = 1; k < chunk.length; k++) {
+ var part = chunk[k];
+ if (typeof part === "string") { // String, write as-is.
+ for (var l = 0; l < part.length;) {
+ var code = part.charCodeAt(l++);
+ if (0xD800 <= code && code < 0xDC00) { // Decode surrogate
+ var codeTrail = part.charCodeAt(l++);
+ if (0xDC00 <= codeTrail && codeTrail < 0xE000)
+ writeTable[curAddr++] = 0x10000 + (code - 0xD800) * 0x400 + (codeTrail - 0xDC00);
+ else
+ throw new Error("Incorrect surrogate pair in " + this.encodingName + " at chunk " + chunk[0]);
+ }
+ else if (0x0FF0 < code && code <= 0x0FFF) { // Character sequence (our own encoding used)
+ var len = 0xFFF - code + 2;
+ var seq = [];
+ for (var m = 0; m < len; m++)
+ seq.push(part.charCodeAt(l++)); // Simple variation: don't support surrogates or subsequences in seq.
+
+ writeTable[curAddr++] = SEQ_START - this.decodeTableSeq.length;
+ this.decodeTableSeq.push(seq);
+ }
+ else
+ writeTable[curAddr++] = code; // Basic char
+ }
+ }
+ else if (typeof part === "number") { // Integer, meaning increasing sequence starting with prev character.
+ var charCode = writeTable[curAddr - 1] + 1;
+ for (var l = 0; l < part; l++)
+ writeTable[curAddr++] = charCode++;
+ }
+ else
+ throw new Error("Incorrect type '" + typeof part + "' given in " + this.encodingName + " at chunk " + chunk[0]);
+ }
+ if (curAddr > 0xFF)
+ throw new Error("Incorrect chunk in " + this.encodingName + " at addr " + chunk[0] + ": too long" + curAddr);
+}
+
+// Encoder helpers
+DBCSCodec.prototype._getEncodeBucket = function(uCode) {
+ var high = uCode >> 8; // This could be > 0xFF because of astral characters.
+ if (this.encodeTable[high] === undefined)
+ this.encodeTable[high] = UNASSIGNED_NODE.slice(0); // Create bucket on demand.
+ return this.encodeTable[high];
+}
+
+DBCSCodec.prototype._setEncodeChar = function(uCode, dbcsCode) {
+ var bucket = this._getEncodeBucket(uCode);
+ var low = uCode & 0xFF;
+ if (bucket[low] <= SEQ_START)
+ this.encodeTableSeq[SEQ_START-bucket[low]][DEF_CHAR] = dbcsCode; // There's already a sequence, set a single-char subsequence of it.
+ else if (bucket[low] == UNASSIGNED)
+ bucket[low] = dbcsCode;
+}
+
+DBCSCodec.prototype._setEncodeSequence = function(seq, dbcsCode) {
+
+ // Get the root of character tree according to first character of the sequence.
+ var uCode = seq[0];
+ var bucket = this._getEncodeBucket(uCode);
+ var low = uCode & 0xFF;
+
+ var node;
+ if (bucket[low] <= SEQ_START) {
+ // There's already a sequence with - use it.
+ node = this.encodeTableSeq[SEQ_START-bucket[low]];
+ }
+ else {
+ // There was no sequence object - allocate a new one.
+ node = {};
+ if (bucket[low] !== UNASSIGNED) node[DEF_CHAR] = bucket[low]; // If a char was set before - make it a single-char subsequence.
+ bucket[low] = SEQ_START - this.encodeTableSeq.length;
+ this.encodeTableSeq.push(node);
+ }
+
+ // Traverse the character tree, allocating new nodes as needed.
+ for (var j = 1; j < seq.length-1; j++) {
+ var oldVal = node[uCode];
+ if (typeof oldVal === 'object')
+ node = oldVal;
+ else {
+ node = node[uCode] = {}
+ if (oldVal !== undefined)
+ node[DEF_CHAR] = oldVal
+ }
+ }
+
+ // Set the leaf to given dbcsCode.
+ uCode = seq[seq.length-1];
+ node[uCode] = dbcsCode;
+}
+
+DBCSCodec.prototype._fillEncodeTable = function(nodeIdx, prefix, skipEncodeChars) {
+ var node = this.decodeTables[nodeIdx];
+ for (var i = 0; i < 0x100; i++) {
+ var uCode = node[i];
+ var mbCode = prefix + i;
+ if (skipEncodeChars[mbCode])
+ continue;
+
+ if (uCode >= 0)
+ this._setEncodeChar(uCode, mbCode);
+ else if (uCode <= NODE_START)
+ this._fillEncodeTable(NODE_START - uCode, mbCode << 8, skipEncodeChars);
+ else if (uCode <= SEQ_START)
+ this._setEncodeSequence(this.decodeTableSeq[SEQ_START - uCode], mbCode);
+ }
+}
+
+
+
+// == Encoder ==================================================================
+
+function DBCSEncoder(options, codec) {
+ // Encoder state
+ this.leadSurrogate = -1;
+ this.seqObj = undefined;
+
+ // Static data
+ this.encodeTable = codec.encodeTable;
+ this.encodeTableSeq = codec.encodeTableSeq;
+ this.defaultCharSingleByte = codec.defCharSB;
+ this.gb18030 = codec.gb18030;
+}
+
+DBCSEncoder.prototype.write = function(str) {
+ var newBuf = Buffer.alloc(str.length * (this.gb18030 ? 4 : 3)),
+ leadSurrogate = this.leadSurrogate,
+ seqObj = this.seqObj, nextChar = -1,
+ i = 0, j = 0;
+
+ while (true) {
+ // 0. Get next character.
+ if (nextChar === -1) {
+ if (i == str.length) break;
+ var uCode = str.charCodeAt(i++);
+ }
+ else {
+ var uCode = nextChar;
+ nextChar = -1;
+ }
+
+ // 1. Handle surrogates.
+ if (0xD800 <= uCode && uCode < 0xE000) { // Char is one of surrogates.
+ if (uCode < 0xDC00) { // We've got lead surrogate.
+ if (leadSurrogate === -1) {
+ leadSurrogate = uCode;
+ continue;
+ } else {
+ leadSurrogate = uCode;
+ // Double lead surrogate found.
+ uCode = UNASSIGNED;
+ }
+ } else { // We've got trail surrogate.
+ if (leadSurrogate !== -1) {
+ uCode = 0x10000 + (leadSurrogate - 0xD800) * 0x400 + (uCode - 0xDC00);
+ leadSurrogate = -1;
+ } else {
+ // Incomplete surrogate pair - only trail surrogate found.
+ uCode = UNASSIGNED;
+ }
+
+ }
+ }
+ else if (leadSurrogate !== -1) {
+ // Incomplete surrogate pair - only lead surrogate found.
+ nextChar = uCode; uCode = UNASSIGNED; // Write an error, then current char.
+ leadSurrogate = -1;
+ }
+
+ // 2. Convert uCode character.
+ var dbcsCode = UNASSIGNED;
+ if (seqObj !== undefined && uCode != UNASSIGNED) { // We are in the middle of the sequence
+ var resCode = seqObj[uCode];
+ if (typeof resCode === 'object') { // Sequence continues.
+ seqObj = resCode;
+ continue;
+
+ } else if (typeof resCode == 'number') { // Sequence finished. Write it.
+ dbcsCode = resCode;
+
+ } else if (resCode == undefined) { // Current character is not part of the sequence.
+
+ // Try default character for this sequence
+ resCode = seqObj[DEF_CHAR];
+ if (resCode !== undefined) {
+ dbcsCode = resCode; // Found. Write it.
+ nextChar = uCode; // Current character will be written too in the next iteration.
+
+ } else {
+ // TODO: What if we have no default? (resCode == undefined)
+ // Then, we should write first char of the sequence as-is and try the rest recursively.
+ // Didn't do it for now because no encoding has this situation yet.
+ // Currently, just skip the sequence and write current char.
+ }
+ }
+ seqObj = undefined;
+ }
+ else if (uCode >= 0) { // Regular character
+ var subtable = this.encodeTable[uCode >> 8];
+ if (subtable !== undefined)
+ dbcsCode = subtable[uCode & 0xFF];
+
+ if (dbcsCode <= SEQ_START) { // Sequence start
+ seqObj = this.encodeTableSeq[SEQ_START-dbcsCode];
+ continue;
+ }
+
+ if (dbcsCode == UNASSIGNED && this.gb18030) {
+ // Use GB18030 algorithm to find character(s) to write.
+ var idx = findIdx(this.gb18030.uChars, uCode);
+ if (idx != -1) {
+ var dbcsCode = this.gb18030.gbChars[idx] + (uCode - this.gb18030.uChars[idx]);
+ newBuf[j++] = 0x81 + Math.floor(dbcsCode / 12600); dbcsCode = dbcsCode % 12600;
+ newBuf[j++] = 0x30 + Math.floor(dbcsCode / 1260); dbcsCode = dbcsCode % 1260;
+ newBuf[j++] = 0x81 + Math.floor(dbcsCode / 10); dbcsCode = dbcsCode % 10;
+ newBuf[j++] = 0x30 + dbcsCode;
+ continue;
+ }
+ }
+ }
+
+ // 3. Write dbcsCode character.
+ if (dbcsCode === UNASSIGNED)
+ dbcsCode = this.defaultCharSingleByte;
+
+ if (dbcsCode < 0x100) {
+ newBuf[j++] = dbcsCode;
+ }
+ else if (dbcsCode < 0x10000) {
+ newBuf[j++] = dbcsCode >> 8; // high byte
+ newBuf[j++] = dbcsCode & 0xFF; // low byte
+ }
+ else {
+ newBuf[j++] = dbcsCode >> 16;
+ newBuf[j++] = (dbcsCode >> 8) & 0xFF;
+ newBuf[j++] = dbcsCode & 0xFF;
+ }
+ }
+
+ this.seqObj = seqObj;
+ this.leadSurrogate = leadSurrogate;
+ return newBuf.slice(0, j);
+}
+
+DBCSEncoder.prototype.end = function() {
+ if (this.leadSurrogate === -1 && this.seqObj === undefined)
+ return; // All clean. Most often case.
+
+ var newBuf = Buffer.alloc(10), j = 0;
+
+ if (this.seqObj) { // We're in the sequence.
+ var dbcsCode = this.seqObj[DEF_CHAR];
+ if (dbcsCode !== undefined) { // Write beginning of the sequence.
+ if (dbcsCode < 0x100) {
+ newBuf[j++] = dbcsCode;
+ }
+ else {
+ newBuf[j++] = dbcsCode >> 8; // high byte
+ newBuf[j++] = dbcsCode & 0xFF; // low byte
+ }
+ } else {
+ // See todo above.
+ }
+ this.seqObj = undefined;
+ }
+
+ if (this.leadSurrogate !== -1) {
+ // Incomplete surrogate pair - only lead surrogate found.
+ newBuf[j++] = this.defaultCharSingleByte;
+ this.leadSurrogate = -1;
+ }
+
+ return newBuf.slice(0, j);
+}
+
+// Export for testing
+DBCSEncoder.prototype.findIdx = findIdx;
+
+
+// == Decoder ==================================================================
+
+function DBCSDecoder(options, codec) {
+ // Decoder state
+ this.nodeIdx = 0;
+ this.prevBuf = Buffer.alloc(0);
+
+ // Static data
+ this.decodeTables = codec.decodeTables;
+ this.decodeTableSeq = codec.decodeTableSeq;
+ this.defaultCharUnicode = codec.defaultCharUnicode;
+ this.gb18030 = codec.gb18030;
+}
+
+DBCSDecoder.prototype.write = function(buf) {
+ var newBuf = Buffer.alloc(buf.length*2),
+ nodeIdx = this.nodeIdx,
+ prevBuf = this.prevBuf, prevBufOffset = this.prevBuf.length,
+ seqStart = -this.prevBuf.length, // idx of the start of current parsed sequence.
+ uCode;
+
+ if (prevBufOffset > 0) // Make prev buf overlap a little to make it easier to slice later.
+ prevBuf = Buffer.concat([prevBuf, buf.slice(0, 10)]);
+
+ for (var i = 0, j = 0; i < buf.length; i++) {
+ var curByte = (i >= 0) ? buf[i] : prevBuf[i + prevBufOffset];
+
+ // Lookup in current trie node.
+ var uCode = this.decodeTables[nodeIdx][curByte];
+
+ if (uCode >= 0) {
+ // Normal character, just use it.
+ }
+ else if (uCode === UNASSIGNED) { // Unknown char.
+ // TODO: Callback with seq.
+ //var curSeq = (seqStart >= 0) ? buf.slice(seqStart, i+1) : prevBuf.slice(seqStart + prevBufOffset, i+1 + prevBufOffset);
+ i = seqStart; // Try to parse again, after skipping first byte of the sequence ('i' will be incremented by 'for' cycle).
+ uCode = this.defaultCharUnicode.charCodeAt(0);
+ }
+ else if (uCode === GB18030_CODE) {
+ var curSeq = (seqStart >= 0) ? buf.slice(seqStart, i+1) : prevBuf.slice(seqStart + prevBufOffset, i+1 + prevBufOffset);
+ var ptr = (curSeq[0]-0x81)*12600 + (curSeq[1]-0x30)*1260 + (curSeq[2]-0x81)*10 + (curSeq[3]-0x30);
+ var idx = findIdx(this.gb18030.gbChars, ptr);
+ uCode = this.gb18030.uChars[idx] + ptr - this.gb18030.gbChars[idx];
+ }
+ else if (uCode <= NODE_START) { // Go to next trie node.
+ nodeIdx = NODE_START - uCode;
+ continue;
+ }
+ else if (uCode <= SEQ_START) { // Output a sequence of chars.
+ var seq = this.decodeTableSeq[SEQ_START - uCode];
+ for (var k = 0; k < seq.length - 1; k++) {
+ uCode = seq[k];
+ newBuf[j++] = uCode & 0xFF;
+ newBuf[j++] = uCode >> 8;
+ }
+ uCode = seq[seq.length-1];
+ }
+ else
+ throw new Error("iconv-lite internal error: invalid decoding table value " + uCode + " at " + nodeIdx + "/" + curByte);
+
+ // Write the character to buffer, handling higher planes using surrogate pair.
+ if (uCode > 0xFFFF) {
+ uCode -= 0x10000;
+ var uCodeLead = 0xD800 + Math.floor(uCode / 0x400);
+ newBuf[j++] = uCodeLead & 0xFF;
+ newBuf[j++] = uCodeLead >> 8;
+
+ uCode = 0xDC00 + uCode % 0x400;
+ }
+ newBuf[j++] = uCode & 0xFF;
+ newBuf[j++] = uCode >> 8;
+
+ // Reset trie node.
+ nodeIdx = 0; seqStart = i+1;
+ }
+
+ this.nodeIdx = nodeIdx;
+ this.prevBuf = (seqStart >= 0) ? buf.slice(seqStart) : prevBuf.slice(seqStart + prevBufOffset);
+ return newBuf.slice(0, j).toString('ucs2');
+}
+
+DBCSDecoder.prototype.end = function() {
+ var ret = '';
+
+ // Try to parse all remaining chars.
+ while (this.prevBuf.length > 0) {
+ // Skip 1 character in the buffer.
+ ret += this.defaultCharUnicode;
+ var buf = this.prevBuf.slice(1);
+
+ // Parse remaining as usual.
+ this.prevBuf = Buffer.alloc(0);
+ this.nodeIdx = 0;
+ if (buf.length > 0)
+ ret += this.write(buf);
+ }
+
+ this.nodeIdx = 0;
+ return ret;
+}
+
+// Binary search for GB18030. Returns largest i such that table[i] <= val.
+function findIdx(table, val) {
+ if (table[0] > val)
+ return -1;
+
+ var l = 0, r = table.length;
+ while (l < r-1) { // always table[l] <= val < table[r]
+ var mid = l + Math.floor((r-l+1)/2);
+ if (table[mid] <= val)
+ l = mid;
+ else
+ r = mid;
+ }
+ return l;
+}
+
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