Annotation of XML/encoding.c, revision 1.13
1.1 daniel 1: /*
2: * encoding.c : implements the encoding conversion functions needed for XML
3: *
4: * Related specs:
5: * rfc2044 (UTF-8 and UTF-16) F. Yergeau Alis Technologies
6: * [ISO-10646] UTF-8 and UTF-16 in Annexes
7: * [ISO-8859-1] ISO Latin-1 characters codes.
8: * [UNICODE] The Unicode Consortium, "The Unicode Standard --
9: * Worldwide Character Encoding -- Version 1.0", Addison-
10: * Wesley, Volume 1, 1991, Volume 2, 1992. UTF-8 is
11: * described in Unicode Technical Report #4.
12: * [US-ASCII] Coded Character Set--7-bit American Standard Code for
13: * Information Interchange, ANSI X3.4-1986.
14: *
1.9 daniel 15: * Original code for IsoLatin1 and UTF-16 by "Martin J. Duerst" <duerst@w3.org>
1.1 daniel 16: *
17: * See Copyright for the status of this software.
18: *
19: * Daniel.Veillard@w3.org
20: */
21:
1.7 daniel 22: #include <ctype.h>
1.9 daniel 23: #include <string.h>
24: #include <stdio.h>
1.1 daniel 25: #include "encoding.h"
1.12 daniel 26: #ifdef HAVE_UNICODE_H
27: #include <unicode.h>
28: #endif
1.3 daniel 29:
1.12 daniel 30: #ifdef HAVE_UNICODE_H
31:
32: #else /* ! HAVE_UNICODE_H */
1.3 daniel 33: /*
34: * From rfc2044: encoding of the Unicode values on UTF-8:
35: *
36: * UCS-4 range (hex.) UTF-8 octet sequence (binary)
37: * 0000 0000-0000 007F 0xxxxxxx
38: * 0000 0080-0000 07FF 110xxxxx 10xxxxxx
39: * 0000 0800-0000 FFFF 1110xxxx 10xxxxxx 10xxxxxx
40: *
41: * I hope we won't use values > 0xFFFF anytime soon !
42: */
1.1 daniel 43:
44: /**
45: * isolat1ToUTF8:
46: * @out: a pointer ot an array of bytes to store the result
47: * @outlen: the lenght of @out
48: * @in: a pointer ot an array of ISO Latin 1 chars
49: * @inlen: the lenght of @in
50: *
51: * Take a block of ISO Latin 1 chars in and try to convert it to an UTF-8
52: * block of chars out.
1.6 daniel 53: * Returns the number of byte written, or -1 by lack of space.
1.1 daniel 54: */
55: int
56: isolat1ToUTF8(unsigned char* out, int outlen, unsigned char* in, int inlen)
57: {
58: unsigned char* outstart= out;
59: unsigned char* outend= out+outlen;
60: unsigned char* inend= in+inlen;
61: unsigned char c;
62:
63: while (in < inend) {
64: c= *in++;
65: if (c < 0x80) {
66: if (out >= outend) return -1;
67: *out++ = c;
68: }
69: else {
70: if (out >= outend) return -1;
71: *out++ = 0xC0 | (c >> 6);
72: if (out >= outend) return -1;
73: *out++ = 0x80 | (0x3F & c);
74: }
75: }
76: return out-outstart;
77: }
78:
79: /**
80: * UTF8Toisolat1:
81: * @out: a pointer ot an array of bytes to store the result
82: * @outlen: the lenght of @out
83: * @in: a pointer ot an array of UTF-8 chars
84: * @inlen: the lenght of @in
85: *
86: * Take a block of UTF-8 chars in and try to convert it to an ISO Latin 1
87: * block of chars out.
88: * TODO: need a fallback mechanism ...
1.6 daniel 89: * Returns the number of byte written, or -1 by lack of space, or -2
1.1 daniel 90: * if the transcoding failed.
91: */
92: int
93: UTF8Toisolat1(unsigned char* out, int outlen, unsigned char* in, int inlen)
94: {
95: unsigned char* outstart= out;
96: unsigned char* outend= out+outlen;
97: unsigned char* inend= in+inlen;
98: unsigned char c;
99:
100: while (in < inend) {
101: c= *in++;
102: if (c < 0x80) {
103: if (out >= outend) return -1;
104: *out++= c;
105: }
106: else if (((c & 0xFE) == 0xC2) && in<inend) {
107: if (out >= outend) return -1;
108: *out++= ((c & 0x03) << 6) | (*in++ & 0x3F);
109: }
110: else return -2;
111: }
112: return out-outstart;
113: }
114:
115: /**
116: * UTF16ToUTF8:
117: * @out: a pointer ot an array of bytes to store the result
118: * @outlen: the lenght of @out
119: * @in: a pointer ot an array of UTF-16 chars (array of unsigned shorts)
120: * @inlen: the lenght of @in
121: *
122: * Take a block of UTF-16 ushorts in and try to convert it to an UTF-8
123: * block of chars out.
1.6 daniel 124: * Returns the number of byte written, or -1 by lack of space.
1.1 daniel 125: */
126: int
127: UTF16ToUTF8(unsigned char* out, int outlen, unsigned short* in, int inlen)
128: {
129: unsigned char* outstart= out;
130: unsigned char* outend= out+outlen;
131: unsigned short* inend= in+inlen;
132: unsigned int c, d;
133: int bits;
134:
135: while (in < inend) {
136: c= *in++;
137: if ((c & 0xFC00) == 0xD800) { /* surrogates */
138: if ((in<inend) && (((d=*in++) & 0xFC00) == 0xDC00)) {
139: c &= 0x03FF;
140: c <<= 10;
141: c |= d & 0x03FF;
142: c += 0x10000;
143: }
144: else return -1;
145: }
146:
147: /* assertion: c is a single UTF-4 value */
148:
149: if (out >= outend) return -1;
150: if (c < 0x80) { *out++= c; bits= -6; }
151: else if (c < 0x800) { *out++= (c >> 6) | 0xC0; bits= 0; }
152: else if (c < 0x10000) { *out++= (c >> 12) | 0xE0; bits= 6; }
153: else { *out++= (c >> 18) | 0xF0; bits= 12; }
154:
155: for ( ; bits < 0; bits-= 6) {
156: if (out >= outend) return -1;
157: *out++= (c >> bits) & 0x3F;
158: }
159: }
160: return out-outstart;
161: }
162:
163: /**
164: * UTF8ToUTF16:
165: * @out: a pointer ot an array of shorts to store the result
166: * @outlen: the lenght of @out (number of shorts)
167: * @in: a pointer ot an array of UTF-8 chars
168: * @inlen: the lenght of @in
169: *
170: * Take a block of UTF-8 chars in and try to convert it to an UTF-16
171: * block of chars out.
172: * TODO: need a fallback mechanism ...
1.6 daniel 173: * Returns the number of byte written, or -1 by lack of space, or -2
1.1 daniel 174: * if the transcoding failed.
175: */
176: int
177: UTF8ToUTF16(unsigned short* out, int outlen, unsigned char* in, int inlen)
178: {
179: unsigned short* outstart= out;
180: unsigned short* outend= out+outlen;
181: unsigned char* inend= in+inlen;
182: unsigned int c, d, trailing;
183:
184: while (in < inend) {
185: d= *in++;
186: if (d < 0x80) { c= d; trailing= 0; }
187: else if (d < 0xC0) return -2; /* trailing byte in leading position */
188: else if (d < 0xE0) { c= d & 0x1F; trailing= 1; }
189: else if (d < 0xF0) { c= d & 0x0F; trailing= 2; }
190: else if (d < 0xF8) { c= d & 0x07; trailing= 3; }
191: else return -2; /* no chance for this in UTF-16 */
192:
193: for ( ; trailing; trailing--) {
194: if ((in >= inend) || (((d= *in++) & 0xC0) != 0x80)) return -1;
195: c <<= 6;
196: c |= d & 0x3F;
197: }
198:
199: /* assertion: c is a single UTF-4 value */
200: if (c < 0x10000) {
201: if (out >= outend) return -1;
202: *out++ = c;
203: }
204: else if (c < 0x110000) {
205: if (out+1 >= outend) return -1;
206: c -= 0x10000;
207: *out++ = 0xD800 | (c >> 10);
208: *out++ = 0xDC00 | (c & 0x03FF);
209: }
210: else return -1;
211: }
212: return out-outstart;
213: }
214:
1.12 daniel 215: #endif /* ! HAVE_UNICODE_H */
1.1 daniel 216:
1.7 daniel 217: /**
218: * xmlDetectCharEncoding:
219: * @in: a pointer to the first bytes of the XML entity, must be at least
220: * 4 bytes long.
221: *
222: * Guess the encoding of the entity using the first bytes of the entity content
223: * accordingly of the non-normative appendix F of the XML-1.0 recommendation.
224: *
225: * Returns one of the XML_CHAR_ENCODING_... values.
226: */
227: xmlCharEncoding
1.8 daniel 228: xmlDetectCharEncoding(const unsigned char* in)
1.7 daniel 229: {
230: if ((in[0] == 0x00) && (in[1] == 0x00) &&
231: (in[2] == 0x00) && (in[3] == 0x3C))
232: return(XML_CHAR_ENCODING_UCS4BE);
233: if ((in[0] == 0x3C) && (in[1] == 0x00) &&
234: (in[2] == 0x00) && (in[3] == 0x00))
235: return(XML_CHAR_ENCODING_UCS4LE);
236: if ((in[0] == 0x00) && (in[1] == 0x00) &&
237: (in[2] == 0x3C) && (in[3] == 0x00))
238: return(XML_CHAR_ENCODING_UCS4_2143);
239: if ((in[0] == 0x00) && (in[1] == 0x3C) &&
240: (in[2] == 0x00) && (in[3] == 0x00))
241: return(XML_CHAR_ENCODING_UCS4_3412);
242: if ((in[0] == 0xFE) && (in[1] == 0xFF))
243: return(XML_CHAR_ENCODING_UTF16BE);
244: if ((in[0] == 0xFF) && (in[1] == 0xFE))
245: return(XML_CHAR_ENCODING_UTF16LE);
246: if ((in[0] == 0x4C) && (in[1] == 0x6F) &&
247: (in[2] == 0xA7) && (in[3] == 0x94))
248: return(XML_CHAR_ENCODING_EBCDIC);
249: if ((in[0] == 0x3C) && (in[1] == 0x3F) &&
250: (in[2] == 0x78) && (in[3] == 0x6D))
251: return(XML_CHAR_ENCODING_UTF8);
252: return(XML_CHAR_ENCODING_NONE);
253: }
254:
255: /**
256: * xmlParseCharEncoding:
257: * @name: the encoding name as parsed, in UTF-8 format (ASCCI actually)
258: *
259: * Conpare the string to the known encoding schemes already known. Note
260: * that the comparison is case insensitive accordingly to the section
261: * [XML] 4.3.3 Character Encoding in Entities.
262: *
263: * Returns one of the XML_CHAR_ENCODING_... values or XML_CHAR_ENCODING_NONE
264: * if not recognized.
265: */
266: xmlCharEncoding
1.8 daniel 267: xmlParseCharEncoding(const char* name)
1.7 daniel 268: {
269: char upper[500];
270: int i;
271:
272: for (i = 0;i < 499;i++) {
273: upper[i] = toupper(name[i]);
274: if (upper[i] == 0) break;
275: }
276: upper[i] = 0;
277:
278: if (!strcmp(upper, "")) return(XML_CHAR_ENCODING_NONE);
279: if (!strcmp(upper, "UTF-8")) return(XML_CHAR_ENCODING_UTF8);
280: if (!strcmp(upper, "UTF8")) return(XML_CHAR_ENCODING_UTF8);
281:
282: /*
283: * NOTE: if we were able to parse this, the endianness of UTF16 is
284: * already found and in use
285: */
286: if (!strcmp(upper, "UTF-16")) return(XML_CHAR_ENCODING_UTF16LE);
287: if (!strcmp(upper, "UTF16")) return(XML_CHAR_ENCODING_UTF16LE);
288:
289: if (!strcmp(upper, "ISO-10646-UCS-2")) return(XML_CHAR_ENCODING_UCS2);
290: if (!strcmp(upper, "UCS-2")) return(XML_CHAR_ENCODING_UCS2);
291: if (!strcmp(upper, "UCS2")) return(XML_CHAR_ENCODING_UCS2);
292:
293: /*
294: * NOTE: if we were able to parse this, the endianness of UCS4 is
295: * already found and in use
296: */
297: if (!strcmp(upper, "ISO-10646-UCS-4")) return(XML_CHAR_ENCODING_UCS4LE);
298: if (!strcmp(upper, "UCS-4")) return(XML_CHAR_ENCODING_UCS4LE);
299: if (!strcmp(upper, "UCS4")) return(XML_CHAR_ENCODING_UCS4LE);
300:
301:
302: if (!strcmp(upper, "ISO-8859-1")) return(XML_CHAR_ENCODING_8859_1);
303: if (!strcmp(upper, "ISO-LATIN-1")) return(XML_CHAR_ENCODING_8859_1);
304: if (!strcmp(upper, "ISO LATIN 1")) return(XML_CHAR_ENCODING_8859_1);
305:
306: if (!strcmp(upper, "ISO-8859-2")) return(XML_CHAR_ENCODING_8859_2);
307: if (!strcmp(upper, "ISO-LATIN-2")) return(XML_CHAR_ENCODING_8859_2);
308: if (!strcmp(upper, "ISO LATIN 2")) return(XML_CHAR_ENCODING_8859_2);
309:
310: if (!strcmp(upper, "ISO-8859-3")) return(XML_CHAR_ENCODING_8859_3);
311: if (!strcmp(upper, "ISO-8859-4")) return(XML_CHAR_ENCODING_8859_4);
312: if (!strcmp(upper, "ISO-8859-5")) return(XML_CHAR_ENCODING_8859_5);
313: if (!strcmp(upper, "ISO-8859-6")) return(XML_CHAR_ENCODING_8859_6);
314: if (!strcmp(upper, "ISO-8859-7")) return(XML_CHAR_ENCODING_8859_7);
315: if (!strcmp(upper, "ISO-8859-8")) return(XML_CHAR_ENCODING_8859_8);
316: if (!strcmp(upper, "ISO-8859-9")) return(XML_CHAR_ENCODING_8859_9);
317:
318: if (!strcmp(upper, "ISO-2022-JP")) return(XML_CHAR_ENCODING_2022_JP);
319: if (!strcmp(upper, "Shift_JIS")) return(XML_CHAR_ENCODING_SHIFT_JIS);
320: if (!strcmp(upper, "EUC-JP")) return(XML_CHAR_ENCODING_EUC_JP);
321: return(XML_CHAR_ENCODING_ERROR);
322: }
1.9 daniel 323:
324: /****************************************************************
325: * *
326: * Char encoding handlers *
327: * *
328: ****************************************************************/
329:
330: /* the size should be growable, but it's not a big deal ... */
331: #define MAX_ENCODING_HANDLERS 50
332: static xmlCharEncodingHandlerPtr *handlers = NULL;
333: static int nbCharEncodingHandler = 0;
334:
335: /*
336: * The default is UTF-8 for XML, that's also the default used for the
337: * parser internals, so the default encoding handler is NULL
338: */
339:
340: static xmlCharEncodingHandlerPtr xmlDefaultCharEncodingHandler = NULL;
341:
342: /**
343: * xmlNewCharEncodingHandler:
344: * @name: the encoding name, in UTF-8 format (ASCCI actually)
345: * @input: the xmlCharEncodingInputFunc to read that encoding
346: * @output: the xmlCharEncodingOutputFunc to write that encoding
347: *
348: * Create and registers an xmlCharEncodingHandler.
349: * Returns the xmlCharEncodingHandlerPtr created (or NULL in case of error).
350: */
351: xmlCharEncodingHandlerPtr
352: xmlNewCharEncodingHandler(const char *name, xmlCharEncodingInputFunc input,
353: xmlCharEncodingOutputFunc output) {
354: xmlCharEncodingHandlerPtr handler;
355: char upper[500];
356: int i;
357: char *up = 0;
358:
359: /*
360: * Keep only the uppercase version of the encoding.
361: */
362: if (name == NULL) {
363: fprintf(stderr, "xmlNewCharEncodingHandler : no name !\n");
364: return(NULL);
365: }
366: for (i = 0;i < 499;i++) {
367: upper[i] = toupper(name[i]);
368: if (upper[i] == 0) break;
369: }
370: upper[i] = 0;
371: up = strdup(upper);
372: if (up == NULL) {
373: fprintf(stderr, "xmlNewCharEncodingHandler : out of memory !\n");
374: return(NULL);
375: }
376:
377: /*
378: * allocate and fill-up an handler block.
379: */
380: handler = (xmlCharEncodingHandlerPtr)
381: malloc(sizeof(xmlCharEncodingHandler));
382: if (handler == NULL) {
383: fprintf(stderr, "xmlNewCharEncodingHandler : out of memory !\n");
384: return(NULL);
385: }
386: handler->input = input;
387: handler->output = output;
388: handler->name = up;
389:
390: /*
391: * registers and returns the handler.
392: */
393: xmlRegisterCharEncodingHandler(handler);
394: return(handler);
395: }
396:
397: /**
398: * xmlInitCharEncodingHandlers:
399: *
400: * Initialize the char encoding support, it registers the default
401: * encoding supported.
402: * NOTE: while public theis function usually don't need to be called
403: * in normal processing.
404: */
405: void
406: xmlInitCharEncodingHandlers(void) {
407: if (handlers != NULL) return;
408:
409: handlers = (xmlCharEncodingHandlerPtr *)
410: malloc(MAX_ENCODING_HANDLERS * sizeof(xmlCharEncodingHandlerPtr));
411:
412: if (handlers == NULL) {
413: fprintf(stderr, "xmlInitCharEncodingHandlers : out of memory !\n");
414: return;
415: }
1.10 daniel 416: xmlNewCharEncodingHandler("UTF-8", NULL, NULL);
1.12 daniel 417: #ifdef HAVE_UNICODE_H
418: #else
1.13 ! daniel 419: /* xmlNewCharEncodingHandler("UTF-16", UTF16ToUTF8, UTF8ToUTF16); */
1.10 daniel 420: xmlNewCharEncodingHandler("ISO-8859-1", isolat1ToUTF8, UTF8Toisolat1);
1.12 daniel 421: #endif
1.9 daniel 422: }
423:
424: /**
425: * xmlRegisterCharEncodingHandler:
426: * @handler: the xmlCharEncodingHandlerPtr handler block
427: *
428: * Register the char encoding handler, surprizing, isn't it ?
429: */
430: void
431: xmlRegisterCharEncodingHandler(xmlCharEncodingHandlerPtr handler) {
432: if (handlers == NULL) xmlInitCharEncodingHandlers();
433: if (handler == NULL) {
434: fprintf(stderr, "xmlRegisterCharEncodingHandler: NULL handler !\n");
435: return;
436: }
437:
438: if (nbCharEncodingHandler >= MAX_ENCODING_HANDLERS) {
439: fprintf(stderr,
440: "xmlRegisterCharEncodingHandler: Too many handler registered\n");
441: fprintf(stderr, "\tincrease MAX_ENCODING_HANDLERS : %s\n", __FILE__);
442: return;
443: }
444: handlers[nbCharEncodingHandler++] = handler;
445: }
446:
447: /**
448: * xmlGetCharEncodingHandler:
449: * @enc: an xmlCharEncoding value.
450: *
451: * Search in the registrered set the handler able to read/write that encoding.
452: *
453: * Returns the handler or NULL if not found
454: */
455: xmlCharEncodingHandlerPtr
456: xmlGetCharEncodingHandler(xmlCharEncoding enc) {
457: if (handlers == NULL) xmlInitCharEncodingHandlers();
1.11 daniel 458: /* TODO !!!!!!! */
1.9 daniel 459: return(NULL);
460: }
461:
462: /**
463: * xmlGetCharEncodingHandler:
464: * @enc: a string describing the char encoding.
465: *
466: * Search in the registrered set the handler able to read/write that encoding.
467: *
468: * Returns the handler or NULL if not found
469: */
470: xmlCharEncodingHandlerPtr
471: xmlFindCharEncodingHandler(const char *name) {
472: char upper[500];
473: int i;
474:
475: if (handlers == NULL) xmlInitCharEncodingHandlers();
476: if (name == NULL) return(xmlDefaultCharEncodingHandler);
477: if (name[0] == 0) return(xmlDefaultCharEncodingHandler);
478:
479: for (i = 0;i < 499;i++) {
480: upper[i] = toupper(name[i]);
481: if (upper[i] == 0) break;
482: }
483: upper[i] = 0;
484:
485: for (i = 0;i < nbCharEncodingHandler; i++)
486: if (!strcmp(name, handlers[i]->name))
487: return(handlers[i]);
488:
489: return(NULL);
490: }
491:
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