/**********************************************************************
transcode.c -
$Author: duerst $
$Date: 2007-10-30 16:10:22 +0900 (Tue, 30 Oct 2007) $
created at: Tue Oct 30 16:10:22 JST 2007
Copyright (C) 2007 Martin Duerst
**********************************************************************/
#include "ruby/ruby.h"
#include "ruby/encoding.h"
#include "transcode_data.h"
/*
* prototypes and macros copied from string.c (temporarily !!!)
*/
VALUE str_new(VALUE klass, const char *ptr, long len);
int str_independent(VALUE str);
#define STR_NOCAPA_P(s) (FL_TEST(s,STR_NOEMBED) && FL_ANY(s,ELTS_SHARED|STR_ASSOC))
#define STR_NOEMBED FL_USER1
#define STR_ASSOC FL_USER3
#define STR_SET_NOEMBED(str) do {\
FL_SET(str, STR_NOEMBED);\
STR_SET_EMBED_LEN(str, 0);\
} while (0)
#define STR_UNSET_NOCAPA(s) do {\
if (FL_TEST(s,STR_NOEMBED)) FL_UNSET(s,(ELTS_SHARED|STR_ASSOC));\
} while (0)
#define STR_SET_EMBED_LEN(str, n) do { \
long tmp_n = (n);\
RBASIC(str)->flags &= ~RSTRING_EMBED_LEN_MASK;\
RBASIC(str)->flags |= (tmp_n) << RSTRING_EMBED_LEN_SHIFT;\
} while (0)
#define STR_SET_LEN(str, n) do { \
if (STR_EMBED_P(str)) {\
STR_SET_EMBED_LEN(str, n);\
}\
else {\
RSTRING(str)->as.heap.len = (n);\
}\
} while (0)
#define STR_EMBED_P(str) (!FL_TEST(str, STR_NOEMBED))
#define RESIZE_CAPA(str,capacity) do {\
if (STR_EMBED_P(str)) {\
if ((capacity) > RSTRING_EMBED_LEN_MAX) {\
char *tmp = ALLOC_N(char, capacity+1);\
memcpy(tmp, RSTRING_PTR(str), RSTRING_LEN(str));\
RSTRING(str)->as.heap.ptr = tmp;\
RSTRING(str)->as.heap.len = RSTRING_LEN(str);\
STR_SET_NOEMBED(str);\
RSTRING(str)->as.heap.aux.capa = (capacity);\
}\
}\
else {\
REALLOC_N(RSTRING(str)->as.heap.ptr, char, (capacity)+1);\
if (!STR_NOCAPA_P(str))\
RSTRING(str)->as.heap.aux.capa = (capacity);\
}\
} while (0)
/* end of copied prototypes and macros */
/*
* Dispatch data and logic
*/
/* extern declarations, should use some include file here */
extern const BYTE_LOOKUP from_ISO_8859_1;
extern const BYTE_LOOKUP from_ISO_8859_2;
extern const BYTE_LOOKUP from_ISO_8859_3;
extern const BYTE_LOOKUP from_ISO_8859_4;
extern const BYTE_LOOKUP from_ISO_8859_5;
extern const BYTE_LOOKUP from_ISO_8859_6;
extern const BYTE_LOOKUP from_ISO_8859_7;
extern const BYTE_LOOKUP from_ISO_8859_8;
extern const BYTE_LOOKUP from_ISO_8859_9;
extern const BYTE_LOOKUP from_ISO_8859_10;
extern const BYTE_LOOKUP from_ISO_8859_11;
extern const BYTE_LOOKUP from_ISO_8859_13;
extern const BYTE_LOOKUP from_ISO_8859_14;
extern const BYTE_LOOKUP from_ISO_8859_15;
extern const BYTE_LOOKUP to_ISO_8859_1;
extern const BYTE_LOOKUP to_ISO_8859_2;
extern const BYTE_LOOKUP to_ISO_8859_3;
extern const BYTE_LOOKUP to_ISO_8859_4;
extern const BYTE_LOOKUP to_ISO_8859_5;
extern const BYTE_LOOKUP to_ISO_8859_6;
extern const BYTE_LOOKUP to_ISO_8859_7;
extern const BYTE_LOOKUP to_ISO_8859_8;
extern const BYTE_LOOKUP to_ISO_8859_9;
extern const BYTE_LOOKUP to_ISO_8859_10;
extern const BYTE_LOOKUP to_ISO_8859_11;
extern const BYTE_LOOKUP to_ISO_8859_13;
extern const BYTE_LOOKUP to_ISO_8859_14;
extern const BYTE_LOOKUP to_ISO_8859_15;
/* declarations probably need to go into separate header file, e.g. transcode.h */
/* static structure, one per supported encoding pair */
typedef struct {
const char *from_encoding;
const char *to_encoding;
BYTE_LOOKUP *conv_tree_start;
int max_output;
int from_utf8;
} transcoder;
/* todo: dynamic structure, one per conversion (stream) */
/* in the future, add some mechanism for dynamically adding stuff here */
#define MAX_TRANSCODERS 29 /* todo: fix: this number has to be adjusted by hand */
static transcoder transcoder_table[MAX_TRANSCODERS];
/* not sure why it's not possible to do relocatable initializations */
/* maybe the code here can be removed (changed to simple initialization) */
/* if we move this to another file???? */
static void
register_transcoder (const char *from_e, const char *to_e,
const BYTE_LOOKUP *tree_start, int max_output, int from_utf8)
{
static int n = 0;
if (n >= MAX_TRANSCODERS) {
/* we are initializing, is it okay to use rb_raise here? */
rb_raise(rb_eRuntimeError /*change exception*/, "not enough transcoder slots");
}
transcoder_table[n].from_encoding = from_e;
transcoder_table[n].to_encoding = to_e;
transcoder_table[n].conv_tree_start = (BYTE_LOOKUP *)tree_start;
transcoder_table[n].max_output = max_output;
transcoder_table[n].from_utf8 = from_utf8;
n++;
}
static void
init_transcoder_table (void)
{
register_transcoder("ISO-8859-1", "UTF-8", &from_ISO_8859_1, 2, 0);
register_transcoder("ISO-8859-2", "UTF-8", &from_ISO_8859_2, 2, 0);
register_transcoder("ISO-8859-3", "UTF-8", &from_ISO_8859_3, 2, 0);
register_transcoder("ISO-8859-4", "UTF-8", &from_ISO_8859_4, 2, 0);
register_transcoder("ISO-8859-5", "UTF-8", &from_ISO_8859_5, 3, 0);
register_transcoder("ISO-8859-6", "UTF-8", &from_ISO_8859_6, 2, 0);
register_transcoder("ISO-8859-7", "UTF-8", &from_ISO_8859_7, 3, 0);
register_transcoder("ISO-8859-8", "UTF-8", &from_ISO_8859_8, 3, 0);
register_transcoder("ISO-8859-9", "UTF-8", &from_ISO_8859_9, 2, 0);
register_transcoder("ISO-8859-10", "UTF-8", &from_ISO_8859_10, 3, 0);
register_transcoder("ISO-8859-11", "UTF-8", &from_ISO_8859_11, 3, 0);
register_transcoder("ISO-8859-13", "UTF-8", &from_ISO_8859_13, 3, 0);
register_transcoder("ISO-8859-14", "UTF-8", &from_ISO_8859_14, 3, 0);
register_transcoder("ISO-8859-15", "UTF-8", &from_ISO_8859_15, 3, 0);
register_transcoder("UTF-8", "ISO-8859-1", &to_ISO_8859_1, 1, 1);
register_transcoder("UTF-8", "ISO-8859-2", &to_ISO_8859_2, 1, 1);
register_transcoder("UTF-8", "ISO-8859-3", &to_ISO_8859_3, 1, 1);
register_transcoder("UTF-8", "ISO-8859-4", &to_ISO_8859_4, 1, 1);
register_transcoder("UTF-8", "ISO-8859-5", &to_ISO_8859_5, 1, 1);
register_transcoder("UTF-8", "ISO-8859-6", &to_ISO_8859_6, 1, 1);
register_transcoder("UTF-8", "ISO-8859-7", &to_ISO_8859_7, 1, 1);
register_transcoder("UTF-8", "ISO-8859-8", &to_ISO_8859_8, 1, 1);
register_transcoder("UTF-8", "ISO-8859-9", &to_ISO_8859_9, 1, 1);
register_transcoder("UTF-8", "ISO-8859-10", &to_ISO_8859_10, 1, 1);
register_transcoder("UTF-8", "ISO-8859-11", &to_ISO_8859_11, 1, 1);
register_transcoder("UTF-8", "ISO-8859-13", &to_ISO_8859_13, 1, 1);
register_transcoder("UTF-8", "ISO-8859-14", &to_ISO_8859_14, 1, 1);
register_transcoder("UTF-8", "ISO-8859-15", &to_ISO_8859_15, 1, 1);
register_transcoder(NULL, NULL, NULL, 0, 0);
}
static transcoder*
transcode_dispatch (char* from_encoding, char* to_encoding)
{
transcoder *candidate = transcoder_table;
for (candidate = transcoder_table; candidate->from_encoding; candidate++)
if (0==strcasecmp(from_encoding, candidate->from_encoding)
&& 0==strcasecmp(to_encoding, candidate->to_encoding))
break;
/* in the future, add multistep transcoding logic here */
return candidate->from_encoding ? candidate : NULL;
}
/* dynamic structure, one per conversion (similar to iconv_t) */
/* may carry conversion state (e.g. for iso-2022-jp) */
typedef struct {
VALUE ruby_string_dest; /* the String used as the conversion destination,
or NULL if something else is being converted */
} transcoding;
/*
* Transcoding engine logic
*/
static void
transcode_loop (unsigned char **in_pos, unsigned char **out_pos,
unsigned char *in_stop, unsigned char *out_stop,
transcoder *my_transcoder,
transcoding *my_transcoding)
{
unsigned char *input = *in_pos, *output = *out_pos;
unsigned char *in_p = *in_pos, *out_p = *out_pos;
BYTE_LOOKUP *conv_tree_start = my_transcoder->conv_tree_start;
BYTE_LOOKUP *next_table;
unsigned int next_offset;
unsigned int next_info;
unsigned char next_byte;
int from_utf8 = my_transcoder->from_utf8;
unsigned char *out_s = out_stop - my_transcoder->max_output + 1;
while (in_p < in_stop) {
unsigned char *char_start = in_p;
next_table = conv_tree_start;
if (out_p >= out_s) {
VALUE dest_string = my_transcoding->ruby_string_dest;
if (!dest_string) {
rb_raise(rb_eArgError /*@@@change exception*/, "Unable to obtain more space for transcoding");
}
else {
int len = (out_p - *out_pos);
int new_len = (len + my_transcoder->max_output) * 2;
RESIZE_CAPA(dest_string, new_len);
STR_SET_LEN(dest_string, new_len);
*out_pos = RSTRING_PTR(dest_string);
out_p = *out_pos + len;
out_s = *out_pos + new_len - my_transcoder->max_output;
}
}
next_byte = *in_p++;
follow_byte:
next_offset = next_table->base[next_byte];
next_info = (unsigned int)next_table->info[next_offset];
switch (next_info & 0x1F) {
case NOMAP:
*out_p++ = next_byte;
continue;
case 0x00: case 0x04: case 0x08: case 0x0C:
case 0x10: case 0x14: case 0x18: case 0x1C:
if (in_p >= in_stop) {
/* todo: deal with the case of backtracking */
/* todo: deal with incomplete input (streaming) */
goto illegal;
}
next_byte = *in_p++;
if (from_utf8) {
if ((next_byte&0xC0) == 0x80)
next_byte -= 0x80;
else
goto illegal;
}
next_table = (BYTE_LOOKUP*)next_info;
goto follow_byte;
/* maybe rewrite the following cases to use fallthrough???? */
case ZERObt: /* drop input */
continue;
case ONEbt:
*out_p++ = getBT1(next_info);
continue;
case TWObt:
*out_p++ = getBT1(next_info);
*out_p++ = getBT2(next_info);
continue;
case FOURbt:
*out_p++ = getBT0(next_info);
case THREEbt: /* fall through */
*out_p++ = getBT1(next_info);
*out_p++ = getBT2(next_info);
*out_p++ = getBT3(next_info);
continue;
case ILLEGAL:
goto illegal;
case UNDEF:
/* todo: add code for alternative behaviors */
rb_raise(rb_eRuntimeError /*@@@change exception*/, "conversion undefined for byte sequence");
continue;
}
continue;
illegal:
/* deal with illegal byte sequence */
/* todo: add code for alternative behaviors */
rb_raise(rb_eRuntimeError /*change exception*/, "illegal byte sequence");
continue;
}
/* cleanup */
*in_pos = in_p;
*out_pos = out_p;
}
/*
* String-specific code
*/
static VALUE
str_transcode(int argc, VALUE *argv, VALUE str, int bang)
{
VALUE dest;
long blen, slen, len;
char *buf, *bp, *sp, *fromp;
int tainted = 0;
rb_encoding *from_enc, *to_enc;
char *from_e, *to_e;
transcoder *my_transcoder;
int idx;
transcoding my_transcoding;
if (argc<1 || argc>2) {
rb_raise(rb_eArgError, "wrong number of arguments (%d for 2)", argc);
}
to_enc = NULL; /* todo: work out later, 'to' parameter may be Encoding,
or we want an encoding to set on result */
to_e = RSTRING_PTR(StringValue(argv[0]));
if (argc==1) {
from_enc = rb_enc_get(str);
from_e = (char *)rb_enc_name(from_enc);
}
else {
from_enc = NULL; /* todo: work out later, 'from' parameter may be Encoding */
from_e = RSTRING_PTR(StringValue(argv[1]));
}
/* strcasecmp: hope we are in C locale or locale-insensitive */
if (0==strcasecmp(from_e, to_e)) { /* TODO: add tests for US-ASCII-clean data and ASCII-compatible encodings */
if (bang) return str;
return rb_str_dup(str);
}
if (!(my_transcoder = transcode_dispatch(from_e, to_e))) {
rb_raise(rb_eArgError, "transcoding not supported (from %s to %s)", from_e, to_e);
}
fromp = sp = RSTRING_PTR(str);
slen = RSTRING_LEN(str);
blen = slen + 30; /* len + margin */
dest = str_new(0, 0, blen);
bp = buf = RSTRING_PTR(dest);
my_transcoding.ruby_string_dest = dest;
rb_str_locktmp(dest);
/* for simple testing: */
transcode_loop((unsigned char **)&fromp, (unsigned char **)&bp,
(unsigned char*)(sp+slen), (unsigned char*)(bp+blen),
my_transcoder, &my_transcoding);
if (fromp != sp+slen) {
rb_raise(rb_eArgError, "not fully converted, %d bytes left", sp+slen-fromp);
}
buf = RSTRING_PTR(dest);
blen = RSTRING_LEN(dest);
*bp = '\0';
rb_str_unlocktmp(dest);
if (bang) {
if (str_independent(str) && !STR_EMBED_P(str)) {
free(RSTRING_PTR(str));
}
STR_SET_NOEMBED(str);
STR_UNSET_NOCAPA(str);
RSTRING(str)->as.heap.ptr = buf;
RSTRING(str)->as.heap.aux.capa = blen;
RSTRING(dest)->as.heap.ptr = 0;
RSTRING(dest)->as.heap.len = 0;
}
else {
RBASIC(dest)->klass = rb_obj_class(str);
OBJ_INFECT(dest, str);
str = dest;
}
STR_SET_LEN(str, bp - buf);
/* set encoding */ /* would like to have an easier way to do this */
if ((idx = rb_enc_find_index(to_e)) < 0) {
if ((idx = rb_enc_find_index("ASCII-8BIT")) < 0) {
rb_raise(rb_eArgError, "unknown encoding name: ASCII-8BIT");
}
}
rb_enc_associate(str, rb_enc_from_index(idx));
if (tainted) OBJ_TAINT(str); /* is this needed??? */
return str;
}
/*
* call-seq:
* str.encode!(encoding) => str
* str.encode!(to_encoding, from_encoding) => str
*
* With one argument, transcodes the contents of str from
* str.encoding to +encoding+.
* With two arguments, transcodes the contents of str from
* from_encoding to to_encoding.
* Returns the string even if no changes were made.
*/
static VALUE
rb_str_transcode_bang(int argc, VALUE *argv, VALUE str)
{
return str_transcode(argc, argv, str, 1);
}
/*
* call-seq:
* str.encode(encoding) => str
*
* With one argument, returns a copy of str transcoded
* to encoding +encoding+.
* With two arguments, returns a copy of str transcoded
* from from_encoding to to_encoding.
*/
static VALUE
rb_str_transcode(int argc, VALUE *argv, VALUE str)
{
return str_transcode(argc, argv, str, 0);
}
/* function to fool the optimizer (avoid inlining transcode_loop) */
void
transcode_fool_the_optimizer (void)
{
unsigned char **in_pos, **out_pos, *in_stop, *out_stop;
transcoder *my_transcoder;
transcoding *my_transcoding;
transcode_loop(in_pos, out_pos, in_stop, out_stop,
my_transcoder, my_transcoding);
}
void
Init_transcode(void)
{
init_transcoder_table();
rb_define_method(rb_cString, "encode", rb_str_transcode, -1);
rb_define_method(rb_cString, "encode!", rb_str_transcode_bang, -1);
}