tune.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#include <u.h>
#include <libc.h>
#include <bio.h>
#include "hdr.h"
#include "conv.h"

typedef struct Tmap Tmap;
struct Tmap
{
	Rune u;
	Rune t;
};

static Tmap t1[] =
{
	{0x0b85/*அ*/, 0xe201/**/},
	{0x0b86/*ஆ*/, 0xe202/**/},
	{0x0b87/*இ*/, 0xe203/**/},
	{0x0b88/*ஈ*/, 0xe204/**/},
	{0x0b89/*உ*/, 0xe205/**/},
	{0x0b8a/*ஊ*/, 0xe206/**/},
	{0x0b8e/*எ*/, 0xe207/**/},
	{0x0b8f/*ஏ*/, 0xe208/**/},
	{0x0b90/*ஐ*/, 0xe209/**/},
	{0x0b92/*ஒ*/, 0xe20a/**/},
	{0x0b93/*ஓ*/, 0xe20b/**/},
	{0x0b94/*ஔ*/, 0xe20c/**/},
	{0x0b83/*ஃ*/, 0xe20d/**/}
};

static Rune t2[] =
{
	0x0bcd/*்*/, 
	0x0bcd/*்*/,	// filler
	0x0bbe/*ா*/,
	0x0bbf/*ி*/,
	0x0bc0/*ீ*/,
	0x0bc1/*ு*/,
	0x0bc2/*ூ*/,
	0x0bc6/*ெ*/,
	0x0bc7/*ே*/,
	0x0bc8/*ை*/,
	0x0bca/*ொ*/,
	0x0bcb/*ோ*/,
	0x0bcc/*ௌ*/
};

static Tmap t3[] =
{
	{0x0b95/*க*/, 0xe211/**/},
	{0x0b99/*ங*/, 0xe221/**/},
	{0x0b9a/*ச*/, 0xe231/**/},
	{0x0b9c/*ஜ*/, 0xe331/**/},
	{0x0b9e/*ஞ*/, 0xe241/**/},
	{0x0b9f/*ட*/, 0xe251/**/},
	{0x0ba3/*ண*/, 0xe261/**/},
	{0x0ba4/*த*/, 0xe271/**/},
	{0x0ba8/*ந*/, 0xe281/**/},
	{0x0ba9/*ன*/, 0xe321/**/},
	{0x0baa/*ப*/, 0xe291/**/},
	{0x0bae/*ம*/, 0xe2a1/**/},
	{0x0baf/*ய*/, 0xe2b1/**/},
	{0x0bb0/*ர*/, 0xe2c1/**/},
	{0x0bb1/*ற*/, 0xe311/**/},
	{0x0bb2/*ல*/, 0xe2d1/**/},
	{0x0bb3/*ள*/, 0xe301/**/},
	{0x0bb4/*ழ*/, 0xe2f1/**/},
	{0x0bb5/*வ*/, 0xe2e1/**/},
 	{0x0bb6/*ஶ*/, 0xe341/**/},
	{0x0bb7/*ஷ*/, 0xe351/**/},
	{0x0bb8/*ஸ*/, 0xe361/**/},
	{0x0bb9/*ஹ*/, 0xe371/**/}
};

static Rune
findbytune(Tmap *tab, int size, Rune t)
{
	int i;

	for(i = 0; i < size; i++)
		if(tab[i].t == t)
			return tab[i].u;
	return Runeerror;
}

static Rune
findbyuni(Tmap *tab, int size, Rune u)
{
	int i;

	for(i = 0; i < size; i++)
		if(tab[i].u == u)
			return tab[i].t;
	return Runeerror;
}

static int
findindex(Rune *rstr, int size, Rune r)
{
	int i;

	for(i = 0; i < size; i++)
		if(rstr[i] == r)
			return i;
	return -1;
}

void
tune_in(int fd, long *x, struct convert *out)
{
	Biobuf b;
	Rune rbuf[N];
	Rune *r, *er, tr;
	int c, i;
	
	USED(x);
	r = rbuf;
	er = rbuf+N-3;
	Binit(&b, fd, OREAD);
	while((c = Bgetrune(&b)) != Beof){
		ninput += b.runesize;
		if(r >= er){
			OUT(out, rbuf, r-rbuf);
			r = rbuf;
		}
		if(c>=0xe210/**/ && c <= 0xe38c/**/ && (i = c%16) < nelem(t2)){
			if(c >= 0xe380/**/){
				*r++ = 0x0b95/*க*/;
				*r++ = 0x0bcd/*்*/;
				*r++ = 0x0bb7/*ஷ*/;
			}else
				*r++ = findbytune(t3, nelem(t3), c-i+1);
			if(i != 1)
				*r++ = t2[i];
		}else if((tr = findbytune(t1, nelem(t1), c)) != Runeerror)
			*r++ = tr;
		else switch(c){
			case 0xe3d0/**/:
				*r++ = 0x0ba3/*ண*/; *r++ = 0x0bbe/*ா*/;
				break;
			case 0xe3d1/**/:
				*r++ = 0x0bb1/*ற*/; *r++ = 0x0bbe/*ா*/;
				break;
			case 0xe3d2/**/:
				*r++ = 0x0ba9/*ன*/; *r++ = 0x0bbe/*ா*/;
				break;
			case 0xe3d4/**/:
				*r++ = 0x0ba3/*ண*/; *r++ = 0x0bc8/*ை*/;
				break;
			case 0xe3d5/**/:
				*r++ = 0x0bb2/*ல*/; *r++ = 0x0bc8/*ை*/;
				break;
			case 0xe3d6/**/:
				*r++ = 0x0bb3/*ள*/; *r++ = 0x0bc8/*ை*/;
				break;
			case 0xe3d7/**/:
				*r++ = 0x0ba9/*ன*/; *r++ = 0x0bc8/*ை*/;
				break;
			case 0xe38d/**/:
				*r++ = 0x0bb6/*ஶ*/; *r++ = 0x0bcd/*்*/; *r++ = 0x0bb0/*ர*/; *r++ = 0x0bc0/*ீ*/;
				break;
			default: 
				if(c >= 0xe200 && c <= 0xe3ff){
					if(squawk)
						EPR "%s: rune 0x%x not in output cs\n", argv0, c);
					nerrors++;
					if(clean)
						break;
					c = BADMAP;
				}
				*r++ = c;
				break;
		}
	}
	if(r > rbuf)
		OUT(out, rbuf, r-rbuf);
	OUT(out, rbuf, 0);
}

void
tune_out(Rune *r, int n, long *x)
{
	static int state = 0;
	static Rune lastr;
	Rune *er, tr, rr;
	char *p;
	int i;

	USED(x);
	nrunes += n;
	er = r+n;
	for(p = obuf; r < er; r++){
		switch(state){
		case 0:
		case0:
			if((tr = findbyuni(t3, nelem(t3), *r)) != Runeerror){
				lastr = tr;
				state = 1;
			}else if(*r == 0x0b92/*ஒ*/){
				lastr = 0xe20a/**/;
				state = 3;
			}else if((tr = findbyuni(t1, nelem(t1), *r)) != Runeerror)
				p += runetochar(p, &tr);
			else
				p += runetochar(p, r);
			break;
		case 1:
		case1:
			if((i = findindex(t2, nelem(t2), *r)) != -1){
				if(lastr && lastr != Runeerror)
					lastr += i-1;
				if(*r ==0x0bc6/*ெ*/)
					state = 5;
				else if(*r ==0x0bc7/*ே*/)
					state = 4;
				else if(lastr == 0xe210/**/)
					state = 2;
				else if(lastr == 0xe340/**/)
					state = 6;
				else{
					if(lastr)
						p += runetochar(p, &lastr);
					state = 0;
				}
			}else if(lastr && lastr != Runeerror && (*r == 0x00b2/*²*/ || *r == 0x00b3/*³*/ || *r == 0x2074/*⁴*/)){
				if(squawk)
					EPR "%s: character <U+%.4X, U+%.4X> not in output cs\n", argv0, lastr, *r);
				lastr = clean ? 0 : Runeerror;
				nerrors++;
			}else{
				if(lastr)
					p += runetochar(p, &lastr);
				state = 0;
				goto case0;
			}
			break;
		case 2:
			if(*r == 0x0bb7/*ஷ*/){
				lastr = 0xe381/**/;
				state = 1;
				break;
			}
			p += runetochar(p, &lastr);
			state = 0;
			goto case0;
		case 3:
			state = 0;
			if(*r == 0x0bd7/*ௗ*/){
				rr = 0xe20c/**/;
				p += runetochar(p, &rr);
				break;
			}
			p += runetochar(p, &lastr);
			goto case0;
		case 4:
			state = 0;
			if(*r == 0x0bbe/*ா*/){
				if(lastr){
					if(lastr != Runeerror)
						lastr += 3;
					p += runetochar(p, &lastr);
				}
				break;
			}
			if(lastr)
				p += runetochar(p, &lastr);
			goto case0;
		case 5:
			state = 0;
			if(*r == 0x0bbe/*ா*/ || *r == 0x0bd7/*ௗ*/){
				if(lastr){
					if(lastr != Runeerror)
						lastr += *r == 0x0bbe/*ா*/ ? 3 : 5;
					p += runetochar(p, &lastr);
				}
				break;
			}
			if(lastr)
				p += runetochar(p, &lastr);
			goto case0;
		case 6:
			if(*r == 0x0bb0/*ர*/){
				state = 7;
				break;
			}
			p += runetochar(p, &lastr);
			state = 0;
			goto case0;
		case 7:
			if(*r == 0x0bc0/*ீ*/){
				rr = 0xe38d/**/;
				p += runetochar(p, &rr);
				state = 0;
				break;
			}
			p += runetochar(p, &lastr);
			lastr = 0xe2c1/**/;
			state = 1;
			goto case1;
		}
	}
	if(n == 0 && state != 0){
		if(lastr)
			p += runetochar(p, &lastr);
		state = 0;
	}
	noutput += p-obuf;
	write(1, obuf, p-obuf);
}