#include <u.h>#include <libc.h>#include <ctype.h>#include "pdf.h" Object *pdfstring(Stream *s);Object *pdfname(Stream *s);Object *pdfarray(Pdf *pdf, Stream *s);Object *pdfdict(Pdf *pdf, Stream *s); /* returns 1 if str is at the beginning of the stream, and	is followed either by whitespace or, if delim is 1,	a delimiter.	strlen(str) must be in (0, 16)	on match, the stream seeks to right after the string.	otherwise, the stream position is unchanged. */static intsismatch(Stream *s, char *str, int delim){	long len = strlen(str);	vlong off = Soffset(s);	char b[16];	if(len == 0 || len > 16)		return 0;	if(Sread(s, b, len + 1) == len + 1 && memcmp(b, str, len) == 0 && (isws(b[len]) || (delim && isdelim(b[len])))){		Sungetc(s);		return 1;	} 	Sseek(s, off, 0);	return 0;} char *suntilend(Stream *s){	int sz, c, full = 0;	char buf[8];	for(sz = 0; sz < 7;){		c = Sgetc(s);		if(c < 0)			break;		if(isws(c) || isdelim(c)){			Sungetc(s);			full = 1;			break;		}		buf[sz] = c;		sz += 1;	}	if(!full)		return nil;	buf[sz] = 0;	return strdup(buf);} /* General function to parse an object of any type. */Object *pdfobj(Pdf *pdf, Stream *s){	Object *o, *o2;	vlong off;	int c;	Xref xref; 	o = o2 = nil;	do; while(isws(c = Sgetc(s)));	if(c < 0)		goto err; 	if(isascii(c) && isalpha(c)){		Sungetc(s);		// bool, null, or op		if(sismatch(s, "null", 1)){			fprint(1, "NULL\n");			return &null;		}		if((o = calloc(1, sizeof(*o))) == nil)			goto err;		o->type = Obool;		o->pdf = pdf;		if(sismatch(s, "true", 1)){			o->bool = 1;			return o;		}		if(sismatch(s, "false", 1)){			o->bool = 0;			return o;		}		o->type = Oop;		o->str = suntilend(s);		return o;	} 	switch(c){	case '<': /* dictionary or a string */		c = Sgetc(s);		if(c == '<'){			Sseek(s, -2, 1);			if((o = pdfdict(pdf, s)) != nil){				/* check for attached stream */				off = Soffset(s);				do; while(isws(Sgetc(s)));				Sungetc(s);				if(sismatch(s, "stream", 0)){					c = Sgetc(s);					/* there IS a stream */					if(c == '\r' && (c = Sgetc(s)) < 0)						goto err;					if(c != '\n'){						werrstr("stream has no newline after dict");						goto err;					}					o->stream.off = Soffset(s);					o->type = Ostream;					o->stream.len = dictint(o, "Length");					return o;				}				Sseek(s, off, 0);			}			return o;		}		Sungetc(s);		/* fall through */ 	case '(':		Sungetc(s);		if((o = pdfstring(s)) != nil)			o->pdf = pdf;		return o; 	case '/':		Sungetc(s);		if((o = pdfname(s)) != nil)			o->pdf = pdf;		return o; 	case '[':		Sungetc(s);		if((o = pdfarray(pdf, s)) != nil)			o->pdf = pdf;		return o; 	default:		if(!isdigit(c) && c != '-'){			Sungetc(s);			werrstr("unexpected char '%c' at %#x+%#x (%d left)", c, Sobjoffset(s), Soffset(s), Ssize(s));			goto err;		}		 /* it could be a number or an indirect object */		Sungetc(s);		if((o = calloc(1, sizeof(*o))) == nil)			goto err;		o->pdf = pdf;		// IMPORTANT: since we modify the union here, we MUST NOT		// assume any members are zero initialized! Might be worth		// switching to malloc to avoid giving that false impression.		Sgetd(s, &o->num.d); /* get the first number */		o->num.i = o->num.d;		off = Soffset(s); /* seek here if not an indirect object later */ 		if((o2 = pdfobj(pdf, s)) != nil && o2->type == Onum){ /* second object is number too */			do; while(isws(c = Sgetc(s)));			if(c < 0)				goto err;			if(c == 'R'){ /* indirect object */				o->type = Oindir;				o->indir.id = o->num.i;				o->indir.gen = o2->num.i;				// See note above; this is NOT zero initialized by calloc				o->indir.o = nil;				pdfobjfree(o2);				return o;			}			if(c == 'o' && Sgetc(s) == 'b' && Sgetc(s) == 'j'){ /* object */				xref.id = o->num.i;				xref.gen = o2->num.i;				/* FIXME put into a map */				pdfobjfree(o2);				if((o2 = pdfobj(pdf, s)) != nil){					pdfobjfree(o);					return o2;				}else{					werrstr("obj: %r");					goto err;				}			}		} 		/* just a number, go back and return it */		o->type = Onum;		if(Sseek(s, off, 0) != off){			werrstr("seek failed");			goto err;		}		return o;	} err:	werrstr("object: %r");	pdfobjfree(o);	pdfobjfree(o2);	return nil;} voidpdfobjfree(Object *o){	int i; 	if(o == nil || --o->ref >= 0)		return; 	switch(o->type){	case Onull:		return; 	case Ostr:	case Oop:	case Oname:		free(o->str);		break; 	case Obool:	case Onum:		break; 	case Oarray:		for(i = 0; i < o->array.ne; i++)			pdfobjfree(o->array.e[i]);		free(o->array.e);		break; 	case Odict:	case Ostream:		for(i = 0; i < o->dict.nkv; i++){			free(o->dict.kv[i].key);			pdfobjfree(o->dict.kv[i].value);		}		free(o->dict.kv);		break; 	case Oindir:		break;	} 	free(o);} Object *pdfref(Object *o){	o->ref++;	return o;}