#include <u.h>#include <libc.h>#include <bio.h>#include <ctype.h>#include "ndb.h"#include "ndbhf.h" /* *  Parse a data base entry.  Entries may span multiple *  lines.  An entry starts on a left margin.  All subsequent *  lines must be indented by white space.  An entry consists *  of tuples of the forms: *	attribute-name *	attribute-name=value *	attribute-name="value with white space" * *  The parsing returns a 2-dimensional structure.  The first *  dimension joins all tuples. All tuples on the same line *  form a ring along the second dimension. */ static Ndbtuple *tfree; #define ISWHITE(x) ((x) == ' ' || (x) == '\t')#define EATWHITE(x) while(ISWHITE(*(x)))(x)++ /* *  parse a single tuple */static char*parsetuple(char *cp, Ndbtuple **tp){	char *p;	int len;	Ndbtuple *t; 	/* a '#' starts a comment lasting till new line */	EATWHITE(cp);	if(*cp == '#' || *cp == '\n')		return 0; 	/* we keep our own free list to reduce mallocs */	if(tfree){		t = tfree;		tfree = tfree->entry;	} else {		t = malloc(sizeof(Ndbtuple));		if(t == 0)			return 0;	}	memset(t, 0, sizeof(*t));	*tp = t; 	/* parse attribute */	p = cp;	while(*cp != '=' && !ISWHITE(*cp) && *cp != '\n')		cp++;	len = cp - p;	if(len >= Ndbalen)		len = Ndbalen;	strncpy(t->attr, p, len); 	/* parse value */	EATWHITE(cp);	if(*cp == '='){		cp++;		EATWHITE(cp);		if(*cp == '"'){			p = ++cp;			while(*cp != '\n' && *cp != '"')				cp++;			len = cp - p;			if(*cp == '"')				cp++;		} else {			p = cp;			while(!ISWHITE(*cp) && *cp != '\n')				cp++;			len = cp - p;		}		if(len >= Ndbvlen)			len = Ndbvlen;		strncpy(t->val, p, len);	} 	return cp;} /* *  parse all tuples in a line.  we assume that the  *  line ends in a '\n'. * *  the tuples are linked as a list using ->entry and *  as a ring using ->line. */static Ndbtuple*parseline(char *cp){	Ndbtuple *t;	Ndbtuple *first, *last; 	first = last = 0;	while(*cp != '#' && *cp != '\n'){		t = 0;		cp = parsetuple(cp, &t);		if(cp == 0)			break;		if(first){			last->line = t;			last->entry = t;		} else			first = t;		last = t;		t->line = 0;		t->entry = 0;	}	if(first)		last->line = first;	return first;} /* *  parse the next entry in the file */Ndbtuple*ndbparse(Ndb *db){	char *line;	Ndbtuple *t;	Ndbtuple *first, *last;	int len; 	first = last = 0;	for(;;){		if(db->line){			line = db->line;			db->line = 0;			len = db->linelen;		} else {			if((line = Brdline(db, '\n')) == 0)				break;			len = Blinelen(db);			if(line[len-1] != '\n')				break;		}		if(first && !ISWHITE(*line)){			db->line = line;			db->linelen = len;			return first;		}		db->offset += len;		t = parseline(line);		if(t == 0)			continue;		if(first)			last->entry = t;		else			first = t;		last = t;		while(last->entry)			last = last->entry;	}	return first;} /* *  free a parsed entry */voidndbfree(Ndbtuple *t){	Ndbtuple *tn; 	if(t == 0)		return;	for(; t; t = tn){		tn = t->entry;		t->entry = tfree;		tfree = t;	}}  /* *  free the hash files belonging to a db */static voidhffree(Ndb *db){	Ndbhf *hf, *next; 	for(hf = db->hf; hf; hf = next){		next = hf->next;		close(hf->fd);		free(hf);	}	db->hf = 0;} intndbreopen(Ndb *db){	int fd;	Dir d; 	/* forget what we know about the open files */	if(db->mtime){		hffree(db);		Bclose(db);		db->mtime = 0;	} 	/* try the open again */	fd = open(db->file, OREAD);	if(fd < 0)		return -1;	if(dirfstat(fd, &d) < 0){		close(fd);		return -1;	} 	db->qid = d.qid;	db->mtime = d.mtime;	db->line = 0;	db->offset = 0;	Binits(db, fd, OREAD, db->buf, sizeof(db->buf));	return 0;} Ndb*ndbopen(char *file){	Ndb *db, *gdb; 	if(file == 0){		db = ndbopen("/lib/ndb/local");		gdb = ndbopen("/lib/ndb/global");		if(db){			db->next = gdb;			return db;		}else			return gdb;	} 	db = (Ndb*)malloc(sizeof(Ndb));	if(db == 0)		return 0;	strncpy(db->file, file, sizeof(db->file)-1);	db->next = 0;	db->hf = 0;	db->mtime = 0; 	if(ndbreopen(db) < 0){		free(db);		return 0;	} 	return db;} voidndbclose(Ndb *db){	Ndb *nextdb; 	for(; db; db = nextdb){		nextdb = db->next;		hffree(db);		Bclose(db);		free(db);	}} longndbseek(Ndb *db, long off, int whence){	if(whence == 0 && off == db->offset)		return off; 	db->line = 0;	db->offset = off;	return Bseek(db, off, whence);}