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rockbox/apps/plugins/searchengine/parser.c
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or 
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

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8.9 KiB
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 by Michiel van der Kolk
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "searchengine.h"
#include "token.h"
#include "dbinterface.h"
#include "parser.h"
struct token *currentToken, curtoken;
unsigned char *filter[20],*nofilter=0;
int currentlevel=0;
int syntaxerror;
int parse_fd;
char errormsg[250];
unsigned char *parse(int fd) {
unsigned char *ret=0;
int i;
syntaxerror=0;
parse_fd=fd;
currentlevel=0;
if(nofilter==0) {
nofilter=my_malloc(sizeof(unsigned char)*rb->tagdbheader->filecount);
rb->memset(nofilter,1,rb->tagdbheader->filecount);
}
for(i=0;i<20;i++)
filter[i]=nofilter;
database_init();
parser_acceptIt();
currentToken=&curtoken;
PUTS("parse");
ret=parseMExpr();
if(syntaxerror) {
PUTS("Syntaxerror");
rb->splash(HZ*3,errormsg);
}
parser_accept(TOKEN_EOF);
return ret;
}
void parser_acceptIt(void) {
if(syntaxerror) return;
rb->read(parse_fd,&curtoken,sizeof(struct token));
}
int parser_accept(unsigned char kind) {
if(currentToken->kind!=kind) {
syntaxerror=1;
rb->snprintf(errormsg,250,"'%d' found where '%d' expected\n",currentToken->kind,kind);
return 0;
}
else {
parser_acceptIt();
return 1;
}
}
unsigned char *parseCompareNum() {
struct token number1,number2;
unsigned char *ret;
int i,n1=-1,n2=-1;
int op;
if(syntaxerror) return 0;
PUTS("parseCompareNum");
if(currentToken->kind==TOKEN_NUM ||
currentToken->kind==TOKEN_NUMIDENTIFIER) {
rb->memcpy(&number1,currentToken,sizeof(struct token));
parser_acceptIt();
}
else {
syntaxerror=1;
rb->snprintf(errormsg,250,"'%d' found where NUM/NUMID expected\n",currentToken->kind);
return 0;
}
if(currentToken->kind>=TOKEN_GT && currentToken->kind <= TOKEN_NE) {
op=currentToken->kind;
parser_acceptIt();
}
else {
syntaxerror=1;
rb->snprintf(errormsg,250,"'%d' found where NUMOP expected\n",currentToken->kind);
return 0;
}
if(currentToken->kind==TOKEN_NUM ||
currentToken->kind==TOKEN_NUMIDENTIFIER) {
rb->memcpy(&number2,currentToken,sizeof(struct token));
parser_acceptIt();
}
else {
syntaxerror=1;
rb->snprintf(errormsg,250,"'%d' found where NUM/NUMID expected\n",currentToken->kind);
return 0;
}
ret=my_malloc(sizeof(unsigned char)*rb->tagdbheader->filecount);
if(number1.kind==TOKEN_NUM)
n1=getvalue(&number1);
if(number2.kind==TOKEN_NUM)
n2=getvalue(&number2);
for(i=0;i<rb->tagdbheader->filecount;i++)
if(filter[currentlevel][i]) {
loadentry(i);
if(number1.kind==TOKEN_NUMIDENTIFIER)
n1=getvalue(&number1);
if(number2.kind==TOKEN_NUMIDENTIFIER)
n2=getvalue(&number2);
switch(op) {
case TOKEN_GT:
ret[i]=n1 > n2;
break;
case TOKEN_GTE:
ret[i]=n1 >= n2;
break;
case TOKEN_LT:
ret[i]=n1 < n2;
break;
case TOKEN_LTE:
ret[i]=n1 <= n2;
break;
case TOKEN_EQ:
ret[i]=n1 == n2;
break;
case TOKEN_NE:
ret[i]=n1 != n2;
break;
}
}
return ret;
}
unsigned char *parseCompareString() {
struct token string1,string2;
unsigned char *ret;
char *s1=NULL,*s2=NULL;
int i,i2;
int op;
if(syntaxerror) return 0;
PUTS("parseCompareString");
if(currentToken->kind==TOKEN_STRING ||
currentToken->kind==TOKEN_STRINGIDENTIFIER) {
rb->memcpy(&string1,currentToken,sizeof(struct token));
parser_acceptIt();
}
else {
syntaxerror=1;
rb->snprintf(errormsg,250,"'%d' found where STRING/STRINGID expected\n",currentToken->kind);
return 0;
}
op=currentToken->kind;
if(op>=TOKEN_CONTAINS&&op<=TOKEN_ENDSWITH) {
parser_acceptIt();
} else {
syntaxerror=1;
rb->snprintf(errormsg,250,"'%d' found where STROP expected\n",op);
return 0;
}
if(currentToken->kind==TOKEN_STRING ||
currentToken->kind==TOKEN_STRINGIDENTIFIER) {
rb->memcpy(&string2,currentToken,sizeof(struct token));
parser_acceptIt();
}
else {
syntaxerror=1;
rb->snprintf(errormsg,250,"'%d' found where STRING/STRINGID expected\n",currentToken->kind);
return 0;
}
ret=my_malloc(sizeof(unsigned char)*rb->tagdbheader->filecount);
if(string1.kind==TOKEN_STRING)
s1=getstring(&string1);
if(string2.kind==TOKEN_STRING)
s2=getstring(&string2);
for(i=0;i<rb->tagdbheader->filecount;i++)
if(filter[currentlevel][i]) {
loadentry(i);
if(string1.kind==TOKEN_STRINGIDENTIFIER)
s1=getstring(&string1);
if(string2.kind==TOKEN_STRINGIDENTIFIER)
s2=getstring(&string2);
switch(op) {
case TOKEN_CONTAINS:
ret[i]=rb->strcasestr(s1,s2)!=0;
break;
case TOKEN_EQUALS:
ret[i]=rb->strcasecmp(s1,s2)==0;
break;
case TOKEN_STARTSWITH:
ret[i]=rb->strncasecmp(s1,s2,rb->strlen(s2))==0;
break;
case TOKEN_ENDSWITH:
i2=rb->strlen(s2);
ret[i]=rb->strncasecmp(s1+rb->strlen(s1)-i2,s2,i2)==0;
break;
}
}
return ret;
}
unsigned char *parseExpr() {
unsigned char *ret;
int i;
if(syntaxerror) return 0;
PUTS("parseExpr");
switch(currentToken->kind) {
case TOKEN_NOT:
parser_accept(TOKEN_NOT);
PUTS("parseNot");
ret = parseExpr();
if(ret==NULL) return 0;
for(i=0;i<rb->tagdbheader->filecount;i++)
if(filter[currentlevel][i])
ret[i]=!ret[i];
break;
case TOKEN_LPAREN:
parser_accept(TOKEN_LPAREN);
currentlevel++;
ret = parseMExpr();
currentlevel--;
if(ret==NULL) return 0;
parser_accept(TOKEN_RPAREN);
break;
case TOKEN_NUM:
case TOKEN_NUMIDENTIFIER:
ret = parseCompareNum();
if(ret==NULL) return 0;
break;
case TOKEN_STRING:
case TOKEN_STRINGIDENTIFIER:
ret = parseCompareString();
if(ret==NULL) return 0;
break;
default:
// error, unexpected symbol
syntaxerror=1;
rb->snprintf(errormsg,250,"unexpected '%d' found at parseExpr\n",currentToken->kind);
ret=0;
break;
}
return ret;
}
unsigned char *parseMExpr() {
unsigned char *ret,*ret2;
int i;
if(syntaxerror) return 0;
PUTS("parseMExpr");
ret=parseLExpr();
while(currentToken->kind==TOKEN_OR) {
parser_accept(TOKEN_OR);
PUTS("parseOr");
ret2 = parseLExpr();
if(ret2==NULL) return 0;
for(i=0;i<rb->tagdbheader->filecount;i++)
if(filter[currentlevel][i]) // this should always be true
ret[i]=ret[i] || ret2[i];
else
rb->splash(HZ*2,"An or is having a filter, bad.");
}
return ret;
}
unsigned char *parseLExpr() {
unsigned char *ret,*ret2;
int i;
if(syntaxerror) return 0;
PUTS("parseLExpr");
filter[currentlevel]=nofilter;
ret=parseExpr();
filter[currentlevel]=ret;
while(currentToken->kind==TOKEN_AND) {
parser_accept(TOKEN_AND);
PUTS("parseAnd");
ret2 = parseExpr();
if(ret2==NULL) return 0;
for(i=0;i<rb->tagdbheader->filecount;i++)
ret[i]=ret[i] && ret2[i];
}
filter[currentlevel]=nofilter;
return ret;
}
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