Aegisub/core/mythes.cxx

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/*
* Copyright 2003 Kevin B. Hendricks, Stratford, Ontario, Canada
* And Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. All modifications to the source code must be clearly marked as
* such. Binary redistributions based on modified source code
* must be clearly marked as modified versions in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY KEVIN B. HENDRICKS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* KEVIN B. HENDRICKS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include "mythes.hxx"
// some basic utility routines
// return index of char in string
int mystr_indexOfChar(const char * d, int c)
{
const char * p = strchr(d,c);
if (p) return (int)(p-d);
return -1;
}
MyThes::MyThes(const char* idxpath, const char * datpath)
{
nw = 0;
encoding = NULL;
list = NULL;
offst = NULL;
if (thInitialize(idxpath, datpath) != 1) {
fprintf(stderr,"Error - can't open %s or %s\n",idxpath, datpath);
fflush(stderr);
if (encoding) free((void*)encoding);
if (list) free((void*)list);
if (offst) free((void*)offst);
// did not initialize properly - throw exception?
}
}
MyThes::~MyThes()
{
if (thCleanup() != 1) {
/* did not cleanup properly - throw exception? */
}
if (encoding) free((void*)encoding);
encoding = NULL;
list = NULL;
offst = NULL;
}
int MyThes::thInitialize(const char* idxpath, const char* datpath)
{
// open the index file
FILE * pifile = fopen(idxpath,"r");
if (!pifile) {
pifile = NULL;
return 0;
}
// parse in encoding and index size */
char * wrd;
wrd = (char *)calloc(1, MAX_WD_LEN);
int len = readLine(pifile,wrd,MAX_WD_LEN);
encoding = mystrdup(wrd);
len = readLine(pifile,wrd,MAX_WD_LEN);
int idxsz = atoi(wrd);
// now allocate list, offst for the given size
list = (char**) calloc(idxsz,sizeof(char*));
offst = (unsigned int*) calloc(idxsz,sizeof(unsigned int));
if ( (!(list)) || (!(offst)) ) {
fprintf(stderr,"Error - bad memory allocation\n");
fflush(stderr);
return 0;
}
// now parse the remaining lines of the index
len = readLine(pifile,wrd,MAX_WD_LEN);
while (len > 0)
{
int np = mystr_indexOfChar(wrd,'|');
if (nw < idxsz) {
if (np >= 0) {
*(wrd+np) = '\0';
list[nw] = (char *)calloc(1,(np+1));
memcpy((list[nw]),wrd,np);
offst[nw] = atoi(wrd+np+1);
nw++;
}
}
len = readLine(pifile,wrd,MAX_WD_LEN);
}
free((void *)wrd);
fclose(pifile);
pifile=NULL;
/* next open the data file */
pdfile = fopen(datpath,"r");
if (!pdfile) {
pdfile = NULL;
return 0;
}
return 1;
}
int MyThes::thCleanup()
{
/* first close the data file */
if (pdfile) {
fclose(pdfile);
pdfile=NULL;
}
/* now free up all the allocated strings on the list */
for (int i=0; i < nw; i++)
{
if (list[i]) {
free(list[i]);
list[i] = 0;
}
}
if (list) free((void*)list);
if (offst) free((void*)offst);
nw = 0;
return 1;
}
// lookup text in index and count of meanings and a list of meaning entries
// with each entry having a synonym count and pointer to an
// array of char * (i.e the synonyms)
//
// note: calling routine should call CleanUpAfterLookup with the original
// meaning point and count to properly deallocate memory
int MyThes::Lookup(const char * pText, int len, mentry** pme)
{
*pme = NULL;
// handle the case of missing file or file related errors
if (! pdfile) return 0;
long offset = 0;
/* copy search word and make sure null terminated */
char * wrd = (char *) calloc(1,(len+1));
memcpy(wrd,pText,len);
/* find it in the list */
int idx = binsearch(wrd,list,nw);
free(wrd);
if (idx < 0) return 0;
// now seek to the offset
offset = (long) offst[idx];
int rc = fseek(pdfile,offset,SEEK_SET);
if (rc) {
return 0;
}
// grab the count of the number of meanings
// and allocate a list of meaning entries
char * buf = NULL;
buf = (char *) malloc( MAX_LN_LEN );
if (!buf) return 0;
readLine(pdfile, buf, (MAX_LN_LEN-1));
int np = mystr_indexOfChar(buf,'|');
if (np < 0) {
free(buf);
return 0;
}
int nmeanings = atoi(buf+np+1);
*pme = (mentry*) malloc( nmeanings * sizeof(mentry) );
if (!(*pme)) {
free(buf);
return 0;
}
// now read in each meaning and parse it to get defn, count and synonym lists
mentry* pm = *(pme);
char dfn[MAX_WD_LEN];
for (int j = 0; j < nmeanings; j++) {
readLine(pdfile, buf, (MAX_LN_LEN-1));
pm->count = 0;
pm->psyns = NULL;
pm->defn = NULL;
// store away the part of speech for later use
char * p = buf;
char * pos = NULL;
np = mystr_indexOfChar(p,'|');
if (np >= 0) {
*(buf+np) = '\0';
pos = mystrdup(p);
p = p + np + 1;
} else {
pos = mystrdup("");
}
// count the number of fields in the remaining line
int nf = 1;
char * d = p;
np = mystr_indexOfChar(d,'|');
while ( np >= 0 ) {
nf++;
d = d + np + 1;
np = mystr_indexOfChar(d,'|');
}
pm->count = nf;
pm->psyns = (char **) malloc(nf*sizeof(char*));
// fill in the synonym list
d = p;
for (int j = 0; j < nf; j++) {
np = mystr_indexOfChar(d,'|');
if (np > 0) {
*(d+np) = '\0';
pm->psyns[j] = mystrdup(d);
d = d + np + 1;
} else {
pm->psyns[j] = mystrdup(d);
}
}
// add pos to first synonym to create the definition
int k = strlen(pos);
int m = strlen(pm->psyns[0]);
if ((k+m) < (MAX_WD_LEN - 1)) {
strncpy(dfn,pos,k);
*(dfn+k) = ' ';
strncpy((dfn+k+1),(pm->psyns[0]),m+1);
pm->defn = mystrdup(dfn);
} else {
pm->defn = mystrdup(pm->psyns[0]);
}
free(pos);
pm++;
}
free(buf);
return nmeanings;
}
void MyThes::CleanUpAfterLookup(mentry ** pme, int nmeanings)
{
if (nmeanings == 0) return;
if ((*pme) == NULL) return;
mentry * pm = *pme;
for (int i = 0; i < nmeanings; i++) {
int count = pm->count;
for (int j = 0; j < count; j++) {
if (pm->psyns[j]) free(pm->psyns[j]);
pm->psyns[j] = NULL;
}
if (pm->psyns) free(pm->psyns);
pm->psyns = NULL;
if (pm->defn) free(pm->defn);
pm->defn = NULL;
pm->count = 0;
pm++;
}
pm = *pme;
free(pm);
*pme = NULL;
return;
}
// read a line of text from a text file stripping
// off the line terminator and replacing it with
// a null string terminator.
// returns: -1 on error or the number of characters in
// in the returning string
// A maximum of nc characters will be returned
int MyThes::readLine(FILE * pf, char * buf, int nc)
{
if (fgets(buf,nc,pf)) {
mychomp(buf);
return strlen(buf);
}
return -1;
}
// performs a binary search on null terminated character
// strings
//
// returns: -1 on not found
// index of wrd in the list[]
int MyThes::binsearch(char * sw, char* list[], int nlst)
{
int lp, up, mp, j, indx;
lp = 0;
up = nlst-1;
indx = -1;
if (strcmp(sw,list[lp]) < 0) return -1;
if (strcmp(sw,list[up]) > 0) return -1;
while (indx < 0 ) {
mp = (int)((lp+up) >> 1);
j = strcmp(sw,list[mp]);
if ( j > 0) {
lp = mp + 1;
} else if (j < 0 ) {
up = mp - 1;
} else {
indx = mp;
}
if (lp > up) return -1;
}
return indx;
}
char * MyThes::get_th_encoding()
{
if (encoding) return encoding;
return NULL;
}